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Cohle SD, Wygant CM. Lesions of the Cardiac Conduction System and Sudden Death. Am J Forensic Med Pathol 2024; 45:3-9. [PMID: 37994486 DOI: 10.1097/paf.0000000000000895] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
ABSTRACT When a young previously healthy person dies suddenly, occasionally, the scene is noncontributory and the autopsy and drug screen are negative. In such cases, additional studies, including genetic assessment and cardiac conduction system examination, should be performed. We performed a literature search and reviewed our own material to identify possible or definite conduction system anomalies that may cause death. We identified intrinsic conduction system disease including cystic tumor of the atrioventricular node, atrioventricular node (cystic tumor of the AV node), and fibromuscular dysplasia of the atrioventricular node artery to be likely causes of death. Extrinsic causes, in which a generalized disease affects the conduction system, include tumors, autoimmune disease, infiltrative disorders, and others, are a second category of diseases that can affect the conduction system and cause atrioventricular block and sudden death.
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Affiliation(s)
- Stephen D Cohle
- From the Department of Pathology and Laboratory Medicine, Corewell Health, Grand Rapids, MI
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2
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Machida N, Sasaki T, Kimura Y, Hirakawa A. The anatomical basis of third-degree atrioventricular block in dogs with atrioventricular valve endocardiosis. J Comp Pathol 2023; 201:63-69. [PMID: 36709730 DOI: 10.1016/j.jcpa.2022.12.014] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/30/2022] [Accepted: 12/29/2022] [Indexed: 01/30/2023]
Abstract
The cardiac conduction system was examined histologically in 13 canine cases of atrioventricular (AV) valve endocardiosis with third-degree AV block. In all cases, gross examination revealed marked thickening and distortion of the base of the central fibrous body (CFB) and varying degrees of endocardial thickening of the upper portion of the ventricular septum (VS) as well as marked thickening of the mitral and tricuspid valve leaflets due to myxomatous degeneration. Microscopically, the thickened and distorted CFB had encased or trapped, either partly or totally, the underlying penetrating and branching portions of the AV bundle. The myxomatous and/or fibrofatty tissue, which had proliferated at the base of the extensive CFB, protruded into or encroached on the AV bundle, causing severe (51-75%) to very severe (76% or more) reduction of the conduction fibres. The upper portions of the left and right bundle branches were involved in the endocardial thickening due to degenerative and fibrotic changes at the uppermost VS; however, both bundle branches were much less severely affected than the AV bundle, the degree of reduction of the conduction fibres ranging from mild (25% or less) to moderate (26-50%). These observations suggest that the sites most vulnerable to lesions in the AV conduction system are the penetrating and branching portions of the AV bundle, which would represent the anatomical basis for third-degree AV block in canine cases of AV valve endocardiosis.
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Affiliation(s)
- Noboru Machida
- Laboratory of Veterinary Clinical Oncology, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan.
| | - Takafumi Sasaki
- Laboratory of Veterinary Clinical Oncology, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
| | - Yusuke Kimura
- Laboratory of Veterinary Clinical Oncology, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
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3
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Han B, Trew ML, Zgierski-Johnston CM. Cardiac Conduction Velocity, Remodeling and Arrhythmogenesis. Cells 2021; 10:cells10112923. [PMID: 34831145 PMCID: PMC8616078 DOI: 10.3390/cells10112923] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/14/2021] [Accepted: 10/22/2021] [Indexed: 02/06/2023] Open
Abstract
Cardiac electrophysiological disorders, in particular arrhythmias, are a key cause of morbidity and mortality throughout the world. There are two basic requirements for arrhythmogenesis: an underlying substrate and a trigger. Altered conduction velocity (CV) provides a key substrate for arrhythmogenesis, with slowed CV increasing the probability of re-entrant arrhythmias by reducing the length scale over which re-entry can occur. In this review, we examine methods to measure cardiac CV in vivo and ex vivo, discuss underlying determinants of CV, and address how pathological variations alter CV, potentially increasing arrhythmogenic risk. Finally, we will highlight future directions both for methodologies to measure CV and for possible treatments to restore normal CV.
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Affiliation(s)
- Bo Han
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, 79110 Freiburg im Breisgau, Germany;
- Faculty of Medicine, University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, 79104 Freiburg im Breisgau, Germany
- Department of Cardiovascular Surgery, The Fourth People’s Hospital of Jinan, 250031 Jinan, China
| | - Mark L. Trew
- Auckland Bioengineering Institute, University of Auckland, Auckland 1010, New Zealand;
| | - Callum M. Zgierski-Johnston
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, 79110 Freiburg im Breisgau, Germany;
- Faculty of Medicine, University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Correspondence:
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4
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Filgueiras-Rama D, Vasilijevic J, Jalife J, Noujaim SF, Alfonso JM, Nicolas-Avila JA, Gutierrez C, Zamarreño N, Hidalgo A, Bernabé A, Cop CP, Ponce-Balbuena D, Guerrero-Serna G, Calle D, Desco M, Ruiz-Cabello J, Nieto A, Falcon A. Human influenza A virus causes myocardial and cardiac-specific conduction system infections associated with early inflammation and premature death. Cardiovasc Res 2021; 117:876-889. [PMID: 32346730 PMCID: PMC7898948 DOI: 10.1093/cvr/cvaa117] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [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: 01/21/2020] [Revised: 03/27/2020] [Accepted: 04/22/2020] [Indexed: 12/20/2022] Open
Abstract
AIMS Human influenza A virus (hIAV) infection is associated with important cardiovascular complications, although cardiac infection pathophysiology is poorly understood. We aimed to study the ability of hIAV of different pathogenicity to infect the mouse heart, and establish the relationship between the infective capacity and the associated in vivo, cellular and molecular alterations. METHODS AND RESULTS We evaluated lung and heart viral titres in mice infected with either one of several hIAV strains inoculated intranasally. 3D reconstructions of infected cardiac tissue were used to identify viral proteins inside mouse cardiomyocytes, Purkinje cells, and cardiac vessels. Viral replication was measured in mouse cultured cardiomyocytes. Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were used to confirm infection and study underlying molecular alterations associated with the in vivo electrophysiological phenotype. Pathogenic and attenuated hIAV strains infected and replicated in cardiomyocytes, Purkinje cells, and hiPSC-CMs. The infection was also present in cardiac endothelial cells. Remarkably, lung viral titres did not statistically correlate with viral titres in the mouse heart. The highly pathogenic human recombinant virus PAmut showed faster replication, higher level of inflammatory cytokines in cardiac tissue and higher viral titres in cardiac HL-1 mouse cells and hiPSC-CMs compared with PB2mut-attenuated virus. Correspondingly, cardiac conduction alterations were especially pronounced in PAmut-infected mice, associated with high mortality rates, compared with PB2mut-infected animals. Consistently, connexin43 and NaV1.5 expression decreased acutely in hiPSC-CMs infected with PAmut virus. YEM1L protease also decreased more rapidly and to lower levels in PAmut-infected hiPSC-CMs compared with PB2mut-infected cells, consistent with mitochondrial dysfunction. Human IAV infection did not increase myocardial fibrosis at 4-day post-infection, although PAmut-infected mice showed an early increase in mRNAs expression of lysyl oxidase. CONCLUSION Human IAV can infect the heart and cardiac-specific conduction system, which may contribute to cardiac complications and premature death.
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Affiliation(s)
- David Filgueiras-Rama
- Cardiac Electrophysiology Unit, Hospital Clínico San Carlos,
Madrid, Spain
- Centro Nacional de Investigaciones Cardiovasculares (CNIC),
Madrid, Spain
- Consortium CIBER of Cardiovascular Diseases (CIBERCV), Spain
| | - Jasmina Vasilijevic
- Department of Molecular and Cellular Biology, National Center for
Biotechnology, Spanish National Research Council, Madrid, Spain
- Consortium CIBER of Respiratory Diseases, Spain
| | - Jose Jalife
- Centro Nacional de Investigaciones Cardiovasculares (CNIC),
Madrid, Spain
- Consortium CIBER of Cardiovascular Diseases (CIBERCV), Spain
- Center for Arrhythmia Research, Health System, University of
Michigan, MI, USA
| | - Sami F Noujaim
- Morsani College of Medicine Molecular Pharmacology & Physiology, University
of South Florida, Tampa, FL, USA
| | - Jose M Alfonso
- Centro Nacional de Investigaciones Cardiovasculares (CNIC),
Madrid, Spain
| | | | - Celia Gutierrez
- Department of Molecular and Cellular Biology, National Center for
Biotechnology, Spanish National Research Council, Madrid, Spain
| | - Noelia Zamarreño
- Department of Molecular and Cellular Biology, National Center for
Biotechnology, Spanish National Research Council, Madrid, Spain
| | - Andres Hidalgo
- Centro Nacional de Investigaciones Cardiovasculares (CNIC),
Madrid, Spain
| | - Alejandro Bernabé
- Centro Nacional de Investigaciones Cardiovasculares (CNIC),
Madrid, Spain
| | | | | | | | - Daniel Calle
- Centro Nacional de Investigaciones Cardiovasculares (CNIC),
Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid,
Spain
| | - Manuel Desco
- Centro Nacional de Investigaciones Cardiovasculares (CNIC),
Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid,
Spain
- Department of Bioengineering and Aerospace Engineering, University Carlos III
of Madrid, Madrid, Spain
- Consortium CIBER of Mental Health (CIBERSAM), Spain
| | - Jesus Ruiz-Cabello
- Consortium CIBER of Respiratory Diseases, Spain
- Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque
Research and Technology Alliance (BRTA), San Sebastian, Spain
- IKERBASQUE, Basque Foundation for Science, Spain
- Universidad Complutense Madrid, Madrid, Spain
| | - Amelia Nieto
- Department of Molecular and Cellular Biology, National Center for
Biotechnology, Spanish National Research Council, Madrid, Spain
- Consortium CIBER of Respiratory Diseases, Spain
| | - Ana Falcon
- Department of Molecular and Cellular Biology, National Center for
Biotechnology, Spanish National Research Council, Madrid, Spain
- Consortium CIBER of Respiratory Diseases, Spain
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Parahuleva MS, Kockskämper J, Heger J, Grimm W, Scherer A, Bühler S, Kreutz J, Schulz R, Euler G. Structural, Pro-Inflammatory and Calcium Handling Remodeling Underlies Spontaneous Onset of Paroxysmal Atrial Fibrillation in JDP2-Overexpressing Mice. Int J Mol Sci 2020; 21:E9095. [PMID: 33265909 PMCID: PMC7731172 DOI: 10.3390/ijms21239095] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Cardiac-specific JDP2 overexpression provokes ventricular dysfunction and atrial dilatation in mice. We performed in vivo studies on JDP2-overexpressing mice to investigate the impact of JDP2 on the predisposition to spontaneous atrial fibrillation (AF). METHODS JDP2-overexpression was started by withdrawal of a doxycycline diet in 4-week-old mice. The spontaneous onset of AF was documented by ECG within 4 to 5 weeks of JDP2 overexpression. Gene expression was analyzed by real-time RT-PCR and Western blots. RESULTS In atrial tissue of JDP2 mice, besides the 3.6-fold increase of JDP2 mRNA, no changes could be detected within one week of JDP2 overexpression. Atrial dilatation and hypertrophy, combined with elongated cardiomyocytes and fibrosis, became evident after 5 weeks of JDP2 overexpression. Electrocardiogram (ECG) recordings revealed prolonged PQ-intervals and broadened P-waves and QRS-complexes, as well as AV-blocks and paroxysmal AF. Furthermore, reductions were found in the atrial mRNA and protein level of the calcium-handling proteins NCX, Cav1.2 and RyR2, as well as of connexin40 mRNA. mRNA of the hypertrophic marker gene ANP, pro-inflammatory MCP1, as well as markers of immune cell infiltration (CD68, CD20) were increased in JDP2 mice. CONCLUSION JDP2 is an important regulator of atrial calcium and immune homeostasis and is involved in the development of atrial conduction defects and arrhythmogenic substrates preceding paroxysmal AF.
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Affiliation(s)
- Mariana S. Parahuleva
- Internal Medicine/Cardiology and Angiology, University Hospital of Giessen and Marburg, 35033 Marburg, Germany; (W.G.); (J.K.)
| | - Jens Kockskämper
- Biochemical-Pharmacological Centre (BPC) Marburg, Institute of Pharmacology and Clinical Pharmacy, University of Marburg, 35043 Marburg, Germany; (J.K.); (A.S.); (S.B.)
| | - Jacqueline Heger
- Institute of Physiology, Justus Liebig University, 35392 Giessen, Germany; (J.H.); (R.S.); (G.E.)
| | - Wolfram Grimm
- Internal Medicine/Cardiology and Angiology, University Hospital of Giessen and Marburg, 35033 Marburg, Germany; (W.G.); (J.K.)
| | - Anna Scherer
- Biochemical-Pharmacological Centre (BPC) Marburg, Institute of Pharmacology and Clinical Pharmacy, University of Marburg, 35043 Marburg, Germany; (J.K.); (A.S.); (S.B.)
| | - Sarah Bühler
- Biochemical-Pharmacological Centre (BPC) Marburg, Institute of Pharmacology and Clinical Pharmacy, University of Marburg, 35043 Marburg, Germany; (J.K.); (A.S.); (S.B.)
| | - Julian Kreutz
- Internal Medicine/Cardiology and Angiology, University Hospital of Giessen and Marburg, 35033 Marburg, Germany; (W.G.); (J.K.)
| | - Rainer Schulz
- Institute of Physiology, Justus Liebig University, 35392 Giessen, Germany; (J.H.); (R.S.); (G.E.)
| | - Gerhild Euler
- Institute of Physiology, Justus Liebig University, 35392 Giessen, Germany; (J.H.); (R.S.); (G.E.)
