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Scacchi S, Pavarino LF, Mazzanti A, Trancuccio A, Priori SG, Colli Franzone P. Transmural APD heterogeneity determines ventricular arrhythmogenesis in LQT8 syndrome: Insights from Bidomain computational modeling. PLoS One 2024; 19:e0305248. [PMID: 38968219 PMCID: PMC11226139 DOI: 10.1371/journal.pone.0305248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 05/27/2024] [Indexed: 07/07/2024] Open
Abstract
Long QT Syndrome type 8 (LQT8) is a cardiac arrhythmic disorder associated with Timothy Syndrome, stemming from mutations in the CACNA1C gene, particularly the G406R mutation. While prior studies hint at CACNA1C mutations' role in ventricular arrhythmia genesis, the mechanisms, especially in G406R presence, are not fully understood. This computational study explores how the G406R mutation, causing increased transmural dispersion of repolarization, induces and sustains reentrant ventricular arrhythmias. Using three-dimensional numerical simulations on an idealized left-ventricular model, integrating the Bidomain equations with the ten Tusscher-Panfilov ionic model, we observe that G406R mutation with 11% and 50% heterozygosis significantly increases transmural dispersion of repolarization. During S1-S4 stimulation protocols, these gradients facilitate conduction blocks, triggering reentrant ventricular tachycardia. Sustained reentry pathways occur only with G406R mutation at 50% heterozygosis, while neglecting transmural heterogeneities of action potential duration prevents stable reentry, regardless of G406R mutation presence.
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Affiliation(s)
- Simone Scacchi
- Dipartimento di Matematica, Università degli Studi di Milano, Milano, Italy
| | - Luca F. Pavarino
- Dipartimento di Matematica, Università degli Studi di Pavia, Pavia, Italy
| | - Andrea Mazzanti
- Molecular Cardiology, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Molecular Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Pavia, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Alessandro Trancuccio
- Molecular Cardiology, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Molecular Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Pavia, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Silvia G. Priori
- Molecular Cardiology, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Molecular Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Pavia, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
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Horváth B, Kovács Z, Dienes C, Barta Z, Óvári J, Szentandrássy N, Magyar J, Bányász T, Nánási PP. Relationship between ion currents and membrane capacitance in canine ventricular myocytes. Sci Rep 2024; 14:11241. [PMID: 38755246 PMCID: PMC11099174 DOI: 10.1038/s41598-024-61736-6] [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: 02/21/2024] [Accepted: 05/09/2024] [Indexed: 05/18/2024] Open
Abstract
Current density, the membrane current value divided by membrane capacitance (Cm), is widely used in cellular electrophysiology. Comparing current densities obtained in different cell populations assume that Cm and ion current magnitudes are linearly related, however data is scarce about this in cardiomyocytes. Therefore, we statistically analyzed the distributions, and the relationship between parameters of canine cardiac ion currents and Cm, and tested if dividing original parameters with Cm had any effect. Under conventional voltage clamp conditions, correlations were high for IK1, moderate for IKr and ICa,L, while negligible for IKs. Correlation between Ito1 peak amplitude and Cm was negligible when analyzing all cells together, however, the analysis showed high correlations when cells of subepicardial, subendocardial or midmyocardial origin were analyzed separately. In action potential voltage clamp experiments IK1, IKr and ICa,L parameters showed high correlations with Cm. For INCX, INa,late and IKs there were low-to-moderate correlations between Cm and these current parameters. Dividing the original current parameters with Cm reduced both the coefficient of variation, and the deviation from normal distribution. The level of correlation between ion currents and Cm varies depending on the ion current studied. This must be considered when evaluating ion current densities in cardiac cells.
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Affiliation(s)
- Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
- Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary.
| | - Zsigmond Kovács
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Csaba Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zalán Barta
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - József Óvári
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Norbert Szentandrássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Department of Basic Medical Sciences, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Division of Sport Physiology, Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter P Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
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Tonko JB, Lambiase PD. The proarrhythmogenic role of autonomics and emerging neuromodulation approaches to prevent sudden death in cardiac ion channelopathies. Cardiovasc Res 2024; 120:114-131. [PMID: 38195920 PMCID: PMC10936753 DOI: 10.1093/cvr/cvae009] [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: 09/18/2023] [Revised: 11/06/2023] [Accepted: 11/30/2023] [Indexed: 01/11/2024] Open
Abstract
Ventricular arrhythmias in cardiac channelopathies are linked to autonomic triggers, which are sub-optimally targeted in current management strategies. Improved molecular understanding of cardiac channelopathies and cellular autonomic signalling could refine autonomic therapies to target the specific signalling pathways relevant to the specific aetiologies as well as the central nervous system centres involved in the cardiac autonomic regulation. This review summarizes key anatomical and physiological aspects of the cardiac autonomic nervous system and its impact on ventricular arrhythmias in primary inherited arrhythmia syndromes. Proarrhythmogenic autonomic effects and potential therapeutic targets in defined conditions including the Brugada syndrome, early repolarization syndrome, long QT syndrome, and catecholaminergic polymorphic ventricular tachycardia will be examined. Pharmacological and interventional neuromodulation options for these cardiac channelopathies are discussed. Promising new targets for cardiac neuromodulation include inhibitory and excitatory G-protein coupled receptors, neuropeptides, chemorepellents/attractants as well as the vagal and sympathetic nuclei in the central nervous system. Novel therapeutic strategies utilizing invasive and non-invasive deep brain/brain stem stimulation as well as the rapidly growing field of chemo-, opto-, or sonogenetics allowing cell-specific targeting to reduce ventricular arrhythmias are presented.
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Affiliation(s)
- Johanna B Tonko
- Institute of Cardiovascular Science, University College London, 5 University Street, London WC1E 6JF, London, UK
| | - Pier D Lambiase
- Institute of Cardiovascular Science, University College London, 5 University Street, London WC1E 6JF, London, UK
- Department for Cardiology, Bart’s Heart Centre, West Smithfield EC1A 7BE, London, UK
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Zhang Z, Brugada P, Weiss JN, Qu Z. Phase 2 Re-Entry Without I to: Role of Sodium Channel Kinetics in Brugada Syndrome Arrhythmias. JACC Clin Electrophysiol 2023; 9:2459-2474. [PMID: 37831035 DOI: 10.1016/j.jacep.2023.08.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/27/2023] [Accepted: 08/23/2023] [Indexed: 10/14/2023]
Abstract
BACKGROUND In Brugada syndrome (BrS), phase 2 re-excitation/re-entry (P2R) induced by the transient outward potassium current (Ito) is a proposed arrhythmia mechanism; yet, the most common genetic defects are loss-of-function sodium channel mutations. OBJECTIVES The authors used computer simulations to investigate how sodium channel dysfunction affects P2R-mediated arrhythmogenesis in the presence and absence of Ito. METHODS Computer simulations were carried out in 1-dimensional cables and 2-dimensional tissue using guinea pig and human ventricular action potential models. RESULTS In the presence of Ito sufficient to generate robust P2R, reducing sodium current (INa) peak amplitude alone only slightly potentiated P2R. When INa inactivation kinetics were also altered to simulate reported effects of BrS mutations and sodium channel blockers, however, P2R occurred even in the absence of Ito. These effects could be potentiated by delaying L-type calcium channel activation or increasing ATP-sensitive potassium current, consistent with experimental and clinical findings. INa-mediated P2R also accounted for sex-related, day and night-related, and fever-related differences in arrhythmia risk in BrS patients. CONCLUSIONS Altered INa kinetics synergize powerfully with reduced INa amplitude to promote P2R-induced arrhythmias in BrS in the absence of Ito, establishing a robust mechanistic link between altered INa kinetics and the P2R-mediated arrhythmia mechanism.
