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Zhao J, Kennelly J, Nalar A, Kulathilaka A, Sharma R, Bai J, Li N, Fedorov VV. Chamber-specific wall thickness features in human atrial fibrillation. Interface Focus 2023; 13:20230044. [PMID: 38106912 PMCID: PMC10722209 DOI: 10.1098/rsfs.2023.0044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 11/15/2023] [Indexed: 12/19/2023] Open
Abstract
Persistent atrial fibrillation (AF) is not effectively treated due to a lack of adequate tools for identifying patient-specific AF substrates. Recent studies revealed that in 30-50% of patients, persistent AF is maintained by localized drivers not only in the left atrium (LA) but also in the right atrium (RA). The chamber-specific atrial wall thickness (AWT) features underlying AF remain elusive, though the important role of AWT in AF is widely acknowledged. We aimed to provide direct evidence of the existence of distinguished RA and LA AWT features underlying AF drivers by analysing functionally and structurally mapped human hearts ex vivo. Coronary-perfused intact human atria (n = 7, 47 ± 14 y.o.; two female) were mapped using panoramic near-infrared optical mapping during pacing-induced AF. Then the hearts were imaged at approximately 170 µm3 resolution by 9.4 T gadolinium-enhanced MRI. The heart was segmented, and 3D AWT throughout atrial chambers was estimated and analysed. Optical mapping identified six localized RA re-entrant drivers in four hearts and four LA drivers in three hearts. All RA AF drivers were anchored to the pectinate muscle junctions with the crista terminalis or atrial walls. The four LA AF drivers were in the posterior LA. RA (n = 4) with AF drivers were thicker with greater AWT variation than RA (n = 3) without drivers (5.4 ± 2.6 mm versus 5.0 ± 2.4 mm, T-test p < 0.05; F-test p < 0.05). Furthermore, AWT in RA driver regions was thicker and varied more than in RA non-driver regions (5.1 ± 2.5 mm versus 4.4 ± 2.2 mm, T-test p < 0.05; F-test p < 0.05). On the other hand, LA (n = 3) with drivers was thinner than the LA (n = 4) without drivers. In particular, LA driver regions were thinner than the rest of LA regions (3.4 ± 1.0 mm versus 4.2 ± 1.0 mm, T-test p < 0.05). This study demonstrates chamber-specific AWT features of AF drivers. In RA, driver regions are thicker and have more variable AWT than non-driver regions. By contrast, LA drivers are thinner than non-drivers. Robust evaluation of patient-specific AWT features should be considered for chamber-specific targeted ablation.
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Affiliation(s)
- Jichao Zhao
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - James Kennelly
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Aaqel Nalar
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Anuradha Kulathilaka
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Roshan Sharma
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Jieyun Bai
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Ning Li
- Department of Physiology and Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
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Zhao J, Sharma R, Kalyanasundaram A, Kennelly J, Bai J, Li N, Panfilov A, Fedorov VV. Mechanistic insight into the functional role of human sinoatrial node conduction pathways and pacemaker compartments heterogeneity: A computer model analysis. PLoS Comput Biol 2023; 19:e1011708. [PMID: 38109436 PMCID: PMC10760897 DOI: 10.1371/journal.pcbi.1011708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/02/2024] [Accepted: 11/23/2023] [Indexed: 12/20/2023] Open
Abstract
The sinoatrial node (SAN), the primary pacemaker of the heart, is responsible for the initiation and robust regulation of sinus rhythm. 3D mapping studies of the ex-vivo human heart suggested that the robust regulation of sinus rhythm relies on specialized fibrotically-insulated pacemaker compartments (head, center and tail) with heterogeneous expressions of key ion channels and receptors. They also revealed up to five sinoatrial conduction pathways (SACPs), which electrically connect the SAN with neighboring right atrium (RA). To elucidate the role of these structural-molecular factors in the functional robustness of human SAN, we developed comprehensive biophysical computer models of the SAN based on 3D structural, functional and molecular mapping of ex-vivo human hearts. Our key finding is that the electrical insulation of the SAN except SACPs, the heterogeneous expression of If, INa currents and adenosine A1 receptors (A1R) across SAN pacemaker-conduction compartments are required to experimentally reproduce observed SAN activation patterns and important phenomena such as shifts of the leading pacemaker and preferential SACP. In particular, we found that the insulating border between the SAN and RA, is required for robust SAN function and protection from SAN arrest during adenosine challenge. The heterogeneity in the expression of A1R within the human SAN compartments underlies the direction of pacemaker shift and preferential SACPs in the presence of adenosine. Alterations of INa current and fibrotic remodelling in SACPs can significantly modulate SAN conduction and shift the preferential SACP/exit from SAN. Finally, we show that disease-induced fibrotic remodeling, INa suppression or increased adenosine make the human SAN vulnerable to pacing-induced exit blocks and reentrant arrhythmia. In summary, our computer model recapitulates the structural and functional features of the human SAN and can be a valuable tool for investigating mechanisms of SAN automaticity and conduction as well as SAN arrhythmia mechanisms under different pathophysiological conditions.
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Affiliation(s)
- Jichao Zhao
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Roshan Sharma
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Anuradha Kalyanasundaram
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia; The Ohio State University Wexner Medical Center, Columbus, Ohio, United States of America
| | - James Kennelly
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Jieyun Bai
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Ning Li
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia; The Ohio State University Wexner Medical Center, Columbus, Ohio, United States of America
| | | | - Vadim V. Fedorov
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia; The Ohio State University Wexner Medical Center, Columbus, Ohio, United States of America
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Li N, Hansen BJ, Kennelly J, Kalyanasundaram A, Kanaan A, Simonetti OP, Mohler PJ, Whitson B, Hummel JD, Zhao J, Fedorov VV. High-Resolution 3-Dimensional Multimodality Imaging to Resolve Intramural Human Sinoatrial Node Pacemakers and Epicardial-Endocardial Atrial Exit Sites. Circ Arrhythm Electrophysiol 2023; 16:e011528. [PMID: 36916270 PMCID: PMC10208092 DOI: 10.1161/circep.122.011528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Affiliation(s)
- Ning Li
- Department of Physiology & Cell Biology The Ohio State University Wexner Medical Center, Columbus, OH
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center, Columbus, OH
| | - Brian J. Hansen
- Department of Physiology & Cell Biology The Ohio State University Wexner Medical Center, Columbus, OH
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center, Columbus, OH
| | - James Kennelly
- Auckland Bioengineering Institute, The University of Auckland; Auckland, New Zealand
| | - Anuradha Kalyanasundaram
- Department of Physiology & Cell Biology The Ohio State University Wexner Medical Center, Columbus, OH
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center, Columbus, OH
| | - Adel Kanaan
- Department of Physiology & Cell Biology The Ohio State University Wexner Medical Center, Columbus, OH
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center, Columbus, OH
| | - Orlando P. Simonetti
- Division of Cardiovascular Medicine The Ohio State University Wexner Medical Center, Columbus, OH
- Department of Radiology The Ohio State University Wexner Medical Center, Columbus, OH
| | - Peter J. Mohler
- Department of Physiology & Cell Biology The Ohio State University Wexner Medical Center, Columbus, OH
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center, Columbus, OH
| | - Bryan Whitson
- Division of Cardiac Surgery, The Ohio State University Wexner Medical Center, Columbus, OH
| | - John D. Hummel
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center, Columbus, OH
- Division of Cardiovascular Medicine The Ohio State University Wexner Medical Center, Columbus, OH
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland; Auckland, New Zealand
| | - Vadim V. Fedorov
- Department of Physiology & Cell Biology The Ohio State University Wexner Medical Center, Columbus, OH
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center, Columbus, OH
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Shugurov KY, Mozharov AM, Fedorov VV, Blokhin SA, Neplokh VV, Mukhin IS. Extremely high frequency Schottky diodes based on single GaN nanowires. Nanotechnology 2023; 34:245204. [PMID: 36928235 DOI: 10.1088/1361-6528/acc4cb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 03/15/2023] [Indexed: 06/18/2023]
Abstract
Gallium nitride (GaN) is one of the most promising materials for high-frequency devices owing to its prominent material properties. We report on the fabrication and study of a series of Schottky diodes in the ground-signal-ground topology based on individual GaN nanowires. The electrical characterization ofI-Vcurves demonstrated relatively high ideality factor value (about 6-9) in comparison to the planar Au/GaN diodes that can be attributed to the nanowire geometry. The effective barrier height in the studied structures was defined in the range of 0.25-0.4 eV. The small-signal frequency analysis was employed to study the dependency of the scattering parameters in the broad range from 0.1 to 40 GHz. The approximation fitting of the experimental data indicated the record high cutoff frequency of about 165.8 GHz.
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Affiliation(s)
| | | | - V V Fedorov
- Alferov University, Saint-Petersburg, Russia
| | | | - V V Neplokh
- Alferov University, Saint-Petersburg, Russia
- Peter the Great St.Petersburg Polytechnic University, Saint-Petersburg, Russia
- St. Petersburg State University, Saint-Petersburg, Russia
| | - I S Mukhin
- Alferov University, Saint-Petersburg, Russia
- Peter the Great St.Petersburg Polytechnic University, Saint-Petersburg, Russia
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Kalyanasundaram A, Li N, Augostini RS, Weiss R, Hummel JD, Fedorov VV. Three-dimensional functional anatomy of the human sinoatrial node for epicardial and endocardial mapping and ablation. Heart Rhythm 2023; 20:122-133. [PMID: 36113768 PMCID: PMC9897959 DOI: 10.1016/j.hrthm.2022.08.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 08/25/2022] [Accepted: 08/30/2022] [Indexed: 02/05/2023]
Abstract
The sinoatrial node (SAN) is the primary pacemaker of the human heart. It is a single, elongated, 3-dimensional (3D) intramural fibrotic structure located at the junction of the superior vena cava intercaval region bordering the crista terminalis (CT). SAN activation originates in the intranodal pacemakers and is conducted to the atria through 1 or more discrete sinoatrial conduction pathways. The complexity of the 3D SAN pacemaker structure and intramural conduction are underappreciated during clinical multielectrode mapping and ablation procedures of SAN and atrial arrhythmias. In fact, defining and targeting SAN is extremely challenging because, even during sinus rhythm, surface-only multielectrode mapping may not define the leading pacemaker sites in intramural SAN but instead misinterpret them as epicardial or endocardial exit sites through sinoatrial conduction pathways. These SAN exit sites may be distributed up to 50 mm along the CT beyond the ∼20-mm-long anatomic SAN structure. Moreover, because SAN reentrant tachycardia beats may exit through the same sinoatrial conduction pathway as during sinus rhythm, many SAN arrhythmias are underdiagnosed. Misinterpretation of arrhythmia sources and/or mechanisms (eg, enhanced automaticity, intranodal vs CT reentry) limits diagnosis and success of catheter ablation treatments for poorly understood SAN arrhythmias. The aim of this review is to provide a state-of-the-art overview of the 3D structure and function of the human SAN complex, mechanisms of SAN arrhythmias and available approaches for electrophysiological mapping, 3D structural imaging, pharmacologic interventions, and ablation to improve diagnosis and mechanistic treatment of SAN and atrial arrhythmias.
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Affiliation(s)
- Anuradha Kalyanasundaram
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Ning Li
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Ralph S Augostini
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, Ohio; Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Raul Weiss
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, Ohio; Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - John D Hummel
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, Ohio; Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Vadim V Fedorov
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, Ohio.
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Kalyanasundaram A, Mylavarapu U, Li N, Hansen B, Khambhampati S, Mohler PJ, Simonetti OP, Hummel JD, Fedorov VV. PO-646-08 HETEROGENEOUS TRANSMURAL FIBROSIS REMODELING CREATES ARRHYTHMOGENIC SUBSTRATES IN A CANINE MODEL OF PERSISTENT ATRIAL FIBRILLATION. Heart Rhythm 2022. [DOI: 10.1016/j.hrthm.2022.03.197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Li N, Artiga E, Kalyanasundaram A, Hansen BJ, Webb A, Pietrzak M, Biesiadecki B, Whitson B, Mokadam NA, Janssen PML, Hummel JD, Mohler PJ, Dobrzynski H, Fedorov VV. Altered microRNA and mRNA profiles during heart failure in the human sinoatrial node. Sci Rep 2021; 11:19328. [PMID: 34588502 PMCID: PMC8481550 DOI: 10.1038/s41598-021-98580-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 09/03/2021] [Indexed: 11/09/2022] Open
Abstract
Heart failure (HF) is frequently accompanied with the sinoatrial node (SAN) dysfunction, which causes tachy-brady arrhythmias and increased mortality. MicroRNA (miR) alterations are associated with HF progression. However, the transcriptome of HF human SAN, and its role in HF-associated remodeling of ion channels, transporters, and receptors responsible for SAN automaticity and conduction impairments is unknown. We conducted comprehensive high-throughput transcriptomic analysis of pure human SAN primary pacemaker tissue and neighboring right atrial tissue from human transplanted HF hearts (n = 10) and non-failing (nHF) donor hearts (n = 9), using next-generation sequencing. Overall, 47 miRs and 832 mRNAs related to multiple signaling pathways, including cardiac diseases, tachy-brady arrhythmias and fibrosis, were significantly altered in HF SAN. Of the altered miRs, 27 are predicted to regulate mRNAs of major ion channels and neurotransmitter receptors which are involved in SAN automaticity (e.g. HCN1, HCN4, SLC8A1) and intranodal conduction (e.g. SCN5A, SCN8A) or both (e.g. KCNJ3, KCNJ5). Luciferase reporter assays were used to validate interactions of miRs with predicted mRNA targets. In conclusion, our study provides a profile of altered miRs in HF human SAN, and a novel transcriptome blueprint to identify molecular targets for SAN dysfunction and arrhythmia treatments in HF.
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Affiliation(s)
- Ning Li
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, 43210-1218, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, USA
| | - Esthela Artiga
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, 43210-1218, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, USA
| | - Anuradha Kalyanasundaram
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, 43210-1218, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, USA
| | - Brian J Hansen
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, 43210-1218, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, USA
| | - Amy Webb
- Biomedical Informatics Shared Resources, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, USA
| | - Maciej Pietrzak
- Biomedical Informatics Shared Resources, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, USA
| | - Brandon Biesiadecki
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, 43210-1218, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, USA
| | - Bryan Whitson
- Department of Surgery, Division of Cardiac Surgery, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, USA
| | - Nahush A Mokadam
- Department of Surgery, Division of Cardiac Surgery, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, USA
| | - Paul M L Janssen
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, 43210-1218, USA
| | - John D Hummel
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, USA
| | - Peter J Mohler
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, 43210-1218, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, USA
| | - Halina Dobrzynski
- Division of Cardiovascular Sciences, University of Manchester, Manchester, UK.,Department of Anatomy, Jagiellonian University Medical College, Cracow, Poland
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, 43210-1218, USA. .,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University College of Medicine and Wexner Medical Center, Columbus, OH, USA.
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Fedorov VV, Dvoretckaia LN, Kirilenko DA, Mukhin IS, Dubrovskii VG. Formation of wurtzite sections in self-catalyzed GaP nanowires by droplet consumption. Nanotechnology 2021; 32:495601. [PMID: 34433149 DOI: 10.1088/1361-6528/ac20fe] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 08/25/2021] [Indexed: 06/13/2023]
Abstract
Wurtzite GaP nanowires are interesting for the direct bandgap engineering and can be used as templates for further growth of hexagonal Si shells. Most wurtzite GaP nanowires have previously been obtained with Au catalysts. Here, we show that long (∼500 nm) wurtzite sections are formed in the top parts of self-catalyzed GaP nanowires grown by molecular beam epitaxy on Si(111) substrates in the droplet consumption stage, which is achieved by abruptly increasing the atomic V/III flux ratio from 2 to 3. We investigate the temperature dependence of the length of wurtzite sections and show that the longest sections are obtained at 610 °C. A supporting model explains the observed trends using a phase diagram of GaP nanowires, where the wurtzite phase is formed within a certain range of the droplet contact angles. The optimal growth temperature for growing wurtzite nanowires corresponds to the largest diffusion length of Ga adatoms, which helps to maintain the required contact angle for the longest time.
