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Tonko J, Ehnesh M, Vigmond E, Chow A, Roney C, Lambiase PD. Omnipolar Conduction Velocity Mapping for Ventricular Substrate Characterisation: Impact of CV Estimation Method and EGM Type on In-Vivo Conduction Velocity Measurements. Heart Rhythm 2024:S1547-5271(24)02674-2. [PMID: 38851622 DOI: 10.1016/j.hrthm.2024.05.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 05/29/2024] [Accepted: 05/30/2024] [Indexed: 06/10/2024]
Abstract
BACKGROUND Areas of abnormal and/or heterogenous conduction velocity (CV) are important ablation targets for ventricular tachycardias. Yet, precise assessment of CV in clinical contact mapping remains challenging. Numerous different CV estimation methods have been proposed. OBJECTIVE To compare the automated LAT-independent omnipolar-based CV estimation method termed "Wave Speed" (WS) with four established LAT-based methods and formally establish the quantitative differences between them. METHODS High-density contact maps in patients with structurally normal hearts during sinus rhythm and ventricular ectopy (VE) were retrospectively analysed. CV was assessed and compared using five methods: 1.Omnipolar WS, 2.Gradient method, 3.Planar wavefront fitting (PWF) 4.Circular wavefront fitting (CWF), 5.Radial basis function (RBF). CV variations based on EGM type (uni-/bi-/omnipolar), catheter movement and surrogate markers for catheter contact were analysed. RESULTS 23 patients (47.8% male, 45.7±17.3 years) with 22 sinus (11 LV/11 RV) and 16 VE maps (9 LV/7 RV) were included. WS algorithm yielded statistically significant higher CV estimates in SR (mean 1.41 ±0.18m/s) and VE maps (mean 1.23±0.18m/s) compared to all LAT-based estimation methods with absolute differences ranging from 0.1m/s to 0.81m/s. Median pointwise differences in SR and VE between WS and LAT-based methods were high, ranging from 0.55±0.15m/s (WS vs. PWF) to 0.67±0.16m/s (WS vs. RBF). For LAT-based methods, use of unipolar EGMs yielded significantly higher CV estimates than bi-/omnipolar EGMs in sinus. CONCLUSION The CV estimation method has an important, statistically significant impact on ventricular CV measurements. Future work will focus on how these differences impact identification of pathological conduction slowing in scar-related substrate.
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Affiliation(s)
- Johanna Tonko
- Institute for Cardiovascular Science, University College London, WC1E 6JF, UK,.
| | - Mahmoud Ehnesh
- School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, UK
| | - Edmon Vigmond
- IHU Liryc, Electrophysiology and Heart Modelling Institute, Fondation Bordeaux Universite, France
| | - Anthony Chow
- Barts Heart Centre, St. Bartholomew's Hospital, London, UK
| | - Caroline Roney
- School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, UK
| | - Pier D Lambiase
- Institute for Cardiovascular Science, University College London, WC1E 6JF, UK,; Barts Heart Centre, St. Bartholomew's Hospital, London, UK
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Rossi P, Cauti FM, Polselli M, Magnocavallo M, Niscola M, Fanti V, Limite LR, Evangelista A, Bellisario A, De Paolis R, Facchetti S, Quaglione R, Piccirillo G, Bianchi S. Ablation of persistent atrial fibrillation based on atrial electrogram duration map: methodology and clinical outcomes from the AEDUM pilot study. J Interv Card Electrophysiol 2024:10.1007/s10840-023-01721-7. [PMID: 38206451 DOI: 10.1007/s10840-023-01721-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 12/06/2023] [Indexed: 01/12/2024]
Abstract
BACKGROUND Catheter ablation of persistent atrial fibrillation (PsAF) represents a challenge for the electrophysiologist and there are still divergences regarding the best ablative approach to adopt. Create a new map of the duration of atrial bipolar electrograms (Atrial Electrogram DUration Map, AEDUM) to recognize a functional substrate during sinus rhythm and guide a patient-tailored ablative strategy for PsAF. METHODS Forty PsAF subjects were assigned in a 1:1 ratio to either for PVI alone (Group B1) or PVI+AEDUM areas ablation (Group B2). A cohort of 15 patients without AF history undergoing left-sided accessory pathway ablation was used as a control group (Group A). In all patients, voltage and AEDUM maps were created during sinus rhythm. The minimum follow-up was 12 months, with rhythm monitoring via 48-h ECG Holter or by implantable cardiac device. RESULTS Electrogram (EGM) duration was higher in Group