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6
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Marazzato J, Marazzi R, Angeli F, Vilotta M, Bagliani G, Leonelli FM, De Ponti R. Ablation of Accessory Pathways with Challenging Anatomy. Card Electrophysiol Clin 2020; 12:555-566. [PMID: 33162003 DOI: 10.1016/j.ccep.2020.08.003] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although catheter ablation of accessory pathways is deemed highly safe and effective, peculiar location of these pathways might lead to complex and potentially hazardous procedures requiring ablation in anatomic regions such as para-Hisian area, coronary sinus, and epicardial surface. The electrophysiologist should know these possible scenarios to plan the best strategy for safe and effective ablation of these uncommon accessory pathways.
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Affiliation(s)
- Jacopo Marazzato
- Department of Heart and Vessels, Ospedale di Circolo, Viale Borri, 57, Varese 21100, Italy; Department of Medicine and Surgery, University of Insubria, Viale Guicciardini, 9, Varese 21100, Italy
| | - Raffaella Marazzi
- Department of Heart and Vessels, Ospedale di Circolo, Viale Borri, 57, Varese 21100, Italy
| | - Fabio Angeli
- Department of Medicine and Surgery, University of Insubria, Viale Guicciardini, 9, Varese 21100, Italy; Department of Medicine and Cardiopulmonary Rehabilitation, Maugeri Care and Research Institutes, IRCCS, Via Crotto Roncaccio, 16, Tradate, Varese 21049, Italy
| | - Manola Vilotta
- Department of Heart and Vessels, Ospedale di Circolo, Viale Borri, 57, Varese 21100, Italy
| | - Giuseppe Bagliani
- Arrhythmology Unit, Cardiology Department, Foligno General Hospital, Via Massimo Arcamone, Foligno, Perugia 06034, Italy; Cardiovascular Disease Department, University of Perugia, Piazza Menghini 1, Perugia 06129, Italy
| | - Fabio M Leonelli
- Cardiology Department, James A. Haley Veterans' Hospital, University of South Florida, 13000 Bruce B Down Boulevard, Tampa, FL 33612, USA; University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620, USA
| | - Roberto De Ponti
- Department of Heart and Vessels, Ospedale di Circolo, Viale Borri, 57, Varese 21100, Italy; Department of Medicine and Surgery, University of Insubria, Viale Guicciardini, 9, Varese 21100, Italy.
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7
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Lawson BAJ, Oliveira RS, Berg LA, Silva PAA, Burrage K, dos Santos RW. Variability in electrophysiological properties and conducting obstacles controls re-entry risk in heterogeneous ischaemic tissue. Philos Trans A Math Phys Eng Sci 2020; 378:20190341. [PMID: 32448068 PMCID: PMC7287337 DOI: 10.1098/rsta.2019.0341] [Citation(s) in RCA: 5] [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] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Ischaemia, in which inadequate blood supply compromises and eventually kills regions of cardiac tissue, can cause many types of arrhythmia, some life-threatening. A significant component of this is the effects of the resulting hypoxia, and concomitant hyperklaemia and acidosis, on the electrophysiological properties of myocytes. Clinical and experimental data have also shown that regions of structural heterogeneity (fibrosis, necrosis, fibro-fatty infiltration) can act as triggers for arrhythmias under acute ischaemic conditions. Mechanistic models have successfully captured these effects in silico. However, the relative significance of these separate facets of the condition, and how sensitive arrhythmic risk is to the extents of each, is far less explored. In this work, we use partitioned Gaussian process emulation and new metrics for source-sink mismatch that rely on simulations of bifurcating cardiac fibres to interrogate a model of heterogeneous ischaemic tissue. Re-entries were most sensitive to the level of hypoxia and the fraction of non-excitable tissue. In addition, our results reveal both protective and pro-arrhythmic effects of hyperklaemia, and present the levels of hyperklaemia, hypoxia and percentage of non-excitable tissue that pose the highest arrhythmic risks. This article is part of the theme issue 'Uncertainty quantification in cardiac and cardiovascular modelling and simulation'.
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Affiliation(s)
- Brodie A. J. Lawson
- ARC Centre of Excellence for Mathematical and Statistical Frontiers Queensland University of Technology, Brisbane, Australia
| | - Rafael S. Oliveira
- Department of Computer Science, Universidade Federal de São João del-Rei, São João del-Rei, Brazil
| | - Lucas A. Berg
- Graduate Program in Computational Modelling, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Pedro A. A. Silva
- Graduate Program in Computational Modelling, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Kevin Burrage
- ARC Centre of Excellence for Mathematical and Statistical Frontiers Queensland University of Technology, Brisbane, Australia
- Visiting Professor, Department of Computer Science, University of Oxford, Oxford, UK
| | - Rodrigo Weber dos Santos
- Graduate Program in Computational Modelling, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
- e-mail:
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8
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Liu W, Wang G, Zhang C, Ding W, Cheng W, Luo Y, Wei C, Liu J. MG53, A Novel Regulator of KChIP2 and I to,f, Plays a Critical Role in Electrophysiological Remodeling in Cardiac Hypertrophy. Circulation 2020; 139:2142-2156. [PMID: 30760025 DOI: 10.1161/circulationaha.118.029413] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND KChIP2 (K+ channel interacting protein) is the auxiliary subunit of the fast transient outward K+ current ( Ito,f) in the heart, and insufficient KChIP2 expression induces Ito,f downregulation and arrhythmogenesis in cardiac hypertrophy. Studies have shown muscle-specific mitsugumin 53 (MG53) has promiscuity of function in the context of normal and diseased heart. This study investigates the possible roles of cardiac MG53 in regulation of KChIP2 expression and Ito,f, and the arrhythmogenic potential in hypertrophy. METHODS MG53 expression is manipulated by genetic ablation of MG53 in mice and adenoviral overexpression or knockdown of MG53 by RNA interference in cultured neonatal rat ventricular myocytes. Cardiomyocyte hypertrophy is produced by phenylephrine stimulation in neonatal rat ventricular myocytes, and pressure overload-induced mouse cardiac hypertrophy is produced by transverse aortic constriction. RESULTS KChIP2 expression and Ito,f density are downregulated in hearts from MG53-knockout mice and MG53-knockdown neonatal rat ventricular myocytes, but upregulated in MG53-overexpressing cells. In phenylephrine-induced cardiomyocyte hypertrophy, MG53 expression is reduced with concomitant downregulation of KChIP2 and Ito,f, which can be reversed by MG53 overexpression, but exaggerated by MG53 knockdown. MG53 knockout enhances Ito,f remodeling and action potential duration prolongation and increases susceptibility to ventricular arrhythmia in mouse cardiac hypertrophy. Mechanistically, MG53 regulates NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) activity and subsequently controls KChIP2 transcription. Chromatin immunoprecipitation demonstrates NF-κB protein has interaction with KChIP2 gene. MG53 overexpression decreases, whereas MG53 knockdown increases NF-κB enrichment at the 5' regulatory region of KChIP2 gene. Normalizing NF-κB activity reverses the alterations in KChIP2 in MG53-overexpressing or knockdown cells. Coimmunoprecipitation and Western blotting assays demonstrate MG53 has physical interaction with TAK1 (transforming growth factor-b [TGFb]-activated kinase 1) and IκBα (nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha), critical components of the NF-κB pathway. CONCLUSIONS These findings establish MG53 as a novel regulator of KChIP2 and Ito,f by modulating NF-κB activity and reveal its critical role in electrophysiological remodeling in cardiac hypertrophy.
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Affiliation(s)
- Wenjuan Liu
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Guangdong Key Laboratory of Regional Immunity and Diseases, Department of Pathophysiology (W.L., G.W., W.C., Y.L., J.L.), School of Medicine, Shenzhen University, China
| | - Gang Wang
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Guangdong Key Laboratory of Regional Immunity and Diseases, Department of Pathophysiology (W.L., G.W., W.C., Y.L., J.L.), School of Medicine, Shenzhen University, China
| | - Cuicui Zhang
- Prenatal Diagnosis Center, The Women and Children Hospital of Guangdong Province, Guangzhou, China (C.Z.)
| | - Wenwen Ding
- Department of Basic Medicine, School of Medicine, Jingchu University of Technology, Jingmen, China (W.D.)
| | - Wanwen Cheng
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Guangdong Key Laboratory of Regional Immunity and Diseases, Department of Pathophysiology (W.L., G.W., W.C., Y.L., J.L.), School of Medicine, Shenzhen University, China
| | - Yizhi Luo
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Guangdong Key Laboratory of Regional Immunity and Diseases, Department of Pathophysiology (W.L., G.W., W.C., Y.L., J.L.), School of Medicine, Shenzhen University, China
| | - Chaoliang Wei
- Department of Cell Biology and Medical Genetics (C.W.), School of Medicine, Shenzhen University, China
| | - Jie Liu
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Guangdong Key Laboratory of Regional Immunity and Diseases, Department of Pathophysiology (W.L., G.W., W.C., Y.L., J.L.), School of Medicine, Shenzhen University, China
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9
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Salvarani N, Crasto S, Miragoli M, Bertero A, Paulis M, Kunderfranco P, Serio S, Forni A, Lucarelli C, Dal Ferro M, Larcher V, Sinagra G, Vezzoni P, Murry CE, Faggian G, Condorelli G, Di Pasquale E. The K219T-Lamin mutation induces conduction defects through epigenetic inhibition of SCN5A in human cardiac laminopathy. Nat Commun 2019; 10:2267. [PMID: 31118417 PMCID: PMC6531493 DOI: 10.1038/s41467-019-09929-w] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [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: 08/04/2017] [Accepted: 04/06/2019] [Indexed: 12/14/2022] Open
Abstract
Mutations in LMNA, which encodes the nuclear proteins Lamin A/C, can cause cardiomyopathy and conduction disorders. Here, we employ induced pluripotent stem cells (iPSCs) generated from human cells carrying heterozygous K219T mutation on LMNA to develop a disease model. Cardiomyocytes differentiated from these iPSCs, and which thus carry K219T-LMNA, have altered action potential, reduced peak sodium current and diminished conduction velocity. Moreover, they have significantly downregulated Nav1.5 channel expression and increased binding of Lamin A/C to the promoter of SCN5A, the channel's gene. Coherently, binding of the Polycomb Repressive Complex 2 (PRC2) protein SUZ12 and deposition of the repressive histone mark H3K27me3 are increased at SCN5A. CRISPR/Cas9-mediated correction of the mutation re-establishes sodium current density and SCN5A expression. Thus, K219T-LMNA cooperates with PRC2 in downregulating SCN5A, leading to decreased sodium current density and slower conduction velocity. This mechanism may underlie the conduction abnormalities associated with LMNA-cardiomyopathy.
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Affiliation(s)
- Nicolò Salvarani
- Institute of Genetic and Biomedical Research (IRGB), UOS of Milan, National Research Council of Italy, Milan, 20138, Italy
- Department of Cardiovascular Medicine and Laboratory of Medical Biotechnology, Humanitas Clinical and Research Center - IRCCS, Rozzano (MI), 20089, Italy
| | - Silvia Crasto
- Institute of Genetic and Biomedical Research (IRGB), UOS of Milan, National Research Council of Italy, Milan, 20138, Italy
- Department of Cardiovascular Medicine and Laboratory of Medical Biotechnology, Humanitas Clinical and Research Center - IRCCS, Rozzano (MI), 20089, Italy
| | - Michele Miragoli
- Institute of Genetic and Biomedical Research (IRGB), UOS of Milan, National Research Council of Italy, Milan, 20138, Italy
- Department of Cardiovascular Medicine and Laboratory of Medical Biotechnology, Humanitas Clinical and Research Center - IRCCS, Rozzano (MI), 20089, Italy
- Department of Medicine and Surgery, University of Parma, Parma, 43121, Italy
| | - Alessandro Bertero
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, 98109, WA, USA
| | - Marianna Paulis
- Institute of Genetic and Biomedical Research (IRGB), UOS of Milan, National Research Council of Italy, Milan, 20138, Italy
- Department of Cardiovascular Medicine and Laboratory of Medical Biotechnology, Humanitas Clinical and Research Center - IRCCS, Rozzano (MI), 20089, Italy
| | - Paolo Kunderfranco
- Department of Cardiovascular Medicine and Laboratory of Medical Biotechnology, Humanitas Clinical and Research Center - IRCCS, Rozzano (MI), 20089, Italy
| | - Simone Serio
- Department of Cardiovascular Medicine and Laboratory of Medical Biotechnology, Humanitas Clinical and Research Center - IRCCS, Rozzano (MI), 20089, Italy
| | - Alberto Forni
- Division of Cardiac Surgery, University of Verona, Verona, 37129, Italy
| | - Carla Lucarelli
- Division of Cardiac Surgery, University of Verona, Verona, 37129, Italy
| | - Matteo Dal Ferro
- Cardiovascular Department, "Ospedali Riuniti" and University of Trieste, Trieste, 34129, Italy
| | - Veronica Larcher
- Department of Cardiovascular Medicine and Laboratory of Medical Biotechnology, Humanitas Clinical and Research Center - IRCCS, Rozzano (MI), 20089, Italy
| | - Gianfranco Sinagra
- Cardiovascular Department, "Ospedali Riuniti" and University of Trieste, Trieste, 34129, Italy
| | - Paolo Vezzoni
- Institute of Genetic and Biomedical Research (IRGB), UOS of Milan, National Research Council of Italy, Milan, 20138, Italy
- Department of Cardiovascular Medicine and Laboratory of Medical Biotechnology, Humanitas Clinical and Research Center - IRCCS, Rozzano (MI), 20089, Italy
| | - Charles E Murry
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, 98109, WA, USA
| | - Giuseppe Faggian
- Division of Cardiac Surgery, University of Verona, Verona, 37129, Italy
| | - Gianluigi Condorelli
- Institute of Genetic and Biomedical Research (IRGB), UOS of Milan, National Research Council of Italy, Milan, 20138, Italy.