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Affiliation(s)
- V V Fedorov
- Nanotechnology Research and Education Centre of the Russian Academy of Sciences, Alferov University, Khlopina 8/3, 194021 St. Petersburg, Russia
- Institute of Physics, Nanotechnology and Telecommunications, Peter the Great St. Petersburg Polytechnic University, Politekhnicheskaya 29, 195251 St. Petersburg, Russia
| | - L N Dvoretckaia
- Nanotechnology Research and Education Centre of the Russian Academy of Sciences, Alferov University, Khlopina 8/3, 194021 St. Petersburg, Russia
| | - D A Kirilenko
- Ioffe Institute, Politekhnicheskaya 26, 194021 St. Petersburg, Russia
| | - I S Mukhin
- Nanotechnology Research and Education Centre of the Russian Academy of Sciences, Alferov University, Khlopina 8/3, 194021 St. Petersburg, Russia
- School of Photonics, ITMO University, Kronverksky Prospekt 49, 197101 St. Petersburg, Russia
| | - V G Dubrovskii
- Faculty of Physics, St. Petersburg State University, Universitetskaya Emb. 13B, 199034, St. Petersburg, Russia
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Mikhailov A, Subr M, Mylavarapu U, Hoenie L, Nalar A, Kennelly J, Yen YL, Li N, Pan Y, Helfrich KM, Scott SS, Kalyanasundaram A, Wilson A, Joseph M, Buck BH, Hansen B, Bratazc A, Mohler PJ, Zhao J, Hummel JD, Simonetti OP, Fedorov VV. B-PO05-017 IN VIVO TO EX VIVO HIGH RESOLUTION OPTICAL MAPPING AND CONTRAST ENHANCED MAGNETIC RESONANCE IMAGING TO REVEAL ATRIAL FIBRILLATION DRIVERS AND IMPROVE IDENTIFICATION OF ARRHYTHMOGENIC STRUCTURAL SUBSTRATES IN PERSISTENT ATRIAL FIBRILLATION CANINE MODEL. Heart Rhythm 2021. [DOI: 10.1016/j.hrthm.2021.06.937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Li N, Artiga E, Mikhailov A, Kalyanasundaram A, Mylavarapu U, Hoenie L, Hansen B, Whitson B, Mokadam N, Janssen P, Mohler PJ, Fedorov VV. B-PO04-013 PERIOSTIN AS A MARKER OF FIBROTIC SUBSTRATE FOR REENTRANT ATRIAL FIBRILLATION DRIVERS IN HUMAN HEARTS. Heart Rhythm 2021. [DOI: 10.1016/j.hrthm.2021.06.710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Kalyanasundaram A, Li N, Gardner ML, Artiga EJ, Hansen BJ, Webb A, Freitas MA, Pietrzak M, Whitson BA, Mokadam NA, Janssen PML, Mohler PJ, Fedorov VV. Fibroblast-Specific Proteotranscriptomes Reveal Distinct Fibrotic Signatures of Human Sinoatrial Node in Nonfailing and Failing Hearts. Circulation 2021; 144:126-143. [PMID: 33874740 DOI: 10.1161/circulationaha.120.051583] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Up to 50% of the adult human sinoatrial node (SAN) is composed of dense connective tissue. Cardiac diseases including heart failure (HF) may increase fibrosis within the SAN pacemaker complex, leading to impaired automaticity and conduction of electric activity to the atria. Unlike the role of cardiac fibroblasts in pathologic fibrotic remodeling and tissue repair, nothing is known about fibroblasts that maintain the inherently fibrotic SAN environment. METHODS Intact SAN pacemaker complex was dissected from cardioplegically arrested explanted nonfailing hearts (non-HF; n=22; 48.7±3.1 years of age) and human failing hearts (n=16; 54.9±2.6 years of age). Connective tissue content was quantified from Masson trichrome-stained head-center and center-tail SAN sections. Expression of extracellular matrix proteins, including collagens 1 and 3A1, CILP1 (cartilage intermediate layer protein 1), and POSTN (periostin), and fibroblast and myofibroblast numbers were quantified by in situ and in vitro immunolabeling. Fibroblasts from the central intramural SAN pacemaker compartment (≈10×5×2 mm3) and right atria were isolated, cultured, passaged once, and treated ± transforming growth factor β1 and subjected to comprehensive high-throughput next-generation sequencing of whole transcriptome, microRNA, and proteomic analyses. RESULTS Intranodal fibrotic content was significantly higher in SAN pacemaker complex from HF versus non-HF hearts (57.7±2.6% versus 44.0±1.2%; P<0.0001). Proliferating phosphorylated histone 3+/vimentin+/CD31- (cluster of differentiation 31) fibroblasts were higher in HF SAN. Vimentin+/α-smooth muscle actin+/CD31- myofibroblasts along with increased interstitial POSTN expression were found only in HF SAN. RNA sequencing and proteomic analyses identified unique differences in mRNA, long noncoding RNA, microRNA, and proteomic profiles between non-HF and HF SAN and right atria fibroblasts and transforming growth factor β1-induced myofibroblasts. Specifically, proteins and signaling pathways associated with extracellular matrix flexibility, stiffness, focal adhesion, and metabolism were altered in HF SAN fibroblasts compared with non-HF SAN. CONCLUSIONS This study revealed increased SAN-specific fibrosis with presence of myofibroblasts, CILP1, and POSTN-positive interstitial fibrosis only in HF versus non-HF human hearts. Comprehensive proteotranscriptomic profiles of SAN fibroblasts identified upregulation of genes and proteins promoting stiffer SAN extracellular matrix in HF hearts. Fibroblast-specific profiles generated by our proteotranscriptomic analyses of the human SAN provide a comprehensive framework for future studies to investigate the role of SAN-specific fibrosis in cardiac rhythm regulation and arrhythmias.
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Affiliation(s)
- Anuradha Kalyanasundaram
- Department of Physiology & Cell Biology (A.K., N.L., E.J.A., B.J.H., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart & Lung Research Institute (A.K., N.L., E.J.A., B.J.H., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus
| | - Ning Li
- Department of Physiology & Cell Biology (A.K., N.L., E.J.A., B.J.H., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart & Lung Research Institute (A.K., N.L., E.J.A., B.J.H., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus
| | - Miranda L Gardner
- Cancer Biology and Genetics (M.L.G., M.A.F.), The Ohio State University Wexner Medical Center, Columbus
| | - Esthela J Artiga
- Department of Physiology & Cell Biology (A.K., N.L., E.J.A., B.J.H., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart & Lung Research Institute (A.K., N.L., E.J.A., B.J.H., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus
| | - Brian J Hansen
- Department of Physiology & Cell Biology (A.K., N.L., E.J.A., B.J.H., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart & Lung Research Institute (A.K., N.L., E.J.A., B.J.H., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus
| | - Amy Webb
- Biomedical Informatics Shared Resources (A.W., M.P.), The Ohio State University Wexner Medical Center, Columbus
| | - Michael A Freitas
- Cancer Biology and Genetics (M.L.G., M.A.F.), The Ohio State University Wexner Medical Center, Columbus
| | - Maciej Pietrzak
- Biomedical Informatics Shared Resources (A.W., M.P.), The Ohio State University Wexner Medical Center, Columbus
| | - Bryan A Whitson
- Department of Surgery (B.A.W., N.A.M.), The Ohio State University Wexner Medical Center, Columbus
| | - Nahush A Mokadam
- Department of Surgery (B.A.W., N.A.M.), The Ohio State University Wexner Medical Center, Columbus
| | - Paul M L Janssen
- Department of Physiology & Cell Biology (A.K., N.L., E.J.A., B.J.H., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus
| | - Peter J Mohler
- Department of Physiology & Cell Biology (A.K., N.L., E.J.A., B.J.H., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart & Lung Research Institute (A.K., N.L., E.J.A., B.J.H., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus
| | - Vadim V Fedorov
- Department of Physiology & Cell Biology (A.K., N.L., E.J.A., B.J.H., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart & Lung Research Institute (A.K., N.L., E.J.A., B.J.H., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus
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12
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Kochetkov FM, Neplokh V, Fedorov VV, Bolshakov AD, Sharov VA, Eliseev IE, Tchernycheva M, Cirlin GE, Nasibulin AG, Islamova RM, Mukhin IS. Fabrication and electrical study of large area free-standing membrane with embedded GaP NWs for flexible devices. Nanotechnology 2020; 31:46LT01. [PMID: 32877371 DOI: 10.1088/1361-6528/abae98] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Flexible optoelectronic structures are required in a wide range of applications. Large scale modified silicone-embedded n-GaP nanowire arrays of a record 6 µm thin membranes were studied. A homogeneous silicone encapsulation was enabled by G-coating using a heavy-load centrifuge. The synthesized graft-copolymers of polydimethylsiloxane (PDMS) and polystyrene demonstrated two times lower adhesion to Si compared to standard PDMS, allowing 3 square inch area high quality silicone/nanowire membrane mechanical release, preserving the growth Si substrate for a further re-use after chemical cleaning. The 90% transparent single-walled carbon nanotubes electrical contacts to the embedded n-GaP nanowires demonstrated mechanical and electrical stability. The presented methods can be used for the fabrication of large scale flexible inorganic optoelectronic devices.
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13
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Mikhailov AV, Kalyanasundaram A, Li N, Scott SS, Artiga EJ, Subr MM, Zhao J, Hansen BJ, Hummel JD, Fedorov VV. Comprehensive evaluation of electrophysiological and 3D structural features of human atrial myocardium with insights on atrial fibrillation maintenance mechanisms. J Mol Cell Cardiol 2020; 151:56-71. [PMID: 33130148 DOI: 10.1016/j.yjmcc.2020.10.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/14/2022]
Abstract
Atrial fibrillation (AF) occurrence and maintenance is associated with progressive remodeling of electrophysiological (repolarization and conduction) and 3D structural (fibrosis, fiber orientations, and wall thickness) features of the human atria. Significant diversity in AF etiology leads to heterogeneous arrhythmogenic electrophysiological and structural substrates within the 3D structure of the human atria. Since current clinical methods have yet to fully resolve the patient-specific arrhythmogenic substrates, mechanism-based AF treatments remain underdeveloped. Here, we review current knowledge from in-vivo, ex-vivo, and in-vitro human heart studies, and discuss how these studies may provide new insights on the synergy of atrial electrophysiological and 3D structural features in AF maintenance. In-vitro studies on surgically acquired human atrial samples provide a great opportunity to study a wide spectrum of AF pathology, including functional changes in single-cell action potentials, ion channels, and gene/protein expression. However, limited size of the samples prevents evaluation of heterogeneous AF substrates and reentrant mechanisms. In contrast, coronary-perfused ex-vivo human hearts can be studied with state-of-the-art functional and structural technologies, such as high-resolution near-infrared optical mapping and contrast-enhanced MRI. These imaging modalities can resolve atrial arrhythmogenic substrates and their role in reentrant mechanisms maintaining AF and validate clinical approaches. Nonetheless, longitudinal studies are not feasible in explanted human hearts. As no approach is perfect, we suggest that combining the strengths of direct human atrial studies with high fidelity approaches available in the laboratory and in realistic patient-specific computer models would elucidate deeper knowledge of AF mechanisms. We propose that a comprehensive translational pipeline from ex-vivo human heart studies to longitudinal clinically relevant AF animal studies and finally to clinical trials is necessary to identify patient-specific arrhythmogenic substrates and develop novel AF treatments.
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Affiliation(s)
- Aleksei V Mikhailov
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Arrhythmology Research Department, Almazov National Medical Research Centre, Saint-Petersburg, Russia
| | - Anuradha Kalyanasundaram
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Ning Li
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Shane S Scott
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Esthela J Artiga
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Megan M Subr
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Brian J Hansen
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - John D Hummel
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Vadim V Fedorov
- Department of Physiology & Cell Biology, Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
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14
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Petkova M, Atkinson AJ, Yanni J, Stuart L, Aminu AJ, Ivanova AD, Pustovit KB, Geragthy C, Feather A, Li N, Zhang Y, Oceandy D, Perde F, Molenaar P, D’Souza A, Fedorov VV, Dobrzynski H. Identification of Key Small Non-Coding MicroRNAs Controlling Pacemaker Mechanisms in the Human Sinus Node. J Am Heart Assoc 2020; 9:e016590. [PMID: 33059532 PMCID: PMC7763385 DOI: 10.1161/jaha.120.016590] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 08/27/2020] [Indexed: 01/01/2023]
Abstract
Background The sinus node (SN) is the primary pacemaker of the heart. SN myocytes possess distinctive action potential morphology with spontaneous diastolic depolarization because of a unique expression of ion channels and Ca2+-handling proteins. MicroRNAs (miRs) inhibit gene expression. The role of miRs in controlling the expression of genes responsible for human SN pacemaking and conduction has not been explored. The aim of this study was to determine miR expression profile of the human SN as compared with that of non-pacemaker atrial muscle. Methods and Results SN and atrial muscle biopsies were obtained from donor or post-mortem hearts (n=10), histology/immunolabeling were used to characterize the tissues, TaqMan Human MicroRNA Arrays were used to measure 754 miRs, Ingenuity Pathway Analysis was used to identify miRs controlling SN pacemaker gene expression. Eighteen miRs were significantly more and 48 significantly less abundant in the SN than atrial muscle. The most interesting miR was miR-486-3p predicted to inhibit expression of pacemaking channels: HCN1 (hyperpolarization-activated cyclic nucleotide-gated 1), HCN4, voltage-gated calcium channel (Cav)1.3, and Cav3.1. A luciferase reporter gene assay confirmed that miR-486-3p can control HCN4 expression via its 3' untranslated region. In ex vivo SN preparations, transfection with miR-486-3p reduced the beating rate by ≈35±5% (P<0.05) and HCN4 expression (P<0.05). Conclusions The human SN possesses a unique pattern of expression of miRs predicted to target functionally important genes. miR-486-3p has an important role in SN pacemaker activity by targeting HCN4, making it a potential target for therapeutic treatment of SN disease such as sinus tachycardia.
