1
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Kataoka N, Imamura T, Uchida K, Koi T, Kinugawa K. Significance of J waves in unexplained ventricular fibrillation among elderly populations with various comorbidities. Heart Rhythm O2 2024; 5:417-420. [PMID: 38984359 PMCID: PMC11228269 DOI: 10.1016/j.hroo.2024.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024] Open
Affiliation(s)
- Naoya Kataoka
- Second Department of Internal Medicine, University of Toyama, Toyama, Japan
| | - Teruhiko Imamura
- Second Department of Internal Medicine, University of Toyama, Toyama, Japan
| | - Keisuke Uchida
- Second Department of Internal Medicine, University of Toyama, Toyama, Japan
| | - Takahisa Koi
- Second Department of Internal Medicine, University of Toyama, Toyama, Japan
| | - Koichiro Kinugawa
- Second Department of Internal Medicine, University of Toyama, Toyama, Japan
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2
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Abrasheva VO, Kovalenko SG, Slotvitsky M, Romanova SА, Aitova AA, Frolova S, Tsvelaya V, Syunyaev RA. Human sodium current voltage-dependence at physiological temperature measured by coupling a patch-clamp experiment to a mathematical model. J Physiol 2024; 602:633-661. [PMID: 38345560 DOI: 10.1113/jp285162] [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: 06/16/2023] [Accepted: 01/02/2024] [Indexed: 02/20/2024] Open
Abstract
Voltage-gated Na+ channels are crucial to action potential propagation in excitable tissues. Because of the high amplitude and rapid activation of the Na+ current, voltage-clamp measurements are very challenging and are usually performed at room temperature. In this study, we measured Na+ current voltage-dependence in stem cell-derived cardiomyocytes at physiological temperature. While the apparent activation and inactivation curves, measured as the dependence of current amplitude on voltage, fall within the range reported in previous studies, we identified a systematic error in our measurements. This error is caused by the deviation of the membrane potential from the command potential of the amplifier. We demonstrate that it is possible to account for this artifact using computer simulation of the patch-clamp experiment. We obtained surprising results through patch-clamp model optimization: a half-activation of -11.5 mV and a half-inactivation of -87 mV. Although the half-activation deviates from previous research, we demonstrate that this estimate reproduces the conduction velocity dependence on extracellular potassium concentration. KEY POINTS: Voltage-gated Na+ currents play a crucial role in excitable tissues including neurons, cardiac and skeletal muscle. Measurement of Na+ current is challenging because of its high amplitude and rapid kinetics, especially at physiological temperature. We have used the patch-clamp technique to measure human Na+ current voltage-dependence in human induced pluripotent stem cell-derived cardiomyocytes. The patch-clamp data were processed by optimization of the model accounting for voltage-clamp experiment artifacts, revealing a large difference between apparent parameters of Na+ current and the results of the optimization. We conclude that actual Na+ current activation is extremely depolarized in comparison to previous studies. The new Na+ current model provides a better understanding of action potential propagation; we demonstrate that it explains propagation in hyperkalaemic conditions.
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Affiliation(s)
| | - Sandaara G Kovalenko
- Moscow Institute of Physics and Technology, Moscow, Russia
- M. F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow, Russia
- ITMO University, St Petersburg, Russia
| | - Mihail Slotvitsky
- Moscow Institute of Physics and Technology, Moscow, Russia
- M. F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow, Russia
- ITMO University, St Petersburg, Russia
| | - Serafima А Romanova
- Moscow Institute of Physics and Technology, Moscow, Russia
- M. F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow, Russia
| | - Aleria A Aitova
- Moscow Institute of Physics and Technology, Moscow, Russia
- M. F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow, Russia
- ITMO University, St Petersburg, Russia
| | - Sheida Frolova
- Moscow Institute of Physics and Technology, Moscow, Russia
- M. F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow, Russia
| | - Valeria Tsvelaya
- Moscow Institute of Physics and Technology, Moscow, Russia
- M. F. Vladimirsky Moscow Regional Research Clinical Institute, Moscow, Russia
- ITMO University, St Petersburg, Russia
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3
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Sassu E, Tumlinson G, Stefanovska D, Fernández MC, Iaconianni P, Madl J, Brennan TA, Koch M, Cameron BA, Preissl S, Ravens U, Schneider-Warme F, Kohl P, Zgierski-Johnston CM, Hortells L. Age-related structural and functional changes of the intracardiac nervous system. J Mol Cell Cardiol 2024; 187:1-14. [PMID: 38103633 DOI: 10.1016/j.yjmcc.2023.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 11/14/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