B than in Group A (49±16.2ms vs 34.2±3.8ms; p-value<0.001). In Group B the mean cumulative AEDUM area was 21.8±8.2cm2; no difference between the two subgroups was observed (22.3±9.1cm2 vs 21.2±7.2cm2; p-value=0.45). The overall bipolar voltage recorded inside the AEDUM areas was lower than in the remaining atrial areas [median: 1.30mV (IQR: 0.71-2.38mV) vs 1.54mV (IQR: 0.79-2.97mV); p-value: <0.001)]. Low voltage areas (<0.5mV) were recorded in three (7.5%) patients in Group B. During the follow-up [median 511 days (376-845days)] patients who underwent PVI-only experienced more AF recurrence than those receiving a tailored approach (65% vs 35%; p-value= 0.04). CONCLUSIONS All PsAF patients exhibited AEDUM areas. An ablation approach targeting these areas resulted in a more effective strategy compared with PVI only.
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Affiliation(s)
- Pietro Rossi
- Arrhythmology Unit, Ospedale Fatebenefratelli Isola Tiberina-Gemelli Isola, Via Ponte Quattro Capi, 39, 00186, Rome, Italy.
| | - Filippo Maria Cauti
- Arrhythmology Unit, Ospedale Fatebenefratelli Isola Tiberina-Gemelli Isola, Via Ponte Quattro Capi, 39, 00186, Rome, Italy
| | - Marco Polselli
- Arrhythmology Unit, Ospedale Fatebenefratelli Isola Tiberina-Gemelli Isola, Via Ponte Quattro Capi, 39, 00186, Rome, Italy
| | - Michele Magnocavallo
- Arrhythmology Unit, Ospedale Fatebenefratelli Isola Tiberina-Gemelli Isola, Via Ponte Quattro Capi, 39, 00186, Rome, Italy
| | - Marta Niscola
- Abbott Medical, Via Paracelso 20, 20864, Agrate Brianza, Italy
| | - Veronica Fanti
- Abbott Medical, Via Paracelso 20, 20864, Agrate Brianza, Italy
| | | | - Antonietta Evangelista
- Arrhythmology Unit, Ospedale Fatebenefratelli Isola Tiberina-Gemelli Isola, Via Ponte Quattro Capi, 39, 00186, Rome, Italy
| | | | | | | | - Raffaele Quaglione
- Department of Internal, Anesthesiology and Cardiovascular Sciences, Policlinico Umberto I, Sapienza University of Rome, 00185, Rome, Italy
| | - Gianfranco Piccirillo
- Department of Internal, Anesthesiology and Cardiovascular Sciences, Policlinico Umberto I, Sapienza University of Rome, 00185, Rome, Italy
| | - Stefano Bianchi
- Arrhythmology Unit, Ospedale Fatebenefratelli Isola Tiberina-Gemelli Isola, Via Ponte Quattro Capi, 39, 00186, Rome, Italy
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3
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Wang T, Karel J, Invers-Rubio E, Hernández-Romero I, Peeters R, Bonizzi P, Guillem MS. Standardized 2D atrial mapping and its clinical applications. Comput Biol Med 2024; 168:107755. [PMID: 38039895 DOI: 10.1016/j.compbiomed.2023.107755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 10/10/2023] [Accepted: 11/20/2023] [Indexed: 12/03/2023]
Abstract
The visualization and comparison of electrophysiological information in the atrium among different patients could be facilitated by a standardized 2D atrial mapping. However, due to the complexity of the atrial anatomy, unfolding the 3D geometry into a 2D atrial mapping is challenging. In this study, we aim to develop a standardized approach to achieve a 2D atrial mapping that connects the left and right atria, while maintaining fixed positions and sizes of atrial segments across individuals. Atrial segmentation is a prerequisite for the process. Segmentation includes 19 different segments with 12 segments from the left atrium, 5 segments from the right atrium, and two segments for the atrial septum. To ensure consistent and physiologically meaningful segment connections, an automated procedure is applied to open up the atrial surfaces and project the 3D information into 2D. The corresponding 2D atrial mapping can then be utilized to visualize different electrophysiological information of a patient, such as activation time patterns or phase maps. This can in turn provide useful information for guiding catheter ablation. The proposed standardized 2D maps can also be used to compare more easily structural information like fibrosis distribution with rotor presence and location. We show several examples of visualization of different electrophysiological properties for both healthy subjects and patients affected by atrial fibrillation. These examples show that the proposed maps provide an easy way to visualize and interpret intra-subject information and perform inter-subject comparison, which may provide a reference framework for the analysis of the atrial fibrillation substrate before treatment, and during a catheter ablation procedure.