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Affiliation(s)
- Zhaoyang Zhang
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo, Zhejiang, China; Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Pedro Brugada
- Heart Rhythm Management Centre, Postgraduate Program in Cardiac Electrophysiology and Pacing, Universitair Ziekenhuis Brussel-Vrije Universiteit Brussel, European Reference Networks Guard-Heart, Brussels, Belgium
| | - James N Weiss
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Zhilin Qu
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA.
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Bukhari HA, Sánchez C, Laguna P, Potse M, Pueyo E. Differences in ventricular wall composition may explain inter-patient variability in the ECG response to variations in serum potassium and calcium. Front Physiol 2023; 14:1060919. [PMID: 37885805 PMCID: PMC10598848 DOI: 10.3389/fphys.2023.1060919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 09/18/2023] [Indexed: 10/28/2023] Open
Abstract
Objective: Chronic kidney disease patients have a decreased ability to maintain normal electrolyte concentrations in their blood, which increases the risk for ventricular arrhythmias and sudden cardiac death. Non-invasive monitoring of serum potassium and calcium concentration, [K+] and [Ca2+], can help to prevent arrhythmias in these patients. Electrocardiogram (ECG) markers that significantly correlate with [K+] and [Ca2+] have been proposed, but these relations are highly variable between patients. We hypothesized that inter-individual differences in cell type distribution across the ventricular wall can help to explain this variability. Methods: A population of human heart-torso models were built with different proportions of endocardial, midmyocardial and epicardial cells. Propagation of ventricular electrical activity was described by a reaction-diffusion model, with modified Ten Tusscher-Panfilov dynamics. [K+] and [Ca2+] were varied individually and in combination. Twelve-lead ECGs were simulated and the width, amplitude and morphological variability of T waves and QRS complexes were quantified. Results were compared to measurements from 29 end-stage renal disease (ESRD) patients undergoing hemodialysis (HD). Results: Both simulations and patients data showed that most of the analyzed T wave and QRS complex markers correlated strongly with [K+] (absolute median Pearson correlation coefficients, r, ranging from 0.68 to 0.98) and [Ca2+] (ranging from 0.70 to 0.98). The same sign and similar magnitude of median r was observed in the simulations and the patients. Different cell type distributions in the ventricular wall led to variability in ECG markers that was accentuated at high [K+] and low [Ca2+], in agreement with the larger variability between patients measured at the onset of HD. The simulated ECG variability explained part of the measured inter-patient variability. Conclusion: Changes in ECG markers were similarly related to [K+] and [Ca2+] variations in our models and in the ESRD patients. The high inter-patient ECG variability may be explained by variations in cell type distribution across the ventricular wall, with high sensitivity to variations in the proportion of epicardial cells. Significance: Differences in ventricular wall composition help to explain inter-patient variability in ECG response to [K+] and [Ca2+]. This finding can be used to improve serum electrolyte monitoring in ESRD patients.
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Affiliation(s)
- Hassaan A. Bukhari
- BSICoS Group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain
- CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
- Carmen Team, Inria Bordeaux—Sud-Ouest, Talence, France
- University of Bordeaux, IMB, UMR 5251, Talence, France
| | - Carlos Sánchez
- BSICoS Group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain
- CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
| | - Pablo Laguna
- BSICoS Group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain
- CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
| | - Mark Potse
- Carmen Team, Inria Bordeaux—Sud-Ouest, Talence, France
- University of Bordeaux, IMB, UMR 5251, Talence, France
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Bordeaux, France
| | - Esther Pueyo
- BSICoS Group, I3A Institute, University of Zaragoza, IIS Aragón, Zaragoza, Spain
- CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
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Abramochkin DV, Filatova TS, Pustovit KB, Voronina YA, Kuzmin VS, Vornanen M. Ionic currents underlying different patterns of electrical activity in working cardiac myocytes of mammals and non-mammalian vertebrates. Comp Biochem Physiol A Mol Integr Physiol 2022; 268:111204. [PMID: 35346823 DOI: 10.1016/j.cbpa.2022.111204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/21/2022] [Accepted: 03/22/2022] [Indexed: 12/19/2022]
Abstract
The orderly contraction of the vertebrate heart is determined by generation and propagation of cardiac action potentials (APs). APs are generated by the integrated activity of time- and voltage-dependent ionic channels which carry inward Na+ and Ca2+ currents, and outward K+ currents. This review compares atrial and ventricular APs and underlying ion currents between different taxa of vertebrates. We have collected literature data and attempted to find common electrophysiological features for two or more vertebrate groups, show differences between taxa and cardiac chambers, and indicate gaps in the existing data. Although electrical excitability of the heart in all vertebrates is based on the same superfamily of channels, there is a vast variability of AP waveforms between atrial and ventricular myocytes, between different species of the same vertebrate class and between endothermic and ectothermic animals. The wide variability of AP shapes is related to species-specific differences in animal size, heart rate, stage of ontogenetic development, excitation-contraction coupling, temperature and oxygen availability. Some of the differences between taxa are related to evolutionary development of genomes, which appear e.g. in the expression of different Na+ and K+ channel orthologues in cardiomyocytes of vertebrates. There is a wonderful variability of AP shapes and underlying ion currents with which electrical excitability of vertebrate heart can be generated depending on the intrinsic and extrinsic conditions of animal body. This multitude of ionic mechanisms provides excellent material for studying how the function of the vertebrate heart can adapt or acclimate to prevailing physiological and environmental conditions.
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Affiliation(s)
- Denis V Abramochkin
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia.
| | - Tatiana S Filatova
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia
| | - Ksenia B Pustovit
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia
| | - Yana A Voronina
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia; Laboratory of Cardiac Electrophysiology, National Medical Research Center for Cardiology, 3(rd) Cherepkovskaya str., 15A, Moscow, Russia
| | - Vladislav S Kuzmin
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia; Department of Physiology, Pirogov Russian National Research Medical University, Ostrovityanova str., 1, Moscow, Russia
| | - Matti Vornanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
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Horváth B, Szentandrássy N, Almássy J, Dienes C, Kovács ZM, Nánási PP, Banyasz T. Late Sodium Current of the Heart: Where Do We Stand and Where Are We Going? Pharmaceuticals (Basel) 2022; 15:ph15020231. [PMID: 35215342 PMCID: PMC8879921 DOI: 10.3390/ph15020231] [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: 01/13/2022] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 02/05/2023] Open
Abstract
Late sodium current has long been linked to dysrhythmia and contractile malfunction in the heart. Despite the increasing body of accumulating information on the subject, our understanding of its role in normal or pathologic states is not complete. Even though the role of late sodium current in shaping action potential under physiologic circumstances is debated, it’s unquestioned role in arrhythmogenesis keeps it in the focus of research. Transgenic mouse models and isoform-specific pharmacological tools have proved useful in understanding the mechanism of late sodium current in health and disease. This review will outline the mechanism and function of cardiac late sodium current with special focus on the recent advances of the area.