BACKGROUND Although aging is known to be associated with an increased incidence of both atrial and ventricular arrhythmias, there is limited knowledge about how Schwann cells (SC) and the intracardiac nervous system (iCNS) remodel with age. Here we investigate the differences in cardiac SC, parasympathetic nerve fibers, and muscarinic acetylcholine receptor M2 (M2R) expression in young and old mice. Additionally, we examine age-related changes in cardiac responses to sympathomimetic and parasympathomimetic drugs. METHODS AND RESULTS Lower SC density, lower SC proliferation and fewer parasympathetic nerve fibers were observed in cardiac and, as a control sciatic nerves from old (20-24 months) compared to young mice (2-3 months). In old mice, chondroitin sulfate proteoglycan 4 (CSPG4) was increased in sciatic but not cardiac nerves. Expression of M2R was lower in ventricular myocardium and ventricular conduction system from old mice compared to young mice, while no significant difference was seen in M2R expression in sino-atrial or atrio-ventricular node pacemaker tissue. Heart rate was slower and PQ intervals were longer in Langendorff-perfused hearts from old mice. Ventricular tachycardia and fibrillation were more frequently observed in response to carbachol administration in hearts from old mice versus those from young mice. CONCLUSIONS On the background of reduced presence of SC and parasympathetic nerve fibers, and of lower M2R expression in ventricular cardiomyocytes and conduction system of aged hearts, the propensity of ventricular arrhythmogenesis upon parasympathomimetic drug application is increased. Whether this is caused by an increase in heterogeneity of iCNS structure and function remains to be elucidated.
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Affiliation(s)
- Eliza Sassu
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg Bad Krozingen, University of Freiburg, 79110 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany; Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, 79110 Freiburg, Germany
| | - Gavin Tumlinson
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg Bad Krozingen, University of Freiburg, 79110 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Dragana Stefanovska
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, 79110 Freiburg, Germany
| | - Marbely C Fernández
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg Bad Krozingen, University of Freiburg, 79110 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Pia Iaconianni
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg Bad Krozingen, University of Freiburg, 79110 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Josef Madl
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg Bad Krozingen, University of Freiburg, 79110 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Tomás A Brennan
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg Bad Krozingen, University of Freiburg, 79110 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Manuel Koch
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg Bad Krozingen, University of Freiburg, 79110 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Breanne A Cameron
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg Bad Krozingen, University of Freiburg, 79110 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Sebastian Preissl
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, 79110 Freiburg, Germany
| | - Ursula Ravens
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg Bad Krozingen, University of Freiburg, 79110 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Franziska Schneider-Warme
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg Bad Krozingen, University of Freiburg, 79110 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, and Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg Bad Krozingen, University of Freiburg, 79110 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, and Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Callum M Zgierski-Johnston
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg Bad Krozingen, University of Freiburg, 79110 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany.
| | - Luis Hortells
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg Bad Krozingen, University of Freiburg, 79110 Freiburg, Germany; Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany; Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, 79110 Freiburg, Germany.
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4
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Xia YX, Xie LH, He YJ, Pan JT, Panfilov AV, Zhang H. Numerical study of the drift of scroll waves by optical feedback in cardiac tissue. Phys Rev E 2023; 108:064406. [PMID: 38243456 DOI: 10.1103/physreve.108.064406] [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: 07/05/2023] [Accepted: 11/16/2023] [Indexed: 01/21/2024]
Abstract
Nonlinear waves were found in various types of physical, chemical, and biological excitable media, e.g., in heart muscle. They can form three-dimensional (3D) vortices, called scroll waves, that are of particular significance in the heart, as they underlie lethal cardiac arrhythmias. Thus controlling the behavior of scroll waves is interesting and important. Recently, the optical feedback control procedure for two-dimensional vortices, called spiral waves, was developed. It can induce directed linear drift of spiral waves in optogenetically modified cardiac tissue. However, the extension of this methodology to 3D scroll waves is nontrivial, as optogenetic signals only penetrate close to the surface of cardiac tissue. Here we present a study of this extension in a two-variable reaction-diffusion model and in a detailed model of cardiac tissue. We show that the success of the control procedure is determined by the tension of the scroll wave filament. In tissue with positive filament tension the control procedure works in all cases. However, in the case of negative filament tension for a sufficiently large medium, instabilities occur and make drift and control of scroll waves impossible. Because in normal cardiac tissue the filament tension is assumed to be positive, we conclude that the proposed optical feedback scheme can be a robust method in inducing the linear drift of scroll waves that can control their positions in cardiac tissue.