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Affiliation(s)
- Tiantian Wang
- Department of Advanced Computing Sciences, Maastricht University, The Netherlands
| | - Joël Karel
- Department of Advanced Computing Sciences, Maastricht University, The Netherlands.
| | - Eric Invers-Rubio
- Arrhythmia Unit, Hospital Clínic de Barcelona Cardiovascular Institute (ICCV), Universitat de Barcelona, Barcelona, Catalonia, Spain
| | | | - Ralf Peeters
- Department of Advanced Computing Sciences, Maastricht University, The Netherlands
| | - Pietro Bonizzi
- Department of Advanced Computing Sciences, Maastricht University, The Netherlands
| | - Maria S Guillem
- ITACA Institute, Universitat Politècnica de València, Valencia, Spain
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4
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Subramanian M, Saggu DK, Atreya AR, Shekar V, Yalagudri SD, Narasimhan C. Radiofrequency catheter ablation of ventricular arrhythmias in patients with hypertrophic cardiomyopathy. Indian Pacing Electrophysiol J 2024; 24:9-13. [PMID: 38040092 PMCID: PMC10927980 DOI: 10.1016/j.ipej.2023.11.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 11/05/2023] [Accepted: 11/25/2023] [Indexed: 12/03/2023] Open
Abstract
BACKGROUND Compared to other non-ischemic substrates, there is limited data on the role and outcome of catheter ablation in HCM. The objective of this study is to assess the safety and efficacy of catheter ablation for the treatment of VT in patients with HCM. METHODS Fourteen patients with HCM and drug refractory VT who underwent catheter ablation at a single center were included in this study. The data was evaluated retrospectively. Acute success, procedure-related complications, and long-term outcomes were documented during follow up. RESULTS Among the 14 patients (mean age 48.2 ± 8.2 years, 85.7% males, mean LVEF 42.6 ± 6.5%), 4 had an apical aneurysm. Eleven patients had evidence of scar-related VT and three patients had a bundle-branch re-entry VT. The most common sites for scar-related VT were the border-zones of the apical aneurysms, basal septum, and LV lateral wall. Patient either underwent an endocardial ablation or a combined endocardial and epicardial ablation. Acute success was achieved in all patients. In 6 patients VT was terminated during ablation. In two patients, non-clinical VTs were inducible at the end of the procedure. No major or minor complications were observed during and after the procedure in all patients. During long-term follow up, elimination of VTs reached 78%. CONCLUSION Catheter ablation of VT in patients with HCM is safe and successful in eliminating VT. Combining endocardial and epicardial ablation techniques can potentially lead to better outcomes in these patients. Bundle branch re-entry should be considered as a potential mechanism of VT in patients with HCM.
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Affiliation(s)
| | - Daljeet Kaur Saggu
- AIG Hospitals Institute of Cardiac Sciences and Research, Hyderabad, India
| | - Auras R Atreya
- AIG Hospitals Institute of Cardiac Sciences and Research, Hyderabad, India
| | - Vijay Shekar
- AIG Hospitals Institute of Cardiac Sciences and Research, Hyderabad, India
| | - Sachin D Yalagudri
- AIG Hospitals Institute of Cardiac Sciences and Research, Hyderabad, India
| | - C Narasimhan
- AIG Hospitals Institute of Cardiac Sciences and Research, Hyderabad, India.