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Affiliation(s)
- Maria Petkova
- Division of Cardiovascular SciencesUniversity of ManchesterUnited Kingdom
| | - Andrew J. Atkinson
- Division of Cardiovascular SciencesUniversity of ManchesterUnited Kingdom
| | - Joseph Yanni
- Division of Cardiovascular SciencesUniversity of ManchesterUnited Kingdom
| | - Luke Stuart
- Division of Cardiovascular SciencesUniversity of ManchesterUnited Kingdom
| | - Abimbola J. Aminu
- Division of Cardiovascular SciencesUniversity of ManchesterUnited Kingdom
| | - Alexandra D. Ivanova
- Department of Human and Animal PhysiologyLomonosov Moscow State UniversityMoscowRussia
| | - Ksenia B. Pustovit
- Department of Human and Animal PhysiologyLomonosov Moscow State UniversityMoscowRussia
| | - Connor Geragthy
- Division of Cardiovascular SciencesUniversity of ManchesterUnited Kingdom
| | - Amy Feather
- Division of Cardiovascular SciencesUniversity of ManchesterUnited Kingdom
| | - Ning Li
- Physiology and Cell Biology DepartmentThe Bob and Corrine Frick Center for Heart Failure and ArrhythmiaThe Ohio State University Wexner Medical CenterColumbusOH
| | - Yu Zhang
- Division of Cardiovascular SciencesUniversity of ManchesterUnited Kingdom
| | - Delvac Oceandy
- Division of Cardiovascular SciencesUniversity of ManchesterUnited Kingdom
| | - Filip Perde
- National Institute of Legal MedicineBucharestRomania
| | - Peter Molenaar
- School of Biomedical SciencesQueensland University of TechnologyBrisbaneAustralia
- Cardiovascular Molecular & Therapeutics Translational Research GroupThe Prince Charles HospitalBrisbaneAustralia
| | - Alicia D’Souza
- Division of Cardiovascular SciencesUniversity of ManchesterUnited Kingdom
| | - Vadim V. Fedorov
- Physiology and Cell Biology DepartmentThe Bob and Corrine Frick Center for Heart Failure and ArrhythmiaThe Ohio State University Wexner Medical CenterColumbusOH
| | - Halina Dobrzynski
- Division of Cardiovascular SciencesUniversity of ManchesterUnited Kingdom
- Department of AnatomyJagiellonian University Medical CollegeKrakowPoland
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15
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Abstract
The spontaneous activity of the sinoatrial node initiates the heartbeat. Sino-atrial node dysfunction (SND) and sick sinoatrial (sick sinus) syndrome are caused by the heart's inability to generate a normal sinoatrial node action potential. In clinical practice, SND is generally considered an age-related pathology, secondary to degenerative fibrosis of the heart pacemaker tissue. However, other forms of SND exist, including idiopathic primary SND, which is genetic, and forms that are secondary to cardiovascular or systemic disease. The incidence of SND in the general population is expected to increase over the next half century, boosting the need to implant electronic pacemakers. During the last two decades, our knowledge of sino-atrial node physiology and of the pathophysiological mechanisms underlying SND has advanced considerably. This review summarizes the current knowledge about SND mechanisms and discusses the possibility of introducing new pharmacologic therapies for treating SND.
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Affiliation(s)
- Pietro Mesirca
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34096 Montpellier, France; .,LabEx Ion Channels Science and Therapeutics (ICST), 06560 Nice, France
| | - Vadim V Fedorov
- Frick Center for Heart Failure and Arrhythmia at the Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio 43210, USA.,Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Wexner Medical Center, Columbus, Ohio 43210, USA
| | - Thomas J Hund
- Frick Center for Heart Failure and Arrhythmia at the Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio 43210, USA.,Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio 43210, USA
| | - Angelo G Torrente
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34096 Montpellier, France; .,LabEx Ion Channels Science and Therapeutics (ICST), 06560 Nice, France
| | - Isabelle Bidaud
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34096 Montpellier, France; .,LabEx Ion Channels Science and Therapeutics (ICST), 06560 Nice, France
| | - Peter J Mohler
- Frick Center for Heart Failure and Arrhythmia at the Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio 43210, USA.,Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Wexner Medical Center, Columbus, Ohio 43210, USA.,Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, Ohio 43210, USA
| | - Matteo E Mangoni
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34096 Montpellier, France; .,LabEx Ion Channels Science and Therapeutics (ICST), 06560 Nice, France
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16
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Hansen BJ, Zhao J, Helfrich KM, Li N, Iancau A, Zolotarev AM, Zakharkin SO, Kalyanasundaram A, Subr M, Dastagir N, Sharma R, Artiga EJ, Salgia N, Houmsse MM, Kahaly O, Janssen PML, Mohler PJ, Mokadam NA, Whitson BA, Afzal MR, Simonetti OP, Hummel JD, Fedorov VV. Unmasking Arrhythmogenic Hubs of Reentry Driving Persistent Atrial Fibrillation for Patient-Specific Treatment. J Am Heart Assoc 2020; 9:e017789. [PMID: 33006292 PMCID: PMC7792422 DOI: 10.1161/jaha.120.017789] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Background Atrial fibrillation (AF) driver mechanisms are obscured to clinical multielectrode mapping approaches that provide partial, surface‐only visualization of unstable 3‐dimensional atrial conduction. We hypothesized that transient modulation of refractoriness by pharmacologic challenge during multielectrode mapping improves visualization of hidden paths of reentrant AF drivers for targeted ablation. Methods and Results Pharmacologic challenge with adenosine was tested in ex vivo human hearts with a history of AF and cardiac diseases by multielectrode and high‐resolution subsurface near‐infrared optical mapping, integrated with 3‐dimensional structural imaging and heart‐specific computational simulations. Adenosine challenge was also studied on acutely terminated AF drivers in 10 patients with persistent AF. Ex vivo, adenosine stabilized reentrant driver paths within arrhythmogenic fibrotic hubs and improved visualization of reentrant paths, previously seen as focal or unstable breakthrough activation pattern, for targeted AF ablation. Computational simulations suggested that shortening of atrial refractoriness by adenosine may (1) improve driver stability by annihilating spatially unstable functional blocks and tightening reentrant circuits around fibrotic substrates, thus unmasking the common reentrant path; and (2) destabilize already stable reentrant drivers along fibrotic substrates by accelerating competing fibrillatory wavelets or secondary drivers. In patients with persistent AF, adenosine challenge unmasked hidden common reentry paths (9/15 AF drivers, 41±26% to 68±25% visualization), but worsened visualization of previously visible reentry paths (6/15, 74±14% to 34±12%). AF driver ablation led to acute termination of AF. Conclusions Our ex vivo to in vivo human translational study suggests that transiently altering atrial refractoriness can stabilize reentrant paths and unmask arrhythmogenic hubs to guide targeted AF driver ablation treatment.
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Affiliation(s)
- Brian J Hansen
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | | | - Katelynn M Helfrich
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | - Ning Li
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | - Alexander Iancau
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH
| | - Alexander M Zolotarev
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Skolkovo Institute of Science and Technology Moscow Russia
| | - Stanislav O Zakharkin
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH
| | - Anuradha Kalyanasundaram
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | - Megan Subr
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH
| | | | | | - Esthela J Artiga
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | - Nicholas Salgia
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH
| | - Mustafa M Houmsse
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH
| | - Omar Kahaly
- Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH.,Department of Internal Medicine The Ohio State University Wexner Medical Center Columbus OH
| | - Paul M L Janssen
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | - Peter J Mohler
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
| | - Nahush A Mokadam
- Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH.,Division of Cardiac Surgery The Ohio State University Wexner Medical Center Columbus OH
| | - Bryan A Whitson
- Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH.,Division of Cardiac Surgery The Ohio State University Wexner Medical Center Columbus OH
| | - Muhammad R Afzal
- Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH.,Department of Internal Medicine The Ohio State University Wexner Medical Center Columbus OH
| | - Orlando P Simonetti
- Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH.,Department of Biomedical Engineering The Ohio State University Wexner Medical Center Columbus OH
| | - John D Hummel
- Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH.,Department of Internal Medicine The Ohio State University Wexner Medical Center Columbus OH
| | - Vadim V Fedorov
- Department of Physiology & Cell Biology and Frick Center for Heart Failure and Arrhythmia The Ohio State University Wexner Medical Center Columbus OH.,Davis Heart & Lung Research InstituteThe Ohio State University Wexner Medical Center Columbus OH
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17
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Zolotarev AM, Hansen BJ, Ivanova EA, Helfrich KM, Li N, Janssen PML, Mohler PJ, Mokadam NA, Whitson BA, Fedorov MV, Hummel JD, Dylov DV, Fedorov VV. Optical Mapping-Validated Machine Learning Improves Atrial Fibrillation Driver Detection by Multi-Electrode Mapping. Circ Arrhythm Electrophysiol 2020; 13:e008249. [PMID: 32921129 DOI: 10.1161/circep.119.008249] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Atrial fibrillation (AF) can be maintained by localized intramural reentrant drivers. However, AF driver detection by clinical surface-only multielectrode mapping (MEM) has relied on subjective interpretation of activation maps. We hypothesized that application of machine learning to electrogram frequency spectra may accurately automate driver detection by MEM and add some objectivity to the interpretation of MEM findings. METHODS Temporally and spatially stable single AF drivers were mapped simultaneously in explanted human atria (n=11) by subsurface near-infrared optical mapping (NIOM; 0.3 mm2 resolution) and 64-electrode MEM (higher density or lower density with 3 and 9 mm2 resolution, respectively). Unipolar MEM and NIOM recordings were processed by Fourier transform analysis into 28 407 total Fourier spectra. Thirty-five features for machine learning were extracted from each Fourier spectrum. RESULTS Targeted driver ablation and NIOM activation maps efficiently defined the center and periphery of AF driver preferential tracks and provided validated annotations for driver versus nondriver electrodes in MEM arrays. Compared with analysis of single electrogram frequency features, averaging the features from each of the 8 neighboring electrodes, significantly improved classification of AF driver electrograms. The classification metrics increased when less strict annotation, including driver periphery electrodes, were added to driver center annotation. Notably, f1-score for the binary classification of higher-density catheter data set was significantly higher than that of lower-density catheter (0.81±0.02 versus 0.66±0.04, P<0.05). The trained algorithm correctly highlighted 86% of driver regions with higher density but only 80% with lower-density MEM arrays (81% for lower-density+higher-density arrays together). CONCLUSIONS The machine learning model pretrained on Fourier spectrum features allows efficient classification of electrograms recordings as AF driver or nondriver compared with the NIOM gold-standard. Future application of NIOM-validated machine learning approach may improve the accuracy of AF driver detection for targeted ablation treatment in patients.
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Affiliation(s)
- Alexander M Zolotarev
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Center of Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow, Russia (A.M.Z., E.A.I., M.V.F., D.V.D.)
| | - Brian J Hansen
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Ekaterina A Ivanova
- Center of Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow, Russia (A.M.Z., E.A.I., M.V.F., D.V.D.)
| | - Katelynn M Helfrich
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Ning Li
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Paul M L Janssen
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Peter J Mohler
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Nahush A Mokadam
- Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Division of Cardiac Surgery (N.A.M., B.A.W., J.D.H.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Bryan A Whitson
- Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Division of Cardiac Surgery (N.A.M., B.A.W., J.D.H.), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Maxim V Fedorov
- Center of Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow, Russia (A.M.Z., E.A.I., M.V.F., D.V.D.)
| | - John D Hummel
- Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Division of Cardiac Surgery (N.A.M., B.A.W., J.D.H.), The Ohio State University Wexner Medical Center, Columbus, OH.,Department of Internal Medicine (J.D.H), The Ohio State University Wexner Medical Center, Columbus, OH
| | - Dmitry V Dylov
- Center of Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow, Russia (A.M.Z., E.A.I., M.V.F., D.V.D.)
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia (A.M.Z., B.J.H., K.M.H., N.L., P.M.L.J., P.J.M., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart and Lung Research Institute (N.L., P.M.L.J., P.J.M., N.A.M., B.A.W., J.D.H., V.V.F.), The Ohio State University Wexner Medical Center, Columbus, OH
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18
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Yanni J, D'Souza A, Wang Y, Li N, Hansen BJ, Zakharkin SO, Smith M, Hayward C, Whitson BA, Mohler PJ, Janssen PML, Zeef L, Choudhury M, Zi M, Cai X, Logantha SJRJ, Nakao S, Atkinson A, Petkova M, Doris U, Ariyaratnam J, Cartwright EJ, Griffiths-Jones S, Hart G, Fedorov VV, Oceandy D, Dobrzynski H, Boyett MR. Silencing miR-370-3p rescues funny current and sinus node function in heart failure. Sci Rep 2020; 10:11279. [PMID: 32647133 PMCID: PMC7347645 DOI: 10.1038/s41598-020-67790-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 06/02/2020] [Indexed: 01/13/2023] Open
Abstract
Bradyarrhythmias are an important cause of mortality in heart failure and previous studies indicate a mechanistic role for electrical remodelling of the key pacemaking ion channel HCN4 in this process. Here we show that, in a mouse model of heart failure in which there is sinus bradycardia, there is upregulation of a microRNA (miR-370-3p), downregulation of the pacemaker ion channel, HCN4, and downregulation of the corresponding ionic current, If, in the sinus node. In vitro, exogenous miR-370-3p inhibits HCN4 mRNA and causes downregulation of HCN4 protein, downregulation of If, and bradycardia in the isolated sinus node. In vivo, intraperitoneal injection of an antimiR to miR-370-3p into heart failure mice silences miR-370-3p and restores HCN4 mRNA and protein and If in the sinus node and blunts the sinus bradycardia. In addition, it partially restores ventricular function and reduces mortality. This represents a novel approach to heart failure treatment.
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Affiliation(s)
- Joseph Yanni
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Alicia D'Souza
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Yanwen Wang
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Ning Li
- Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia Research and Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH, 43210, USA
| | - Brian J Hansen
- Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia Research and Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH, 43210, USA
| | - Stanislav O Zakharkin
- Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Matthew Smith
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Christina Hayward
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Bryan A Whitson
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia Research and Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH, 43210, USA
- Department of Surgery, Division of Cardiac Surgery, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Peter J Mohler
- Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia Research and Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH, 43210, USA
- Department of Internal Medicine, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Paul M L Janssen
- Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia Research and Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH, 43210, USA
- Department of Internal Medicine, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Leo Zeef
- Bioinformatics Core Facility, University of Manchester, Manchester, UK
| | - Moinuddin Choudhury
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Min Zi
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Xue Cai
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Sunil Jit R J Logantha
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
- Liverpool Centre for Cardiovascular Science, University of Liverpool, Liverpool, UK
| | - Shu Nakao
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Andrew Atkinson
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Maria Petkova
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Ursula Doris
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Jonathan Ariyaratnam
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Elizabeth J Cartwright
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Sam Griffiths-Jones
- Division of Evolution and Genomics Sciences, University of Manchester, Manchester, UK
| | - George Hart
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Vadim V Fedorov
- Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia Research and Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH, 43210, USA
| | - Delvac Oceandy
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Halina Dobrzynski
- Division of Cardiovascular Sciences, University of Manchester, 46 Grafton Street, Manchester, M13 9NT, UK
- Department of Anatomy, Jagiellonian University Medical College, Kraków, Poland
| | - Mark R Boyett
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200N, Copenhagen, Denmark.
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19
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Lo ACY, Bai J, Gladding PA, Fedorov VV, Zhao J. Afterdepolarizations and abnormal calcium handling in atrial myocytes with modulated SERCA uptake: a sensitivity analysis of calcium handling channels. Philos Trans A Math Phys Eng Sci 2020; 378:20190557. [PMID: 32448059 PMCID: PMC7287332 DOI: 10.1098/rsta.2019.0557] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/23/2020] [Indexed: 05/21/2023]
Abstract
Delayed afterdepolarizations (DADs) and spontaneous depolarizations (SDs) are typically triggered by spontaneous diastolic Ca2+ release from the sarcoplasmic reticulum (SR) which is caused by an elevated SR Ca2+-ATPase (SERCA) uptake and dysfunctional ryanodine receptors. However, recent studies on the T-box transcription factor gene (TBX5) demonstrated that abnormal depolarizations could occur despite a reduced SERCA uptake. Similar findings have also been reported in experimental or clinical studies of diabetes and heart failure. To investigate the sensitivity of SERCA in the genesis of DADs/SDs as well as its dependence on other Ca2+ handling channels, we performed systematic analyses using the Maleckar et al. model. Results showed that the modulation of SERCA alone cannot trigger abnormal depolarizations, but can instead affect the interdependency of other Ca2+ handling channels in triggering DADs/SDs. Furthermore, we discovered the existence of a threshold value for the intracellular concentration of Ca2+ ([Ca2+]i) for abnormal depolarizations, which is modulated by the maximum SERCA uptake and the concentration of Ca2+ in the uptake and release compartments in the SR ([Ca2+]up and [Ca2+]rel). For the first time, our modelling study reconciles different mechanisms of abnormal depolarizations in the setting of 'lone' AF, reduced TBX5, diabetes and heart failure, and may lead to more targeted treatment for these patients. This article is part of the theme issue 'Uncertainty quantification in cardiac and cardiovascular modelling and simulation'.