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Affiliation(s)
- Balázs Horváth
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Norbert Szentandrássy
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
- Department of Basic Medical Sciences, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
| | - János Almássy
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Csaba Dienes
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Zsigmond Máté Kovács
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Péter P. Nánási
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
- Department of Dental Physiology and Pharmacology, University of Debrecen, 4032 Debrecen, Hungary
| | - Tamas Banyasz
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
- Correspondence: ; Tel.: +36-(52)-255-575; Fax: +36-(52)-255-116
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Ng GA, Mistry A, Newton M, Schlindwein FS, Barr C, Bates MG, Caldwell J, Das M, Farooq M, Herring N, Lambiase P, Osman F, Sohal M, Staniforth A, Tayebjee M, Tomlinson D, Whinnett Z, Yue A, Nicolson WB. Rationale and study design of the MINERVA study: Multicentre Investigation of Novel Electrocardiogram Risk markers in Ventricular Arrhythmia prediction-UK multicentre collaboration. BMJ Open 2022; 12:e059527. [PMID: 34980634 PMCID: PMC8724816 DOI: 10.1136/bmjopen-2021-059527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 12/08/2021] [Indexed: 11/15/2022] Open
Abstract
INTRODUCTION The purpose of this study is to assess the ability of two new ECG markers (Regional Repolarisation Instability Index (R2I2) and Peak Electrical Restitution Slope) to predict sudden cardiac death (SCD) or ventricular arrhythmia (VA) events in patients with ischaemic cardiomyopathy undergoing implantation of an implantable cardioverter defibrillator for primary prevention indication. METHODS AND ANALYSIS Multicentre Investigation of Novel Electrocardiogram Risk markers in Ventricular Arrhythmia prediction is a prospective, open label, single blinded, multicentre observational study to establish the efficacy of two ECG biomarkers in predicting VA risk. 440 participants with ischaemic cardiomyopathy undergoing routine first time implantable cardioverter-defibrillator (ICD) implantation for primary prevention indication are currently being recruited. An electrophysiological (EP) study is performed using a non-invasive programmed electrical stimulation protocol via the implanted device. All participants will undergo the EP study hence no randomisation is required. Participants will be followed up over a minimum of 18 months and up to 3 years. The first patient was recruited in August 2016 and the study will be completed at the final participant follow-up visit. The primary endpoint is ventricular fibrillation or sustained ventricular tachycardia >200 beats/min as recorded by the ICD. The secondary endpoint is SCD. Analysis of the ECG data obtained during the EP study will be performed by the core lab where blinding of patient health status and endpoints will be maintained. ETHICS AND DISSEMINATION Ethical approval has been granted by Research Ethics Committees Northern Ireland (reference no. 16/NI/0069). The results will inform the design of a definitive Randomised Controlled Trial (RCT). Dissemination will include peer reviewed journal articles reporting the qualitative and quantitative results, as well as presentations at conferences and lay summaries. TRIAL REGISTRATION NUMBER NCT03022487.
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Affiliation(s)
- G Andre Ng
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre Cardiovascular Diseases, Leicester, UK
- Department of Cardiology, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Amar Mistry
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- Department of Cardiology, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Michelle Newton
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Fernando Soares Schlindwein
- NIHR Leicester Biomedical Research Centre Cardiovascular Diseases, Leicester, UK
- Department of Engineering, University of Leicester, Leicester, UK
| | - Craig Barr
- Cardiology, Dudley Group NHS Foundation Trust, Dudley, UK
| | | | - Jane Caldwell
- Cardiology, Castle Hill Hosptial, Hull and East Yorkshire NHS Trust, Hull, UK
| | - Moloy Das
- Cardiology, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
| | - Mohsin Farooq
- Cardiology, Kettering General Hospital, Kettering, UK
| | - Neil Herring
- Cardiology, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Pier Lambiase
- Cardiology, University College London Hospitals NHS Foundation Trust, London, UK
| | - Faizel Osman
- Cardiology, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK
| | - Manav Sohal
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Andrew Staniforth
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Muzahir Tayebjee
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - David Tomlinson
- Cardiology, University Hospitals Plymouth NHS Trust, Plymouth, UK
| | | | - Arthur Yue
- Cardiology, University Hospital Southampton, Southampton, UK
| | - Will B Nicolson
- NIHR Leicester Biomedical Research Centre Cardiovascular Diseases, Leicester, UK
- Department of Cardiology, University Hospitals of Leicester NHS Trust, Leicester, UK
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Howlett LA, Kirton HM, Al‐Owais MM, Steele D, Lancaster MK. Action potential responses to changes in stimulation frequency and isoproterenol in rat ventricular myocytes. Physiol Rep 2022; 10:e15166. [PMID: 35076184 PMCID: PMC8787729 DOI: 10.14814/phy2.15166] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/16/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023] Open
Abstract
PURPOSE Current understanding of ventricular action potential adaptation to physiological stress is generally based on protocols using non-physiological rates and conditions isolating rate effects from escalating adrenergic stimulation. To permit refined understanding, ventricular action potentials were assessed across physiological pacing frequencies in the presence and absence of adrenergic stimuli. Isolated and combined effects were analyzed to assess their ability to replicate in-vivo responses. METHODS Steady-state action potentials from ventricular myocytes isolated from male Wistar rats (3 months; N = 8 animals) were recorded at 37°C with steady-state pacing at 1, 2, 4, 6, 8 and 10 Hz using whole-cell patch-clamp. Action potential repolarization to 25, 50, 75, 90 and 100% of full repolarization (APD25-100 ) was compared before and after 5 nM, 100 nM and 1 µM isoproterenol doses. RESULTS A Repeated measures ANOVA found APD50-90 shortened with 5 nM isoproterenol infusion by 6-25% (but comparable across doses) (p ≤ 0.03). Pacing frequencies emulating a normal rat heart rate (6 Hz) prolonged APD50 23% compared with 1 Hz pacing. Frequencies emulating exercise or stress (10 Hz) shortened APD90 (29%). CONCLUSION These results demonstrate modest action potential shortening in response to adrenergic stimulation and elevations in pacing beyond physiological resting rates. Our findings indicate changes in action potential plateau and late repolarization predominantly underlie simulated exercise responses in the rat heart. This work provides novel action potential reference data and will help model cardiac responses to physiological stimuli in the rat heart via computational techniques.
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Affiliation(s)
| | | | | | - Derek Steele
- Faculty of Biological SciencesUniversity of LeedsLeedsUK
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10
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Canine Myocytes Represent a Good Model for Human Ventricular Cells Regarding Their Electrophysiological Properties. Pharmaceuticals (Basel) 2021; 14:ph14080748. [PMID: 34451845 PMCID: PMC8398821 DOI: 10.3390/ph14080748] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/18/2021] [Accepted: 07/20/2021] [Indexed: 12/19/2022] Open
Abstract
Due to the limited availability of healthy human ventricular tissues, the most suitable animal model has to be applied for electrophysiological and pharmacological studies. This can be best identified by studying the properties of ion currents shaping the action potential in the frequently used laboratory animals, such as dogs, rabbits, guinea pigs, or rats, and comparing them to those of human cardiomyocytes. The authors of this article with the experience of three decades of electrophysiological studies, performed in mammalian and human ventricular tissues and isolated cardiomyocytes, summarize their results obtained regarding the major canine and human cardiac ion currents. Accordingly, L-type Ca2+ current (ICa), late Na+ current (INa-late), rapid and slow components of the delayed rectifier K+ current (IKr and IKs, respectively), inward rectifier K+ current (IK1), transient outward K+ current (Ito1), and Na+/Ca2+ exchange current (INCX) were characterized and compared. Importantly, many of these measurements were performed using the action potential voltage clamp technique allowing for visualization of the actual current profiles flowing during the ventricular action potential. Densities and shapes of these ion currents, as well as the action potential configuration, were similar in human and canine ventricular cells, except for the density of IK1 and the recovery kinetics of Ito. IK1 displayed a largely four-fold larger density in canine than human myocytes, and Ito recovery from inactivation displayed a somewhat different time course in the two species. On the basis of these results, it is concluded that canine ventricular cells represent a reasonably good model for human myocytes for electrophysiological studies, however, it must be borne in mind that due to their stronger IK1, the repolarization reserve is more pronounced in canine cells, and moderate differences in the frequency-dependent repolarization patterns can also be anticipated.