- Department of Cardiovascular Medicine and Laboratory of Medical Biotechnology, Humanitas Clinical and Research Center - IRCCS, Rozzano (MI), 20089, Italy.
- Humanitas University, Rozzano (MI), 20089, Italy.
| | - Elisa Di Pasquale
- Institute of Genetic and Biomedical Research (IRGB), UOS of Milan, National Research Council of Italy, Milan, 20138, Italy.
- Department of Cardiovascular Medicine and Laboratory of Medical Biotechnology, Humanitas Clinical and Research Center - IRCCS, Rozzano (MI), 20089, Italy.
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10
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Garcia-Bustos V, Sebastian R, Izquierdo M, Rios-Navarro C, Bodí V, Chorro FJ, Ruiz-Sauri A. Changes in the spatial distribution of the Purkinje network after acute myocardial infarction in the pig. PLoS One 2019; 14:e0212096. [PMID: 30742681 PMCID: PMC6370232 DOI: 10.1371/journal.pone.0212096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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: 08/16/2018] [Accepted: 01/28/2019] [Indexed: 12/25/2022] Open
Abstract
Purkinje cells (PCs) are more resistant to ischemia than myocardial cells, and are suspected to participate in ventricular arrhythmias following myocardial infarction (MI). Histological studies afford little evidence on the behavior and adaptation of PCs in the different stages of MI, especially in the chronic stage, and no quantitative data have been reported to date beyond subjective qualitative depictions. The present study uses a porcine model to present the first quantitative analysis of the distal cardiac conduction system and the first reported change in the spatial distribution of PCs in three representative stages of MI: an acute model both with and without reperfusion; a subacute model one week after reperfusion; and a chronic model one month after reperfusion. Purkinje cells are able to survive after 90 minutes of ischemia and subsequent reperfusion to a greater extent than cardiomyocytes. A decrease is observed in the number of PCs, which suffer reversible subcellular alterations such as cytoplasm vacuolization, together with redistribution from the mesocardium—the main localization of PCs in the heart of ungulate species—towards the endocardium and perivascular epicardial areas. However, these changes mainly occur during the first week after ischemia and reperfusion, and are maintained in the chronic stages. This anatomical substrate can explain the effectiveness of endo-epicardial catheter ablation of monomorphic ventricular tachycardias in the chronic scar after infarction, and sets a basis for further electrophysiological and molecular studies, and future therapeutic strategies.
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Affiliation(s)
- Victor Garcia-Bustos
- Department of Pathology, Faculty of Medicine, Universitat de Valencia, Valencia, Spain
- Department of Internal Medicine Unit, Hospital Universitari i Politècnic La Fe, Valencia, Spain
| | - Rafael Sebastian
- Computational Multiscale Simulation Lab, Universitat de Valencia, Valencia, Spain
- * E-mail:
| | - Maite Izquierdo
- INCLIVA Biomedical Research Institute, Valencia, Spain
- Department of Cardiology, Hospital Clínico Universitario de Valencia, Valencia, Spain
| | | | - Vicente Bodí
- INCLIVA Biomedical Research Institute, Valencia, Spain
- Department of Cardiology, Hospital Clínico Universitario de Valencia, Valencia, Spain
- CIBERCV, Carlos III Health Institute, Madrid, Spain
| | - Francisco Javier Chorro
- INCLIVA Biomedical Research Institute, Valencia, Spain
- Department of Cardiology, Hospital Clínico Universitario de Valencia, Valencia, Spain
- CIBERCV, Carlos III Health Institute, Madrid, Spain
| | - Amparo Ruiz-Sauri
- Department of Pathology, Faculty of Medicine, Universitat de Valencia, Valencia, Spain
- INCLIVA Biomedical Research Institute, Valencia, Spain
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11
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Vandersickel N, Watanabe M, Tao Q, Fostier J, Zeppenfeld K, Panfilov AV. Dynamical anchoring of distant arrhythmia sources by fibrotic regions via restructuring of the activation pattern. PLoS Comput Biol 2018; 14:e1006637. [PMID: 30571689 PMCID: PMC6319787 DOI: 10.1371/journal.pcbi.1006637] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [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: 07/04/2018] [Revised: 01/04/2019] [Accepted: 11/09/2018] [Indexed: 11/27/2022] Open
Abstract
Rotors are functional reentry sources identified in clinically relevant cardiac arrhythmias, such as ventricular and atrial fibrillation. Ablation targeting rotor sites has resulted in arrhythmia termination. Recent clinical, experimental and modelling studies demonstrate that rotors are often anchored around fibrotic scars or regions with increased fibrosis. However, the mechanisms leading to abundance of rotors at these locations are not clear. The current study explores the hypothesis whether fibrotic scars just serve as anchoring sites for the rotors or whether there are other active processes which drive the rotors to these fibrotic regions. Rotors were induced at different distances from fibrotic scars of various sizes and degree of fibrosis. Simulations were performed in a 2D model of human ventricular tissue and in a patient-specific model of the left ventricle of a patient with remote myocardial infarction. In both the 2D and the patient-specific model we found that without fibrotic scars, the rotors were stable at the site of their initiation. However, in the presence of a scar, rotors were eventually dynamically anchored from large distances by the fibrotic scar via a process of dynamical reorganization of the excitation pattern. This process coalesces with a change from polymorphic to monomorphic ventricular tachycardia. Rotors are waves of cardiac excitation like a tornado causing cardiac arrhythmia. Recent research shows that they are found in ventricular and atrial fibrillation. Burning (via ablation) the site of a rotor can result in the termination of the arrhythmia. Recent studies showed that rotors are often anchored to regions surrounding scar tissue, where part of the tissue still survived called fibrotic tissue. However, it is unclear why these rotors anchor to these locations. Therefore, in this work, we investigated why rotors are so abundant in fibrotic tissue with the help of computer simulations. We performed simulations in a 2D model of human ventricular tissue and in a patient-specific model of a patient with an infarction. We found that even when rotors are initially at large distances from the fibrotic region, they are attracted by this region, to finally end up at the fibrotic tissue. We called this process dynamical anchoring and explained how the process works.
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Affiliation(s)
- Nele Vandersickel
- Department of Physics and Astronomy, Ghent University, Belgium
- * E-mail: (NV); (AVP)
| | - Masaya Watanabe
- Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Qian Tao
- Department of Radiology, Division of Image Processing, Leiden University Medical Centre, Leiden, the Netherlands
| | - Jan Fostier
- Department of Information Technology (INTEC), IDLab, Ghent University — imec, Ghent, Belgium
| | - Katja Zeppenfeld
- Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Alexander V. Panfilov
- Department of Physics and Astronomy, Ghent University, Belgium
- Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands
- Laboratory of Computational Biology and Medicine, Ural Federal University, Ekaterinburg, Russia
- * E-mail: (NV); (AVP)
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12
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Sledz J, Labus M, Mazij M, Klank-Szafran M, Karbarz D, Ludwik B, Kusa J, Deutsch K, Szydlowski L, Mscisz A, Spikowski J, Morka A, Kameczura T, Swietoniowska-Mscisz A, Stec S. A simplified approach for evaluating sustained slow pathway conduction for diagnosis and treatment of atrioventricular nodal reentry tachycardia in children and adults. Adv Med Sci 2018; 63:249-256. [PMID: 29433068 DOI: 10.1016/j.advms.2018.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 01/05/2018] [Accepted: 01/08/2018] [Indexed: 11/17/2022]
Abstract
PURPOSE During incremental atrial pacing in patients with atrioventricular nodal reentrant tachycardia, the PR interval often exceeds the RR interval (PR > RR) during stable 1:1 AV conduction. However, the PR/RR ratio has never been evaluated in a large group of patients with pacing from the proximal coronary sinus and after isoproterenol challenge. Our study validates new site of pacing and easier method of identification of PR > RR. MATERIAL AND METHODS A prospective protocol of incremental atrial pacing from the proximal coronary sinus was carried out in 398 patients (AVNRT-228 and control-170). The maximum stimulus to the Q wave interval (S-Q = PR), SS interval (S-S), and Q-Q (RR) interval were measured at baseline and 10 min after successful slow pathway ablation and after isoproterenol challenge (obligatory). RESULTS The mean maximum PR/RR ratios at baseline were 1.17 ± 0.24 and 0.82 ± 0.13 (p < 0.00001) in the AVNRT and controls respectively. There were no PR/RR ratios ≥1 at baseline and after isoproterenol challenge in 12.3% of the AVNRT group and in 95.9% of the control group (p < 0.0001). PR/RR ratios ≥1 were absent in 98% of AVNRT cases after slow pathway ablation/modification in children and 99% of such cases in adults (P = NS). The diagnostic performance of PR/RR ratio evaluation before and after isoproterenol challenge had the highest diagnostic performance for AVNRT with PR/RR > = 1 (sensitivity: 88%, specificity: 96%, PPV-97%, NPV-85%). CONCLUSIONS The PR/RR ratio is a simple tool for slow pathway substrate and AVNRT evaluation. Eliminating PR/RR ratios ≥1 may serve as a surrogate endpoint for slow pathway ablation in children and adults with AVNRT.
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Affiliation(s)
- Janusz Sledz
- Elmedica, EP-Network, Kielce, Poland; Department of Cardiology, G.V.M. Carint, Ostrowiec Swietokrzyski, Poland; Carint Medica, EP-Network, Cracow, Poland
| | - Michal Labus
- Department of Cardiology, Regional Specialist Hospital, Centre for Research and Development, Wroclaw, Poland
| | - Mariusz Mazij
- Department of Cardiology, Regional Specialist Hospital, Centre for Research and Development, Wroclaw, Poland
| | | | | | - Bartosz Ludwik
- Department of Cardiology, Regional Specialist Hospital, Centre for Research and Development, Wroclaw, Poland
| | - Jacek Kusa
- Department of Cardiology, Regional Specialist Hospital, Centre for Research and Development, Wroclaw, Poland
| | | | - Leslaw Szydlowski
- Department of Pediatric Cardiology, Medical University of Silesia, Katowice, Poland
| | - Adrian Mscisz
- Chair of Electroradiology, Faculty of Medicine, University of Rzeszow, Rzeszow, Poland
| | - Jerzy Spikowski
- Department of Cardiology, Regional Specialist Hospital, Centre for Research and Development, Wroclaw, Poland
| | - Aleksandra Morka
- Department of Pediatric Cardiosurgery and Cardiosurgical Intensive Care University Children Hospital, Faculty of Health Sciences Jagiellonian University Medical College, Krakow, Poland.
| | - Tomasz Kameczura
- Podkarpackie Center for Cardiovascular Intervention, G.V.M. Carint, Sanok, Poland; Chair of Electroradiology, Faculty of Medicine, University of Rzeszow, Rzeszow, Poland
| | | | - Sebastian Stec
- Elmedica, EP-Network, Kielce, Poland; Chair of Electroradiology, Faculty of Medicine, University of Rzeszow, Rzeszow, Poland; Podkarpackie Center for Cardiovascular Intervention, G.V.M. Carint, Sanok, Poland
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13
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Swift LM, Asfour H, Muselimyan N, Larson C, Armstrong K, Sarvazyan NA. Hyperspectral imaging for label-free in vivo identification of myocardial scars and sites of radiofrequency ablation lesions. Heart Rhythm 2017; 15:564-575. [PMID: 29246829 DOI: 10.1016/j.hrthm.2017.12.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [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: 04/29/2017] [Indexed: 12/14/2022]
Abstract
BACKGROUND Treatment of cardiac arrhythmias often involves ablating viable muscle tissue within or near islands of scarred myocardium. Yet, today there are limited means by which the boundaries of such scars can be visualized during surgery and distinguished from the sites of acute injury caused by radiofrequency (RF) ablation. OBJECTIVE We sought to explore a hyperspectral imaging (HSI) methodology to delineate and distinguish scar tissue from tissue injury caused by RF ablation. METHODS RF ablation of the ventricular surface of live rats that underwent thoracotomy was followed by a 2-month animal recovery period. During a second surgery, new RF lesions were placed next to the scarred tissue from the previous ablation procedure. The myocardial infarction model was used as an alternative way to create scar tissue. RESULTS Excitation-emission matrices acquired from the sites of RF lesions, scar region, and the surrounding unablated tissue revealed multiple spectral changes. These findings justified HSI of the heart surface using illumination with 365 nm UV light while acquiring spectral images within the visible range. Autofluorescence-based HSI enabled to distinguish sites of RF lesions from scar or unablated myocardium in open-chest rats. A pilot version of a percutaneous HSI catheter was used to demonstrate the feasibility of RF lesion visualization in atrial tissue of live pigs. CONCLUSION HSI based on changes in tissue autofluorescence is a highly effective tool for revealing-in vivo and with high spatial resolution-surface boundaries of myocardial scar and discriminating it from areas of acute necrosis caused by RF ablation.
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Affiliation(s)
- Luther M Swift
- The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia
| | - Huda Asfour
- The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia
| | - Narine Muselimyan
- The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia
| | | | | | - Narine A Sarvazyan
- The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia.