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Affiliation(s)
- Andy C. Y. Lo
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Jieyun Bai
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
- Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou, People's Republic of China
| | - Patrick A. Gladding
- Department of Cardiology, Waitemata District Health Board, Auckland, New Zealand
| | - Vadim V. Fedorov
- Department of Physiology and Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
- e-mail:
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20
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Shugurov KY, Mozharov AM, Bolshakov AD, Fedorov VV, Sapunov GA, Shtrom IV, Uvarov AV, Kudryashov DA, Baranov AI, Yu Mikhailovskii V, Neplokh VV, Tchernycheva M, Cirlin GE, Mukhin IS. Hydrogen passivation of the n-GaN nanowire/p-Si heterointerface. Nanotechnology 2020; 31:244003. [PMID: 32066120 DOI: 10.1088/1361-6528/ab76f2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The influence of hydrogen plasma treatment on the electrical and optical properties of vertical GaN nanowire (NW)/Si heterostructures synthesized via plasma assisted molecular beam epitaxy is studied. The effect of the treatment is thoroughly studied via variation of the passivation duration. Photoluminescence investigation demonstrates that the passivation affects the doping of the GaN NWs. The samples were processed as photodiodes with a top transparent electrode to obtain detailed information about the n-GaN NWs/p-Si heterointerface under illumination. The electron beam induced current measurements demonstrated the absence of potential barriers between the active parts of the diode and the contacts, indicating ohmic behavior of the latter. I-V characteristics obtained in the dark and under illumination show that hydrogen can effectively passivate the recombination centers at the GaN NWs/Si heterointerface. The optimum passivation duration, providing improved electrical properties, is found to be 10 min within the studied passivation regimes. It is demonstrated that longer treatment causes degradation of the electrical properties. The discovered phenomenon is discussed in detail.
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Affiliation(s)
- K Yu Shugurov
- Alferov university (former St Petersburg Academic university), Khlopina 8/3, 194021, St. Petersburg, Russia
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21
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Bai J, Lo A, Gladding PA, Stiles MK, Fedorov VV, Zhao J. In silico investigation of the mechanisms underlying atrial fibrillation due to impaired Pitx2. PLoS Comput Biol 2020; 16:e1007678. [PMID: 32097431 PMCID: PMC7059955 DOI: 10.1371/journal.pcbi.1007678] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 03/06/2020] [Accepted: 01/22/2020] [Indexed: 01/04/2023] Open
Abstract
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is a major cause of stroke and morbidity. Recent genome-wide association studies have shown that paired-like homeodomain transcription factor 2 (Pitx2) to be strongly associated with AF. However, the mechanisms underlying Pitx2 modulated arrhythmogenesis and variable effectiveness of antiarrhythmic drugs (AADs) in patients in the presence or absence of impaired Pitx2 expression remain unclear. We have developed multi-scale computer models, ranging from a single cell to tissue level, to mimic control and Pitx2-knockout atria by incorporating recent experimental data on Pitx2-induced electrical and structural remodeling in humans, as well as the effects of AADs. The key findings of this study are twofold. We have demonstrated that shortened action potential duration, slow conduction and triggered activity occur due to electrical and structural remodelling under Pitx2 deficiency conditions. Notably, the elevated function of calcium transport ATPase increases sarcoplasmic reticulum Ca2+ concentration, thereby enhancing susceptibility to triggered activity. Furthermore, heterogeneity is further elevated due to Pitx2 deficiency: 1) Electrical heterogeneity between left and right atria increases; and 2) Increased fibrosis and decreased cell-cell coupling due to structural remodelling slow electrical propagation and provide obstacles to attract re-entry, facilitating the initiation of re-entrant circuits. Secondly, our study suggests that flecainide has antiarrhythmic effects on AF due to impaired Pitx2 by preventing spontaneous calcium release and increasing wavelength. Furthermore, our study suggests that Na+ channel effects alone are insufficient to explain the efficacy of flecainide. Our study may provide the mechanisms underlying Pitx2-induced AF and possible explanation behind the AAD effects of flecainide in patients with Pitx2 deficiency.
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Affiliation(s)
- Jieyun Bai
- Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou, China
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Andy Lo
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Patrick A. Gladding
- Department of Cardiology, Waitemata District Health Board, Auckland, New Zealand
| | - Martin K. Stiles
- Waikato Clinical School, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
| | - Vadim V. Fedorov
- Department of Physiology & Cell Biology and Bob and Corrine Frick Center for Heart Failure and Arrhythmia, The Ohio State University Wexner Medical Center, Columbus, Ohio, United States of America
| | - Jichao Zhao
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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22
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Li N, Kalyanasundaram A, Hansen BJ, Artiga EJ, Sharma R, Abudulwahed SH, Helfrich KM, Rozenberg G, Wu PJ, Zakharkin S, Gyorke S, Janssen PM, Whitson BA, Mokadam NA, Biesiadecki BJ, Accornero F, Hummel JD, Mohler PJ, Dobrzynski H, Zhao J, Fedorov VV. Impaired neuronal sodium channels cause intranodal conduction failure and reentrant arrhythmias in human sinoatrial node. Nat Commun 2020; 11:512. [PMID: 31980605 PMCID: PMC6981137 DOI: 10.1038/s41467-019-14039-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 12/16/2019] [Indexed: 01/26/2023] Open
Abstract
Mechanisms for human sinoatrial node (SAN) dysfunction are poorly understood and whether human SAN excitability requires voltage-gated sodium channels (Nav) remains controversial. Here, we report that neuronal (n)Nav blockade and selective nNav1.6 blockade during high-resolution optical mapping in explanted human hearts depress intranodal SAN conduction, which worsens during autonomic stimulation and overdrive suppression to conduction failure. Partial cardiac (c)Nav blockade further impairs automaticity and intranodal conduction, leading to beat-to-beat variability and reentry. Multiple nNav transcripts are higher in SAN vs atria; heterogeneous alterations of several isoforms, specifically nNav1.6, are associated with heart failure and chronic alcohol consumption. In silico simulations of Nav distributions suggest that INa is essential for SAN conduction, especially in fibrotic failing hearts. Our results reveal that not only cNav but nNav are also integral for preventing disease-induced failure in human SAN intranodal conduction. Disease-impaired nNav may underlie patient-specific SAN dysfunctions and should be considered to treat arrhythmias. The role of of voltage-gated sodium channels (Nav) in pacemaking and conduction of the human sinoatrial node is unclear. Here, the authors investigate existence and function of neuronal and cardiac Nav in human sinoatrial nodes, and demonstrate their alterations in explanted human diseased hearts.
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Affiliation(s)
- Ning Li
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Anuradha Kalyanasundaram
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Brian J Hansen
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Esthela J Artiga
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Roshan Sharma
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Suhaib H Abudulwahed
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Katelynn M Helfrich
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Galina Rozenberg
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Pei-Jung Wu
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Stanislav Zakharkin
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Sandor Gyorke
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Paul Ml Janssen
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Bryan A Whitson
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Nahush A Mokadam
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Brandon J Biesiadecki
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Federica Accornero
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - John D Hummel
- Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Peter J Mohler
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Halina Dobrzynski
- Division of Cardiovascular Sciences, The University of Manchester, Manchester, UK.,Department of Anatomy, Jagiellonian University Medical College, Cracow, Poland
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA. .,Bob and Corrine Frick Center for Heart Failure and Arrhythmia, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
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23
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Xiong Z, Nalar A, Jamart K, Stiles MK, Fedorov VV, Zhao J. Fully Automatic 3D Bi-Atria Segmentation from Late Gadolinium-Enhanced MRIs Using Double Convolutional Neural Networks. Statistical Atlases and Computational Models of the Heart. Multi-Sequence CMR Segmentation, CRT-EPiggy and LV Full Quantification Challenges 2020. [DOI: 10.1007/978-3-030-39074-7_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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24
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Long VP, Bonilla IM, Baine S, Glynn P, Kumar S, Schober K, Mowrey K, Weiss R, Lee NY, Mohler PJ, Györke S, Hund TJ, Fedorov VV, Carnes CA. Chronic heart failure increases negative chronotropic effects of adenosine in canine sinoatrial cells via A1R stimulation and GIRK-mediated I Kado. Life Sci 2019; 240:117068. [PMID: 31751583 DOI: 10.1016/j.lfs.2019.117068] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/07/2019] [Accepted: 11/14/2019] [Indexed: 12/12/2022]
Abstract
AIMS Bradycardia contributes to tachy-brady arrhythmias or sinus arrest during heart failure (HF). Sinoatrial node (SAN) adenosine A1 receptors (ADO A1Rs) are upregulated in HF, and adenosine is known to exert negative chronotropic effects on the SAN. Here, we investigated the role of A1R signaling at physiologically relevant ADO concentrations on HF SAN pacemaker cells. MAIN METHODS Dogs with tachypacing-induced chronic HF and normal controls (CTL) were studied. SAN tissue was collected for A1R and GIRK mRNA quantification. SAN cells were isolated for perforated patch clamp recordings and firing rate (bpm), slope of slow diastolic depolarization (SDD), and maximum diastolic potential (MDP) were measured. Action potentials (APs) and currents were recorded before and after addition of 1 and 10 μM ADO. To assess contributions of A1R and G protein-coupled Inward Rectifier Potassium Current (GIRK) to ADO effects, APs were measured after the addition of DPCPX (selective A1R antagonist) or TPQ (selective GIRK blocker). KEY FINDINGS A1R and GIRK mRNA expression were significantly increased in HF. In addition, ADO induced greater rate slowing and membrane hyperpolarization in HF vs CTL (p < 0.05). DPCPX prevented ADO-induced rate slowing in CTL and HF cells. The ADO-induced inward rectifying current, IKado, was observed significantly more frequently in HF than in CTL. TPQ prevented ADO-induced rate slowing in HF. SIGNIFICANCE An increase in A1R and GIRK expression enhances IKAdo, causing hyperpolarization, and subsequent negative chronotropic effects in canine chronic HF at relevant [ADO]. GIRK blockade may be a useful strategy to mitigate bradycardia in HF.
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Affiliation(s)
- Victor P Long
- College of Pharmacy, The Ohio State University, Columbus, OH, USA; Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Ingrid M Bonilla
- College of Pharmacy, The Ohio State University, Columbus, OH, USA; Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Stephen Baine
- College of Pharmacy, The Ohio State University, Columbus, OH, USA; Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Patric Glynn
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Sanjay Kumar
- Department of Pharmacology, University of Arizona, Tucson, AZ, USA
| | - Karsten Schober
- College of Veterinary Medicine, The Ohio State University, Columbus, OH
| | | | - Raul Weiss
- Division of Cardiovascular Medicine, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Nam Y Lee
- Department of Pharmacology, University of Arizona, Tucson, AZ, USA
| | - Peter J Mohler
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA; Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Sandor Györke
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA; Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Thomas J Hund
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Vadim V Fedorov
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA; Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Cynthia A Carnes
- College of Pharmacy, The Ohio State University, Columbus, OH, USA; Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA.
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25
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Patel NJ, Nassal DM, Greer-Short AD, Unudurthi SD, Scandling BW, Gratz D, Xu X, Kalyanasundaram A, Fedorov VV, Accornero F, Mohler PJ, Gooch KJ, Hund TJ. βIV-Spectrin/STAT3 complex regulates fibroblast phenotype, fibrosis, and cardiac function. JCI Insight 2019; 4:131046. [PMID: 31550236 DOI: 10.1172/jci.insight.131046] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 09/18/2019] [Indexed: 01/30/2023] Open
Abstract
Increased fibrosis is a characteristic remodeling response to biomechanical and neurohumoral stress and a determinant of cardiac mechanical and electrical dysfunction in disease. Stress-induced activation of cardiac fibroblasts (CFs) is a critical step in the fibrotic response, although the precise sequence of events underlying activation of these critical cells in vivo remain unclear. Here, we tested the hypothesis that a βIV-spectrin/STAT3 complex is essential for maintenance of a quiescent phenotype (basal nonactivated state) in CFs. We reported increased fibrosis, decreased cardiac function, and electrical impulse conduction defects in genetic and acquired mouse models of βIV-spectrin deficiency. Loss of βIV-spectrin function promoted STAT3 nuclear accumulation and transcriptional activity, and it altered gene expression and CF activation. Furthermore, we demonstrate that a quiescent phenotype may be restored in βIV-spectrin-deficient fibroblasts by expressing a βIV-spectrin fragment including the STAT3-binding domain or through pharmacological STAT3 inhibition. We found that in vivo STAT3 inhibition abrogates fibrosis and cardiac dysfunction in the setting of global βIV-spectrin deficiency. Finally, we demonstrate that fibroblast-specific deletion of βIV-spectrin is sufficient to induce fibrosis and decreased cardiac function. We propose that the βIV-spectrin/STAT3 complex is a determinant of fibroblast phenotype and fibrosis, with implications for remodeling response in cardiovascular disease (CVD).
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Affiliation(s)
- Nehal J Patel
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Drew M Nassal
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Amara D Greer-Short
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Sathya D Unudurthi
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Benjamin W Scandling
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Daniel Gratz
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Xianyao Xu
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Anuradha Kalyanasundaram
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Physiology and Cell Biology, and
| | - Vadim V Fedorov
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Physiology and Cell Biology, and
| | - Federica Accornero
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Physiology and Cell Biology, and
| | - Peter J Mohler
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Physiology and Cell Biology, and.,Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Keith J Gooch
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Thomas J Hund
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA.,Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
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26
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Greer-Short A, Musa H, Alsina KM, Ni L, Word TA, Reynolds JO, Gratz D, Lane C, El-Refaey M, Unudurthi S, Skaf M, Li N, Fedorov VV, Wehrens XHT, Mohler PJ, Hund TJ. Calmodulin kinase II regulates atrial myocyte late sodium current, calcium handling, and atrial arrhythmia. Heart Rhythm 2019; 17:503-511. [PMID: 31622781 DOI: 10.1016/j.hrthm.2019.10.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND Atrial fibrillation (AF) is the most common type of arrhythmia. Abnormal atrial myocyte Ca2+ handling promotes aberrant membrane excitability and remodeling that are important for atrial arrhythmogenesis. The sequence of molecular events leading to loss of normal atrial myocyte Ca2+ homeostasis is not established. Late Na+ current (INa,L) is increased in atrial myocytes from AF patients together with an increase in activity of Ca2+/calmodulin-dependent kinase II (CaMKII). OBJECTIVE The purpose of this study was to determine whether CaMKII-dependent phosphorylation at Ser571 on NaV1.5 increases atrial INa,L, leading to aberrant atrial Ca2+ cycling, altered electrophysiology, and increased AF risk. METHODS Atrial myocyte electrophysiology, Ca2+ handling, and arrhythmia susceptibility were studied in wild-type and Scn5a knock-in mice expressing phosphomimetic (S571E) or phosphoresistant (S571A) NaV1.5 at Ser571. RESULTS Atrial myocytes from S571E but not S571A mice displayed an increase in INa,L and action potential duration, and with adrenergic stress have increased delayed afterdepolarizations. Frequency of Ca2+ sparks and waves was increased in S571E atrial myocytes compared to wild type. S571E mice showed an increase in atrial events induced by adrenergic stress and AF inducibility in vivo. Isolated S571E atria were more susceptible to spontaneous atrial events, which were abrogated by inhibiting sarcoplasmic reticulum Ca2+ release, CaMKII, or the Na+/Ca2+ exchanger. Expression of phospho-NaV1.5 at Ser571 and autophosphorylated CaMKII were increased in atrial samples from human AF patients. CONCLUSION This study identified CaMKII-dependent regulation of NaV1.5 as an important upstream event in Ca2+ handling defects and abnormal impulse generation in the setting of AF.