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Odening KE, Gomez AM, Dobrev D, Fabritz L, Heinzel FR, Mangoni ME, Molina CE, Sacconi L, Smith G, Stengl M, Thomas D, Zaza A, Remme CA, Heijman J. ESC working group on cardiac cellular electrophysiology position paper: relevance, opportunities, and limitations of experimental models for cardiac electrophysiology research. Europace 2021; 23:1795-1814. [PMID: 34313298 DOI: 10.1093/europace/euab142] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/19/2021] [Indexed: 12/19/2022] Open
Abstract
Cardiac arrhythmias are a major cause of death and disability. A large number of experimental cell and animal models have been developed to study arrhythmogenic diseases. These models have provided important insights into the underlying arrhythmia mechanisms and translational options for their therapeutic management. This position paper from the ESC Working Group on Cardiac Cellular Electrophysiology provides an overview of (i) currently available in vitro, ex vivo, and in vivo electrophysiological research methodologies, (ii) the most commonly used experimental (cellular and animal) models for cardiac arrhythmias including relevant species differences, (iii) the use of human cardiac tissue, induced pluripotent stem cell (hiPSC)-derived and in silico models to study cardiac arrhythmias, and (iv) the availability, relevance, limitations, and opportunities of these cellular and animal models to recapitulate specific acquired and inherited arrhythmogenic diseases, including atrial fibrillation, heart failure, cardiomyopathy, myocarditis, sinus node, and conduction disorders and channelopathies. By promoting a better understanding of these models and their limitations, this position paper aims to improve the quality of basic research in cardiac electrophysiology, with the ultimate goal to facilitate the clinical translation and application of basic electrophysiological research findings on arrhythmia mechanisms and therapies.
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Affiliation(s)
- Katja E Odening
- Translational Cardiology, Department of Cardiology, Inselspital, Bern University Hospital, Bern, Switzerland.,Institute of Physiology, University of Bern, Bern, Switzerland
| | - Ana-Maria Gomez
- Signaling and cardiovascular pathophysiology-UMR-S 1180, Inserm, Université Paris-Saclay, 92296 Châtenay-Malabry, France
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany
| | - Larissa Fabritz
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK.,Department of Cardiology, University Hospital Birmingham NHS Trust, Birmingham, UK
| | - Frank R Heinzel
- Department of Internal Medicine and Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site, Berlin, Germany
| | - Matteo E Mangoni
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Cristina E Molina
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,German Centre for Cardiovascular Research (DZHK), Partner Site, Hamburg/Kiel/Lübeck, Germany
| | - Leonardo Sacconi
- National Institute of Optics and European Laboratory for Non Linear Spectroscopy, Italy.,Institute for Experimental Cardiovascular Medicine, University Freiburg, Germany
| | - Godfrey Smith
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, UK
| | - Milan Stengl
- Department of Physiology, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic
| | - Dierk Thomas
- Department of Cardiology, University Hospital Heidelberg, Heidelberg, Germany; Heidelberg Center for Heart Rhythm Disorders (HCR), University Hospital Heidelberg, Heidelberg, Germany.,German Centre for Cardiovascular Research (DZHK), Partner Site, Heidelberg/Mannheim, Germany
| | - Antonio Zaza
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milano, Italy
| | - Carol Ann Remme
- Department of Experimental Cardiology, Amsterdam UMC, location AMC, Amsterdam, The Netherlands
| | - Jordi Heijman
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands
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13
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Varró A, Tomek J, Nagy N, Virág L, Passini E, Rodriguez B, Baczkó I. Cardiac transmembrane ion channels and action potentials: cellular physiology and arrhythmogenic behavior. Physiol Rev 2020; 101:1083-1176. [PMID: 33118864 DOI: 10.1152/physrev.00024.2019] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cardiac arrhythmias are among the leading causes of mortality. They often arise from alterations in the electrophysiological properties of cardiac cells and their underlying ionic mechanisms. It is therefore critical to further unravel the pathophysiology of the ionic basis of human cardiac electrophysiology in health and disease. In the first part of this review, current knowledge on the differences in ion channel expression and properties of the ionic processes that determine the morphology and properties of cardiac action potentials and calcium dynamics from cardiomyocytes in different regions of the heart are described. Then the cellular mechanisms promoting arrhythmias in congenital or acquired conditions of ion channel function (electrical remodeling) are discussed. The focus is on human-relevant findings obtained with clinical, experimental, and computational studies, given that interspecies differences make the extrapolation from animal experiments to human clinical settings difficult. Deepening the understanding of the diverse pathophysiology of human cellular electrophysiology will help in developing novel and effective antiarrhythmic strategies for specific subpopulations and disease conditions.
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Affiliation(s)
- András Varró
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary.,MTA-SZTE Cardiovascular Pharmacology Research Group, Hungarian Academy of Sciences, Szeged, Hungary
| | - Jakub Tomek
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Norbert Nagy
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary.,MTA-SZTE Cardiovascular Pharmacology Research Group, Hungarian Academy of Sciences, Szeged, Hungary
| | - László Virág
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Elisa Passini
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Blanca Rodriguez
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - István Baczkó
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
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14
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Arteyeva NV. Dispersion of ventricular repolarization: Temporal and spatial. World J Cardiol 2020; 12:437-449. [PMID: 33014291 PMCID: PMC7509993 DOI: 10.4330/wjc.v12.i9.437] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/11/2020] [Accepted: 08/25/2020] [Indexed: 02/06/2023] Open
Abstract
Repolarization heterogeneity (RH) is an intrinsic property of ventricular myocardium and the reason for T-wave formation on electrocardiogram (ECG). Exceeding the physiologically based RH level is associated with appearance of life-threatening ventricular arrhythmias and sudden cardiac death. In this regard, an accurate and comprehensive evaluation of the degree of RH parameters is of importance for assessment of heart state and arrhythmic risk. This review is devoted to comprehensive consideration of RH phenomena in terms of electrophysiological processes underlying RH, cardiac electric field formation during ventricular repolarization, as well as clinical significance of RH and its reflection on ECG parameters. The formation of transmural, apicobasal, left-to-right and anterior-posterior gradients of action potential durations and end of repolarization times resulting from the heterogenous distribution of repolarizing ion currents and action potential morphology throughout the heart ventricles, and the different sensitivity of myocardial cells in different ventricular regions to the action of pharmacological agents, temperature, frequency of stimulation, etc., are being discussed. The review is focused on the fact that RH has different aspects – temporal and spatial, global and local; ECG reflection of various RH aspects and their clinical significance are being discussed. Strategies for comprehensive assessment of ventricular RH using different ECG indices reflecting various RH aspects are presented.
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Affiliation(s)
- Natalia V Arteyeva
- Laboratory of Cardiac Physiology, Institute of Physiology of Komi Science Centre of the Ural Branch of the Russian Academy of Sciences, Syktyvkar 167982, Russia
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15
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Bragard JR, Camara O, Echebarria B, Gerardo Giorda L, Pueyo E, Saiz J, Sebastián R, Soudah E, Vázquez M. Cardiac computational modelling. ACTA ACUST UNITED AC 2020; 74:65-71. [PMID: 32807708 DOI: 10.1016/j.rec.2020.05.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 05/25/2020] [Indexed: 12/26/2022]
Abstract
Cardiovascular diseases currently have a major social and economic impact, constituting one of the leading causes of mortality and morbidity. Personalized computational models of the heart are demonstrating their usefulness both to help understand the mechanisms underlying cardiac disease, and to optimize their treatment and predict the patient's response. Within this framework, the Spanish Research Network for Cardiac Computational Modelling (VHeart-SN) has been launched. The general objective of the VHeart-SN network is the development of an integrated, modular and multiscale multiphysical computational model of the heart. This general objective is addressed through the following specific objectives: a) to integrate the different numerical methods and models taking into account the specificity of patients; b) to assist in advancing knowledge of the mechanisms associated with cardiac and vascular diseases; and c) to support the application of different personalized therapies. This article presents the current state of cardiac computational modelling and different scientific works conducted by the members of the network to gain greater understanding of the characteristics and usefulness of these models.