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14
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Campos FO, Shiferaw Y, Vigmond EJ, Plank G. Stochastic spontaneous calcium release events and sodium channelopathies promote ventricular arrhythmias. Chaos 2017; 27:093910. [PMID: 28964108 PMCID: PMC5568869 DOI: 10.1063/1.4999612] [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] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Premature ventricular complexes (PVCs), the first initiating beats of a variety of cardiac arrhythmias, have been associated with spontaneous calcium release (SCR) events at the cell level. However, the mechanisms underlying the degeneration of such PVCs into arrhythmias are not fully understood. The objective of this study was to investigate the conditions under which SCR-mediated PVCs can lead to ventricular arrhythmias. In particular, we sought to determine whether sodium (Na+) current loss-of-function in the structurally normal ventricles provides a substrate for unidirectional conduction block and reentry initiated by SCR-mediated PVCs. To achieve this goal, a stochastic model of SCR was incorporated into an anatomically accurate compute model of the rabbit ventricles with the His-Purkinje system (HPS). Simulations with reduced Na+ current due to a negative-shift in the steady-state channel inactivation showed that SCR-mediated delayed afterdepolarizations led to PVC formation in the HPS, where the electrotonic load was lower, conduction block, and reentry in the 3D myocardium. Moreover, arrhythmia initiation was only possible when intrinsic electrophysiological heterogeneity in action potential within the ventricles was present. In conclusion, while benign in healthy individuals SCR-mediated PVCs can lead to life-threatening ventricular arrhythmias when combined with Na+ channelopathies.
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Affiliation(s)
- Fernando O Campos
- Department of Congenital Heart Diseases and Pediatric Cardiology, German Heart Institute Berlin, Berlin, Germany
| | - Yohannes Shiferaw
- Department of Physics, California State University, Northridge, California 91330, USA
| | | | - Gernot Plank
- Institute of Biophysics, Medical University of Graz, Graz, Austria
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15
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Liao WC, Juo LY, Shih YL, Chen YH, Yan YT. HSPB7 prevents cardiac conduction system defect through maintaining intercalated disc integrity. PLoS Genet 2017; 13:e1006984. [PMID: 28827800 PMCID: PMC5587339 DOI: 10.1371/journal.pgen.1006984] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [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: 04/27/2017] [Revised: 09/06/2017] [Accepted: 08/17/2017] [Indexed: 01/19/2023] Open
Abstract
HSPB7 is a member of the small heat-shock protein (HSPB) family and is expressed in the cardiomyocytes from cardiogenesis onwards. A dramatic increase in HSPB7 is detected in the heart and blood plasma immediately after myocardial infarction. Additionally, several single-nucleotide polymorphisms of HSPB7 have been identified to be associated with heart failure caused by cardiomyopathy in human patients. Although a recent study has shown that HSPB7 is required for maintaining myofiber structure in skeletal muscle, its molecular and physiological functions in the heart remain unclear. In the present study, we generated a cardiac-specific inducible HSPB7 knockout mouse and demonstrated that the loss of HSPB7 in cardiomyocytes results in rapid heart failure and sudden death. The electrocardiogram showed cardiac arrhythmia with abnormal conduction in the HSPB7 mutant mice before death. In HSPB7 CKO cardiomyocytes, no significant defect was detected in the organization of contractile proteins in sarcomeres, but a severe structural disruption was observed in the intercalated discs. The expression of connexin 43, a gap-junction protein located at the intercalated discs, was downregulated in HSPB7 knockout cardiomyocytes. Mislocalization of desmoplakin, and N-cadherin, the intercalated disc proteins, was also observed in the HSPB7 CKO hearts. Furthermore, filamin C, the interaction protein of HSPB7, was upregulated and aggregated in HSPB7 mutant cardiomyocytes. In conclusion, our findings characterize HSPB7 as an intercalated disc protein and suggest it has an essential role in maintaining intercalated disc integrity and conduction function in the adult heart. The intercalated disc is an indispensable structure that connects neighboring cardiomyocytes. It is also considered to be a single functional unit for cellular electric, mechanical, and signaling communication to maintain cardiomyocyte rigidity and synchrony. Mutation or defect in intercalated disc components usually results in distortions in the structure of intercalated discs and lethal cardiac abnormalities in patients. In this study, we found that the dynamic expression and subcellular location of HSPB7 are highly associated with intercalated disc component protein, N-cadherin, during the assembly and maturation of intercalated discs in cardiomyocytes. To identify the functional role of HSPB7 in the adult heart, we conducted a loss-of-function study of HSPB7 using a gene conditional knockout approach. We found that the loss of HSPB7 quickly results in the disruption of the intercalated disc structure, decreasing the expression of connexin 43 and mislocalization of N-cadherin and desmoplakin, and further inducing arrhythmic sudden death. In conclusion, our mouse model demonstrates that HSPB7 is required to maintain the structure and function of gap-junction complexes and intercalated discs, which has important implications for human heart disease.
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Affiliation(s)
- Wern-Chir Liao
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan
- Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan
| | - Liang-Yi Juo
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan
- Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan
| | - Yen-Ling Shih
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan
- Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan
| | - Yen-Hui Chen
- Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan
| | - Yu-Ting Yan
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan
- Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan
- * E-mail:
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16
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Shi S, Liu T, Wang D, Zhang Y, Liang J, Yang B, Hu D. Activation of N-methyl-d-aspartate receptors reduces heart rate variability and facilitates atrial fibrillation in rats. Europace 2017; 19:1237-1243. [PMID: 27170002 DOI: 10.1093/europace/euw086] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/09/2016] [Indexed: 11/15/2022] Open
Abstract
AIMS The goal of this study was to assess the effects of N-methyl-d-aspartate (NMDA) receptors activation on heart rate variability (HRV) and susceptibility to atrial fibrillation (AF). METHODS AND RESULTS Rats were randomized for treatment with saline, NMDA (agonist of NMDA receptors), or NMDA plus MK-801 (antagonist of NMDA receptors) for 2 weeks. Heart rate variability was evaluated by using implantable electrocardiogram telemeters. Atrial fibrillation susceptibility was assessed with programmed stimulation in isolated hearts. Compared with the controls, the NMDA-treated rats displayed a decrease in the standard deviation of normal RR intervals, the standard deviation of the average RR intervals, the mean of the 5-min standard deviations of RR intervals, the root mean square of successive differences, and high frequency (HF); and an increase in low frequency (LF) and LF/HF (all P< 0.01). Additionally, the NMDA-treated rats showed prolonged activation latency and reduced effective refractory period (all P< 0.01). Importantly, AF was induced in all NMDA-treated rats. While atrial fibrosis developed, connexin40 downgraded and metalloproteinase 9 upgraded in the NMDA-treated rats (all P< 0.01). Most of the above alterations were mitigated by co-administering with MK-801. CONCLUSION These results indicate that NMDA receptors activation reduces HRV and enhances AF inducibility, with cardiac autonomic imbalance, atrial fibrosis, and degradation of gap junction protein identified as potential mechanistic contributors.
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Affiliation(s)
- Shaobo Shi
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, Wuhan, Hubei 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
| | - Tao Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, Wuhan, Hubei 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Montreal Heart Institute, University of Montreal, Montreal, QC, Canada
| | - Dandan Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, Wuhan, Hubei 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
| | - Yan Zhang
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, Wuhan, Hubei 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
| | - Jinjun Liang
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, Wuhan, Hubei 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
| | - Bo Yang
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, Wuhan, Hubei 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
| | - Dan Hu
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, Wuhan, Hubei 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, China
- Masonic Medical Research Laboratory, 2150 Bleecker Street, Utica, NY 13501, USA
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18
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Vigmond E, Pashaei A, Amraoui S, Cochet H, Hassaguerre M. Percolation as a mechanism to explain atrial fractionated electrograms and reentry in a fibrosis model based on imaging data. Heart Rhythm 2016; 13:1536-43. [PMID: 26976038 DOI: 10.1016/j.hrthm.2016.03.019] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Indexed: 11/17/2022]
Abstract
BACKGROUND Complex fractionated atrial electrograms (CFAEs) have long been associated with proarrhythmic alterations in atrial structure or electrophysiology. Structural alterations disrupt and slow smoothly propagating wavefronts, leading to wavebreaks and electrogram (EGM) fractionation, but the exact nature and characteristics for arrhythmia remain unknown. Clinically, in atrial fibrillation (AF) patients, increases in frequency, whether by pacing or fibrillation, increase EGM fractionation and duration, and reentry can occur in relation with the conduction disturbance. Recently, percolation has been proposed as an arrhythmogenic mechanism, but its role in AF has not been investigated. OBJECTIVE We sought to determine if percolation can explain reentry formation and EGM behavior observed in AF patients. METHODS Computer models of fibrotic tissue with different densities were generated based on late gadolinium-enhanced magnetic resonance images, using pixel intensity as a fibrosis probability to avoid an arbitrary binary threshold. Clinical pacing protocols were followed to induce AF, and EGMs were computed. RESULTS Reentry could be elicited, with a biphasic behavior dependent on fibrotic density. CFAEs were recorded above fibrotic regions, and consistent with clinical data, EGM duration and fractionation increased with more rapid pacing. CONCLUSION These findings confirm percolation as a potential mechanism to explain AF in humans and give new insights into dynamics underlying conduction distortions and fractionated signals in excitable media, which correlate well with the experimental findings in fibrotic regions. The greater understanding of the different patterns of conduction changes and related EGMs could lead to more individualized and effective approaches to AF ablation therapy.
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Affiliation(s)
- Edward Vigmond
- L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Fondation Université de Bordeaux, Hôpital Xavier-Arnozan, Pessac, France; Institut de Mathématiques de Bordeaux, Université de Bordeaux, Talence, France.
| | - Ali Pashaei
- L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Fondation Université de Bordeaux, Hôpital Xavier-Arnozan, Pessac, France; Institut de Mathématiques de Bordeaux, Université de Bordeaux, Talence, France
| | - Sana Amraoui
- L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Fondation Université de Bordeaux, Hôpital Xavier-Arnozan, Pessac, France; Hôpital cardiologique de Haut- Lévèque, Pessac, France
| | - Hubert Cochet
- L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Fondation Université de Bordeaux, Hôpital Xavier-Arnozan, Pessac, France; Centre de Recherche Cardio-Thoracique de Bordeaux U1045,Université de Bordeaux, Bordeaux, France; Hôpital cardiologique de Haut- Lévèque, Pessac, France
| | - Michel Hassaguerre
- L'Institut de Rythmologie et Modélisation Cardiaque LIRYC, Fondation Université de Bordeaux, Hôpital Xavier-Arnozan, Pessac, France; Centre de Recherche Cardio-Thoracique de Bordeaux U1045,Université de Bordeaux, Bordeaux, France; Hôpital cardiologique de Haut- Lévèque, Pessac, France
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19
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Chen CJ, Lin SJ, Lu YH, Lee KT. Accessory conduction pathway ablated by myocarditis in a patient with Wolff-Parkinson-White syndrome. Kaohsiung J Med Sci 2015; 31:550-1. [PMID: 26520696 DOI: 10.1016/j.kjms.2015.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 07/27/2015] [Accepted: 08/12/2015] [Indexed: 11/17/2022] Open
Affiliation(s)
- Chang-Jen Chen
- Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Shin-Jing Lin
- Cardiovascular Center, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Ye-Hsu Lu
- Cardiovascular Center, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Kun-Tai Lee
- Cardiovascular Center, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Department of Internal Medicine, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
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Kasirajan V, Sayeed S, Filler E, Knarik A, Koneru JN, Ellenbogen KA. Histopathology of Bipolar Radiofrequency Ablation in the Human Atrium. Ann Thorac Surg 2015; 101:638-43. [PMID: 26387724 DOI: 10.1016/j.athoracsur.2015.07.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Revised: 06/28/2015] [Accepted: 07/09/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND The Cox maze IV operation has become the preferred surgical treatment for atrial fibrillation, as it is associated with less morbidity and complexity than the Cox maze III procedure, yet is still highly effective. Numerous studies have been conducted in animals to examine the histopathology of this operation on the heart but studies on human hearts that have undergone the Cox maze IV operation have not been performed. METHODS We report the histopathologic findings in 3 patients from whom tissue was available for histologic study. In 2 patients it was obtained at autopsy within a month after undergoing a Cox maze IV operation, and in the remaining patient, atrial tissue was obtained immediately after ablation. RESULTS The lesions were clearly visible on the atria at day 6 and day 18. Microscopic examination showed that the hearts were in different stages of healing. We also found that, compared with animal models, human myocardium had significant preexisting underlying damage with myocyte hypertrophy and fibrosis. Although most of the ablative lesions were transmural, not all spanned from the epicardium to the endocardium. The chronic changes present in these hearts may have prevented transmurality by impeding energy delivery from fully penetrating the tissue. CONCLUSIONS The atrial myocardial substrate studied in experimental conditions is markedly different from the human hearts that frequently express histopathologic changes secondary to the underlying disease process. That may prevent creating true transmural lesions and impact final efficacy of the procedure.