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Affiliation(s)
- Yuan-Xun Xia
- Zhejiang Institute of Modern Physics, School of Physics, Zhejiang University, Hangzhou 310058, China
| | - Ling-Hao Xie
- Zhejiang Institute of Modern Physics, School of Physics, Zhejiang University, Hangzhou 310058, China
| | - Yin-Jie He
- Information Engineering College, Zhijiang College of Zhejiang University of Technology, Shaoxing 312030, China
| | - Jun-Ting Pan
- Ocean College, Zhejiang University, Zhoushan 316021, China
| | - Alexander V Panfilov
- Department of Physics and Astronomy, Ghent University, Ghent 9000, Belgium
- Laboratory of Computational Biology and Medicine, Ural Federal University, Ekaterinburg 620002, Russia
- World-Class Research Center "Digital Biodesign and Personalized Healthcare," Sechenov University, Moscow 119146, Russia
| | - Hong Zhang
- Zhejiang Institute of Modern Physics, School of Physics, Zhejiang University, Hangzhou 310058, China
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5
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Yang Z, Zhang L, Aras K, Efimov IR, Adam GC. Hardware-Mappable Cellular Neural Networks for Distributed Wavefront Detection in Next-Generation Cardiac Implants. ADVANCED INTELLIGENT SYSTEMS (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 4:2200032. [PMID: 36035592 PMCID: PMC9400456 DOI: 10.1002/aisy.202200032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Artificial intelligence algorithms are being adopted to analyze medical data, promising faster interpretation to support doctors' diagnostics. The next frontier is to bring these powerful algorithms to implantable medical devices. Herein, a closed-loop solution is proposed, where a cellular neural network is used to detect abnormal wavefronts and wavebrakes in cardiac signals recorded in human tissue is trained to achieve >96% accuracy, >92% precision, >99% specificity, and >93% sensitivity, when floating point precision weights are assumed. Unfortunately, the current hardware technologies for floating point precision are too bulky or energy intensive for compact standalone applications in medical implants. Emerging device technologies, such as memristors, can provide the compact and energy-efficient hardware fabric to support these efforts and can be reliably embedded with existing sensor and actuator platforms in implantable devices. A distributed design that considers the hardware limitations in terms of overhead and limited bit precision is also discussed. The proposed distributed solution can be easily adapted to other medical technologies that require compact and efficient computing, like wearable devices and lab-on-chip platforms.
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Affiliation(s)
- Zhuolin Yang
- Department of Electrical and Computer Engineering, The George Washington University, Washington, DC 20052, USA
| | - Lei Zhang
- Department of Electrical and Computer Engineering, The George Washington University, Washington, DC 20052, USA
| | - Kedar Aras
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Igor R Efimov
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Gina C Adam
- Department of Electrical and Computer Engineering, The George Washington University, Washington, DC 20052, USA
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6
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Aras K, Gams A, Faye R, Brennan J, Goldrick K, Li J, Zhong Y, Chiang CH, Smith EH, Poston MD, Chivers J, Hanna P, Mori S, Ajijola OA, Shivkumar K, Hoover DB, Viventi J, Rogers JA, Bernus O, Efimov IR. Electrophysiology and Arrhythmogenesis in the Human Right Ventricular Outflow Tract. Circ Arrhythm Electrophysiol 2022; 15:e010630. [PMID: 35238622 PMCID: PMC9052172 DOI: 10.1161/circep.121.010630] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 02/17/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Right ventricular outflow tract (RVOT) is a common source of ventricular tachycardia, which often requires ablation. However, the mechanisms underlying the RVOT's unique arrhythmia susceptibility remain poorly understood due to lack of detailed electrophysiological and molecular studies of the human RVOT. METHODS We conducted optical mapping studies in 16 nondiseased donor human RVOT preparations subjected to pharmacologically induced adrenergic and cholinergic stimulation to evaluate susceptibility to arrhythmias and characterize arrhythmia dynamics. RESULTS We found that under control conditions, RVOT has shorter action potential duration at 80% repolarization relative to the right ventricular apical region. Treatment with isoproterenol (100 nM) shortened action potential duration at 80% repolarization and increased incidence of premature ventricular contractions (P=0.003), whereas acetylcholine (100 μM) stimulation alone had no effect on action potential duration at 80% repolarization or premature ventricular contractions. However, acetylcholine treatment after isoproterenol stimulation reduced the incidence of premature ventricular contractions (P=0.034) and partially reversed action potential duration at 80% repolarization shortening (P=0.029). Immunolabeling