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Affiliation(s)
- Jean R Bragard
- Grupo de Biofísica (BIOFIS), Departamento de Física y Matemática Aplicada, Universidad de Navarra, Pamplona, Navarra, Spain
| | - Oscar Camara
- Sensing in Physiology and Biomedicine (PhySense), Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
| | - Blas Echebarria
- Grupo de Biología Computacional y Sistemas Complejos (BIOCOM-SC), Universitat Politècnica de Catalunya, Barcelona, Spain
| | | | - Esther Pueyo
- Biomedical Signal Interpretation and Computational Simulation (BSICoS), Universidad de Zaragoza, CIBER-BBN, Zaragoza, Spain
| | - Javier Saiz
- Centro de Investigación e Innovación en Bioingeniería (Ci2B), Universitat Politècnica de València, Valencia, Spain.
| | - Rafael Sebastián
- Computational Multiscale Simulation Lab (CoMMLab), Universitat de València, Burjassot, Valencia, Spain
| | - Eduardo Soudah
- International Centre for Numerical Methods in Engineering (CIMNE), Universitat Politècnica de Catalunya, Barcelona, Spain
| | - Mariano Vázquez
- Barcelona Supercomputing Center & ELEM Biotech, Barcelona, Spain
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Abstract
The main inherited cardiac arrhythmias are long QT syndrome, short QT syndrome, catecholaminergic polymorphic ventricular tachycardia and Brugada syndrome. These rare diseases are often the underlying cause of sudden cardiac death in young individuals and result from mutations in several genes encoding ion channels or proteins involved in their regulation. The genetic defects lead to alterations in the ionic currents that determine the morphology and duration of the cardiac action potential, and individuals with these disorders often present with syncope or a life-threatening arrhythmic episode. The diagnosis is based on clinical presentation and history, the characteristics of the electrocardiographic recording at rest and during exercise and genetic analyses. Management relies on pharmacological therapy, mostly β-adrenergic receptor blockers (specifically, propranolol and nadolol) and sodium and transient outward current blockers (such as quinidine), or surgical interventions, including left cardiac sympathetic denervation and implantation of a cardioverter-defibrillator. All these arrhythmias are potentially life-threatening and have substantial negative effects on the quality of life of patients. Future research should focus on the identification of genes associated with the diseases and other risk factors, improved risk stratification and, in particular for Brugada syndrome, effective therapies.
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17
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Benson AP, Stevenson-Cocks HJ, Whittaker DG, White E, Colman MA. Multi-scale approaches for the simulation of cardiac electrophysiology: II - Tissue-level structure and function. Methods 2020; 185:60-81. [PMID: 31988002 DOI: 10.1016/j.ymeth.2020.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 11/15/2019] [Accepted: 01/14/2020] [Indexed: 02/06/2023] Open
Abstract
Computational models of the heart, from cell-level models, through one-, two- and three-dimensional tissue-level simplifications, to biophysically-detailed three-dimensional models of the ventricles, atria or whole heart, allow the simulation of excitation and propagation of this excitation, and have provided remarkable insight into the normal and pathological functioning of the heart. In this article we present equations for modelling cellular excitation (i.e. the cell action potential) from both a phenomenological and a biophysical perspective. Hodgkin-Huxley formalism is discussed, along with the current generation of biophysically-detailed cardiac cell models. Alternative Markovian formulations for modelling ionic currents are also presented. Equations describing propagation of this cellular excitation, through one-, two- and three-dimensional idealised or realistic tissues, are then presented. For all types of model, from cell to tissue, methods for discretisation and integration of the underlying equations are discussed. The article finishes with a discussion of two tissue-level experimental imaging techniques - diffusion tensor magnetic resonance imaging and optical imaging - that can be used to provide data for parameterisation and validation of cell- and tissue-level cardiac models.
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Affiliation(s)
- Alan P Benson
- School of Biomedical Sciences University of Leeds, Leeds LS2 9JT, UK.
| | | | - Dominic G Whittaker
- School of Biomedical Sciences University of Leeds, Leeds LS2 9JT, UK; School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Ed White
- School of Biomedical Sciences University of Leeds, Leeds LS2 9JT, UK
| | - Michael A Colman
- School of Biomedical Sciences University of Leeds, Leeds LS2 9JT, UK
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18
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Sattler SM, Skibsbye L, Linz D, Lubberding AF, Tfelt-Hansen J, Jespersen T. Ventricular Arrhythmias in First Acute Myocardial Infarction: Epidemiology, Mechanisms, and Interventions in Large Animal Models. Front Cardiovasc Med 2019; 6:158. [PMID: 31750317 PMCID: PMC6848060 DOI: 10.3389/fcvm.2019.00158] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 10/18/2019] [Indexed: 12/22/2022] Open
Abstract
Ventricular arrhythmia and subsequent sudden cardiac death (SCD) due to acute myocardial infarction (AMI) is one of the most frequent causes of death in humans. Lethal ventricular arrhythmias like ventricular fibrillation (VF) prior to hospitalization have been reported to occur in more than 10% of all AMI cases and survival in these patients is poor. Identification of risk factors and mechanisms for VF following AMI as well as implementing new risk stratification models and therapeutic approaches is therefore an important step to reduce mortality in people with high cardiovascular risk. Studying spontaneous VF following AMI in humans is challenging as it often occurs unexpectedly in a low risk subgroup. Large animal models of AMI can help to bridge this knowledge gap and are utilized to investigate occurrence of arrhythmias, involved mechanisms and therapeutic options. Comparable anatomy and physiology allow for this translational approach. Through experimental focus, using state-of-the-art technologies, including refined electrical mapping equipment and novel pharmacological investigations, valuable insights into arrhythmia mechanisms and possible interventions for arrhythmia-induced SCD during the early phase of AMI are now beginning to emerge. This review describes large experimental animal models of AMI with focus on first AMI-associated ventricular arrhythmias. In this context, epidemiology of first AMI, arrhythmogenic mechanisms and various potential therapeutic pharmacological targets will be discussed.