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Affiliation(s)
| | - Sadia Sayeed
- Department of Pathology, Virginia Commonwealth University Health System, Richmond, Virginia
| | - Elizabeth Filler
- Division of Cardiothoracic Surgery, Pauley Heart Center, Richmond, Virginia
| | - Arkun Knarik
- Department of Pathology, Virginia Commonwealth University Health System, Richmond, Virginia
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Nassal MMJ, Wan X, Laurita KR, Cutler MJ. Atrial SERCA2a Overexpression Has No Affect on Cardiac Alternans but Promotes Arrhythmogenic SR Ca2+ Triggers. PLoS One 2015; 10:e0137359. [PMID: 26352986 PMCID: PMC4564245 DOI: 10.1371/journal.pone.0137359] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [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: 06/04/2015] [Accepted: 08/14/2015] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Atrial fibrillation (AF) is the most common arrhythmia in humans, yet; treatment has remained sub-optimal due to poor understanding of the underlying mechanisms. Cardiac alternans precede AF episodes, suggesting an important arrhythmia substrate. Recently, we demonstrated ventricular SERCA2a overexpression suppresses cardiac alternans and arrhythmias. Therefore, we hypothesized that atrial SERCA2a overexpression will decrease cardiac alternans and arrhythmias. METHODS Adult rat isolated atrial myocytes where divided into three treatment groups 1) Control, 2) SERCA2a overexpression (Ad.SERCA2a) and 3) SERCA2a inhibition (Thapsigargin, 1μm). Intracellular Ca2+ was measured using Indo-1AM and Ca2+ alternans (Ca-ALT) was induced with a standard ramp pacing protocol. RESULTS As predicted, SR Ca2+ reuptake was enhanced with SERCA2a overexpression (p< 0.05) and reduced with SERCA2a inhibition (p<0.05). Surprisingly, there was no difference in susceptibility to Ca-ALT with either SERCA2a overexpression or inhibition when compared to controls (p = 0.73). In contrast, SERCA2a overexpression resulted in increased premature SR Ca2+ (SCR) release compared to control myocytes (28% and 0%, p < 0.05) and concomitant increase in SR Ca2+ load (p<0.05). Based on these observations we tested in-vivo atrial arrhythmia inducibility in control and Ad.SERCA2a animals using an esophageal atrial burst pacing protocol. There were no inducible atrial arrhythmias in Ad.GFP (n = 4) animals though 20% of Ad.SERCA2a (n = 5) animals had inducible atrial arrhythmias (p = 0.20). CONCLUSIONS Our findings suggest that unlike the ventricle, SERCA2a is not a key regulator of cardiac alternans in the atrium. Importantly, SERCA2a overexpression in atrial myocytes can increase SCR, which may be arrhythmogenic.
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Affiliation(s)
- Michelle M. J. Nassal
- Heart and Vascular Research Center, Case Western Reserve University, Cleveland, OH, United States of America
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, United States of America
| | - Xiaoping Wan
- Heart and Vascular Research Center, Case Western Reserve University, Cleveland, OH, United States of America
| | - Kenneth R. Laurita
- Heart and Vascular Research Center, Case Western Reserve University, Cleveland, OH, United States of America
| | - Michael J. Cutler
- Heart and Vascular Research Center, Case Western Reserve University, Cleveland, OH, United States of America
- Intermountain Heart Institute, Salt Lake City, Utah, United States of America
- * E-mail:
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Quan C, Xie B, Wang HY, Chen S. PKB-Mediated Thr649 Phosphorylation of AS160/TBC1D4 Regulates the R-Wave Amplitude in the Heart. PLoS One 2015; 10:e0124491. [PMID: 25923736 PMCID: PMC4414484 DOI: 10.1371/journal.pone.0124491] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/04/2015] [Indexed: 11/18/2022] Open
Abstract
The Rab GTPase activating protein (RabGAP), AS160/TBC1D4, is an important substrate of protein kinase B (PKB), and regulates insulin-stimulated trafficking of glucose transporter 4. Besides, AS160/TBC1D4 has also been shown to regulate trafficking of many other membrane proteins including FA translocase/CD36 in cardiomyocytes. However, it is not clear whether it plays any role in regulating heart functions in vivo. Here, we found that PKB-mediated phosphorylation of Thr649 on AS160/TBC1D4 represented one of the major PAS-binding signals in the heart in response to insulin. Mutation of Thr649 to a non-phosphorylatable alanine increased the R-wave amplitude in the AS160Thr649Ala knockin mice. However, this knockin mutation did not affect the heart functions under both normal and infarct conditions. Interestingly, myocardial infarction induced the expression of a related RabGAP, TBC1D1, in the infarct zone as well as in the border zone. Together, these data show that the Thr649 phosphorylation of AS160/TBC1D4 plays an important role in the heart’s electrical conduction system through regulating the R-wave amplitude.
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Affiliation(s)
- Chao Quan
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, Nanjing, 210061, China
| | - Bingxian Xie
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, Nanjing, 210061, China
| | - Hong Yu Wang
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, Nanjing, 210061, China
- * E-mail: (HYW); ( (SC)
| | - Shuai Chen
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing Biomedical Research Institute, Nanjing University, Nanjing, 210061, China
- * E-mail: (HYW); ( (SC)
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Efimova E, Dinov B, Acou WJ, Schirripa V, Kornej J, Kosiuk J, Rolf S, Sommer P, Richter S, Bollmann A, Hindricks G, Arya A. Differentiating the origin of outflow tract ventricular arrhythmia using a simple, novel approach. Heart Rhythm 2015; 12:1534-40. [PMID: 25847476 DOI: 10.1016/j.hrthm.2015.04.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND Numerous electrocardiographic (ECG) criteria have been proposed to identify localization of outflow tract ventricular arrhythmias (OT-VAs); however, in some cases, it is difficult to accurately localize the origin of OT-VA using the surface ECG. OBJECTIVE The purpose of this study was to assess a simple criterion for localization of OT-VAs during electrophysiology study. METHODS We measured the interval from the onset of the earliest QRS complex of premature ventricular contractions (PVCs) to the distal right ventricular apical signal (the QRS-RVA interval) in 66 patients (31 men aged 53.3 ± 14.0 years; right ventricular outflow tract [RVOT] origin in 37) referred for ablation of symptomatic outflow tract PVCs. We prospectively validated this criterion in 39 patients (22 men aged 52 ± 15 years; RVOT origin in 19). RESULTS Compared with patients with RVOT PVCs, the QRS-RVA interval was significantly longer in patients with left ventricular outflow tract (LVOT) PVCs (70 ± 14 vs 33.4±10 ms, P < .001). Receiver operating characteristic analysis showed that a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 100%, 94.6%, 93.5%, and 100%, respectively, for prediction of an LVOT origin. The same analysis in the validation cohort showed sensitivity, specificity, and positive and negative predictive values of 94.7%, 95%, 95%, and 94.7%, respectively. When these data were combined, a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 98%, 94.6%, 94.1%, and 98.1%, respectively, for prediction of an LVOT origin. CONCLUSION A QRS-RVA interval ≥49 ms suggests an LVOT origin. The QRS-RVA interval is a simple and accurate criterion for differentiating the origin of outflow tract arrhythmia during electrophysiology study; however, the accuracy of this criterion in identifying OT-VA from the right coronary cusp is limited.
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Affiliation(s)
- Elena Efimova
- Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany
| | - Borislav Dinov
- Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany
| | - Willem-Jan Acou
- Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany
| | - Valentina Schirripa
- Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany
| | - Jelena Kornej
- Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany
| | - Jedrzej Kosiuk
- Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany
| | - Sascha Rolf
- Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany
| | - Philipp Sommer
- Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany
| | - Sergio Richter
- Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany
| | - Andreas Bollmann
- Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany
| | - Gerhard Hindricks
- Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany
| | - Arash Arya
- Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany.
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Kovalev D, Bogomolov D, Kul'bitskij N, Zavalishina D, Fedulova D. [The immunohistochemical study of the structures of the cardiac conduction system in the case of death from alcoholic cardiomyopathy]. Sud Med Ekspert 2015; 58:30-31. [PMID: 26036070 DOI: 10.17116/sudmed201558230-31] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The objective of the present study was to study the morphological criteria for toxic cardiopathy with the use of histological and immunohistochemical methods. The results of immunohistochemical studies of the sinoatrial node---???---(SAN) and the working myocardium in the patients presenting with alcoholic cardiomyopathy (ACMP) are presented. It was shown that vimentin expression in the SAN structures and the contractile myocardium is slightly increased whereas the expression of sarcomeric actin is decreased and that of fibrinogen is increased too. The authors put forward an assumption about the role of lesions in the membrane apparatus of the pacemaker cells in the development of arrhythmia characteristic of tanatogenesis associated with alcoholic cardiomyopathy.
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Affiliation(s)
- D Kovalev
- FGBU 'Rossijskij tsentr sudebno-meditsinskoj ekspertizy' Minzdrava Rossii, Moskva, Rossija, 125284
| | - D Bogomolov
- FGBU 'Rossijskij tsentr sudebno-meditsinskoj ekspertizy' Minzdrava Rossii, Moskva, Rossija, 125284
| | - N Kul'bitskij
- FGBU 'Rossijskij tsentr sudebno-meditsinskoj ekspertizy' Minzdrava Rossii, Moskva, Rossija, 125284
| | - D Zavalishina
- FGBU 'Rossijskij tsentr sudebno-meditsinskoj ekspertizy' Minzdrava Rossii, Moskva, Rossija, 125284
| | - D Fedulova
- FGBU 'Rossijskij tsentr sudebno-meditsinskoj ekspertizy' Minzdrava Rossii, Moskva, Rossija, 125284
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Bisbal F, Calvo M, Trucco E, Arbelo E, Berruezo A, Mont L. Left atrial tachycardia after atrial fibrillation ablation: can magnetic resonance imaging assist the ablation? Can J Cardiol 2014; 31:104.e1-3. [PMID: 25547564 DOI: 10.1016/j.cjca.2014.10.002] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 09/16/2014] [Accepted: 10/01/2014] [Indexed: 11/19/2022] Open
Abstract
We present a case of a magnetic resonance imaging-assisted ablation of an atrial tachycardia in a patient with previous atrial fibrillation ablation. A 3-D reconstruction of the delayed-enhanced cardiac magnetic resonance (CMR; CMR model) was created to identify previous ablation lesions and gaps. Multiple gaps around right-sided pulmonary veins were observed. The activation map identified a dual-loop re-entry around both right-sided pulmonary veins, confirming that the substrate identified using delayed-enhanced CMR was critical to sustain the tachycardia. Ablation at this site converted to sinus rhythm. The present case shows the usefulness of delayed-enhanced CMR substrate characterization to complement activation mapping of the tachycardia and more accurately define the anatomical circuit.
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Affiliation(s)
- Felipe Bisbal
- Arrhythmia Section, Cardiology Department, Hospital Clínic, Barcelona, Spain.
| | - Mireia Calvo
- Arrhythmia Section, Cardiology Department, Hospital Clínic, Barcelona, Spain
| | - Emilce Trucco
- Arrhythmia Section, Cardiology Department, Hospital Clínic, Barcelona, Spain
| | - Elena Arbelo
- Arrhythmia Section, Cardiology Department, Hospital Clínic, Barcelona, Spain
| | - Antonio Berruezo
- Arrhythmia Section, Cardiology Department, Hospital Clínic, Barcelona, Spain
| | - Lluís Mont
- Arrhythmia Section, Cardiology Department, Hospital Clínic, Barcelona, Spain
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Jamil-Copley S, Vergara P, Carbucicchio C, Linton N, Koa-Wing M, Luther V, Francis DP, Peters NS, Davies DW, Tondo C, Della Bella P, Kanagaratnam P. Application of ripple mapping to visualize slow conduction channels within the infarct-related left ventricular scar. Circ Arrhythm Electrophysiol 2014; 8:76-86. [PMID: 25527678 DOI: 10.1161/circep.114.001827] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [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] [Indexed: 12/26/2022]
Abstract
BACKGROUND Ripple mapping (RM) displays each electrogram at its 3-dimensional coordinate as a bar changing in length according to its voltage-time relationship with a fiduciary reference. We applied RM to left ventricular ischemic scar for evidence of slow-conducting channels that may act as ventricular tachycardia (VT) substrate. METHODS AND RESULTS CARTO-3© (Biosense Webster Inc, Diamond Bar, CA) maps in patient undergoing VT ablation were analyzed on an offline MatLab RM system. Scar was assessed for sequential movement of ripple bars, during sinus rhythm or pacing, which were distinct from surrounding tissue and termed RM conduction channels (RMCC). Conduction velocity was measured within RMCCs and compared with the healthy myocardium (>1.5 mV). In 21 maps, 77 RMCCs were identified. Conduction velocity in RMCCs was slower when compared with normal left ventricular myocardium (median, 54 [interquartile range, 40-86] versus 150 [interquartile range, 120-160] cm/s; P<0.001). All 7 sites meeting conventional criteria for diastolic pathways coincided with an RMCC. Seven patients had ablation colocating to all identified RMCCs with no VT recurrence during follow-up (median, 480 [interquartile range, 438-841] days). Fourteen patients had ≥1 RMCC with no ablation lesions. Five had recurrence during follow-up (median, 466 [interquartile range, 395-694] days). One of the 2 patients with no RMCC locations ablated had VT recurrence at 605 days post procedure. RMCCs were sensitive (100%; negative predictive value, 100%) for VT recurrence but the specificity (43%; positive predictive value, 35.7%) may be limited by blind alleys channels. CONCLUSIONS RM identifies slow conduction channels within ischemic scar and needs further prospective investigation to understand the role of RMCCs in determining the VT substrate.