of RVOT (n=4) confirmed the presence of cholinergic marker VAChT (vesicular acetylcholine transporter) in the region. Rapid pacing revealed RVOT susceptibility to both concordant and discordant alternans. Investigation into transmural arrhythmia dynamics showed that arrhythmia wave fronts and phase singularities (rotors) were relatively more organized in the endocardium than in the epicardium (P=0.006). Moreover, there was a weak but positive spatiotemporal autocorrelation between epicardial and endocardial arrhythmic wave fronts and rotors. Transcriptome analysis (n=10 hearts) suggests a trend that MAPK (mitogen-activated protein kinase) signaling, calcium signaling, and cGMP-PKG (protein kinase G) signaling are among the pathways that may be enriched in the male RVOT, whereas pathways of neurodegeneration may be enriched in the female RVOT. CONCLUSIONS Human RVOT electrophysiology is characterized by shorter action potential duration relative to the right ventricular apical region. Cholinergic right ventricular stimulation attenuates the arrhythmogenic effects of adrenergic stimulation, including increase in frequency of premature ventricular contractions and shortening of wavelength. Right ventricular arrhythmia is characterized by positive spatial-temporal autocorrelation between epicardial-endocardial arrhythmic wave fronts and rotors that are relatively more organized in the endocardium.
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Affiliation(s)
- Kedar Aras
- Department of Biomedical Engineering, the George Washington University, Washington, DC
- Department of Materials Science and Engineering, Ohio State University, Columbus, OH
| | - Anna Gams
- Department of Biomedical Engineering, the George Washington University, Washington, DC
| | - Rokhaya Faye
- Department of Biomedical Engineering, the George Washington University, Washington, DC
- LIRYC Institute, Bordeaux University, France
| | - Jaclyn Brennan
- Department of Biomedical Engineering, the George Washington University, Washington, DC
| | - Katherine Goldrick
- Department of Biomedical Engineering, the George Washington University, Washington, DC
| | - Jinghua Li
- Department of Biomedical Engineering, Northwestern University, Evanston, IL
- Department of Materials Science and Engineering, Ohio State University, Columbus, OH
| | - Yishan Zhong
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, IL
| | - Chia-Han Chiang
- Department of Biomedical Engineering, Duke University, Durham, NC
| | - Elizabeth H. Smith
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN
| | - Megan D. Poston
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN
| | - Jacqueline Chivers
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN
| | - Peter Hanna
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA
| | - Shumpei Mori
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA
| | - Olujimi A. Ajijola
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California Los Angeles, Los Angeles, CA
| | - Donald B. Hoover
- Department of Biomedical Sciences, East Tennessee State University, Johnson City, TN
| | - Jonathan Viventi
- Department of Biomedical Engineering, Duke University, Durham, NC
| | - John A. Rogers
- Department of Biomedical Engineering, Northwestern University, Evanston, IL
| | | | - Igor R. Efimov
- Department of Biomedical Engineering, the George Washington University, Washington, DC
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7
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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] [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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8
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Avula UMR, Melki L, Kushner JS, Liang S, Wan EY. Theoretical Models and Computational Analysis of Action Potential Dispersion for Cardiac Arrhythmia Risk Stratification. Front Cardiovasc Med 2021; 8:649489. [PMID: 33748198 PMCID: PMC7973016 DOI: 10.3389/fcvm.2021.649489] [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: 01/04/2021] [Accepted: 02/10/2021] [Indexed: 11/24/2022] Open
Abstract
Reentrant cardiac arrhythmias such as atrial fibrillation (AF) and ventricular fibrillation (VF) are common cardiac arrhythmias that account for substantial morbidity and mortality throughout the world. However, the mechanisms and optimal ablation treatment strategies for such arrhythmias are still unclear. Using 2D optical mapping of a mouse model with AF and VF, we have identified regional heterogeneity of the action potential duration (APD) in the atria and ventricles of the heart as key drivers for the initiation and persistence of reentry. The purpose of this paper is to discuss theoretical patterns of dispersion, demonstrate patterns of dispersion seen in our mouse model and discuss the computational analysis of APD dispersion patterns. These analyses and discussions may lead to better understanding of dispersion patterns in patients with these arrhythmias, as well as help comprehend whether and how reducing dispersion can lead to arrhythmia risk stratification and treatment strategies for arrhythmias.