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Affiliation(s)
- Stefan Michael Sattler
- Department of Cardiology, Heart Centre, Copenhagen University Hospital, Copenhagen, Denmark.,Medical Department I, University Hospital Grosshadern, LMU Munich, Munich, Germany
| | - Lasse Skibsbye
- Department of Exploratory Toxicology, H. Lundbeck A/S, Copenhagen, Denmark
| | - Dominik Linz
- Medical Department III, Universitätsklinikum des Saarlandes, Homburg, Germany.,Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, Royal Adelaide Hospital, University of Adelaide, Adelaide, SA, Australia
| | - Anniek Frederike Lubberding
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jacob Tfelt-Hansen
- Department of Cardiology, Heart Centre, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Forensic Medicine, Faculty of Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Jespersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Johnson EK, Springer SJ, Wang W, Dranoff EJ, Zhang Y, Kanter EM, Yamada KA, Nerbonne JM. Differential Expression and Remodeling of Transient Outward Potassium Currents in Human Left Ventricles. Circ Arrhythm Electrophysiol 2019; 11:e005914. [PMID: 29311162 DOI: 10.1161/circep.117.005914] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 11/30/2017] [Indexed: 11/16/2022]
Abstract
BACKGROUND Myocardial, transient, outward currents, Ito, have been shown to play pivotal roles in action potential (AP) repolarization and remodeling in animal models. The properties and contribution of Ito to left ventricular (LV) repolarization in the human heart, however, are poorly defined. METHODS AND RESULTS Whole-cell, voltage-clamp recordings, acquired at physiological (35°C to 37°C) temperatures, from myocytes isolated from the LV of nonfailing human hearts identified 2 distinct transient currents, Ito,fast (Ito,f) and Ito,slow (Ito,s), with significantly (P<0.0001) different rates of recovery from inactivation and pharmacological sensitives: Ito,f recovers in ≈10 ms, 100× faster than Ito,s, and is selectively blocked by the Kv4 channel toxin, SNX-482. Current-clamp experiments revealed regional differences in AP waveforms, notably a phase 1 notch in LV subepicardial myocytes. Dynamic clamp-mediated addition/removal of modeled human ventricular Ito,f, resulted in hyperpolarization or depolarization, respectively, of the notch potential, whereas slowing the rate of Ito,f inactivation resulted in AP collapse. AP-clamp experiments demonstrated that changes in notch potentials modified the time course and amplitudes of voltage-gated Ca2+ currents, ICa. In failing LV subepicardial myocytes, Ito,f was reduced and Ito,s was increased, notch and plateau potentials were depolarized (P<0.0001) and AP durations were prolonged (P<0.001). CONCLUSIONS Ito,f and Ito,s are differentially expressed in nonfailing human LV, contributing to regional heterogeneities in AP waveforms. Ito,f regulates notch and plateau potentials and modulates the time course and amplitude of ICa. Slowing Ito,f inactivation results in dramatic AP shortening. Remodeling of Ito,f in failing human LV subepicardial myocytes attenuates transmural differences in AP waveforms.
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Affiliation(s)
- Eric K Johnson
- From the Cardiovascular Division, Department of Medicine (E.K.J., S.J.S., W.W., E.J.D., Y.Z., E.M.K., K.A.Y., J.M.N.) and Department of Developmental Biology (J.M.N.), Washington University School of Medicine, St. Louis, MO
| | - Steven J Springer
- From the Cardiovascular Division, Department of Medicine (E.K.J., S.J.S., W.W., E.J.D., Y.Z., E.M.K., K.A.Y., J.M.N.) and Department of Developmental Biology (J.M.N.), Washington University School of Medicine, St. Louis, MO
| | - Wei Wang
- From the Cardiovascular Division, Department of Medicine (E.K.J., S.J.S., W.W., E.J.D., Y.Z., E.M.K., K.A.Y., J.M.N.) and Department of Developmental Biology (J.M.N.), Washington University School of Medicine, St. Louis, MO
| | - Edward J Dranoff
- From the Cardiovascular Division, Department of Medicine (E.K.J., S.J.S., W.W., E.J.D., Y.Z., E.M.K., K.A.Y., J.M.N.) and Department of Developmental Biology (J.M.N.), Washington University School of Medicine, St. Louis, MO
| | - Yan Zhang
- From the Cardiovascular Division, Department of Medicine (E.K.J., S.J.S., W.W., E.J.D., Y.Z., E.M.K., K.A.Y., J.M.N.) and Department of Developmental Biology (J.M.N.), Washington University School of Medicine, St. Louis, MO
| | - Evelyn M Kanter
- From the Cardiovascular Division, Department of Medicine (E.K.J., S.J.S., W.W., E.J.D., Y.Z., E.M.K., K.A.Y., J.M.N.) and Department of Developmental Biology (J.M.N.), Washington University School of Medicine, St. Louis, MO
| | - Kathryn A Yamada
- From the Cardiovascular Division, Department of Medicine (E.K.J., S.J.S., W.W., E.J.D., Y.Z., E.M.K., K.A.Y., J.M.N.) and Department of Developmental Biology (J.M.N.), Washington University School of Medicine, St. Louis, MO
| | - Jeanne M Nerbonne
- From the Cardiovascular Division, Department of Medicine (E.K.J., S.J.S., W.W., E.J.D., Y.Z., E.M.K., K.A.Y., J.M.N.) and Department of Developmental Biology (J.M.N.), Washington University School of Medicine, St. Louis, MO.
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20
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Pianca N, Di Bona A, Lazzeri E, Costantini I, Franzoso M, Prando V, Armani A, Rizzo S, Fedrigo M, Angelini A, Basso C, Pavone FS, Rubart M, Sacconi L, Zaglia T, Mongillo M. Cardiac sympathetic innervation network shapes the myocardium by locally controlling cardiomyocyte size through the cellular proteolytic machinery. J Physiol 2019; 597:3639-3656. [DOI: 10.1113/jp276200] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/21/2019] [Indexed: 01/07/2023] Open
Affiliation(s)
- Nicola Pianca
- Veneto Institute of Molecular Medicine Padova Italy
- Department of Biomedical SciencesUniversity of Padova Padova Italy
| | - Anna Di Bona
- Veneto Institute of Molecular Medicine Padova Italy
- Department of Cardiac, Thoracic, Vascular Sciences and Public HealthUniversity of Padova Padova Italy
| | - Erica Lazzeri
- European Laboratory for Non‐linear SpectroscopyUniversity of Florence Florence Italy
| | - Irene Costantini
- European Laboratory for Non‐linear SpectroscopyUniversity of Florence Florence Italy
- National Institute of Optics, National Research CouncilUniversity of Florence Florence Italy
| | - Mauro Franzoso
- Veneto Institute of Molecular Medicine Padova Italy
- Department of Biomedical SciencesUniversity of Padova Padova Italy
| | - Valentina Prando
- Veneto Institute of Molecular Medicine Padova Italy
- Department of Cardiac, Thoracic, Vascular Sciences and Public HealthUniversity of Padova Padova Italy
| | - Andrea Armani
- Veneto Institute of Molecular Medicine Padova Italy
- Department of Biomedical SciencesUniversity of Padova Padova Italy
| | - Stefania Rizzo
- Department of Cardiac, Thoracic, Vascular Sciences and Public HealthUniversity of Padova Padova Italy
| | - Marny Fedrigo
- Department of Cardiac, Thoracic, Vascular Sciences and Public HealthUniversity of Padova Padova Italy
| | - Annalisa Angelini
- Department of Cardiac, Thoracic, Vascular Sciences and Public HealthUniversity of Padova Padova Italy
| | - Cristina Basso
- Department of Cardiac, Thoracic, Vascular Sciences and Public HealthUniversity of Padova Padova Italy
| | - Francesco S. Pavone
- European Laboratory for Non‐linear SpectroscopyUniversity of Florence Florence Italy
- National Institute of Optics, National Research CouncilUniversity of Florence Florence Italy
- Department of Physics and AstronomyUniversity of Florence Florence Italy
| | - Michael Rubart
- Indiana University School of Medicine Indianapolis IN USA
| | - Leonardo Sacconi
- European Laboratory for Non‐linear SpectroscopyUniversity of Florence Florence Italy
- National Institute of Optics, National Research CouncilUniversity of Florence Florence Italy
| | - Tania Zaglia
- Veneto Institute of Molecular Medicine Padova Italy
- Department of Biomedical SciencesUniversity of Padova Padova Italy
- Department of Cardiac, Thoracic, Vascular Sciences and Public HealthUniversity of Padova Padova Italy
| | - Marco Mongillo
- Veneto Institute of Molecular Medicine Padova Italy
- Department of Biomedical SciencesUniversity of Padova Padova Italy
- CNR Institute of Neuroscience Padova Italy
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21
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Tyan L, Foell JD, Vincent KP, Woon MT, Mesquitta WT, Lang D, Best JM, Ackerman MJ, McCulloch AD, Glukhov AV, Balijepalli RC, Kamp TJ. Long QT syndrome caveolin-3 mutations differentially modulate K v 4 and Ca v 1.2 channels to contribute to action potential prolongation. J Physiol 2019; 597:1531-1551. [PMID: 30588629 DOI: 10.1113/jp276014] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 12/14/2018] [Indexed: 01/09/2023] Open
Abstract