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Affiliation(s)
- Shahnaz Jamil-Copley
- From the Department of Cardiac Electrophysiology, Hammersmith Hospital, Imperial College Healthcare Trust, London, United Kingdom (S.J.-C., N.L., M.K.-W., V.L., D.P.F., N.S.P., D.W.D., P.K.); Arrhythmology and Cardiac Electrophysiology Division, San Raffaele Hospital, University of Milan, Milan, Italy (P.V., P.D.B.); and Department of Arrhythmology and Electrophysiology, Centro Cardiologico Monzino, Milan, Italy (C.C., C.T.)
| | - Pasquale Vergara
- From the Department of Cardiac Electrophysiology, Hammersmith Hospital, Imperial College Healthcare Trust, London, United Kingdom (S.J.-C., N.L., M.K.-W., V.L., D.P.F., N.S.P., D.W.D., P.K.); Arrhythmology and Cardiac Electrophysiology Division, San Raffaele Hospital, University of Milan, Milan, Italy (P.V., P.D.B.); and Department of Arrhythmology and Electrophysiology, Centro Cardiologico Monzino, Milan, Italy (C.C., C.T.)
| | - Corrado Carbucicchio
- From the Department of Cardiac Electrophysiology, Hammersmith Hospital, Imperial College Healthcare Trust, London, United Kingdom (S.J.-C., N.L., M.K.-W., V.L., D.P.F., N.S.P., D.W.D., P.K.); Arrhythmology and Cardiac Electrophysiology Division, San Raffaele Hospital, University of Milan, Milan, Italy (P.V., P.D.B.); and Department of Arrhythmology and Electrophysiology, Centro Cardiologico Monzino, Milan, Italy (C.C., C.T.)
| | - Nick Linton
- From the Department of Cardiac Electrophysiology, Hammersmith Hospital, Imperial College Healthcare Trust, London, United Kingdom (S.J.-C., N.L., M.K.-W., V.L., D.P.F., N.S.P., D.W.D., P.K.); Arrhythmology and Cardiac Electrophysiology Division, San Raffaele Hospital, University of Milan, Milan, Italy (P.V., P.D.B.); and Department of Arrhythmology and Electrophysiology, Centro Cardiologico Monzino, Milan, Italy (C.C., C.T.)
| | - Michael Koa-Wing
- From the Department of Cardiac Electrophysiology, Hammersmith Hospital, Imperial College Healthcare Trust, London, United Kingdom (S.J.-C., N.L., M.K.-W., V.L., D.P.F., N.S.P., D.W.D., P.K.); Arrhythmology and Cardiac Electrophysiology Division, San Raffaele Hospital, University of Milan, Milan, Italy (P.V., P.D.B.); and Department of Arrhythmology and Electrophysiology, Centro Cardiologico Monzino, Milan, Italy (C.C., C.T.)
| | - Vishal Luther
- From the Department of Cardiac Electrophysiology, Hammersmith Hospital, Imperial College Healthcare Trust, London, United Kingdom (S.J.-C., N.L., M.K.-W., V.L., D.P.F., N.S.P., D.W.D., P.K.); Arrhythmology and Cardiac Electrophysiology Division, San Raffaele Hospital, University of Milan, Milan, Italy (P.V., P.D.B.); and Department of Arrhythmology and Electrophysiology, Centro Cardiologico Monzino, Milan, Italy (C.C., C.T.)
| | - Darrel P Francis
- From the Department of Cardiac Electrophysiology, Hammersmith Hospital, Imperial College Healthcare Trust, London, United Kingdom (S.J.-C., N.L., M.K.-W., V.L., D.P.F., N.S.P., D.W.D., P.K.); Arrhythmology and Cardiac Electrophysiology Division, San Raffaele Hospital, University of Milan, Milan, Italy (P.V., P.D.B.); and Department of Arrhythmology and Electrophysiology, Centro Cardiologico Monzino, Milan, Italy (C.C., C.T.)
| | - Nicholas S Peters
- From the Department of Cardiac Electrophysiology, Hammersmith Hospital, Imperial College Healthcare Trust, London, United Kingdom (S.J.-C., N.L., M.K.-W., V.L., D.P.F., N.S.P., D.W.D., P.K.); Arrhythmology and Cardiac Electrophysiology Division, San Raffaele Hospital, University of Milan, Milan, Italy (P.V., P.D.B.); and Department of Arrhythmology and Electrophysiology, Centro Cardiologico Monzino, Milan, Italy (C.C., C.T.)
| | - David Wyn Davies
- From the Department of Cardiac Electrophysiology, Hammersmith Hospital, Imperial College Healthcare Trust, London, United Kingdom (S.J.-C., N.L., M.K.-W., V.L., D.P.F., N.S.P., D.W.D., P.K.); Arrhythmology and Cardiac Electrophysiology Division, San Raffaele Hospital, University of Milan, Milan, Italy (P.V., P.D.B.); and Department of Arrhythmology and Electrophysiology, Centro Cardiologico Monzino, Milan, Italy (C.C., C.T.)
| | - Claudio Tondo
- From the Department of Cardiac Electrophysiology, Hammersmith Hospital, Imperial College Healthcare Trust, London, United Kingdom (S.J.-C., N.L., M.K.-W., V.L., D.P.F., N.S.P., D.W.D., P.K.); Arrhythmology and Cardiac Electrophysiology Division, San Raffaele Hospital, University of Milan, Milan, Italy (P.V., P.D.B.); and Department of Arrhythmology and Electrophysiology, Centro Cardiologico Monzino, Milan, Italy (C.C., C.T.)
| | - Paolo Della Bella
- From the Department of Cardiac Electrophysiology, Hammersmith Hospital, Imperial College Healthcare Trust, London, United Kingdom (S.J.-C., N.L., M.K.-W., V.L., D.P.F., N.S.P., D.W.D., P.K.); Arrhythmology and Cardiac Electrophysiology Division, San Raffaele Hospital, University of Milan, Milan, Italy (P.V., P.D.B.); and Department of Arrhythmology and Electrophysiology, Centro Cardiologico Monzino, Milan, Italy (C.C., C.T.)
| | - Prapa Kanagaratnam
- From the Department of Cardiac Electrophysiology, Hammersmith Hospital, Imperial College Healthcare Trust, London, United Kingdom (S.J.-C., N.L., M.K.-W., V.L., D.P.F., N.S.P., D.W.D., P.K.); Arrhythmology and Cardiac Electrophysiology Division, San Raffaele Hospital, University of Milan, Milan, Italy (P.V., P.D.B.); and Department of Arrhythmology and Electrophysiology, Centro Cardiologico Monzino, Milan, Italy (C.C., C.T.).
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Bishop MJ, Connolly A, Plank G. Structural heterogeneity modulates effective refractory period: a mechanism of focal arrhythmia initiation. PLoS One 2014; 9:e109754. [PMID: 25291380 PMCID: PMC4188572 DOI: 10.1371/journal.pone.0109754] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [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: 06/05/2014] [Accepted: 09/03/2014] [Indexed: 11/18/2022] Open
Abstract
Reductions in electrotonic loading around regions of structural and electrophysiological heterogeneity may facilitate capture of focal triggered activity, initiating reentrant arrhythmias. How electrotonic loading, refractoriness and capture of focal ectopics depend upon the intricate nature of physiological structural anatomy, as well as pathological tissue remodelling, however, is not well understood. In this study, we performed computational bidomain simulations with anatomically-detailed models representing the rabbit left ventricle. We used these models to quantify the relationship between local structural anatomy and spatial heterogeneity in action potential (AP) characteristics, electrotonic currents and effective refractory periods (ERPs) under pacing and restitution protocols. Regions surrounding vessel cavities, in addition to tissue surfaces, had significantly lower peak downstream electrotonic currents than well coupled myocardium ( vs A/cm2), with faster maximum AP upstroke velocities ( vs mV/ms), although noticeably very similar APDs ( vs ms) and AP restitution properties. Despite similarities in APDs, ERPs in regions of low electrotonic load in the vicinity of surfaces, intramural vessel cavities and endocardial structures were up to ms shorter compared to neighbouring well-coupled tissue, leading to regions of sharp ERP gradients. Consequently, focal extra-stimuli timed within this window of ERP heterogeneity between neighbouring regions readily induced uni-directional block, inducing reentry. Most effective induction sites were within channels of low ERPs between large vessels and epicardium. Significant differences in ERP driven by reductions in electrotonic loading due to fine-scale physiological structural heterogeneity provides an important mechanism of capture of focal activity and reentry induction. Application to pathological ventricles, particularly myocardial infarction, will have important implications in anti-arrhythmia therapy.
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Affiliation(s)
- Martin J. Bishop
- Department of Biomedical Engineering, Division of Imaging Sciences & Biomedical Engineering, King's College London, London, United Kingdom
- * E-mail:
| | - Adam Connolly
- Department of Biomedical Engineering, Division of Imaging Sciences & Biomedical Engineering, King's College London, London, United Kingdom
| | - Gernot Plank
- Institute of Biophysics, Medical University of Graz, Graz, Austria
- Oxford eResearch Centre, University of Oxford, Oxford, United Kingdom
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Hessling G. [Interventional therapy of tachyarrhythmias in the pediatric population]. Herzschrittmacherther Elektrophysiol 2014; 25:166-171. [PMID: 25148919 DOI: 10.1007/s00399-014-0337-3] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 06/12/2014] [Indexed: 06/03/2023]
Abstract
Over the past decades, interventional therapy of tachyarrhythmias in children without structural heart disease has evolved as an alternative to chronic pharmacological treatment. Catheter ablation in children over 5 years with symptomatic tachycardia using radiofrequency- or cryoenergy is nowadays performed with high success and low complication rates at experienced centers. The use of modern technologies such as non-fluoroscopic 3-dimensional mapping has further increased efficacy and safety of catheter ablation, and has led to a significant reduction of fluoroscopy time and dose.Arrhythmia substrates treated most frequently by catheter ablation in children include accessory pathways (WPW syndrome) leading to atrioventricular reentrant tachycardia (AVRT) and dual AV nodal pathways causing atrioventricular nodal reentrant tachycardia (AVNRT). Success rates of catheter ablation for these substrates during long-term follow up are over 90 %. Less common forms of tachycardias in children, such as focal atrial tachycardia, ventricular outflow tachycardias or idiopathic left ventricular tachycardia, are also amenable to catheter ablation with good long-term results. In asymptomatic children with preexcitation on the surface ECG (accessory pathway with the risk of rapid antegrade conduction during atrial fibrillation) the indication for catheter ablation of the accessory pathway for the prevention of sudden cardiac death should already be evaluated during childhood.
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Affiliation(s)
- Gabriele Hessling
- Abteilung Elektrophysiologie, Deutsches Herzzentrum München, Lazarettstr. 36, 80636, München, Deutschland,
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Gasparovic H, Cikes M, Kopjar T, Biocina B. eReply to: atrial apoptosis and fibrosis adversely affect atrial conduit, reservoir and contractile functions. Interact Cardiovasc Thorac Surg 2014; 19:230-1. [PMID: 25035503 DOI: 10.1093/icvts/ivu192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Hrvoje Gasparovic
- Cardiac Surgery, University of Zagreb, University Hospital Center, Zagreb, Croatia
| | - Maja Cikes
- Cardiac Surgery, University of Zagreb, University Hospital Center, Zagreb, Croatia
| | - Tomislav Kopjar
- Cardiac Surgery, University of Zagreb, University Hospital Center, Zagreb, Croatia
| | - Bojan Biocina
- Cardiac Surgery, University of Zagreb, University Hospital Center, Zagreb, Croatia
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Koivumäki JT, Seemann G, Maleckar MM, Tavi P. In silico screening of the key cellular remodeling targets in chronic atrial fibrillation. PLoS Comput Biol 2014; 10:e1003620. [PMID: 24853123 PMCID: PMC4031057 DOI: 10.1371/journal.pcbi.1003620] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 03/30/2014] [Indexed: 02/07/2023] Open
Abstract
Chronic atrial fibrillation (AF) is a complex disease with underlying changes in electrophysiology, calcium signaling and the structure of atrial myocytes. How these individual remodeling targets and their emergent interactions contribute to cell physiology in chronic AF is not well understood. To approach this problem, we performed in silico experiments in a computational model of the human atrial myocyte. The remodeled function of cellular components was based on a broad literature review of in vitro findings in chronic AF, and these were integrated into the model to define a cohort of virtual cells. Simulation results indicate that while the altered function of calcium and potassium ion channels alone causes a pronounced decrease in action potential duration, remodeling of intracellular calcium handling also has a substantial impact on the chronic AF phenotype. We additionally found that the reduction in amplitude of the calcium transient in chronic AF as compared to normal sinus rhythm is primarily due to the remodeling of calcium channel function, calcium handling and cellular geometry. Finally, we found that decreased electrical resistance of the membrane together with remodeled calcium handling synergistically decreased cellular excitability and the subsequent inducibility of repolarization abnormalities in the human atrial myocyte in chronic AF. We conclude that the presented results highlight the complexity of both intrinsic cellular interactions and emergent properties of human atrial myocytes in chronic AF. Therefore, reversing remodeling for a single remodeled component does little to restore the normal sinus rhythm phenotype. These findings may have important implications for developing novel therapeutic approaches for chronic AF.