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Affiliation(s)
- Uma Mahesh R Avula
- Division of Nephrology, University of Mississippi, Jackson, MS, United States
| | - Lea Melki
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Jared S Kushner
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Stephanie Liang
- Department of Medicine, Prince of Wales Hospital, Hong Kong, China
| | - Elaine Y Wan
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
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9
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Ferraro E, Pozhidaeva L, Pitcher DS, Mansfield C, Koh JHB, Williamson C, Aslanidi O, Gorelik J, Ng FS. Prolonged ursodeoxycholic acid administration reduces acute ischaemia-induced arrhythmias in adult rat hearts. Sci Rep 2020; 10:15284. [PMID: 32943714 PMCID: PMC7499428 DOI: 10.1038/s41598-020-72016-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/07/2020] [Indexed: 12/13/2022] Open
Abstract
Acute myocardial ischaemia and reperfusion (I-R) are major causes of ventricular arrhythmias in patients with a history of coronary artery disease. Ursodeoxycholic acid (UDCA) has previously been shown to be antiarrhythmic in fetal hearts. This study was performed to investigate if UDCA protects against ischaemia-induced and reperfusion-induced arrhythmias in the adult myocardium, and compares the effect of acute (perfusion only) versus prolonged (2 weeks pre-treatment plus perfusion) UDCA administration. Langendorff-perfused adult Sprague-Dawley rat hearts were subjected to acute regional ischaemia by ligation of the left anterior descending artery (10 min), followed by reperfusion (2 min), and arrhythmia incidence quantified. Prolonged UDCA administration reduced the incidence of acute ischaemia-induced arrhythmias (p = 0.028), with a reduction in number of ventricular ectopic beats during the ischaemic phase compared with acute treatment (10 ± 3 vs 58 ± 15, p = 0.036). No antiarrhythmic effect was observed in the acute UDCA administration group. Neither acute nor prolonged UDCA treatment altered the incidence of reperfusion arrhythmias. The antiarrhythmic effect of UDCA may be partially mediated by an increase in cardiac wavelength, due to the attenuation of conduction velocity slowing (p = 0.03), and the preservation of Connexin43 phosphorylation during acute ischaemia (p = 0.0027). The potential antiarrhythmic effects of prolonged UDCA administration merit further investigation.
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Affiliation(s)
- Elisa Ferraro
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Lidia Pozhidaeva
- School of Biomedical Engineering and Imaging Science, King's College London, London, UK
| | - David S Pitcher
- National Heart and Lung Institute, Imperial College London, London, UK
| | | | - Jia Han Benjamin Koh
- School of Biomedical Engineering and Imaging Science, King's College London, London, UK
| | | | - Oleg Aslanidi
- School of Biomedical Engineering and Imaging Science, King's College London, London, UK
| | - Julia Gorelik
- National Heart and Lung Institute, Imperial College London, London, UK.
| | - Fu Siong Ng
- National Heart and Lung Institute, Imperial College London, London, UK.
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10
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Han M, Chen L, Aras K, Liang C, Chen X, Zhao H, Li K, Faye NR, Sun B, Kim JH, Bai W, Yang Q, Ma Y, Lu W, Song E, Baek JM, Lee Y, Liu C, Model JB, Yang G, Ghaffari R, Huang Y, Efimov IR, Rogers JA. Catheter-integrated soft multilayer electronic arrays for multiplexed sensing and actuation during cardiac surgery. Nat Biomed Eng 2020; 4:997-1009. [PMID: 32895515 DOI: 10.1038/s41551-020-00604-w] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 07/17/2020] [Indexed: 01/02/2023]
Abstract
The rigidity and relatively primitive modes of operation of catheters equipped with sensing or actuation elements impede their conformal contact with soft-tissue surfaces, limit the scope of their uses, lengthen surgical times and increase the need for advanced surgical skills. Here, we report materials, device designs and fabrication approaches for integrating advanced electronic functionality with catheters for minimally invasive forms of cardiac surgery. By using multiphysics modelling, plastic heart models and Langendorff animal and human hearts, we show that soft electronic arrays in multilayer configurations on endocardial balloon catheters can establish conformal contact with curved tissue surfaces, support high-density spatiotemporal mapping of temperature, pressure and electrophysiological parameters and allow for programmable electrical stimulation, radiofrequency ablation and irreversible electroporation. Integrating multimodal and multiplexing capabilities into minimally invasive surgical instruments may improve surgical performance and patient outcomes.