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5
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Syomin FA, Galushka VA, Tsaturyan AK. Effect of strain-dependent conduction slowing on the re-entry formation and maintenance in cardiac muscle: 2D computer simulation. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023; 39:e3676. [PMID: 36562353 DOI: 10.1002/cnm.3676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 12/06/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
The effect of mechano-electrical feedback on re-entry formation and maintenance was studied using a model of myocardial electromechanics that accounts for two components of myocardial conductivity and delayed strain-dependent changes in membrane capacitance that causes a conduction slowing. Two scenarios were simulated in 2D numerical experiments: (i) propagation of an excitation-contraction wave beyond the edge of a nonconductive nonexcitable obstacle; (ii) circulation of a re-entry wave around a nonconductive nonexcitable obstacle. The simulations demonstrated that the delayed strain-dependent deceleration of the conduction waves promotes the detachment of the excitation-contraction waves from the sharp edge of an elongated obstacle and modulates the re-entry waves rotating around a compact obstacle. The data show that the mechano-electrical feedback, together with an increase in the stimulation frequency and an increase in the excitation threshold, is an arrhythmogenic factor that must be taken into account when analyzing the possibility of the re-entry formation.
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Affiliation(s)
- Fyodor A Syomin
- Institute of Mechanics, Lomonosov Moscow State University, Moscow, Russia
| | | | - Andrey K Tsaturyan
- Institute of Mechanics, Lomonosov Moscow State University, Moscow, Russia
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6
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Marcotte CD, Hoffman MJ, Fenton FH, Cherry EM. Reconstructing cardiac electrical excitations from optical mapping recordings. CHAOS (WOODBURY, N.Y.) 2023; 33:093141. [PMID: 37756611 PMCID: PMC10539031 DOI: 10.1063/5.0156314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 09/01/2023] [Indexed: 09/29/2023]
Abstract
The reconstruction of electrical excitation patterns through the unobserved depth of the tissue is essential to realizing the potential of computational models in cardiac medicine. We have utilized experimental optical-mapping recordings of cardiac electrical excitation on the epicardial and endocardial surfaces of a canine ventricle as observations directing a local ensemble transform Kalman filter data assimilation scheme. We demonstrate that the inclusion of explicit information about the stimulation protocol can marginally improve the confidence of the ensemble reconstruction and the reliability of the assimilation over time. Likewise, we consider the efficacy of stochastic modeling additions to the assimilation scheme in the context of experimentally derived observation sets. Approximation error is addressed at both the observation and modeling stages through the uncertainty of observations and the specification of the model used in the assimilation ensemble. We find that perturbative modifications to the observations have marginal to deleterious effects on the accuracy and robustness of the state reconstruction. Furthermore, we find that incorporating additional information from the observations into the model itself (in the case of stimulus and stochastic currents) has a marginal improvement on the reconstruction accuracy over a fully autonomous model, while complicating the model itself and thus introducing potential for new types of model errors. That the inclusion of explicit modeling information has negligible to negative effects on the reconstruction implies the need for new avenues for optimization of data assimilation schemes applied to cardiac electrical excitation.