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Affiliation(s)
- Jussi T. Koivumäki
- Simula Research Laboratory, Center for Cardiological Innovation and Center for Biomedical Computing, Oslo, Norway
- Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Gunnar Seemann
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Mary M. Maleckar
- Simula Research Laboratory, Center for Cardiological Innovation and Center for Biomedical Computing, Oslo, Norway
| | - Pasi Tavi
- Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
- * E-mail:
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Ambrosini E, Sicca F, Brignone MS, D'Adamo MC, Napolitano C, Servettini I, Moro F, Ruan Y, Guglielmi L, Pieroni S, Servillo G, Lanciotti A, Valvo G, Catacuzzeno L, Franciolini F, Molinari P, Marchese M, Grottesi A, Guerrini R, Santorelli FM, Priori S, Pessia M. Genetically induced dysfunctions of Kir2.1 channels: implications for short QT3 syndrome and autism-epilepsy phenotype. Hum Mol Genet 2014; 23:4875-86. [PMID: 24794859 PMCID: PMC4140467 DOI: 10.1093/hmg/ddu201] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [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] [Indexed: 12/27/2022] Open
Abstract
Short QT3 syndrome (SQT3S) is a cardiac disorder characterized by a high risk of mortality and associated with mutations in Kir2.1 (KCNJ2) channels. The molecular mechanisms leading to channel dysfunction, cardiac rhythm disturbances and neurodevelopmental disorders, potentially associated with SQT3S, remain incompletely understood. Here, we report on monozygotic twins displaying a short QT interval on electrocardiogram recordings and autism-epilepsy phenotype. Genetic screening identified a novel KCNJ2 variant in Kir2.1 that (i) enhanced the channel's surface expression and stability at the plasma membrane, (ii) reduced protein ubiquitylation and degradation, (iii) altered protein compartmentalization in lipid rafts by targeting more channels to cholesterol-poor domains and (iv) reduced interactions with caveolin 2. Importantly, our study reveals novel physiological mechanisms concerning wild-type Kir2.1 channel processing by the cell, such as binding to both caveolin 1 and 2, protein degradation through the ubiquitin-proteasome pathway; in addition, it uncovers a potential multifunctional site that controls Kir2.1 surface expression, protein half-life and partitioning to lipid rafts. The reported mechanisms emerge as crucial also for proper astrocyte function, suggesting the need for a neuropsychiatric evaluation in patients with SQT3S and offering new opportunities for disease management.
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Affiliation(s)
- Elena Ambrosini
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy,
| | - Federico Sicca
- Clinical Neurophysiology Laboratory, Department of Developmental Neuroscience and
| | - Maria S Brignone
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy
| | - Maria C D'Adamo
- Faculty of Medicine, Section of Physiology & Biochemistry, Department of Experimental Medicine
| | - Carlo Napolitano
- Molecular Cardiology, IRCCS Salvatore Maugeri Foundation, Pavia, Italy
| | - Ilenio Servettini
- Faculty of Medicine, Section of Physiology & Biochemistry, Department of Experimental Medicine
| | - Francesca Moro
- Clinical Neurophysiology Laboratory, Department of Developmental Neuroscience and
| | - Yanfei Ruan
- Molecular Cardiology, IRCCS Salvatore Maugeri Foundation, Pavia, Italy
| | - Luca Guglielmi
- Faculty of Medicine, Section of Physiology & Biochemistry, Department of Experimental Medicine
| | | | | | - Angela Lanciotti
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy
| | - Giulia Valvo
- Clinical Neurophysiology Laboratory, Department of Developmental Neuroscience and
| | - Luigi Catacuzzeno
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Fabio Franciolini
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Paola Molinari
- Department of Pharmacology, Istituto Superiore di Sanità, Rome, Italy
| | - Maria Marchese
- Molecular Medicine Laboratory, IRCCS Stella Maris Foundation, Pisa, Italy
| | | | - Renzo Guerrini
- Clinical Neurophysiology Laboratory, Department of Developmental Neuroscience and Pediatric Neurology Unit and Laboratories, Children's Hospital A. Meyer-University of Florence, Florence, Italy
| | | | - Silvia Priori
- Molecular Cardiology, IRCCS Salvatore Maugeri Foundation, Pavia, Italy
| | - Mauro Pessia
- Faculty of Medicine, Section of Physiology & Biochemistry, Department of Experimental Medicine
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Filippi S, Gizzi A, Cherubini C, Luther S, Fenton FH. Mechanistic insights into hypothermic ventricular fibrillation: the role of temperature and tissue size. Europace 2014; 16:424-34. [PMID: 24569897 PMCID: PMC3934849 DOI: 10.1093/europace/euu031] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [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: 07/15/2013] [Accepted: 01/27/2014] [Indexed: 12/26/2022] Open
Abstract
AIMS Hypothermia is well known to be pro-arrhythmic, yet it has beneficial effects as a resuscitation therapy and valuable during intracardiac surgeries. Therefore, we aim to study the mechanisms that induce fibrillation during hypothermia. A better understanding of the complex spatiotemporal dynamics of heart tissue as a function of temperature will be useful in managing the benefits and risks of hypothermia. METHODS AND RESULTS We perform two-dimensional numerical simulations by using a minimal model of cardiac action potential propagation fine-tuned on experimental measurements. The model includes thermal factors acting on the ionic currents and the gating variables to correctly reproduce experimentally recorded restitution curves at different temperatures. Simulations are implemented using WebGL, which allows long simulations to be performed as they run close to real time. We describe (i) why fibrillation is easier to induce at low temperatures, (ii) that there is a minimum size required for fibrillation that depends on temperature, (iii) why the frequency of fibrillation decreases with decreasing temperature, and (iv) that regional cooling may be an anti-arrhythmic therapy for small tissue sizes however it may be pro-arrhythmic for large tissue sizes. CONCLUSION Using a mathematical cardiac cell model, we are able to reproduce experimental observations, quantitative experimental results, and discuss possible mechanisms and implications of electrophysiological changes during hypothermia.
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Affiliation(s)
- Simonetta Filippi
- Nonlinear Physics and Mathematical Modeling Laboratory, University Campus Bio-Medico of Rome, Via A. del Portillo 21, I-00128 Rome, Italy
- International Center for Relativistic Astrophysics—I.C.R.A, University Campus Bio-Medico of Rome, Via A. del Portillo 21, I-00128 Rome, Italy
| | - Alessio Gizzi
- Nonlinear Physics and Mathematical Modeling Laboratory, University Campus Bio-Medico of Rome, Via A. del Portillo 21, I-00128 Rome, Italy
- International Center for Relativistic Astrophysics—I.C.R.A, University Campus Bio-Medico of Rome, Via A. del Portillo 21, I-00128 Rome, Italy
| | - Christian Cherubini
- Nonlinear Physics and Mathematical Modeling Laboratory, University Campus Bio-Medico of Rome, Via A. del Portillo 21, I-00128 Rome, Italy
- International Center for Relativistic Astrophysics—I.C.R.A, University Campus Bio-Medico of Rome, Via A. del Portillo 21, I-00128 Rome, Italy
| | - Stefan Luther
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, D-37077 Göttingen, Germany
| | - Flavio H. Fenton
- School of Physics, Georgia Institute of Technology, 837 State Street Atlanta, Atlanta, GA 30332, USA
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35
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Kul S, Uyarel H, Gul M, Kucukdaglı OT, Bacaksiz A, Erdogan E, Ekmekci A. Metabolic syndrome and long-term cardiovascular outcomes in NSTEMI with unstable angina. Nutr Metab Cardiovasc Dis 2014; 24:176-182. [PMID: 24439842 DOI: 10.1016/j.numecd.2013.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 06/15/2013] [Accepted: 07/08/2013] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND AIM Metabolic syndrome (MS) is associated with cardiovascular mortality and morbidity in patients with acute coronary syndrome. The purpose of this study was to evaluate the impact of MS on long-term clinical outcomes in patients with pure non-ST segment myocardial infarction (NSTEMI) or unstable angina pectoris (USAP). METHODS AND RESULTS We prospectively enrolled 310 consecutive NSTEMI/USAP patients (74 females; mean age, 59.3 ± 11.9 years). The study population was divided into two groups: MS(+) and MS(-). The clinical outcomes of the patients were followed for up to 3 years. Increased 3-year cardiovascular mortality and reinfarction were observed in the MS(+) group, as compared to the MS(-) group (15 vs. 3.4%, p = 0.001, and 22.2 vs. 8.3%, p = 0.001, respectively). Hospitalization rates for heart failure and stroke were not significantly different between the two groups on follow-up. By a Cox multivariate analysis, a significant association was noted between MS and the adjusted risk of 3-year cardiovascular mortality (odds ratio 3.4, 95% confidence interval, 1.24-9.1, p = 0.02). CONCLUSION These results suggest that MS is associated with an increased risk of 3-year cardiovascular mortality and reinfarction in patients with NSTEMI/USAP.
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Affiliation(s)
- S Kul
- Department of Cardiology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey.
| | - H Uyarel
- Department of Cardiology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - M Gul
- Department of Cardiology, Mehmet Akif Ersoy Thoracic-Cardiovascular Surgery Training and Research Hospital, Istanbul, Turkey
| | - O T Kucukdaglı
- Department of Emergency, Faculty Of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - A Bacaksiz
- Department of Cardiology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - E Erdogan
- Department of Cardiology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - A Ekmekci
- Department of Cardiology, Siyami Ersek Thoracic-Cardiovascular Surgery Training and Research Hospital, Istanbul, Turkey
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36
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Elshrif MM, Cherry EM. A quantitative comparison of the behavior of human ventricular cardiac electrophysiology models in tissue. PLoS One 2014; 9:e84401. [PMID: 24416228 PMCID: PMC3885549 DOI: 10.1371/journal.pone.0084401] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 11/19/2013] [Indexed: 11/19/2022] Open
Abstract
Numerical integration of mathematical models of heart cell electrophysiology provides an important computational tool for studying cardiac arrhythmias, but the abundance of available models complicates selecting an appropriate model. We study the behavior of two recently published models of human ventricular action potentials, the Grandi-Pasqualini-Bers (GPB) and the O'Hara-Virág-Varró-Rudy (OVVR) models, and compare the results with four previously published models and with available experimental and clinical data. We find the shapes and durations of action potentials and calcium transients differ between the GPB and OVVR models, as do the magnitudes and rate-dependent properties of transmembrane currents and the calcium transient. Differences also occur in the steady-state and S1–S2 action potential duration and conduction velocity restitution curves, including a maximum conduction velocity for the OVVR model roughly half that of the GPB model and well below clinical values. Between single cells and tissue, both models exhibit differences in properties, including maximum upstroke velocity, action potential amplitude, and minimum diastolic interval. Compared to experimental data, action potential durations for the GPB and OVVR models agree fairly well (although OVVR epicardial action potentials are shorter), but maximum slopes of steady-state restitution curves are smaller. Although studies show alternans in normal hearts, it occurs only in the OVVR model, and only for a narrow range of cycle lengths. We find initiated spiral waves do not progress to sustained breakup for either model. The dominant spiral wave period of the GPB model falls within clinically relevant values for ventricular tachycardia (VT), but for the OVVR model, the dominant period is longer than periods associated with VT. Our results should facilitate choosing a model to match properties of interest in human cardiac tissue and to replicate arrhythmia behavior more closely. Furthermore, by indicating areas where existing models disagree, our findings suggest avenues for further experimental work.
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Affiliation(s)
- Mohamed M. Elshrif
- B. Thomas Golisano College of Computing and Information Sciences, Rochester Institute of Technology, Rochester, New York, United States of America
| | - Elizabeth M. Cherry
- School of Mathematical Sciences, Rochester Institute of Technology, Rochester, New York, United States of America
- * E-mail:
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37
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Affiliation(s)
- S Rasika Wickramasinghe
- From Penn Cardiovascular Institute and Section of Cardiac Electrophysiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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38
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Zumhagen S, Veldkamp MW, Stallmeyer B, Baartscheer A, Eckardt L, Paul M, Remme CA, Bhuiyan ZA, Bezzina CR, Schulze-Bahr E. A heterozygous deletion mutation in the cardiac sodium channel gene SCN5A with loss- and gain-of-function characteristics manifests as isolated conduction disease, without signs of Brugada or long QT syndrome. PLoS One 2013; 8:e67963. [PMID: 23840796 PMCID: PMC3695936 DOI: 10.1371/journal.pone.0067963] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 05/23/2013] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The SCN5A gene encodes for the α-subunit of the cardiac sodium channel NaV1.5, which is responsible for the rapid upstroke of the cardiac action potential. Mutations in this gene may lead to multiple life-threatening disorders of cardiac rhythm or are linked to structural cardiac defects. Here, we characterized a large family with a mutation in SCN5A presenting with an atrioventricular conduction disease and absence of Brugada syndrome. METHOD AND RESULTS In a large family with a high incidence of sudden cardiac deaths, a heterozygous SCN5A mutation (p.1493delK) with an autosomal dominant inheritance has been identified. Mutation carriers were devoid of any cardiac structural changes. Typical ECG findings were an increased P-wave duration, an AV-block I° and a prolonged QRS duration with an intraventricular conduction delay and no signs for Brugada syndrome. HEK293 cells transfected with 1493delK showed strongly (5-fold) reduced Na(+) currents with altered inactivation kinetics compared to wild-type channels. Immunocytochemical staining demonstrated strongly decreased expression of SCN5A 1493delK in the sarcolemma consistent with an intracellular trafficking defect and thereby a loss-of-function. In addition, SCN5A 1493delK channels that reached cell membrane showed gain-of-function aspects (slowing of the fast inactivation, reduction in the relative fraction of channels that fast inactivate, hastening of the recovery from inactivation). CONCLUSION In a large family, congregation of a heterozygous SCN5A gene mutation (p.1493delK) predisposes for conduction slowing without evidence for Brugada syndrome due to a predominantly trafficking defect that reduces Na(+) current and depolarization force.
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Affiliation(s)
- Sven Zumhagen
- Institute for Genetics of Heart Diseases, Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany.