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Affiliation(s)
- Mengdi Han
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Lin Chen
- Departments of Civil and Environmental Engineering, Northwestern University, Evanston, IL, USA.,State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Kedar Aras
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA
| | - Cunman Liang
- Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education, School of Mechanical Engineering, Tianjin University, Tianjin, China
| | - Xuexian Chen
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Hangbo Zhao
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA.,Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Kan Li
- Departments of Civil and Environmental Engineering, Northwestern University, Evanston, IL, USA.,Department of Mechanical Engineering, Northwestern University, Evanston, IL, USA.,Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA.,Department of Engineering, University of Cambridge, Cambridge, UK
| | - Ndeye Rokhaya Faye
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA
| | - Bohan Sun
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA.,Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Jae-Hwan Kim
- Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign Urbana, Champaign, IL, USA.,Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign Urbana, Champaign, IL, USA
| | - Wubin Bai
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA.,Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
| | - Quansan Yang
- Department of Mechanical Engineering, Northwestern University, Evanston, IL, USA
| | - Yuhang Ma
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA.,School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Wei Lu
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Enming Song
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Janice Mihyun Baek
- Department of Chemistry, University of Illinois at Urbana-Champaign Urbana, Champaign, IL, USA
| | - Yujin Lee
- Department of Chemistry, University of Illinois at Urbana-Champaign Urbana, Champaign, IL, USA
| | - Clifford Liu
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Jeffrey B Model
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA
| | - Guanjun Yang
- State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Roozbeh Ghaffari
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA.,Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Yonggang Huang
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA. .,Departments of Civil and Environmental Engineering, Northwestern University, Evanston, IL, USA. .,Department of Mechanical Engineering, Northwestern University, Evanston, IL, USA. .,Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA.
| | - Igor R Efimov
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA.
| | - John A Rogers
- Querrey Simpson Institute for Bioelectronics, Northwestern University, Evanston, IL, USA. .,Department of Mechanical Engineering, Northwestern University, Evanston, IL, USA. .,Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA. .,Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign Urbana, Champaign, IL, USA. .,Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA. .,Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, USA. .,Department of Chemistry, Northwestern University, Evanston, IL, USA. .,Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, USA.
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11
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Smirnov D, Pikunov A, Syunyaev R, Deviatiiarov R, Gusev O, Aras K, Gams A, Koppel A, Efimov IR. Genetic algorithm-based personalized models of human cardiac action potential. PLoS One 2020; 15:e0231695. [PMID: 32392258 PMCID: PMC7213718 DOI: 10.1371/journal.pone.0231695] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 03/31/2020] [Indexed: 11/21/2022] Open
Abstract
We present a novel modification of genetic algorithm (GA) which determines personalized parameters of cardiomyocyte electrophysiology model based on set of experimental human action potential (AP) recorded at different heart rates. In order to find the steady state solution, the optimized algorithm performs simultaneous search in the parametric and slow variables spaces. We demonstrate that several GA modifications are required for effective convergence. Firstly, we used Cauchy mutation along a random direction in the parametric space. Secondly, relatively large number of elite organisms (6-10% of the population passed on to new generation) was required for effective convergence. Test runs with synthetic AP as input data indicate that algorithm error is low for high amplitude ionic currents (1.6±1.6% for IKr, 3.2±3.5% for IK1, 3.9±3.5% for INa, 8.2±6.3% for ICaL). Experimental signal-to-noise ratio above 28 dB was required for high quality GA performance. GA was validated against optical mapping recordings of human ventricular AP and mRNA expression profile of donor hearts. In particular, GA output parameters were rescaled proportionally to mRNA levels ratio between patients. We have demonstrated that mRNA-based models predict the AP waveform dependence on heart rate with high precision. The latter also provides a novel technique of model personalization that makes it possible to map gene expression profile to cardiac function.