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Affiliation(s)
- C. D. Marcotte
- Department of Computer Science, Durham University, Durham DH1 3LE, United Kingdom
| | - M. J. Hoffman
- School of Mathematical Sciences, Rochester Institute of Technology, Rochester, New York 14623, USA
| | - F. H. Fenton
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - E. M. Cherry
- School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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7
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van Schie MS, Liao R, Ramdat Misier NL, Knops P, Heida A, Taverne YJHJ, de Groot NMS. Atrial extrasystoles enhance low-voltage fractionation electrograms in patients with atrial fibrillation. Europace 2023; 25:euad223. [PMID: 37477953 PMCID: PMC10401323 DOI: 10.1093/europace/euad223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 07/14/2023] [Indexed: 07/22/2023] Open
Abstract
BACKGROUND AND AIMS Atrial extrasystoles (AES) provoke conduction disorders and may trigger episodes of atrial fibrillation (AF). However, the direction- and rate-dependency of electrophysiological tissue properties on epicardial unipolar electrogram (EGM) morphology is unknown. Therefore, this study examined the impact of spontaneous AES on potential amplitude, -fractionation, -duration, and low-voltage areas (LVAs), and correlated these differences with various degrees of prematurity and aberrancy. METHODS AND RESULTS Intra-operative high-resolution epicardial mapping of the right and left atrium, Bachmann's Bundle, and pulmonary vein area was performed during sinus rhythm (SR) in 287 patients (60 with AF). AES were categorized according to their prematurity index (>25% shortening) and degree of aberrancy (none, mild/opposite, moderate and severe). In total, 837 unique AES (457 premature; 58 mild/opposite, 355 moderate, and 154 severe aberrant) were included. The average prematurity index was 28% [12-45]. Comparing SR and AES, average voltage decreased (-1.1 [-1.2, -0.9] mV, P < 0.001) at all atrial regions, whereas the amount of LVAs and fractionation increased (respectively, +3.4 [2.7, 4.1] % and +3.2 [2.6, 3.7] %, P < 0.001). Only weak or moderate correlations were found between EGM morphology parameters and prematurity indices (R2 < 0.299, P < 0.001). All parameters were, however, most severely affected by either mild/opposite or severely aberrant AES, in which the effect was more pronounced in AF patients. Also, there were considerable regional differences in effects provoked by AES. CONCLUSION Unipolar EGM characteristics during spontaneous AES are mainly directional-dependent and not rate-dependent. AF patients have more direction-dependent conduction disorders, indicating enhanced non-uniform anisotropy that is uncovered by spontaneous AES.
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Affiliation(s)
- Mathijs S van Schie
- Department of Cardiology, Erasmus Medical Center, Dr. Molewaterplein 40, 3015GD Rotterdam, the Netherlands
| | - Rongheng Liao
- Department of Cardiology, Erasmus Medical Center, Dr. Molewaterplein 40, 3015GD Rotterdam, the Netherlands
| | - Nawin L Ramdat Misier
- Department of Cardiology, Erasmus Medical Center, Dr. Molewaterplein 40, 3015GD Rotterdam, the Netherlands
| | - Paul Knops
- Department of Cardiology, Erasmus Medical Center, Dr. Molewaterplein 40, 3015GD Rotterdam, the Netherlands
| | - Annejet Heida
- Department of Cardiology, Erasmus Medical Center, Dr. Molewaterplein 40, 3015GD Rotterdam, the Netherlands
| | - Yannick J H J Taverne
- Department of Cardiothoracic Surgery, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Natasja M S de Groot
- Department of Cardiology, Erasmus Medical Center, Dr. Molewaterplein 40, 3015GD Rotterdam, the Netherlands
- Department of Microelectronics, Signal Processing Systems, Faculty of Electrical Engineering, Mathematics and Computer Sciences, Delft University of Technology, Mekelweg 4, 2628CD Delft, the Netherlands
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8
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Ittycheri A, Lipsky ZW, Hookway TA, German GK. Ultraviolet light induces mechanical and structural changes in full thickness human skin. J Mech Behav Biomed Mater 2023; 143:105880. [PMID: 37172426 DOI: 10.1016/j.jmbbm.2023.105880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/07/2023] [Accepted: 04/30/2023] [Indexed: 05/15/2023]
Abstract
While the detrimental health effects of prolonged ultraviolet (UV) irradiation on skin health have been widely accepted, the biomechanical process by which photoaging occurs and the relative effects of irradiation with different UV ranges on skin biomechanics have remained relatively unexplored. In this study, the effects of UV-induced photoageing are explored by quantifying the changes in the mechanical properties of full-thickness human skin irradiated with UVA and UVB light for incident dosages up to 1600 J/cm2. Mechanical testing of skin samples excised parallel and perpendicular to the predominant collagen fiber orientation show a rise in the fractional relative difference of elastic modulus, fracture stress, and toughness with increased UV irradiation. These changes become significant with UVA incident dosages of 1200 J/cm2 for samples excised both parallel and perpendicular to the dominant collagen fiber orientation. However, while mechanical changes occur in samples aligned with the collagen orientation at UVB dosages of 1200 J/cm2, statistical differences in samples perpendicular to the collagen orientation emerge only for UVB dosages of 1600 J/cm2. No notable or consistent trend is observed for the fracture strain. Analyses of toughness changes with maximum absorbed dosage reveals that no one UV range is more impactful in inducing mechanical property changes, but rather these changes scale with maximum absorbed energy. Evaluation of the structural characteristics of collagen further reveals an increase in collagen fiber bundle density with UV irradiation, but not collagen tortuosity, potentially linking mechanical changes to altered microstructure.