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Pazoki R, de Jong JS, Marsman RF, Bruinsma N, Dekker LRC, Wilde AAM, Bezzina CR, Tanck MWT. SNPs identified as modulators of ECG traits in the general population do not markedly affect ECG traits during acute myocardial infarction nor ventricular fibrillation risk in this condition. PLoS One 2013; 8:e57216. [PMID: 23437344 PMCID: PMC3577709 DOI: 10.1371/journal.pone.0057216] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 01/22/2013] [Indexed: 11/18/2022] Open
Abstract
Background Ventricular fibrillation (VF) in the setting of acute ST elevation myocardial infarction (STEMI) is a leading cause of mortality. Although the risk of VF has a genetic component, the underlying genetic factors are largely unknown. Since heart rate and ECG intervals of conduction and repolarization during acute STEMI differ between patients who do and patients who do not develop VF, we investigated whether SNPs known to modulate these ECG indices in the general population also impact on the respective ECG indices during STEMI and on the risk of VF. Methods and Results The study population consisted of participants of the Arrhythmia Genetics in the NEtherlandS (AGNES) study, which enrols patients with a first STEMI that develop VF (cases) and patients that do not develop VF (controls). SNPs known to impact on RR interval, PR interval, QRS duration or QTc interval in the general population were tested for effects on the respective STEMI ECG indices (stage 1). Only those showing a (suggestive) significant association were tested for association with VF (stage 2). On average, VF cases had a shorter RR and a longer QTc interval compared to non-VF controls. Eight SNPs showed a trend for association with the respective STEMI ECG indices. Of these, three were also suggestively associated with VF. Conclusions RR interval and ECG indices of conduction and repolarization during acute STEMI differ between patients who develop VF and patients who do not. Although the effects of the SNPs on ECG indices during an acute STEMI seem to be similar in magnitude and direction as those found in the general population, the effects, at least in isolation, are too small to explain the differences in ECGs between cases and controls and to determine risk of VF.
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Affiliation(s)
- Raha Pazoki
- Department of Clinical Epidemiology, Biostatistics & Bioinformatics, Academic Medical Center, Amsterdam, The Netherlands
- Department of Clinical and Experimental Cardiology, Heart Failure Research Center, Academic Medical Center, Amsterdam, The Netherlands
| | - Jonas S.S.G. de Jong
- Department of Clinical and Experimental Cardiology, Heart Failure Research Center, Academic Medical Center, Amsterdam, The Netherlands
| | - Roos F. Marsman
- Department of Clinical and Experimental Cardiology, Heart Failure Research Center, Academic Medical Center, Amsterdam, The Netherlands
| | - Nienke Bruinsma
- Department of Clinical and Experimental Cardiology, Heart Failure Research Center, Academic Medical Center, Amsterdam, The Netherlands
| | - Lukas R. C. Dekker
- Department of Cardiology, Catharina Hospital, Eindhoven, The Netherlands
| | - Arthur A. M. Wilde
- Department of Clinical and Experimental Cardiology, Heart Failure Research Center, Academic Medical Center, Amsterdam, The Netherlands
| | - Connie R. Bezzina
- Department of Clinical and Experimental Cardiology, Heart Failure Research Center, Academic Medical Center, Amsterdam, The Netherlands
- * E-mail: (MWTT); (CRB)
| | - Michael W. T. Tanck
- Department of Clinical Epidemiology, Biostatistics & Bioinformatics, Academic Medical Center, Amsterdam, The Netherlands
- * E-mail: (MWTT); (CRB)
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Hostiuc S, Popescu A, Guţu ED, Rusu MC, Pop F. Electrical conduction system apoptosis in type II diabetes mellitus. Rom J Morphol Embryol 2013; 54:953-959. [PMID: 24398990] [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] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Even though apoptosis is known to be associated with various cardiovascular pathologies, its presence in cardiac nodal tissue in adults was only scarcely researched. Cardiomyocyte apoptosis was associated with diabetic cardiovascular pathology. Our main objective was to test whether programmed cell death is present in nodal tissue in type II diabetes mellitus and, if present to characterize it. The study was designed as a qualitative one. We used autopsy samples of hearts from 10 patients (56 to 73-year-old, 6:4 male to female ratio), positive for type II diabetes mellitus. Samples from sinoatrial and atrioventricular nodes were stained with Hematoxylin-Eosin. For immunohistochemistry, we used primary antibodies for caspases 3 and 9, cathepsin B, and TRADD. Nodal tissue in all samples was characterized by diffuse interstitial fibrosis and chronic ischemic lesions; nuclear damage and foci of irreversible ischemic necrosis intermingled with isles of relatively morphologically normal myocytes. Sinoatrial and atrioventricular nodes were caspase-3 and -9 positive, and also cathepsin-B-positive, suggesting an overlap between apoptotic and necrotic mechanisms. Central area of the sinus node seemed to have the most severe lesions. As a conclusion, nodal apoptosis is present in nodal tissue in type II diabetes mellitus; it involves the intrinsic pathway and associated concomitant and/or post-apoptotic necrosis.
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Affiliation(s)
- S Hostiuc
- Discipline of Anatomy, Faculty of Dental Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania;
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41
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Arnolds DE, Liu F, Fahrenbach JP, Kim GH, Schillinger KJ, Smemo S, McNally EM, Nobrega MA, Patel VV, Moskowitz IP. TBX5 drives Scn5a expression to regulate cardiac conduction system function. J Clin Invest 2012; 122:2509-18. [PMID: 22728936 PMCID: PMC3386825 DOI: 10.1172/jci62617] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [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: 12/27/2011] [Accepted: 05/17/2012] [Indexed: 11/17/2022] Open
Abstract
Cardiac conduction system (CCS) disease, which results in disrupted conduction and impaired cardiac rhythm, is common with significant morbidity and mortality. Current treatment options are limited, and rational efforts to develop cell-based and regenerative therapies require knowledge of the molecular networks that establish and maintain CCS function. Recent genome-wide association studies (GWAS) have identified numerous loci associated with adult human CCS function, including TBX5 and SCN5A. We hypothesized that TBX5, a critical developmental transcription factor, regulates transcriptional networks required for mature CCS function. We found that deletion of Tbx5 from the mature murine ventricular conduction system (VCS), including the AV bundle and bundle branches, resulted in severe VCS functional consequences, including loss of fast conduction, arrhythmias, and sudden death. Ventricular contractile function and the VCS fate map remained unchanged in VCS-specific Tbx5 knockouts. However, key mediators of fast conduction, including Nav1.5, which is encoded by Scn5a, and connexin 40 (Cx40), demonstrated Tbx5-dependent expression in the VCS. We identified a TBX5-responsive enhancer downstream of Scn5a sufficient to drive VCS expression in vivo, dependent on canonical T-box binding sites. Our results establish a direct molecular link between Tbx5 and Scn5a and elucidate a hierarchy between human GWAS loci that affects function of the mature VCS, establishing a paradigm for understanding the molecular pathology of CCS disease.
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Affiliation(s)
- David E Arnolds
- Department of Pediatrics, University of Chicago, Chicago, IL, USA
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42
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Lemery R. Trials and tribulations of stimulating human cardiac ganglia for autonomic intervention. Heart Rhythm 2012; 9:1393-4. [PMID: 22659212 DOI: 10.1016/j.hrthm.2012.05.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Indexed: 11/18/2022]
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43
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Kul'bitskiĭ BN, Larev ZV, Fedulova MV, Denisova OP, Bogomolov DV. [Pathology of the heart conducting system in the thanatogenesis of sudden death from alcoholic cardiomyopathy and coronary heart disease]. Sud Med Ekspert 2012; 55:62-65. [PMID: 22686063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The present literature review is focused on the contribution of various pathological changes in the heart conducting system to the tanatogenesis of sudden death from alcoholic cardiomyopathy and coronary heart disease viewed from the perspective of a forensic medical expert. The currently available data on the disorders in the heart conducting system in the subjects with these diseases are presented. Various aspects of pathology of the heart conducting system are considered in the modern and historical contexts. The prospects for the further investigations into the tanatogenic mechanisms of sudden death by reason of alcoholic cardiomyopathy and coronary heart disease are outlined.
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Bessière F, Chevalier P. [Intracardiac conduction disturbances]. Rev Prat 2012; 62:269-273. [PMID: 22408881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Francis Bessière
- Département de rythmologie, U50, centre national de référence des troubles du rythme héréditaires, hôpital cardiologique Louis-Pradel, université Claude-Bernard Lyon 1, France.
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45
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Makarov LM, Komoliatova VN, Kolosov VO, Solokhin IA. [Sudden death of two sisters in a family with combined progressive impairment of cardiac conduction system]. Kardiologiia 2012; 52:91-96. [PMID: 23098357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Sudden cardiac death (SCD) of two sisters from a family with combined progressive impairment of cardiac conduction system (CCS) is described. These two sisters (hetero-ovular twins) died suddenly in a kindergarten at the background of physical and emotional effort in the age of 4.8 and 5 years. Resuscitation and electrical defibrillation conducted in one of them after 20 min of heart arrest were not effective. Autopsy gave no clear-cut data relative to pathology of the heart and other organs. Analysis of preserved ECGs showed that in the age of 8 months both sisters had sharp leftward/upward deviation of electric axis of the heart (-41 in one sister and -43 in another). In 2 years these deviations became even more pronounced reaching -63. This was combined with small q-waves and tall R waves in leads I and aVL what corresponded to signs of block of the anterior branch of bundle of His and could be a manifestation of hereditary disease with progressive CCS involvement first of all of the Lev-Lenegre disease.
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Bregel' LV, Belozerov IM, Ogloblina ML, Golubev SS, Zemchenko OA, Pavlenok KN, Antoshkina EP, Bochkareva AK, Popod'ko TN. [Histiocytoid cardiomyopathy in an infant]. Kardiologiia 2012; 52:93-96. [PMID: 22839721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present a description of a clinical observation of a histiocytoid cardiomyopathy in a female patient aged 4 months. This pathology is rare in pediatric cardiology. Its etiology is linked with mutation of the gene encoding mitochondrial cytochrome B (mitochondrial transport of electrons). This mutation leads to a specific morphological and functional abnormalities of cardiomyocytes. Purkinje cells and cells of conduction system at microscopy appear as histiocytolike foam cells cytoplasm of which contain large amount of lipids and glycogen. Girls prevail among those affected. The case reflects clinical picture characteristic for this nosology: malignant arrhythmia and cardiomegaly with fatal outcome.
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Jia X, Song X, Shima M, Tamura K, Deng F, Guo X. Acute effect of ambient ozone on heart rate variability in healthy elderly subjects. J Expo Sci Environ Epidemiol 2011; 21:541-7. [PMID: 21522190 DOI: 10.1038/jes.2011.18] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2010] [Accepted: 02/24/2011] [Indexed: 05/24/2023]
Abstract
Acute ambient ozone (O(3)) exposure is associated with the increased mortality and morbidity of cardiovascular diseases. The dysfunction of cardiac autonomic nervous system (ANS), indicated by the disturbed heart rate variability (HRV), may be the most important underlying mechanism. Previous studies reported the heterogeneous associations between O(3) within several hours' exposure and HRV on general elderly subjects, in which poor surrogate of exposure evaluation and different health status of the subjects may be responsible for the heterogeneous associations. No studies were found focusing on the O(3)-mediated HRV effects within several minutes' exposure on healthy older subjects until recently. We measured the real-time 5-min ambient O(3) concentration and HRV frequency indices in 20 healthy elderly subjects in two surveys, with the 1st and 2nd survey in summer and winter, respectively. Mixed-linear model was used to evaluate the associations between the ambient 5-min average O(3) and concurrent 5-min HRV frequency indices measured during the outdoor period. After adjusting the co-pollutants (ambient PM(2.5) and nitrogen oxides concentrations) and subject characteristics, high frequency (HF) changed -4.87% (95% CI -8.62 to -0.97%) per 10 ppb increment of O(3), whereas decreased low frequency (LF) and increased LFHFR were found to be marginally associated with the elevated O(3) (P values were 0.092 and 0.069). We concluded that the ambient O(3) exert transient decrease effects on HRV, which may induce acute cardiac events.
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Affiliation(s)
- Xiaofeng Jia
- Peking University School of Public Health, Beijing, China
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Sizarov A, Devalla HD, Anderson RH, Passier R, Christoffels VM, Moorman AFM. Molecular analysis of patterning of conduction tissues in the developing human heart. Circ Arrhythm Electrophysiol 2011; 4:532-42. [PMID: 21576278 DOI: 10.1161/circep.111.963421] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Recent studies in experimental animals have revealed some molecular mechanisms underlying the differentiation of the myocardium making up the conduction system. To date, lack of gene expression data for the developing human conduction system has precluded valid extrapolations from experimental studies to the human situation. METHODS AND RESULTS We performed immunohistochemical analyses of the expression of key transcription factors, such as ISL1, TBX3, TBX18, and NKX2-5, ion channel HCN4, and connexins in the human embryonic heart. We supplemented our molecular analyses with 3-dimensional reconstructions of myocardial TBX3 expression. TBX3 is expressed in the developing conduction system and in the right venous valve, atrioventricular ring bundles, and retro-aortic nodal region. TBX3-positive myocardium, with exception of the top of the ventricular septum, is devoid of fast-conducting connexin40 and connexin43 and hence identifies slowly conducting pathways. In the early embryonic heart, we found wide expression of the pacemaker channel HCN4 at the venous pole, including the atrial chambers. HCN4 expression becomes confined during later developmental stages to the components of the conduction system. Patterns of expression of transcription factors, known from experimental studies to regulate the development of the sinus node and atrioventricular conduction system, are similar in the human and mouse developing hearts. CONCLUSIONS Our findings point to the comparability of mechanisms governing the development of the cardiac conduction patterning in human and mouse, which provide a molecular basis for understanding the functioning of the human developing heart before formation of a discrete conduction system.
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Affiliation(s)
- Aleksander Sizarov
- Heart Failure Research Center, Academic Medical Center, Amsterdam, The Netherlands
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Halperin HR, Nazarian S. Magnetic resonance identification of the ventricular tachycardia critical isthmus: finding the needle in the haystack. J Am Coll Cardiol 2011; 57:195-7. [PMID: 21211690 DOI: 10.1016/j.jacc.2010.07.042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 07/18/2010] [Indexed: 11/18/2022]
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