KEY POINTS Mutations in the caveolae scaffolding protein, caveolin-3 (Cav3), have been linked to the long QT type 9 inherited arrhythmia syndrome (LQT9) and the cause of underlying action potential duration prolongation is incompletely understood. In the present study, we show that LQT9 Cav3 mutations, F97C and S141R, cause mutation-specific gain of function effects on Cav 1.2-encoded L-type Ca2+ channels responsible for ICa,L and also cause loss of function effects on heterologously expressed Kv 4.2 and Kv 4.3 channels responsible for Ito . A computational model of the human ventricular myocyte action potential suggests that the major ionic current change causing action potential duration prolongation in the presence of Cav3-F97C is the slowly inactivating ICa,L but, for Cav3-S141R, both increased ICa,L and increased late Na+ current contribute equally to action potential duration prolongation. Overall, the LQT9 Cav3-F97C and Cav3-S141R mutations differentially impact multiple ionic currents, highlighting the complexity of Cav3 regulation of cardiac excitability and suggesting mutation-specific therapeutic approaches. ABSTRACT Mutations in the CAV3 gene encoding caveolin-3 (Cav3), a scaffolding protein integral to caveolae in cardiomyocytes, have been associated with the congenital long-QT syndrome (LQT9). Initial studies demonstrated that LQT9-associated Cav3 mutations, F97C and S141R, increase late sodium current as a potential mechanism to prolong action potential duration (APD) and cause LQT9. Whether these Cav3 LQT9 mutations impact other caveolae related ion channels remains unknown. We used the whole-cell, patch clamp technique to characterize the effect of Cav3-F97C and Cav3-S141R mutations on heterologously expressed Cav 1.2+Cav β2cN4 channels, as well as Kv 4.2 and Kv 4.3 channels, in HEK 293 cells. Expression of Cav3-S141R increased ICa,L density without changes in gating properties, whereas expression of Cav3-F97C reduced Ca2+ -dependent inactivation of ICa,L without changing current density. The Cav3-F97C mutation reduced current density and altered the kinetics of IKv4.2 and IKv4.3 and also slowed recovery from inactivation. Cav3-S141R decreased current density and also slowed activation kinetics and recovery from inactivation of IKv4.2 but had no effect on IKv4.3 . Using the O'Hara-Rudy computational model of the human ventricular myocyte action potential, the Cav3 mutation-induced changes in Ito are predicted to have negligible effect on APD, whereas blunted Ca2+ -dependent inactivation of ICa,L by Cav3-F97C is predicted to be primarily responsible for APD prolongation, although increased ICa,L and late INa by Cav3-S141R contribute equally to APD prolongation. Thus, LQT9 Cav3-associated mutations, F97C and S141R, produce mutation-specific changes in multiple ionic currents leading to different primary causes of APD prolongation, which suggests the use of mutation-specific therapeutic approaches in the future.
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Affiliation(s)
- Leonid Tyan
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Jason D Foell
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Kevin P Vincent
- Department of Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Marites T Woon
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Walatta T Mesquitta
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Di Lang
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Jabe M Best
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Michael J Ackerman
- Departments of Cardiovascular Medicine, Pediatric and Adolescent Medicine and Molecular Pharmacology & Experimental Therapeutics, Divisions of Heart Rhythm Services and Pediatric Cardiology, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Andrew D McCulloch
- Department of Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, USA.,Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, USA
| | - Alexey V Glukhov
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Ravi C Balijepalli
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
| | - Timothy J Kamp
- Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, 1111, Highland Ave, Madison, WI, USA
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22
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Yang JF, Cheng N, Ren S, Liu XM, Li XT. Characterization and molecular basis for the block of Kv1.3 channels induced by carvedilol in HEK293 cells. Eur J Pharmacol 2018; 834:206-212. [PMID: 30016664 DOI: 10.1016/j.ejphar.2018.07.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/04/2018] [Accepted: 07/13/2018] [Indexed: 10/28/2022]
Abstract
Carvedilol is a non-selective β-adrenoreceptor antagonist and exhibits a wide range of biological activities. The voltage-gated K+ (Kv) channel is one of the target ion channels of this compound. The rapidly activating Kv1.3 channel is expressed in several different tissues and plays an important role in the regulation of physiological functions, including cell proliferation and apoptosis. However, little is known about the possible action of carvedilol on Kv1.3 currents. Using the whole-cell configuration of the patch-clamp technique, we have revealed that exposure to carvedilol produced a concentration-dependent blocking of Kv1.3 channels heterologously expressed in HEK293 cells, with an IC50 value of 9.7 μM. This chemical decelerated the deactivation tail current of Kv1.3 currents, resulting in a tail crossover phenomenon. In addition, carvedilol generated a markedly hyperpolarizing shift (20 mV) of the inactivation curve, but failed to affect the activation curve. Mutagenesis experiments of Kv1.3 channels identified G427 and H451, two related sites of TEA block, as important residues for carvedilol-mediated blocking. The present results suggest that carvedilol acts directly on Kv1.3 currents by inducing closed- and open-channel block and helps to elucidate the mechanisms of action of this compound on Kv channels.
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Affiliation(s)
- Jin-Feng Yang
- College of Life Science, South-Central University for Nationalities, Wuhan 430074, China
| | - Neng Cheng
- College of Life Science, South-Central University for Nationalities, Wuhan 430074, China
| | - Sheng Ren
- College of Life Science, South-Central University for Nationalities, Wuhan 430074, China
| | - Xiang-Ming Liu
- GongQing Institute of Science and Technology, Gongqing City 332020, China
| | - Xian-Tao Li
- College of Life Science, South-Central University for Nationalities, Wuhan 430074, China.
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23
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de Boer TP, Stengl M. Action potential contour and inter-species differences. Europace 2018; 20:1395-1396. [PMID: 29096032 DOI: 10.1093/europace/eux308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Teun P de Boer
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht, Yalelaan 50, CM Utrecht, The Netherlands
| | - Milan Stengl
- Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Alej Svobody 76, Pilsen, Czech Republic.,Department of Physiology, Faculty of Medicine in Pilsen, Charles University, Alej Svobody 76, Pilsen, Czech Republic
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24
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Ng GA, Mistry A, Li X, Schlindwein FS, Nicolson WB. LifeMap: towards the development of a new technology in sudden cardiac death risk stratification for clinical use. Europace 2018; 20:f162-f170. [PMID: 29684162 DOI: 10.1093/europace/euy080] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 03/21/2018] [Indexed: 12/20/2022] Open
Abstract
Sudden cardiac death (SCD) is a major cause of mortality presenting a significant unmet clinical need. Patients at risk of SCD are implanted with implantable cardioverter-defibrillators (ICDs) according to international guidelines based on clinical trial evidence. Implantable cardioverter-defibrillators are not inexpensive and not without problem in terms of inappropriate shocks and infection risk. Also, only a minority of patients implanted with the ICD ever use the device during its battery lifetime highlighting the fact that methods used for SCD risk stratification are inadequate. Better ways of predicting who is at risk of SCD are needed. In addition, there is no effective prevention due to the lack of understanding of the electrical mechanisms underlying SCD. Our group has been investigating the electrophysiological basis of ventricular fibrillation and have successfully applied our preclinical findings to translational studies in patients with ischaemic cardiomyopathy. We have developed two ECG markers which have been shown to be strong predictors of ventricular arrhythmias and SCD. Ongoing clinical studies are being carried out including a multicentre UK study to consolidate the evidence base. They are being incorporated into the technology, LifeMap, with the aim to develop a successful clinical tool for the assessment of SCD risk. We hereby present the scientific data leading to the technology and the development to date. The information provided here was presented at the European Heart Rhythm Association (EHRA) Europace/Cardiostim conference at which LifeMap won the EHRA Inventors Award 2016.