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Affiliation(s)
- Abraham Ittycheri
- Department of Biomedical Engineering, Binghamton University, State University of New York, Binghamton, NY, USA
| | - Zachary W Lipsky
- Department of Biomedical Engineering, Binghamton University, State University of New York, Binghamton, NY, USA
| | - Tracy A Hookway
- Department of Biomedical Engineering, Binghamton University, State University of New York, Binghamton, NY, USA
| | - Guy K German
- Department of Biomedical Engineering, Binghamton University, State University of New York, Binghamton, NY, USA.
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9
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Subramanian M, Atreya AR, Yalagudri SD, Shekar PV, Saggu DK, Narasimhan C. Catheter Ablation for Ventricular Arrhythmias in Hypertrophic Cardiomyopathy. Card Electrophysiol Clin 2022; 14:693-699. [PMID: 36396186 DOI: 10.1016/j.ccep.2022.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Implantable cardioverter-defibrillators are the mainstay of therapy for prevention of sudden cardiac death in high-risk patients with hypertrophic cardiomyopathy (HCM). Catheter ablation is a useful option for patients with recurrent, drug refractory monomorphic ventricular tachycardia (VT), and device therapy. Compared with other nonischemic substrates, there are limited data on the role and outcomes of catheter ablation in HCM. The challenges of VT ablation in HCM patients include deep intramural and epicardial substrates, suboptimal power delivery, and higher recurrence due to progression of disease. Patient selection, using cardiac MRI scar localization, and optimizing ablation techniques can improve outcomes in these patients.
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Affiliation(s)
- Muthiah Subramanian
- Electrophysiology Section, AIG Hospitals Institute of Cardiac Sciences and Research, Mindspace Road, Gachibowli, Hyderabad 500032, India
| | - Auras R Atreya
- Electrophysiology Section, AIG Hospitals Institute of Cardiac Sciences and Research, Mindspace Road, Gachibowli, Hyderabad 500032, India; Division of Cardiovascular Medicine, Electrophysiology Section, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Sachin D Yalagudri
- Electrophysiology Section, AIG Hospitals Institute of Cardiac Sciences and Research, Mindspace Road, Gachibowli, Hyderabad 500032, India
| | - P Vijay Shekar
- Electrophysiology Section, AIG Hospitals Institute of Cardiac Sciences and Research, Mindspace Road, Gachibowli, Hyderabad 500032, India
| | - Daljeet Kaur Saggu
- Electrophysiology Section, AIG Hospitals Institute of Cardiac Sciences and Research, Mindspace Road, Gachibowli, Hyderabad 500032, India
| | - Calambur Narasimhan
- Electrophysiology Section, AIG Hospitals Institute of Cardiac Sciences and Research, Mindspace Road, Gachibowli, Hyderabad 500032, India.
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10
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Abstract
The global burden caused by cardiovascular disease is substantial, with heart disease representing the most common cause of death around the world. There remains a need to develop better mechanistic models of cardiac function in order to combat this health concern. Heart rhythm disorders, or arrhythmias, are one particular type of disease which has been amenable to quantitative investigation. Here we review the application of quantitative methodologies to explore dynamical questions pertaining to arrhythmias. We begin by describing single-cell models of cardiac myocytes, from which two and three dimensional models can be constructed. Special focus is placed on results relating to pattern formation across these spatially-distributed systems, especially the formation of spiral waves of activation. Next, we discuss mechanisms which can lead to the initiation of arrhythmias, focusing on the dynamical state of spatially discordant alternans, and outline proposed mechanisms perpetuating arrhythmias such as fibrillation. We then review experimental and clinical results related to the spatio-temporal mapping of heart rhythm disorders. Finally, we describe treatment options for heart rhythm disorders and demonstrate how statistical physics tools can provide insights into the dynamics of heart rhythm disorders.