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Affiliation(s)
- Amara Greer-Short
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio
| | - Hassan Musa
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Katherina M Alsina
- Cardiovascular Research Institute, Departments of Molecular Physiology & Biophysics, Medicine (Cardiology), Pediatrics (Cardiology), and Neuroscience, Center for Space Medicine, Baylor College of Medicine, Houston, Texas
| | - Li Ni
- Cardiovascular Research Institute, Departments of Molecular Physiology & Biophysics, Medicine (Cardiology), Pediatrics (Cardiology), and Neuroscience, Center for Space Medicine, Baylor College of Medicine, Houston, Texas
| | - Tarah A Word
- Cardiovascular Research Institute, Departments of Molecular Physiology & Biophysics, Medicine (Cardiology), Pediatrics (Cardiology), and Neuroscience, Center for Space Medicine, Baylor College of Medicine, Houston, Texas
| | - Julia O Reynolds
- Cardiovascular Research Institute, Departments of Molecular Physiology & Biophysics, Medicine (Cardiology), Pediatrics (Cardiology), and Neuroscience, Center for Space Medicine, Baylor College of Medicine, Houston, Texas
| | - Daniel Gratz
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio
| | - Cemantha Lane
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio
| | - Mona El-Refaey
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Sathya Unudurthi
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio
| | - Michel Skaf
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Ning Li
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Physiology & Cell Biology, The Ohio State University College of Medicine, Columbus, Ohio
| | - Vadim V Fedorov
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Physiology & Cell Biology, The Ohio State University College of Medicine, Columbus, Ohio
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Departments of Molecular Physiology & Biophysics, Medicine (Cardiology), Pediatrics (Cardiology), and Neuroscience, Center for Space Medicine, Baylor College of Medicine, Houston, Texas
| | - Peter J Mohler
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Physiology & Cell Biology, The Ohio State University College of Medicine, Columbus, Ohio; Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, Ohio
| | - Thomas J Hund
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio; Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, Ohio.
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27
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Bolshakov AD, Fedorov VV, Shugurov KY, Mozharov AM, Sapunov GA, Shtrom IV, Mukhin MS, Uvarov AV, Cirlin GE, Mukhin IS. Effects of the surface preparation and buffer layer on the morphology, electronic and optical properties of the GaN nanowires on Si. Nanotechnology 2019; 30:395602. [PMID: 31234150 DOI: 10.1088/1361-6528/ab2c0c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The role of Si (111) substrate surface preparation and buffer layer composition in the growth, electronic and optical properties of the GaN nanowires (NWs) synthesized via plasma-assisted molecular beam epitaxy is studied. A comparison study of GaN NWs growth on the bare Si (111) substrate, silicon nitride interlayer, predeposited AlN and GaO x buffer layers, monolayer thick Ga wetting layer and GaN seeding layer prepared by the droplet epitaxy is performed. It is demonstrated that the homogeneity and the morphology of the NW arrays drastically depend on the chosen buffer layer and surface preparation technique. An effect of the buffer and seeding layers on the nucleation and desorption is also discussed. The lowest NWs surface density of 14 μm-2 is obtained on AlN buffer layer and the highest density exceeding the latter value by more than an order of magnitude corresponds to the growth on the 0.3 ML thick Ga wetting layer. It is shown, that the highest NWs mean elongation rate is obtained with AlN buffer layer, while the lowest elongation rate corresponds to the bare Si (111) surface and it is twice as lower as the first case. It is found, that use of AlN buffer layer corresponds to the most homogeneous NWs array with the smallest length dispersion while the least homogeneous array corresponds to the bare Si substrate. Vertically aligned GaN NWs array on the wide bandgap GaO x semiconductor buffer layer grown by plasma-enhanced chemical vapor deposition demonstrates its potential for electronic applications. Photoluminescence (PL) study of the synthesized samples is characterized by an intense optical response related to the excitons bound to neutral donors. The highest PL intensity is obtained in the sample with AlN buffer layer.
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Affiliation(s)
- A D Bolshakov
- St. Petersburg Academic University, Khlopina 8/3, 194021, St. Petersburg, Russia
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28
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Wang Y, Xiong Z, Nalar A, Hansen BJ, Kharche S, Seemann G, Loewe A, Fedorov VV, Zhao J. A robust computational framework for estimating 3D Bi-Atrial chamber wall thickness. Comput Biol Med 2019; 114:103444. [PMID: 31542646 DOI: 10.1016/j.compbiomed.2019.103444] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 08/23/2019] [Accepted: 09/10/2019] [Indexed: 12/14/2022]
Abstract
Atrial fibrillation (AF) is the most prevalent form of cardiac arrhythmia. The atrial wall thickness (AWT) can potentially improve our understanding of the mechanism underlying atrial structure that drives AF and provides important clinical information. However, most existing studies for estimating AWT rely on ruler-based measurements performed on only a few selected locations in 2D or 3D using digital calipers. Only a few studies have developed automatic approaches to estimate the AWT in the left atrium, and there are currently no methods to robustly estimate the AWT of both atrial chambers. Therefore, we have developed a computational pipeline to automatically calculate the 3D AWT across bi-atrial chambers and extensively validated our pipeline on both ex vivo and in vivo human atria data. The atrial geometry was first obtained by segmenting the atrial wall from the MRIs using a novel machine learning approach. The epicardial and endocardial surfaces were then separated using a multi-planar convex hull approach to define boundary conditions, from which, a Laplace equation was solved numerically to automatically separate bi-atrial chambers. To robustly estimate the AWT in each atrial chamber, coupled partial differential equations by coupling the Laplace solution with two surface trajectory functions were formulated and solved. Our pipeline enabled the reconstruction and visualization of the 3D AWT for bi-atrial chambers with a relative error of 8% and outperformed existing algorithms by >7%. Our approach can potentially lead to improved clinical diagnosis, patient stratification, and clinical guidance during ablation treatment for patients with AF.
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Affiliation(s)
- Yufeng Wang
- Auckland Bioengineering Institute, The University of Auckland, Auckland, 1142, New Zealand
| | - Zhaohan Xiong
- Auckland Bioengineering Institute, The University of Auckland, Auckland, 1142, New Zealand
| | - Aaqel Nalar
- Auckland Bioengineering Institute, The University of Auckland, Auckland, 1142, New Zealand
| | - Brian J Hansen
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA
| | - Sanjay Kharche
- Department of Medical Biophysics, Western University, Canada
| | - Gunnar Seemann
- The Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg, Bad Krozingen, Faculty of Medicine, Albert-Ludwigs University, Freiburg, Germany
| | - Axel Loewe
- The Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, 1142, New Zealand.
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29
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Macri V, Brody JA, Arking DE, Hucker WJ, Yin X, Lin H, Mills RW, Sinner MF, Lubitz SA, Liu CT, Morrison AC, Alonso A, Li N, Fedorov VV, Janssen PM, Bis JC, Heckbert SR, Dolmatova EV, Lumley T, Sitlani CM, Cupples LA, Pulit SL, Newton-Cheh C, Barnard J, Smith JD, Van Wagoner DR, Chung MK, Vlahakes GJ, O'Donnell CJ, Rotter JI, Margulies KB, Morley MP, Cappola TP, Benjamin EJ, Muzny D, Gibbs RA, Jackson RD, Magnani JW, Herndon CN, Rich SS, Psaty BM, Milan DJ, Boerwinkle E, Mohler PJ, Sotoodehnia N, Ellinor PT. Common Coding Variants in SCN10A Are Associated With the Nav1.8 Late Current and Cardiac Conduction. Circ Genom Precis Med 2019; 11:e001663. [PMID: 29752399 DOI: 10.1161/circgen.116.001663] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 03/02/2018] [Indexed: 12/20/2022]
Abstract
BACKGROUND Genetic variants at the SCN5A/SCN10A locus are strongly associated with electrocardiographic PR and QRS intervals. While SCN5A is the canonical cardiac sodium channel gene, the role of SCN10A in cardiac conduction is less well characterized. METHODS We sequenced the SCN10A locus in 3699 European-ancestry individuals to identify variants associated with cardiac conduction, and replicated our findings in 21,000 individuals of European ancestry. We examined association with expression in human atrial tissue. We explored the biophysical effect of variation on channel function using cellular electrophysiology. RESULTS We identified 2 intronic single nucleotide polymorphisms in high linkage disequilibrium (r 2=0.86) with each other to be the strongest signals for PR (rs10428132, β=-4.74, P=1.52×10-14) and QRS intervals (rs6599251, QRS β=-0.73; P=1.2×10-4), respectively. Although these variants were not associated with SCN5A or SCN10A expression in human atrial tissue (n=490), they were in high linkage disequilibrium (r 2≥0.72) with a common SCN10A missense variant, rs6795970 (V1073A). In total, we identified 7 missense variants, 4 of which (I962V, P1045T, V1073A, and L1092P) were associated with cardiac conduction. These 4 missense variants cluster in the cytoplasmic linker of the second and third domains of the SCN10A protein and together form 6 common haplotypes. Using cellular electrophysiology, we found that haplotypes associated with shorter PR intervals had a significantly larger percentage of late current compared with wild-type (I962V+V1073A+L1092P, 20.2±3.3%, P=0.03, and I962V+V1073A, 22.4±0.8%, P=0.0004 versus wild-type 11.7±1.6%), and the haplotype associated with the longest PR interval had a significantly smaller late current percentage (P1045T, 6.4±1.2%, P=0.03). CONCLUSIONS Our findings suggest an association between genetic variation in SCN10A, the late sodium current, and alterations in cardiac conduction.
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Affiliation(s)
- Vincenzo Macri
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (V.M., W.J.H., R.W.M., S.A.L., E.V.D., S.L.P., C.N.-C., D.J.M., P.T.E.)
| | - Jennifer A Brody
- Cardiovascular Health Research Unit, Department of Medicine (J.A.B., J.C.B., S.R.H., C.M.S., N.S.)
| | - Dan E Arking
- University of Washington, Seattle. McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD (D.E.A.)
| | - William J Hucker
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (V.M., W.J.H., R.W.M., S.A.L., E.V.D., S.L.P., C.N.-C., D.J.M., P.T.E.).,Cardiac Arrhythmia Service (W.J.H., S.A.L., D.J.M., P.T.E.)
| | - Xiaoyan Yin
- Massachusetts General Hospital, Boston. NHLBI's & Boston University's Framingham Heart Study, MA (X.Y., H.L., L.A.C.).,Department of Biostatistics (X.Y., L.A.C., C.-T.L.)
| | - Honghuang Lin
- Massachusetts General Hospital, Boston. NHLBI's & Boston University's Framingham Heart Study, MA (X.Y., H.L., L.A.C.).,School of Public Health, Boston University, MA. Computational Biomedicine Section (H.L.)
| | - Robert W Mills
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (V.M., W.J.H., R.W.M., S.A.L., E.V.D., S.L.P., C.N.-C., D.J.M., P.T.E.)
| | - Moritz F Sinner
- Department of Medicine, Boston University School of Medicine, MA. German Centre for Cardiovascular Research (DZHK), partner site: Munich Heart Alliance, Germany and Department of Medicine I, University Hospital Munich, Ludwig-Maximilian's University, Munich, Germany (M.F.S.)
| | - Steven A Lubitz
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (V.M., W.J.H., R.W.M., S.A.L., E.V.D., S.L.P., C.N.-C., D.J.M., P.T.E.).,Cardiac Arrhythmia Service (W.J.H., S.A.L., D.J.M., P.T.E.)
| | - Ching-Ti Liu
- Department of Biostatistics (X.Y., L.A.C., C.-T.L.)
| | - Alanna C Morrison
- Human Genetics Center, University of Texas Health Science Center at Houston (A.C.M., E.B.)
| | - Alvaro Alonso
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA (A.A.)
| | - Ning Li
- Department of Physiology & Cell Biology and Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., V.V.F., P.M.J., P.J.M.)
| | - Vadim V Fedorov
- Department of Physiology & Cell Biology and Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., V.V.F., P.M.J., P.J.M.)
| | - Paul M Janssen
- Department of Physiology & Cell Biology and Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., V.V.F., P.M.J., P.J.M.)
| | - Joshua C Bis
- Cardiovascular Health Research Unit, Department of Medicine (J.A.B., J.C.B., S.R.H., C.M.S., N.S.)
| | - Susan R Heckbert
- Cardiovascular Health Research Unit, Department of Medicine (J.A.B., J.C.B., S.R.H., C.M.S., N.S.).,Department of Epidemiology (S.R.H., T.L.)
| | - Elena V Dolmatova
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (V.M., W.J.H., R.W.M., S.A.L., E.V.D., S.L.P., C.N.-C., D.J.M., P.T.E.)
| | | | - Colleen M Sitlani
- Cardiovascular Health Research Unit, Department of Medicine (J.A.B., J.C.B., S.R.H., C.M.S., N.S.)
| | - L Adrienne Cupples
- Massachusetts General Hospital, Boston. NHLBI's & Boston University's Framingham Heart Study, MA (X.Y., H.L., L.A.C.).,Department of Biostatistics (X.Y., L.A.C., C.-T.L.)
| | - Sara L Pulit
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (V.M., W.J.H., R.W.M., S.A.L., E.V.D., S.L.P., C.N.-C., D.J.M., P.T.E.).,Department of Statistics, University of Auckland, New Zealand (S.L.P.)
| | - Christopher Newton-Cheh
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (V.M., W.J.H., R.W.M., S.A.L., E.V.D., S.L.P., C.N.-C., D.J.M., P.T.E.).,Center for Genomic Medicine (C.N.-C.).,Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA (C.N.-C.)
| | - John Barnard
- Department of Quantitative Health Sciences, Lerner Research Institute (J.B.)
| | - Jonathan D Smith
- Department of Cardiovascular Medicine, Heart and Vascular Institute (J.D.S., D.R.V.W., M.K.C.).,Department of Cellular and Molecular Medicine Biology, Lerner Research Institute (J.D.S.)
| | - David R Van Wagoner
- Department of Cardiovascular Medicine, Heart and Vascular Institute (J.D.S., D.R.V.W., M.K.C.).,Department of Molecular Cardiology, Lerner Research Institute (D.R.V.W., M.K.C.)
| | - Mina K Chung
- Department of Cardiovascular Medicine, Heart and Vascular Institute (J.D.S., D.R.V.W., M.K.C.).,Department of Molecular Cardiology, Lerner Research Institute (D.R.V.W., M.K.C.)
| | | | | | - Jerome I Rotter
- Cleveland Clinic, OH. Institute for Translational Genomics and Population Sciences, Los Angeles BioMedical Research Institute & Department of Pediatrics, Harbor-UCLA Medical Center, Torrance (J.I.R.)
| | - Kenneth B Margulies
- Penn Cardiovascular Institute, Perelman School of Medicine (K.B.M., M.P.M., T.P.C.).,Department of Medicine, Perelman School of Medicine (K.B.M., M.P.M., T.P.C.)
| | - Michael P Morley
- Penn Cardiovascular Institute, Perelman School of Medicine (K.B.M., M.P.M., T.P.C.).,Department of Medicine, Perelman School of Medicine (K.B.M., M.P.M., T.P.C.)
| | - Thomas P Cappola
- Penn Cardiovascular Institute, Perelman School of Medicine (K.B.M., M.P.M., T.P.C.).,Department of Medicine, Perelman School of Medicine (K.B.M., M.P.M., T.P.C.)