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Affiliation(s)
- Dmitrii Smirnov
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Andrey Pikunov
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Roman Syunyaev
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- The George Washington University, Washington, DC, United States of America
- Sechenov University, Moscow, Russia
| | | | | | - Kedar Aras
- The George Washington University, Washington, DC, United States of America
| | - Anna Gams
- The George Washington University, Washington, DC, United States of America
| | - Aaron Koppel
- The George Washington University, Washington, DC, United States of America
| | - Igor R. Efimov
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- The George Washington University, Washington, DC, United States of America
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12
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Handa BS, Li X, Aras KK, Qureshi NA, Mann I, Chowdhury RA, Whinnett ZI, Linton NW, Lim PB, Kanagaratnam P, Efimov IR, Peters NS, Ng FS. Granger Causality-Based Analysis for Classification of Fibrillation Mechanisms and Localization of Rotational Drivers. Circ Arrhythm Electrophysiol 2020; 13:e008237. [PMID: 32064900 PMCID: PMC7069398 DOI: 10.1161/circep.119.008237] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 02/04/2020] [Indexed: 11/16/2022]
Abstract
BACKGROUND The mechanisms sustaining myocardial fibrillation remain disputed, partly due to a lack of mapping tools that can accurately identify the mechanism with low spatial resolution clinical recordings. Granger causality (GC) analysis, an econometric tool for quantifying causal relationships between complex time-series, was developed as a novel fibrillation mapping tool and adapted to low spatial resolution sequentially acquired data. METHODS Ventricular fibrillation (VF) optical mapping was performed in Langendorff-perfused Sprague-Dawley rat hearts (n=18), where novel algorithms were developed using GC-based analysis to (1) quantify causal dependence of neighboring signals and plot GC vectors, (2) quantify global organization with the causality pairing index, a measure of neighboring causal signal pairs, and (3) localize rotational drivers (RDs) by quantifying the circular interdependence of neighboring signals with the circular interdependence value. GC-based mapping tools were optimized for low spatial resolution from downsampled optical mapping data, validated against high-resolution phase analysis and further tested in previous VF optical mapping recordings of coronary perfused donor heart left ventricular wedge preparations (n=12), and adapted for sequentially acquired intracardiac electrograms during human persistent atrial fibrillation mapping (n=16). RESULTS Global VF organization quantified by causality pairing index showed a negative correlation at progressively lower resolutions (50% resolution: P=0.006, R2=0.38, 12.5% resolution, P=0.004, R2=0.41) with a phase analysis derived measure of disorganization, locations occupied by phase singularities. In organized VF with high causality pairing index values, GC vector mapping characterized dominant propagating patterns and localized stable RDs, with the circular interdependence value showing a significant difference in driver versus nondriver regions (0.91±0.05 versus 0.35±0.06, P=0.0002). These findings were further confirmed in human VF. In persistent atrial fibrillation, a positive correlation was found between the causality pairing index and presence of stable RDs (P=0.0005,R2=0.56). Fifty percent of patients had RDs, with a low incidence of 0.9±0.3 RDs per patient. CONCLUSIONS GC-based fibrillation analysis can measure global fibrillation organization, characterize dominant propagating patterns, and map RDs using low spatial resolution sequentially acquired data.
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Affiliation(s)
- Balvinder S. Handa
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Xinyang Li
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Kedar K. Aras
- Department of Biomedical Engineering, George Washington University, Washington, DC (K.K.A., I.R.E.)
| | - Norman A. Qureshi
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Ian Mann
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Rasheda A. Chowdhury
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Zachary I. Whinnett
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Nick W.F. Linton
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Phang Boon Lim
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Prapa Kanagaratnam
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
| | - Igor R. Efimov
- Department of Biomedical Engineering, George Washington University, Washington, DC (K.K.A., I.R.E.)
| | - Nicholas S. Peters
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
- Department of Biomedical Engineering, George Washington University, Washington, DC (K.K.A., I.R.E.)
| | - Fu Siong Ng
- National Heart & Lung Institute, Imperial College London, United Kingdom (B.S.H., X.L., N.A.Q., I.M., R.A.C., Z.I.W., N.W.F.L., P.B.L., P.K., N.S.P., F.S.N.)