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Affiliation(s)
- Wouter-Jan Rappel
- Department of Physics, University of California San Diego, La Jolla, CA 92037
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11
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Atrial conduction velocity mapping: clinical tools, algorithms and approaches for understanding the arrhythmogenic substrate. Med Biol Eng Comput 2022; 60:2463-2478. [PMID: 35867323 PMCID: PMC9365755 DOI: 10.1007/s11517-022-02621-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 06/07/2022] [Indexed: 11/02/2022]
Abstract
Characterizing patient-specific atrial conduction properties is important for understanding arrhythmia drivers, for predicting potential arrhythmia pathways, and for personalising treatment approaches. One metric that characterizes the health of the myocardial substrate is atrial conduction velocity, which describes the speed and direction of propagation of the electrical wavefront through the myocardium. Atrial conduction velocity mapping algorithms are under continuous development in research laboratories and in industry. In this review article, we give a broad overview of different categories of currently published methods for calculating CV, and give insight into their different advantages and disadvantages overall. We classify techniques into local, global, and inverse methods, and discuss these techniques with respect to their faithfulness to the biophysics, incorporation of uncertainty quantification, and their ability to take account of the atrial manifold.
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12
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Dong X, Tse G, Hao G, Du Y. Heterogeneities in Ventricular Conduction Following Treatment with Heptanol: A Multi-Electrode Array Study in Langendorff-Perfused Mouse Hearts. Life (Basel) 2022; 12:life12070996. [PMID: 35888085 PMCID: PMC9321110 DOI: 10.3390/life12070996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/21/2022] [Accepted: 06/30/2022] [Indexed: 11/26/2022] Open
Abstract
Background: Previous studies have associated slowed ventricular conduction with the arrhythmogenesis mediated by the gap junction and sodium channel inhibitor heptanol in mouse hearts. However, they did not study the propagation patterns that might contribute to the arrhythmic substrate. This study used a multi-electrode array mapping technique to further investigate different conduction abnormalities in Langendorff-perfused mouse hearts exposed to 0.1 or 2 mM heptanol. Methods: Recordings were made from the left ventricular epicardium using multi-electrode arrays in spontaneously beating hearts during right ventricular 8 Hz pacing or S1S2 pacing. Results: In spontaneously beating hearts, heptanol at 0.1 and 2 mM significantly reduced the heart rate from 314 ± 25 to 189 ± 24 and 157 ± 7 bpm, respectively (ANOVA, p < 0.05 and p < 0.001). During regular 8 Hz pacing, the mean LATs were increased by 0.1 and 2 mM heptanol from 7.1 ± 2.2 ms to 19.9 ± 5.0 ms (p < 0.05) and 18.4 ± 5.7 ms (p < 0.05). The standard deviation of the mean LATs was increased from 2.5 ± 0.8 ms to 10.3 ± 4.0 ms and 8.0 ± 2.5 ms (p < 0.05), and the median of phase differences was increased from 1.7 ± 1.1 ms to 13.9 ± 7.8 ms and 12.1 ± 5.0 ms by 0.1 and 2 mM heptanol (p < 0.05). P5 took a value of 0.2 ± 0.1 ms and was not significantly altered by heptanol at 0.1 or 2 mM (1.1 ± 0.9 ms and 0.9 ± 0.5 ms, p > 0.05). P50 was increased from 7.3 ± 2.7 ms to 24.0 ± 12.0 ms by 0.1 mM heptanol and then to 22.5 ± 7.5 ms by 2 mM heptanol (p < 0.05). P95 was increased from 1.7 ± 1.1 ms to 13.9 ± 7.8 ms by 0.1 mM heptanol and to 12.1 ± 5.0 ms by 2 mM heptanol (p < 0.05). These changes led to increases in the absolute inhomogeneity in conduction (P5−95) from 7.1 ± 2.6 ms to 31.4 ± 11.3 ms, 2 mM: 21.6 ± 7.2 ms, respectively (p < 0.05). The inhomogeneity index (P5−95/P50) was significantly reduced from 3.7 ± 1.2 to 3.1 ± 0.8 by 0.1 mM and then to 3.3 ± 0.9 by 2 mM heptanol (p < 0.05). Conclusion: Increased activation latencies, reduced CVs, and the increased inhomogeneity index of conduction were associated with both spontaneous and induced ventricular arrhythmias.