| | - Emelia J Benjamin
- Department of Epidemiology (E.J.B.).,Preventive Medicine Section (E.J.B.).,Cardiology Section (E.J.B.)
| | - Donna Muzny
- University of Pennsylvania, Philadelphia. Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX (D.M.M., R.A.G., E.B.)
| | - Richard A Gibbs
- University of Pennsylvania, Philadelphia. Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX (D.M.M., R.A.G., E.B.)
| | - Rebecca D Jackson
- Division of Endocrinology, Diabetes and Metabolism, College of Medicine, The Ohio State University, Columbus (R.D.J.)
| | - Jared W Magnani
- Division of Cardiology, Department of Medicine, UPMC Heart and Vascular Institute (J.W.M.)
| | - Caroline N Herndon
- Program in Medical and Population Genetics, Broad Institute, Cambridge, MA (C.N.H., P.T.E.)
| | - Stephen S Rich
- Center for Public Health Genomics, University of Virginia, Charlottesville (S.S.R.)
| | - Bruce M Psaty
- Cardiovascular Health Research Unit, Departments of Medicine, Epidemiology and Health Services, University of Washington, Seattle; and Kaiser Permanente Washington Health Research Institute, Seattle, WA. (B.M.P.)
| | - David J Milan
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (V.M., W.J.H., R.W.M., S.A.L., E.V.D., S.L.P., C.N.-C., D.J.M., P.T.E.).,Cardiac Arrhythmia Service (W.J.H., S.A.L., D.J.M., P.T.E.)
| | - Eric Boerwinkle
- Human Genetics Center, University of Texas Health Science Center at Houston (A.C.M., E.B.).,University of Pennsylvania, Philadelphia. Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX (D.M.M., R.A.G., E.B.)
| | - Peter J Mohler
- Department of Physiology & Cell Biology and Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., V.V.F., P.M.J., P.J.M.)
| | - Nona Sotoodehnia
- Cardiovascular Health Research Unit, Department of Medicine (J.A.B., J.C.B., S.R.H., C.M.S., N.S.) .,Division of Cardiology (N.S.)
| | - Patrick T Ellinor
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (V.M., W.J.H., R.W.M., S.A.L., E.V.D., S.L.P., C.N.-C., D.J.M., P.T.E.).,Cardiac Arrhythmia Service (W.J.H., S.A.L., D.J.M., P.T.E.).,Program in Medical and Population Genetics, Broad Institute, Cambridge, MA (C.N.H., P.T.E.)
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Xiong Z, Fedorov VV, Fu X, Cheng E, Macleod R, Zhao J. Fully Automatic Left Atrium Segmentation From Late Gadolinium Enhanced Magnetic Resonance Imaging Using a Dual Fully Convolutional Neural Network. IEEE Trans Med Imaging 2019; 38:515-524. [PMID: 30716023 PMCID: PMC6364320 DOI: 10.1109/tmi.2018.2866845] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Atrial fibrillation (AF) is the most prevalent form of cardiac arrhythmia. Current treatments for AF remain suboptimal due to a lack of understanding of the underlying atrial structures that directly sustain AF. Existing approaches for analyzing atrial structures in 3-D, especially from late gadolinium-enhanced (LGE) magnetic resonance imaging, rely heavily on manual segmentation methods that are extremely labor-intensive and prone to errors. As a result, a robust and automated method for analyzing atrial structures in 3-D is of high interest. We have, therefore, developed AtriaNet, a 16-layer convolutional neural network (CNN), on 154 3-D LGE-MRIs with a spatial resolution of 0.625 mm ×0.625 mm ×1.25 mm from patients with AF, to automatically segment the left atrial (LA) epicardium and endocardium. AtriaNet consists of a multi-scaled, dual-pathway architecture that captures both the local atrial tissue geometry and the global positional information of LA using 13 successive convolutions and three further convolutions for merging. By utilizing computationally efficient batch prediction, AtriaNet was able to successfully process each 3-D LGE-MRI within 1 min. Furthermore, benchmarking experiments have shown that AtriaNet has outperformed the state-of-the-art CNNs, with a DICE score of 0.940 and 0.942 for the LA epicardium and endocardium, respectively, and an inter-patient variance of <0.001. The estimated LA diameter and volume computed from the automatic segmentations were accurate to within 1.59 mm and 4.01 cm3 of the ground truths. Our proposed CNN was tested on the largest known data set for LA segmentation, and to the best of our knowledge, it is the most robust approach that has ever been developed for segmenting LGE-MRIs. The increased accuracy of atrial reconstruction and analysis could potentially improve the understanding and treatment of AF.
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Affiliation(s)
- Zhaohan Xiong
- VVF is with Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA. RM is with the Department of Bioengineering, University of Utah, Salt Lake City, USA
| | - Vadim V. Fedorov
- VVF is with Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA. RM is with the Department of Bioengineering, University of Utah, Salt Lake City, USA
| | - Xiaohang Fu
- VVF is with Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA. RM is with the Department of Bioengineering, University of Utah, Salt Lake City, USA
| | - Elizabeth Cheng
- VVF is with Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA. RM is with the Department of Bioengineering, University of Utah, Salt Lake City, USA
| | - Rob Macleod
- VVF is with Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA. RM is with the Department of Bioengineering, University of Utah, Salt Lake City, USA
| | - Jichao Zhao
- VVF is with Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, USA. RM is with the Department of Bioengineering, University of Utah, Salt Lake City, USA
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Hansen BJ, Li N, Helfrich KM, Abudulwahed SH, Artiga E, Joseph M, Mohler PJ, Hummel JD, Fedorov VV. First In Vivo Use of High-Resolution Near-Infrared Optical Mapping to Assess Atrial Activation During Sinus Rhythm and Atrial Fibrillation in a Large Animal Model. Circ Arrhythm Electrophysiol 2018; 11:e006870. [PMID: 30562105 PMCID: PMC6300135 DOI: 10.1161/circep.118.006870] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Brian J. Hansen
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Ning Li
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Katelynn M. Helfrich
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Suhaib H. Abudulwahed
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Esthela Artiga
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Matt Joseph
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Peter J Mohler
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
- Department of Internal Medicine; The Ohio State University Wexner Medical Center, Columbus, OH
| | - John D. Hummel
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
- Department of Internal Medicine; The Ohio State University Wexner Medical Center, Columbus, OH
| | - Vadim V. Fedorov
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
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Hansen BJ, Zhao J, Li N, Zolotarev A, Zakharkin S, Wang Y, Atwal J, Kalyanasundaram A, Abudulwahed SH, Helfrich KM, Bratasz A, Powell KA, Whitson B, Mohler PJ, Janssen PML, Simonetti OP, Hummel JD, Fedorov VV. Human Atrial Fibrillation Drivers Resolved With Integrated Functional and Structural Imaging to Benefit Clinical Mapping. JACC Clin Electrophysiol 2018; 4:1501-1515. [PMID: 30573112 DOI: 10.1016/j.jacep.2018.08.024] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 07/19/2018] [Accepted: 08/23/2018] [Indexed: 12/23/2022]
Abstract
OBJECTIVES This study sought to improve atrial fibrillation (AF) driver identification by integrating clinical multielectrode mapping with driver fingerprints defined by high-resolution ex vivo 3-dimensional (3D) functional and structural imaging. BACKGROUND Clinical multielectrode mapping of AF drivers suffers from variable contact, signal processing, and structural complexity within the 3D human atrial wall, raising questions on the validity of such drivers. METHODS Sustained AF was mapped in coronary-perfused explanted human hearts (n = 11) with transmural near-infrared optical mapping (∼0.3 mm2 resolution). Simultaneously, custom FIRMap catheters (∼9 × 9 mm2 resolution) mapped endocardial and epicardial surfaces, which were analyzed by Focal Impulse and Rotor Mapping activation and Rotational Activity Profile (Abbott Labs, Chicago, Illinois). Functional maps were integrated with contrast-enhanced cardiac magnetic resonance imaging (∼0.1 mm3 resolution) analysis of 3D fibrosis architecture. RESULTS During sustained AF, near-infrared optical mapping identified 1 to 2 intramural, spatially stable re-entrant AF drivers per heart. Driver targeted ablation affecting 2.2 ± 1.1% of the atrial surface terminated and prevented AF. Driver regions had significantly higher phase singularity density and dominant frequency than neighboring nondriver regions. Focal Impulse and Rotor Mapping had 80% sensitivity to near-infrared optical mapping-defined driver locations (16 of 20), and matched 14 of 20 driver visualizations: 10 of 14 re-entries seen with Rotational Activity Profile; and 4 of 6 breakthrough/focal patterns. Focal Impulse and Rotor Mapping detected 1.1 ± 0.9 false-positive rotational activity profiles per recording, but these regions had lower intramural contrast-enhanced cardiac magnetic resonance imaging fibrosis than did driver regions (14.9 ± 7.9% vs. 23.2 ± 10.5%; p < 0.005). CONCLUSIONS The study revealed that both re-entrant and breakthrough/focal AF driver patterns visualized by surface-only clinical multielectrodes can represent projections of 3D intramural microanatomic re-entries. Integration of multielectrode mapping and 3D fibrosis analysis may enhance AF driver detection, thereby improving the efficacy of driver-targeted ablation.
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Affiliation(s)
- Brian J Hansen
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Ning Li
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Alexander Zolotarev
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Phystech School of Biological and Medical Physics, Moscow Institute of Physic and Technology, Dolgoprudny, Russian Federation
| | - Stanislav Zakharkin
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Yufeng Wang
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Josh Atwal
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Anuradha Kalyanasundaram
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Suhaib H Abudulwahed
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Katelynn M Helfrich
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Anna Bratasz
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Kimerly A Powell
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Bryan Whitson
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Peter J Mohler
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Paul M L Janssen
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Orlando P Simonetti
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - John D Hummel
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio; Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio.
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Bai J, Gladding PA, Stiles MK, Fedorov VV, Zhao J. Ionic and cellular mechanisms underlying TBX5/PITX2 insufficiency-induced atrial fibrillation: Insights from mathematical models of human atrial cells. Sci Rep 2018; 8:15642. [PMID: 30353147 PMCID: PMC6199257 DOI: 10.1038/s41598-018-33958-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 09/24/2018] [Indexed: 12/16/2022] Open
Abstract
Transcription factors TBX5 and PITX2 involve in the regulation of gene expression of ion channels and are closely associated with atrial fibrillation (AF), the most common cardiac arrhythmia in developed countries. The exact cellular and molecular mechanisms underlying the increased susceptibility to AF in patients with TBX5/PITX2 insufficiency remain unclear. In this study, we have developed and validated a novel human left atrial cellular model (TPA) based on the ten Tusscher-Panfilov ventricular cell model to systematically investigate how electrical remodeling induced by TBX5/PITX2 insufficiency leads to AF. Using our TPA model, we have demonstrated that spontaneous diastolic depolarization observed in atrial myocytes with TBX5-deletion can be explained by altered intracellular calcium handling and suppression of inward-rectifier potassium current (IK1). Additionally, our computer simulation results shed new light on the novel cellular mechanism underlying AF by indicating that the imbalance between suppressed outward current IK1 and increased inward sodium-calcium exchanger current (INCX) resulted from SR calcium leak leads to spontaneous depolarizations. Furthermore, our simulation results suggest that these arrhythmogenic triggers can be potentially suppressed by inhibiting sarcoplasmic reticulum (SR) calcium leak and reversing remodeled IK1. More importantly, this study has clinically significant implications on the drugs used for maintaining SR calcium homeostasis, whereby drugs such as dantrolene may confer significant improvement for the treatment of AF patients with TBX5/PITX2 insufficiency.
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Affiliation(s)
- Jieyun Bai
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand.
- School of Computer Science and Technology, Harbin Institute Technology, Harbin, China.
| | - Patrick A Gladding
- Department of Cardiology, Waitemata District Health Board, Auckland, New Zealand
| | | | - Vadim V Fedorov
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, United States of America
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand.
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Xiong Z, Nash MP, Cheng E, Fedorov VV, Stiles MK, Zhao J. ECG signal classification for the detection of cardiac arrhythmias using a convolutional recurrent neural network. Physiol Meas 2018; 39:094006. [PMID: 30102248 PMCID: PMC6377428 DOI: 10.1088/1361-6579/aad9ed] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The electrocardiogram (ECG) provides an effective, non-invasive approach for clinical diagnosis in patients with cardiac diseases such as atrial fibrillation (AF). AF is the most common cardiac rhythm disturbance and affects ~2% of the general population in industrialized countries. Automatic AF detection in clinics remains a challenging task due to the high inter-patient variability of ECGs, and unsatisfactory existing approaches for AF diagnosis (e.g. atrial or ventricular activity-based analyses). APPROACH We have developed RhythmNet, a 21-layer 1D convolutional recurrent neural network, trained using 8528 single-lead ECG recordings from the 2017 PhysioNet/Computing in Cardiology (CinC) Challenge, to classify ECGs of different rhythms including AF automatically. Our RhythmNet architecture contained 16 convolutions to extract features directly from raw ECG waveforms, followed by three recurrent layers to process ECGs of varying lengths and to detect arrhythmia events in long recordings. Large 15 × 1 convolutional filters were used to effectively learn the detailed variations of the signal within small time-frames such as the P-waves and QRS complexes. We employed residual connections throughout RhythmNet, along with batch-normalization and rectified linear activation units to improve convergence during training. MAIN RESULTS We evaluated our algorithm on 3658 testing data and obtained an F 1 accuracy of 82% for classifying sinus rhythm, AF, and other arrhythmias. RhythmNet was also ranked 5th in the 2017 CinC Challenge. SIGNIFICANCE Potentially, our approach could aid AF diagnosis in clinics and be used for patient self-monitoring to improve the early detection and effective treatment of AF.
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Affiliation(s)
- Zhaohan Xiong
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Martyn P Nash
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
- Department of Engineering Science, University of Auckland, Auckland, New Zealand
| | - Elizabeth Cheng
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Vadim V. Fedorov
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH 43210-1218
| | - Martin K Stiles
- School of Medicine, University of Auckland, Auckland, New Zealand
- Waikato Hospital, Hamilton, New Zealand
| | - Jichao Zhao
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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Hansen BJ, Csepe TA, Zhao J, Ignozzi AJ, Hummel JD, Fedorov VV. Maintenance of Atrial Fibrillation: Are Reentrant Drivers With Spatial Stability the Key? Circ Arrhythm Electrophysiol 2018; 9:CIRCEP.116.004398. [PMID: 27729340 DOI: 10.1161/circep.116.004398] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 09/07/2016] [Indexed: 11/16/2022]
Affiliation(s)
- Brian J Hansen
- From the Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus (B.J.H., T.A.C., A.J.I., J.D.H., V.V.F.); and Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.)
| | - Thomas A Csepe
- From the Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus (B.J.H., T.A.C., A.J.I., J.D.H., V.V.F.); and Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.)
| | - Jichao Zhao
- From the Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus (B.J.H., T.A.C., A.J.I., J.D.H., V.V.F.); and Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.)
| | - Anthony J Ignozzi
- From the Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus (B.J.H., T.A.C., A.J.I., J.D.H., V.V.F.); and Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.)
| | - John D Hummel
- From the Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus (B.J.H., T.A.C., A.J.I., J.D.H., V.V.F.); and Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.)
| | - Vadim V Fedorov
- From the Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus (B.J.H., T.A.C., A.J.I., J.D.H., V.V.F.); and Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.).