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13
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Swift LM, Jaimes R, McCullough D, Burke M, Reilly M, Maeda T, Zhang H, Ishibashi N, Rogers JM, Posnack NG. Optocardiography and Electrophysiology Studies of Ex Vivo Langendorff-perfused Hearts. J Vis Exp 2019. [PMID: 31762469 DOI: 10.3791/60472] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Small animal models are most commonly used in cardiovascular research due to the availability of genetically modified species and lower cost compared to larger animals. Yet, larger mammals are better suited for translational research questions related to normal cardiac physiology, pathophysiology, and preclinical testing of therapeutic agents. To overcome the technical barriers associated with employing a larger animal model in cardiac research, we describe an approach to measure physiological parameters in an isolated, Langendorff-perfused piglet heart. This approach combines two powerful experimental tools to evaluate the state of the heart: electrophysiology (EP) study and simultaneous optical mapping of transmembrane voltage and intracellular calcium using parameter sensitive dyes (RH237, Rhod2-AM). The described methodologies are well suited for translational studies investigating the cardiac conduction system, alterations in action potential morphology, calcium handling, excitation-contraction coupling and the incidence of cardiac alternans or arrhythmias.
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Affiliation(s)
- Luther M Swift
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Rafael Jaimes
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Damon McCullough
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Morgan Burke
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Marissa Reilly
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital
| | - Takuya Maeda
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital; Center for Neuroscience Research, Children's National Hospital
| | - Hanyu Zhang
- Department of Biomedical Engineering, School of Engineering, University of Alabama at Birmingham
| | - Nobuyuki Ishibashi
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital; Center for Neuroscience Research, Children's National Hospital
| | - Jack M Rogers
- Department of Biomedical Engineering, School of Engineering, University of Alabama at Birmingham
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital; Children's National Heart Institute, Children's National Hospital; Department of Pediatrics, Department of Pharmacology & Physiology, School of Medicine and Health Sciences, George Washington University;
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14
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Abstract
Optical mapping of electrical activity in the heart is based on voltage-sensitive and lipophilic fluorescence dyes. Optical signals recorded from cardiac cells correlate well with their transmembrane potentials. High spatiotemporal resolution, wide field mapping, and high sensitivity to transmembrane potential enable detailed characterization of action potential initiation and propagation. Optical mapping is used to study complex patterns of excitation propagation, including propagation across the sinoatrial and atrioventricular nodes and during atrial and ventricular arrhythmias.Optical mapping is used to study the role of reentrant activity in atrial and ventricular fibrillation.
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15
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Aron M, Herzog S, Parlitz U, Luther S, Lilienkamp T. Spontaneous termination of chaotic spiral wave dynamics in human cardiac ion channel models. PLoS One 2019; 14:e0221401. [PMID: 31461472 PMCID: PMC6713330 DOI: 10.1371/journal.pone.0221401] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 08/06/2019] [Indexed: 11/18/2022] Open
Abstract
Chaotic spiral or scroll wave dynamics can be found in diverse systems. In cardiac dynamics, spiral or scroll waves of electrical excitation determine the dynamics during life-threatening arrhythmias like ventricular fibrillation. In numerical studies it was found that chaotic episodes of spiral and scroll waves can be transient, thus they terminate spontaneously. We show in this study that this behavior can also be observed using models which describe the ion channel dynamics of human cardiomyocytes (Bueno-Orovio-Cherry-Fenton model and the Ten Tusscher-Noble-Noble-Panfilov model). For both models we find that the average lifetime of the chaotic transients grows exponentially with the system size. With this behavior, we classify the systems into the group of type-II supertransients. We observe a significant difference of the breakup behavior between the models, which results in a distinct dynamics during the final phase just before the termination. The observation of a (temporally) stable single-spiral state affects the prevailing description of the dynamics of type-II supertransients as being “quasi-stationary” and also the feasibility of predicting the spontaneous termination of the spiral wave dynamics. In the long term, the relation between the breakup behavior of spiral waves and properties of chaotic transients like predictability or average transient lifetime may contribute to an improved understanding and classification of cardiac arrhythmias.
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Affiliation(s)
- Marcel Aron
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- Institut für Dynamik komplexer Systeme, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Sebastian Herzog
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- Institut für Dynamik komplexer Systeme, Georg-August-Universität Göttingen, Göttingen, Germany
- Third Institute of Physics, Universität Göttingen, Friedrich-Hund Platz 1, Göttingen, Germany
- Bernstein Center for Computational Neuroscience, Friedrich-Hund Platz 1, Göttingen, Germany
| | - Ulrich Parlitz
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- Institut für Dynamik komplexer Systeme, Georg-August-Universität Göttingen, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Stefan Luther
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- Institut für Dynamik komplexer Systeme, Georg-August-Universität Göttingen, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
- Department of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen, Germany
| | - Thomas Lilienkamp
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
- Department of Cardiology and Pneumology, University Medical Center Göttingen, Göttingen, Germany
- * E-mail:
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