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Affiliation(s)
- Xiuming Dong
- Henan SCOPE Research Institute of Electrophysiology Co., Ltd., Kaifeng 475000, China; (X.D.); (G.H.)
| | - Gary Tse
- Cardiac Electrophysiology Unit, Cardiovascular Analytics Group, Hong Kong, China;
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China
- Kent and Medway Medical School, Canterbury CT2 7FS, UK
| | - Guoliang Hao
- Henan SCOPE Research Institute of Electrophysiology Co., Ltd., Kaifeng 475000, China; (X.D.); (G.H.)
- Burdon Sanderson Cardiac Science Centre, BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Yimei Du
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
- Research Center of Ion Channelopathy, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
- Correspondence:
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Anderson RH, Sánchez-Quintana D, Spicer DE, Farré J, Sternick EB. How does the cardiac impulse pass from the sinus to the atrioventricular node? Heart Rhythm 2022; 19:1738-1746. [PMID: 35660474 DOI: 10.1016/j.hrthm.2022.05.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 04/25/2022] [Accepted: 05/17/2022] [Indexed: 11/16/2022]
Abstract
Over a century has passed since Tawara demonstrated the presence of the insulated pathways that extend from the "knoten" at the base of the atrial septum to their ramifications at the ventricular apexes. Having initially doubted the existence of the atrioventricular bundle until reading the monograph produced by Tawara, Keith, together with Flack, soon revealed the presence of the sinus node. Shortly thereafter, Thorel suggested that a special system might be found within the atrial walls, connecting the newly discovered atrial nodes. This prompted the convening of a special session of the German Pathological Society in 1910. The consensus was that no tracts existed within the atrial walls, with Aschoff and Mönckeberg establishing criterions to be met by those proposing recognition of "specialised" atrial conducting pathways. None of those subsequently proposing the presence of such pathways have discussed their findings on the basis of the criterions established at the meeting of 1910. It remains the case, nonetheless, that drawings continue to be offered by cardiological experts showing narrow pathways within the atrial walls that parallel the arrangement used to show the ventricular conduction pathways. A similar drawing adorns the front cover of "Heart Rhythm". We are unaware of any evidence supporting the presence of pathways as illustrated existing within the overall walls of the atrial chambers. In this review, we summarise the evidence that shows, instead, that it is the aggregation of the working atrial cardiomyocytes within the atrial walls that underscores preferential anisotropic interatrial conduction.
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Affiliation(s)
- Robert H Anderson
- Institute of Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | - Diane E Spicer
- Johns Hopkins All Children's Hospital, Johns Hopkins University, Saint Petersburg, Florida, USA; Department of Pediatric Cardiology, University of Florida, Gainesville, Florida, USA
| | - Jeronimo Farré
- Fundación Jiménez Díaz University Hospital and Institute of Biomedical Research, Madrid, Spain
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Electro-Mechanical Whole-Heart Digital Twins: A Fully Coupled Multi-Physics Approach. MATHEMATICS 2021. [DOI: 10.3390/math9111247] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mathematical models of the human heart are evolving to become a cornerstone of precision medicine and support clinical decision making by providing a powerful tool to understand the mechanisms underlying pathophysiological conditions. In this study, we present a detailed mathematical description of a fully coupled multi-scale model of the human heart, including electrophysiology, mechanics, and a closed-loop model of circulation. State-of-the-art models based on human physiology are used to describe membrane kinetics, excitation-contraction coupling and active tension generation in the atria and the ventricles. Furthermore, we highlight ways to adapt this framework to patient specific measurements to build digital twins. The validity of the model is demonstrated through simulations on a personalized whole heart geometry based on magnetic resonance imaging data of a healthy volunteer. Additionally, the fully coupled model was employed to evaluate the effects of a typical atrial ablation scar on the cardiovascular system. With this work, we provide an adaptable multi-scale model that allows a comprehensive personalization from ion channels to the organ level enabling digital twin modeling.
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