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Li N, Hansen BJ, Fedorov VV. Response by Li et al to Letter Regarding Article, "Adenosine-Induced Atrial Fibrillation: Localized Reentrant Drivers in Lateral Right Atria Due to Heterogeneous Expression of Adenosine A1 Receptors and GIRK4 Subunits in the Human Heart". Circulation 2018; 134:e648-e649. [PMID: 27920078 DOI: 10.1161/circulationaha.116.025797] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Ning Li
- From Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus
| | - Brian J Hansen
- From Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus
| | - Vadim V Fedorov
- From Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus
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Csepe TA, Zhao J, Sul LV, Wang Y, Hansen BJ, Li N, Ignozzi AJ, Bratasz A, Powell KA, Kilic A, Mohler PJ, Janssen PML, Hummel JD, Simonetti OP, Fedorov VV. Novel application of 3D contrast-enhanced CMR to define fibrotic structure of the human sinoatrial node in vivo. Eur Heart J Cardiovasc Imaging 2018; 18:862-869. [PMID: 28087602 DOI: 10.1093/ehjci/jew304] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 11/16/2016] [Indexed: 11/13/2022] Open
Abstract
Aims The adult human sinoatrial node (SAN) has a specialized fibrotic intramural structure (35-55% fibrotic tissue) that provides mechanical and electrical protection from the surrounding atria. We hypothesize that late gadolinium-enhanced cardiovascular magnetic resonance (LGE-CMR) can be applied to define the fibrotic human SAN structure in vivo. Methods and results LGE-CMR atrial scans of healthy volunteers (n olu, 23-52 y.o.) using a 3 Tesla magnetic resonance imaging system with a spatial resolution of 1.0 mm3 or 0.625 × 0.625 × 1.25 mm3 were obtained and analysed. Percent fibrosis of total connective and cardiomyocyte tissue area in segmented atrial regions were measured based on signal intensity differences of fibrotic vs. non-fibrotic cardiomyocyte tissue. A distinct ellipsoidal fibrotic region (length: 23.6 ± 1.9 mm; width: 7.2 ± 0.9 mm; depth: 2.9 ± 0.4 mm) in all hearts was observed along the posterior junction of the crista terminalis and superior vena cava extending towards the interatrial septum, corresponding to the anatomical location of the human SAN. The SAN fibrotic region consisted of 41.9 ± 5.4% of LGE voxels above an average threshold of 2.7 SD (range 2-3 SD) from the non-fibrotic right atrial free wall tissue. Fibrosis quantification and SAN identification by in vivo LGE-CMR were validated in optically mapped explanted donor hearts ex vivo (n ivo, 19-65 y.o.) by contrast-enhanced CMR (9.4 Tesla; up to 90 µm3 resolution) correlated with serial histological sections of the SAN. Conclusion This is the first study to visualize the 3D human SAN fibrotic structure in vivo using LGE-CMR. Identification of the 3D SAN location and its high fibrotic content by LGE-CMR may provide a new tool to avoid or target SAN structure during ablation.
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Affiliation(s)
- Thomas A Csepe
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH 43210, USA
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, 70 Symonds Street, Auckland 1142, New Zealand
| | - Lidiya V Sul
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH 43210, USA
| | - Yufeng Wang
- Auckland Bioengineering Institute, The University of Auckland, 70 Symonds Street, Auckland 1142, New Zealand
| | - Brian J Hansen
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH 43210, USA
| | - Ning Li
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH 43210, USA
| | - Anthony J Ignozzi
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH 43210, USA
| | - Anna Bratasz
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH 43210, USA.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, 473 W 12th Avenue, Columbus, OH 43210, USA
| | - Kimerly A Powell
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH 43210, USA.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, 473 W 12th Avenue, Columbus, OH 43210, USA
| | - Ahmet Kilic
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, 473 W 12th Avenue, Columbus, OH 43210, USA.,Department of Surgery, The Ohio State University Wexner Medical Center, 410 W 10th Avenue, Columbus, OH 43210, USA
| | - Peter J Mohler
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH 43210, USA.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, 473 W 12th Avenue, Columbus, OH 43210, USA.,Department of Internal Medicine, The Ohio State University Wexner Medical Center, 395 W 12th Avenue, Columbus, OH 43210, USA
| | - Paul M L Janssen
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH 43210, USA.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, 473 W 12th Avenue, Columbus, OH 43210, USA.,Department of Internal Medicine, The Ohio State University Wexner Medical Center, 395 W 12th Avenue, Columbus, OH 43210, USA
| | - John D Hummel
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, 473 W 12th Avenue, Columbus, OH 43210, USA.,Department of Internal Medicine, The Ohio State University Wexner Medical Center, 395 W 12th Avenue, Columbus, OH 43210, USA
| | - Orlando P Simonetti
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, 473 W 12th Avenue, Columbus, OH 43210, USA.,Department of Biomedical Informatics, The Ohio State University Wexner Medical Center, 250 Lincoln Tower, 1800 Cannon Drive, Columbus, OH 43210, USA
| | - Vadim V Fedorov
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH 43210, USA.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, 473 W 12th Avenue, Columbus, OH 43210, USA
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Li N, Hansen BJ, Csepe TA, Zhao J, Ignozzi AJ, Sul LV, Zakharkin SO, Kalyanasundaram A, Davis JP, Biesiadecki BJ, Kilic A, Janssen PML, Mohler PJ, Weiss R, Hummel JD, Fedorov VV. Redundant and diverse intranodal pacemakers and conduction pathways protect the human sinoatrial node from failure. Sci Transl Med 2018; 9:9/400/eaam5607. [PMID: 28747516 DOI: 10.1126/scitranslmed.aam5607] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 06/16/2017] [Indexed: 11/02/2022]
Abstract
The human sinoatrial node (SAN) efficiently maintains heart rhythm even under adverse conditions. However, the specific mechanisms involved in the human SAN's ability to prevent rhythm failure, also referred to as its robustness, are unknown. Challenges exist because the three-dimensional (3D) intramural structure of the human SAN differs from well-studied animal models, and clinical electrode recordings are limited to only surface atrial activation. Hence, to innovate the translational study of human SAN structural and functional robustness, we integrated intramural optical mapping, 3D histology reconstruction, and molecular mapping of the ex vivo human heart. When challenged with adenosine or atrial pacing, redundant intranodal pacemakers within the human SAN maintained automaticity and delivered electrical impulses to the atria through sinoatrial conduction pathways (SACPs), thereby ensuring a fail-safe mechanism for robust maintenance of sinus rhythm. During adenosine perturbation, the primary central SAN pacemaker was suppressed, whereas previously inactive superior or inferior intranodal pacemakers took over automaticity maintenance. Sinus rhythm was also rescued by activation of another SACP when the preferential SACP was suppressed, suggesting two independent fail-safe mechanisms for automaticity and conduction. The fail-safe mechanism in response to adenosine challenge is orchestrated by heterogeneous differences in adenosine A1 receptors and downstream GIRK4 channel protein expressions across the SAN complex. Only failure of all pacemakers and/or SACPs resulted in SAN arrest or conduction block. Our results unmasked reserve mechanisms that protect the human SAN pacemaker and conduction complex from rhythm failure, which may contribute to treatment of SAN arrhythmias.
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Affiliation(s)
- Ning Li
- Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Brian J Hansen
- Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Thomas A Csepe
- Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Jichao Zhao
- Auckland Bioengineering Institute, University of Auckland, Auckland 1010, New Zealand
| | - Anthony J Ignozzi
- Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Lidiya V Sul
- Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Stanislav O Zakharkin
- Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Anuradha Kalyanasundaram
- Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Jonathan P Davis
- Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Brandon J Biesiadecki
- Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Ahmet Kilic
- Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Division of Cardiac Surgery, Department of Surgery, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Paul M L Janssen
- Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Department of Internal Medicine, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Peter J Mohler
- Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Department of Internal Medicine, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Raul Weiss
- Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Division of Cardiac Surgery, Department of Surgery, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Department of Internal Medicine, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - John D Hummel
- Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Division of Cardiac Surgery, Department of Surgery, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.,Department of Internal Medicine, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA. .,Dorothy M. Davis Heart and Lung Research Institute, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
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Sincore A, Cook J, Tan F, El Halawany A, Riggins A, McDaniel S, Cook G, Martyshkin DV, Fedorov VV, Mirov SB, Shah L, Abouraddy AF, Richardson MC, Schepler KL. High power single-mode delivery of mid-infrared sources through chalcogenide fiber. Opt Express 2018; 26:7313-7323. [PMID: 29609288 DOI: 10.1364/oe.26.007313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 03/01/2018] [Indexed: 06/08/2023]
Abstract
Mechanically robust and low loss single-mode arsenic sulfide fibers are used to deliver high power mid-infrared sources. Anti-reflection coatings were deposited on the fiber facets, enabling 90% transmission through 20 cm length fibers. 10.3 W was transmitted through an anti-reflection coated fiber at 2053 nm, and uncoated fibers sustained 12 MW/cm2 intensities on the facet without failure. A Cr:ZnSe laser transmitted >1 W at 2520 nm, and a Fe:ZnSe laser transmitted 0.5 W at 4102 nm. These results indicate that by improving the anti-reflection coatings and using a high beam quality mid-infrared source, chalcogenide fibers can reliably deliver ≥10 W in a single mode, potentially out to 6.5 µm.
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Kalyanasundaram A, Fedorov VV. Lights on! Can visual light help distinguish fibrotic scars from ablation lesions? Heart Rhythm 2018; 15:576-577. [PMID: 29309840 DOI: 10.1016/j.hrthm.2018.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Indexed: 11/25/2022]
Affiliation(s)
- Anuradha Kalyanasundaram
- Department of Physiology and Cell Biology, Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology, Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio.
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Affiliation(s)
- Vadim V Fedorov
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio.
| | - Brian J Hansen
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio
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42
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Milani-Nejad N, Chung JH, Canan BD, Fedorov VV, Whitson BA, Kilic A, Mohler PJ, Janssen PML. Increased cross-bridge recruitment contributes to transient increase in force generation beyond maximal capacity in human myocardium. J Mol Cell Cardiol 2017; 114:116-123. [PMID: 29141185 DOI: 10.1016/j.yjmcc.2017.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 10/25/2017] [Accepted: 11/10/2017] [Indexed: 11/17/2022]
Abstract
Cross-bridge attachment allows force generation to occur, and rate of tension redevelopment (ktr) is a commonly used index of cross-bridge cycling rate. Tension overshoots have been observed briefly after a slack-restretch ktr maneuver in various species of animal models and humans. In this study, we set out to determine the properties of these overshoots and their possible underlying mechanism. Utilizing human cardiac trabeculae, we have found that tension overshoots are temperature-dependent and that they do not occur at resting states. In addition, we have found that myosin cross-bridge cycle is vital to these overshoots as inhibition of the cycle results in the blunting of the overshoots and the magnitude of the overshoots are dependent on the level of myofilament activation. Lastly, we show that the number of cross-bridges transiently increase during tension overshoots. These findings lead us to conclude that tension overshoots are likely due to a transient enhancement of the recruitment of myosin heads into the cross-bridge cycling, regulated by the myocardium, and with potential physiological significance in determining cardiac output. NEWS AND NOTEWORTHY We show that isolated human myocardium is capable of transiently increasing its maximal force generation capability by increasing cross-bridge recruitment following slack-restretch maneuver. This process can potentially have important implications and significance in cardiac contraction in vivo.
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Affiliation(s)
- Nima Milani-Nejad
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA; Medical Scientist Training Program and Biomedical Sciences Graduate Program, The Ohio State University Wexner Medical Center, USA
| | - Jae-Hoon Chung
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA; Medical Scientist Training Program and Biomedical Sciences Graduate Program, The Ohio State University Wexner Medical Center, USA
| | - Benjamin D Canan
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA
| | - Bryan A Whitson
- Department of Surgery, Division of Cardiac Surgery, The Ohio State University Wexner Medical Center, USA
| | - Ahmet Kilic
- Department of Surgery, Division of Cardiac Surgery, The Ohio State University Wexner Medical Center, USA
| | - Peter J Mohler
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA; Department of Internal Medicine, The Ohio State University Wexner Medical Center, USA
| | - Paul M L Janssen
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA; Department of Internal Medicine, The Ohio State University Wexner Medical Center, USA.
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Affiliation(s)
- Vadim V Fedorov
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio.
| | - Brian J Hansen
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio
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Zhao J, Hansen BJ, Wang Y, Csepe TA, Sul LV, Tang A, Yuan Y, Li N, Bratasz A, Powell KA, Kilic A, Mohler PJ, Janssen PML, Weiss R, Simonetti OP, Hummel JD, Fedorov VV. Three-dimensional Integrated Functional, Structural, and Computational Mapping to Define the Structural "Fingerprints" of Heart-Specific Atrial Fibrillation Drivers in Human Heart Ex Vivo. J Am Heart Assoc 2017; 6:JAHA.117.005922. [PMID: 28862969 PMCID: PMC5586436 DOI: 10.1161/jaha.117.005922] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Structural remodeling of human atria plays a key role in sustaining atrial fibrillation (AF), but insufficient quantitative analysis of human atrial structure impedes the treatment of AF. We aimed to develop a novel 3-dimensional (3D) structural and computational simulation analysis tool that could reveal the structural contributors to human reentrant AF drivers. METHODS AND RESULTS High-resolution panoramic epicardial optical mapping of the coronary-perfused explanted intact human atria (63-year-old woman, chronic hypertension, heart weight 608 g) was conducted during sinus rhythm and sustained AF maintained by spatially stable reentrant AF drivers in the left and right atrium. The whole atria (107×61×85 mm3) were then imaged with contrast-enhancement MRI (9.4 T, 180×180×360-μm3 resolution). The entire 3D human atria were analyzed for wall thickness (0.4-11.7 mm), myofiber orientations, and transmural fibrosis (36.9% subendocardium; 14.2% midwall; 3.4% subepicardium). The 3D computational analysis revealed that a specific combination of wall thickness and fibrosis ranges were primarily present in the optically defined AF driver regions versus nondriver tissue. Finally, a 3D human heart-specific atrial computer model was developed by integrating 3D structural and functional mapping data to test AF induction, maintenance, and ablation strategies. This 3D model reproduced the optically defined reentrant AF drivers, which were uninducible when fibrosis and myofiber anisotropy were removed from the model. CONCLUSIONS Our novel 3D computational high-resolution framework may be used to quantitatively analyze structural substrates, such as wall thickness, myofiber orientation, and fibrosis, underlying localized AF drivers, and aid the development of new patient-specific treatments.
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Affiliation(s)
- Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, New Zealand
| | - Brian J Hansen
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Yufeng Wang
- Auckland Bioengineering Institute, The University of Auckland, New Zealand
| | - Thomas A Csepe
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Lidiya V Sul
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Alan Tang
- Auckland Bioengineering Institute, The University of Auckland, New Zealand
| | - Yiming Yuan
- Auckland Bioengineering Institute, The University of Auckland, New Zealand
| | - Ning Li
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Anna Bratasz
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Kimerly A Powell
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Ahmet Kilic
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Peter J Mohler
- Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Paul M L Janssen
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Raul Weiss
- Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Orlando P Simonetti
- Department of Biomedical Informatics, The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - John D Hummel
- Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH.,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Vadim V Fedorov
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH .,Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH
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Guha A, Xiang X, Haddad D, Buck B, Gao X, Dunleavy M, Liu E, Patel D, Fedorov VV, Daoud EG. Eleven-year trends of inpatient pacemaker implantation in patients diagnosed with sick sinus syndrome. J Cardiovasc Electrophysiol 2017; 28:933-943. [PMID: 28471545 DOI: 10.1111/jce.13248] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 04/26/2017] [Accepted: 04/28/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Pacemakers (PM) are used for managing sick sinus syndrome (SSS). This study evaluates predictors and trends of PM implantation for SSS. METHODS Patients were identified from the National Inpatient Sample dataset (2003-2013). Included patients were ≥18 years old, had a diagnosis of sinus node dysfunction and atrial arrhythmia (i.e., SSS). Patients who died, transferred out, who had prior device, or had a defibrillator or resynchronization therapy device implanted were excluded. Included patients were then stratified by if a PM was implanted. Data regarding SSS, trends of PM utilization, and multivariable models of factors associated with PM implantation are presented. RESULTS Note that 328,670 patients satisfied study criteria. This study compared patients who underwent (87.4%) PM implantation to those who did not undergo (12.6%) PM implantation. The annual trends for hospitalization with SSS and PM placement have been decreasing (P <0.001). Variables associated with lower likelihood for PM implantation include young age, female sex, non-Caucasian race, chronic heart failure, Charlson Comorbidity Score ≥1, emergency room and weekend admission, hospital stay ≤3 days, and high cardiology inpatient volume. Greater likelihood for PM implantation was associated with hyperlipidemia, hypertension, and hospitals that were either private, large, Northeastern location, or with high cardiac procedural volume. CONCLUSIONS Analyzing 11-year data from a national inpatient database demonstrate a number of relevant variables that impact PM utilization that include not only clinical but also nonclinical variables such as socioeconomic status, gender, and hospital features. Racial and gender bias toward PM implantation are unchanged and persist through 2013.
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Affiliation(s)
- Avirup Guha
- Ohio State University Division of Cardiovascular Medicine, Columbus, Ohio, USA
| | - Xiao Xiang
- Ohio State University Division of Epidemiology, College of Public Health, Columbus, Ohio, USA
| | - Devin Haddad
- Ohio State University Division of Internal Medicine, Columbus, Ohio, USA
| | - Benjamin Buck
- Ohio State University Division of Internal Medicine, Columbus, Ohio, USA
| | - Xu Gao
- Ohio State University Division of Internal Medicine, Columbus, Ohio, USA
| | - Michael Dunleavy
- Ohio State University Division of Internal Medicine, Columbus, Ohio, USA
| | - Ellen Liu
- Ohio State University Division of Internal Medicine, Columbus, Ohio, USA
| | - Dilesh Patel
- Ohio State University Division of Cardiovascular Medicine, Columbus, Ohio, USA
| | - Vadim V Fedorov
- Ohio State University Department of Physiology and Cellular Biology, Columbus, Ohio, USA
| | - Emile G Daoud
- Ohio State University Division of Cardiovascular Medicine, Columbus, Ohio, USA
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Oskretkov VI, Gur'yanov AA, Gankov VA, Klimova GI, Andreasyan AR, Balatsky DV, Fedorov VV, Maslikova SA. [Endoscopic surgery for benign diseases and injuries of the esophagus (with commentary)]. Khirurgiia (Mosk) 2016:21-26. [PMID: 27804931 DOI: 10.17116/hirurgia20161021-26] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
AIM To analyze the results of surgical treatment of patients with benign diseases and injuries of the esophagus. MATERIAL AND METHODS We summarized the experience of different endoscopic interventions in 159 patients with various benign diseases and perforation of the esophagus. Patients with achalasia (72 cases) underwent videolaparoscopic Geller's esophagomyotomy with anterior hemiesophagofundoplication by Dor. Video-assisted thoracoscopic extirpation of the esophagus with simultaneous or delayed esophagocolo/gastroplasty was performed in 56 patients with post-ambustial cicatricial stenosis of the esophagus. Patients with esophageal perforation (14 cases) underwent videolaparoscopic transhiatal mediastinal drainage. Esophageal leiomyoma has been excised through thoracoscopic (9 cases) or laparoscopic access (4 cases). Removal of esophageal diverticulum was made via VATS-access in 4 patients. RESULTS Satisfactory early and remote results were achieved in all patients with achalasia. Mortality rate was 5.4% (3 out of 56 patients) and 14.3% (2 out of 14 patients) in groups of cicatricial esophageal stenosis and esophageal perforation respectively. Sutures failure after removal of the diverticulum and leiomyoma occurred in 2 and 1 patient respectively and has been successfully cured. CONCLUSION Endoscopic technologies allow to perform successfully complex reconstructive interventions for dysphagia in patients with cicatricial esophageal stenosis and achalasia even at late stages, to remove benign tumors and diverticula of thoracic esophagus and provide adequate drainage of posterior mediastinum in case of esophageal perforation.
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Affiliation(s)
- V I Oskretkov
- Altai State Medical University, Ministry of Health of the Russian Federation, Barnaul, Russia
| | - A A Gur'yanov
- Altai State Medical University, Ministry of Health of the Russian Federation, Barnaul, Russia
| | - V A Gankov
- Altai State Medical University, Ministry of Health of the Russian Federation, Barnaul, Russia
| | - G I Klimova
- Altai State Medical University, Ministry of Health of the Russian Federation, Barnaul, Russia
| | - A R Andreasyan
- Altai State Medical University, Ministry of Health of the Russian Federation, Barnaul, Russia
| | - D V Balatsky
- Altai State Medical University, Ministry of Health of the Russian Federation, Barnaul, Russia
| | - V V Fedorov
- Altai State Medical University, Ministry of Health of the Russian Federation, Barnaul, Russia
| | - S A Maslikova
- Altai State Medical University, Ministry of Health of the Russian Federation, Barnaul, Russia
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Li N, Csepe TA, Hansen BJ, Sul LV, Kalyanasundaram A, Zakharkin SO, Zhao J, Guha A, Van Wagoner DR, Kilic A, Mohler PJ, Janssen PML, Biesiadecki BJ, Hummel JD, Weiss R, Fedorov VV. Adenosine-Induced Atrial Fibrillation: Localized Reentrant Drivers in Lateral Right Atria due to Heterogeneous Expression of Adenosine A1 Receptors and GIRK4 Subunits in the Human Heart. Circulation 2016; 134:486-98. [PMID: 27462069 DOI: 10.1161/circulationaha.115.021165] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 06/02/2016] [Indexed: 11/16/2022]
Abstract
BACKGROUND Adenosine provokes atrial fibrillation (AF) with a higher activation frequency in right atria (RA) versus left atria (LA) in patients, but the underlying molecular and functional substrates are unclear. We tested the hypothesis that adenosine-induced AF is driven by localized reentry in RA areas with highest expression of adenosine A1 receptor and its downstream GIRK (G protein-coupled inwardly rectifying potassium channels) channels (IK,Ado). METHODS We applied biatrial optical mapping and immunoblot mapping of various atrial regions to reveal the mechanism of adenosine-induced AF in explanted failing and nonfailing human hearts (n=37). RESULTS Optical mapping of coronary-perfused atria (n=24) revealed that adenosine perfusion (10-100 µmol/L) produced more significant shortening of action potential durations in RA (from 290±45 to 239±41 ms, 17.3±10.4%; P<0.01) than LA (from 307±24 to 286±23 ms, 6.7±6.6%; P<0.01). In 10 hearts, adenosine induced AF (317±116 s) that, when sustained (≥2 minutes), was primarily maintained by 1 to 2 localized reentrant drivers in lateral RA. Tertiapin (10-100 nmol/L), a selective GIRK channel blocker, counteracted adenosine-induced action potential duration shortening and prevented AF induction. Immunoblotting showed that the superior/middle lateral RA had significantly higher adenosine A1 receptor (2.7±1.7-fold; P<0.01) and GIRK4 (1.7±0.8-fold; P<0.05) protein expression than lateral/posterior LA. CONCLUSIONS This study revealed a 3-fold RA-to-LA adenosine A1 receptor protein expression gradient in the human heart, leading to significantly greater RA versus LA repolarization sensitivity in response to adenosine. Sustained adenosine-induced AF is maintained by reentrant drivers localized in lateral RA regions with the highest adenosine A1 receptor/GIRK4 expression. Selective atrial GIRK channel blockade may effectively treat AF during conditions with increased endogenous adenosine.
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Affiliation(s)
- Ning Li
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - Thomas A Csepe
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - Brian J Hansen
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - Lidiya V Sul
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - Anuradha Kalyanasundaram
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - Stanislav O Zakharkin
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - Jichao Zhao
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - Avirup Guha
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - David R Van Wagoner
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - Ahmet Kilic
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - Peter J Mohler
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - Paul M L Janssen
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - Brandon J Biesiadecki
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - John D Hummel
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - Raul Weiss
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.)
| | - Vadim V Fedorov
- From Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, S.O.Z., A.G., P.J.M., P.M.L.J., B.J.B., V.V.F.); Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (N.L., T.A.C., B.J.H., L.V.S., A. Kalyanasundaram, A. Kilic, P.J.M., P.M.L.J., B.J.B., J.D.H., R.W., V.V.F.); Auckland Bioengineering Institute, The University of Auckland, New Zealand (J.Z.); Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus (A.G., A. Kilic, P.J.M., P.M.L.J., J.D.H., R.W.); Department of Molecular Cardiology, Cleveland Clinic, OH (D.R.V.W.); and Department of Surgery, Division of Cardiac Surgery, Wexner Medical Center, The Ohio State University, Columbus (A. Kilic, J.D.H., R.W.).
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Milani-Nejad N, Chung JH, Canan BD, Davis JP, Fedorov VV, Higgins RSD, Kilic A, Mohler PJ, Janssen PML. Insights into length-dependent regulation of cardiac cross-bridge cycling kinetics in human myocardium. Arch Biochem Biophys 2016; 601:48-55. [PMID: 26854725 PMCID: PMC4899103 DOI: 10.1016/j.abb.2016.02.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 01/29/2016] [Accepted: 02/02/2016] [Indexed: 11/16/2022]
Abstract
Cross-bridge cycling kinetics play an essential role in the heart's ability to contract and relax. The rate of tension redevelopment (ktr) slows down as a muscle length is increased in intact human myocardium. We set out to determine the effect of rapid length step changes and protein kinase A (PKA) and protein kinase C-βII (PKC-βII) inhibitors on the ktr in ultra-thin non-failing and failing human right ventricular trabeculae. After stabilizing the muscle either at L90 (90% of optimal length) or at Lopt (optimal length), we rapidly changed the length to either Lopt or L90 and measured ktr. We report that length-dependent changes in ktr occur very rapidly (in the order of seconds or faster) in both non-failing and failing muscles and that the length at which a muscle had been stabilized prior to the length change does not significantly affect ktr. In addition, at L90 and at Lopt, PKA and PKC-βII inhibitors did not significantly change ktr. Our results reveal that length-dependent regulation of cross-bridge cycling kinetics predominantly occurs rapidly and involves the intrinsic properties of the myofilament rather than post-translational modifications that are known to occur in the cardiac muscle as a result of a change in muscle/sarcomere length.
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Affiliation(s)
- Nima Milani-Nejad
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA; Medical Scientist Training Program and Biomedical Sciences Graduate Program, The Ohio State University Wexner Medical Center, USA
| | - Jae-Hoon Chung
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA; Medical Scientist Training Program and Biomedical Sciences Graduate Program, The Ohio State University Wexner Medical Center, USA
| | - Benjamin D Canan
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA
| | - Jonathan P Davis
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA
| | - Vadim V Fedorov
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA
| | - Robert S D Higgins
- Department of Surgery, Division of Cardiac Surgery, The Ohio State University Wexner Medical Center, USA
| | - Ahmet Kilic
- Department of Surgery, Division of Cardiac Surgery, The Ohio State University Wexner Medical Center, USA
| | - Peter J Mohler
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA; Department of Internal Medicine, The Ohio State University Wexner Medical Center, USA
| | - Paul M L Janssen
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA; Department of Internal Medicine, The Ohio State University Wexner Medical Center, USA.
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49
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Csepe TA, Hansen BJ, Fedorov VV. Atrial fibrillation driver mechanisms: Insight from the isolated human heart. Trends Cardiovasc Med 2016; 27:1-11. [PMID: 27492815 DOI: 10.1016/j.tcm.2016.05.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 05/17/2016] [Accepted: 05/19/2016] [Indexed: 11/25/2022]
Abstract
Although there have been great technological advances in the treatment of atrial fibrillation (AF), current therapies remain limited due to a narrow understanding of AF mechanisms in the human heart. This review will highlight our recent studies on explanted human hearts where we developed and employed a novel functional-structural mapping approach by integrating high-resolution simultaneous endo-epicardial and panoramic optical mapping with 3D gadolinium-enhanced MRI to define the spatiotemporal characteristics of AF drivers and their structural substrates. The results allow us to postulate that the primary mechanism of AF maintenance in human hearts is a limited number of localized intramural microanatomic reentrant AF drivers anchored to heart-specific 3D fibrotically insulated myobundle tracks, which may remain hidden to clinical single-surface electrode mapping. We suggest that ex vivo human heart studies, by using an integrated 3D functional and structural mapping approach, will help to reveal defining features of AF drivers as well as validate and improve clinical approaches to detect and target these AF drivers in patients with cardiac diseases.
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Affiliation(s)
- Thomas A Csepe
- Department of Physiology & Cell Biology, Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, 300 Hamilton Hall, 1645 Neil Ave, Columbus, OH 43210-1218
| | - Brian J Hansen
- Department of Physiology & Cell Biology, Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, 300 Hamilton Hall, 1645 Neil Ave, Columbus, OH 43210-1218
| | - Vadim V Fedorov
- Department of Physiology & Cell Biology, Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, 300 Hamilton Hall, 1645 Neil Ave, Columbus, OH 43210-1218.
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50
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Unudurthi SD, Wu X, Qian L, Amari F, Onal B, Li N, Makara MA, Smith SA, Snyder J, Fedorov VV, Coppola V, Anderson ME, Mohler PJ, Hund TJ. Two-Pore K+ Channel TREK-1 Regulates Sinoatrial Node Membrane Excitability. J Am Heart Assoc 2016; 5:e002865. [PMID: 27098968 PMCID: PMC4859279 DOI: 10.1161/jaha.115.002865] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Two‐pore K+ channels have emerged as potential targets to selectively regulate cardiac cell membrane excitability; however, lack of specific inhibitors and relevant animal models has impeded the effort to understand the role of 2‐pore K+ channels in the heart and their potential as a therapeutic target. The objective of this study was to determine the role of mechanosensitive 2‐pore K+ channel family member TREK‐1 in control of cardiac excitability. Methods and Results Cardiac‐specific TREK‐1–deficient mice (αMHC‐Kcnkf/f) were generated and found to have a prevalent sinoatrial phenotype characterized by bradycardia with frequent episodes of sinus pause following stress. Action potential measurements from isolated αMHC‐Kcnk2f/f sinoatrial node cells demonstrated decreased background K+ current and abnormal sinoatrial cell membrane excitability. To identify novel pathways for regulating TREK‐1 activity and sinoatrial node excitability, mice expressing a truncated allele of the TREK‐1–associated cytoskeletal protein βIV‐spectrin (qv4J mice) were analyzed and found to display defects in cell electrophysiology as well as loss of normal TREK‐1 membrane localization. Finally, the βIV‐spectrin/TREK‐1 complex was found to be downregulated in the right atrium from a canine model of sinoatrial node dysfunction and in human cardiac disease. Conclusions These findings identify a TREK‐1–dependent pathway essential for normal sinoatrial node cell excitability that serves as a potential target for selectively regulating sinoatrial node cell function.
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Affiliation(s)
- Sathya D Unudurthi
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH
| | - Xiangqiong Wu
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH
| | - Lan Qian
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH
| | - Foued Amari
- Department of Molecular Virology, Immunology & Medical Genetics, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Birce Onal
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH
| | - Ning Li
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Michael A Makara
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Sakima A Smith
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Jedidiah Snyder
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH
| | - Vadim V Fedorov
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Vincenzo Coppola
- Department of Molecular Virology, Immunology & Medical Genetics, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Mark E Anderson
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Peter J Mohler
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Thomas J Hund
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH
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