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Affiliation(s)
- Ghulam André Ng
- Cardiology Group, Department of Cardiovascular Sciences, University of Leicester, Leicester LE39QP, UK.,NIHR Leicester Biomedical Research Centre, Leicester, UK.,Department of Cardiology, Glenfield Hospital, Leicester, UK
| | - Amar Mistry
- Cardiology Group, Department of Cardiovascular Sciences, University of Leicester, Leicester LE39QP, UK.,Department of Cardiology, Glenfield Hospital, Leicester, UK
| | - Xin Li
- Cardiology Group, Department of Cardiovascular Sciences, University of Leicester, Leicester LE39QP, UK.,Department of Engineering, University of Leicester, UK
| | - Fernando S Schlindwein
- NIHR Leicester Biomedical Research Centre, Leicester, UK.,Department of Engineering, University of Leicester, UK
| | - William B Nicolson
- Cardiology Group, Department of Cardiovascular Sciences, University of Leicester, Leicester LE39QP, UK.,NIHR Leicester Biomedical Research Centre, Leicester, UK.,Department of Cardiology, Glenfield Hospital, Leicester, UK
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25
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Mačianskienė R, Martišienė I, Navalinskas A, Treinys R, Andriulė I, Jurevičius J. Mechanism of Action Potential Prolongation During Metabolic Inhibition in the Whole Rabbit Heart. Front Physiol 2018; 9:1077. [PMID: 30140239 PMCID: PMC6095129 DOI: 10.3389/fphys.2018.01077] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 07/19/2018] [Indexed: 11/24/2022] Open
Abstract
Myocardial ischemia is associated with significant changes in action potential (AP) duration, which has a biphasic response to metabolic inhibition. Here, we investigated the mechanism of initial AP prolongation in whole Langendorff-perfused rabbit heart. We used glass microelectrodes to record APs transmurally. Simultaneously, optical AP, calcium transient (CaT), intracellular pH, and magnesium concentration changes were recorded using fluorescent dyes. The fluorescence signals were recorded using an EMCCD camera equipped with emission filters; excitation was induced by LEDs. We demonstrated that metabolic inhibition by carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP) resulted in AP shortening preceded by an initial prolongation and that there were no important differences in the response throughout the wall of the heart and in the apical/basal direction. AP prolongation was reduced by blocking the ICaL and transient outward potassium current (Ito) with diltiazem (DTZ) and 4-aminopyridine (4-AP), respectively. FCCP, an uncoupler of oxidative phosphorylation, induced reductions in CaTs and intracellular pH and increased the intracellular Mg2+ concentration. In addition, resting potential depolarization was observed, clearly indicating a decrease in the inward rectifier K+ current (IK1) that can retard AP repolarization. Thus, we suggest that the main currents responsible for AP prolongation during metabolic inhibition are the ICaL, Ito, and IK1, the activities of which are modulated mainly by changes in intracellular ATP, calcium, magnesium, and pH.
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Affiliation(s)
- Regina Mačianskienė
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Irma Martišienė
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Antanas Navalinskas
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Rimantas Treinys
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Inga Andriulė
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Jonas Jurevičius
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
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26
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Ma D, Liu Z, Loh LJ, Zhao Y, Li G, Liew R, Islam O, Wu J, Chung YY, Teo WS, Ching CK, Tan BY, Chong D, Ho KL, Lim P, Yong RYY, Panama BK, Kaplan AD, Bett GCL, Ware J, Bezzina CR, Verkerk AO, Cook SA, Rasmusson RL, Wei H. Identification of an I Na-dependent and I to-mediated proarrhythmic mechanism in cardiomyocytes derived from pluripotent stem cells of a Brugada syndrome patient. Sci Rep 2018; 8:11246. [PMID: 30050137 PMCID: PMC6062539 DOI: 10.1038/s41598-018-29574-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 07/16/2018] [Indexed: 02/08/2023] Open
Abstract
Brugada syndrome (BrS) is an inherited cardiac arrhythmia commonly associated with SCN5A mutations, yet its ionic mechanisms remain unclear due to a lack of cellular models. Here, we used human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) from a BrS patient (BrS1) to evaluate the roles of Na+ currents (INa) and transient outward K+ currents (Ito) in BrS induced action potential (AP) changes. To understand the role of these current changes in repolarization we employed dynamic clamp to “electronically express” IK1 and restore normal resting membrane potentials and allow normal recovery of the inactivating currents, INa, ICa and Ito. HiPSC-CMs were generated from BrS1 with a compound SCN5A mutation (p. A226V & p. R1629X) and a healthy sibling control (CON1). Genome edited hiPSC-CMs (BrS2) with a milder p. T1620M mutation and a commercial control (CON2) were also studied. CON1, CON2 and BrS2, had unaltered peak INa amplitudes, and normal APs whereas BrS1, with over 75% loss of INa, displayed a loss-of-INa basal AP morphology (at 1.0 Hz) manifested by a reduced maximum upstroke velocity (by ~80%, p < 0.001) and AP amplitude (p < 0.001), and an increased phase-1 repolarization pro-arrhythmic AP morphology (at 0.1 Hz) in ~25% of cells characterized by marked APD shortening (~65% shortening, p < 0.001). Moreover, Ito densities of BrS1 and CON1 were comparable and increased from 1.0 Hz to 0.1 Hz by ~ 100%. These data indicate that a repolarization deficit could be a mechanism underlying BrS.
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Affiliation(s)
- Dongrui Ma
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Zhenfeng Liu
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Li Jun Loh
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Yongxing Zhao
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Guang Li
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Reginald Liew
- Cardiovascular & Metabolic Disorders Program, Duke-NUS Medical School Singapore, Singapore, 169857, Republic of Singapore
| | - Omedul Islam
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Jianjun Wu
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Ying Ying Chung
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Wee Siong Teo
- Department of Cardiology, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Chi Keong Ching
- Department of Cardiology, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Boon Yew Tan
- Department of Cardiology, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Daniel Chong
- Department of Cardiology, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Kah Leng Ho
- Department of Cardiology, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Paul Lim
- Department of Cardiology, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore
| | - Rita Yu Yin Yong
- Defense Medical and Environmental Research Institute, DSO National Laboratories, Singapore, 117510, Republic of Singapore
| | - Brian K Panama
- University at Buffalo, State University of New York, Buffalo, NY, 14214, USA
| | - Aaron D Kaplan
- University at Buffalo, State University of New York, Buffalo, NY, 14214, USA
| | - Glenna C L Bett
- University at Buffalo, State University of New York, Buffalo, NY, 14214, USA
| | - James Ware
- Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Connie R Bezzina
- Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Arie O Verkerk
- Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Stuart A Cook
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore.,Cardiovascular & Metabolic Disorders Program, Duke-NUS Medical School Singapore, Singapore, 169857, Republic of Singapore.,Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Randall L Rasmusson
- University at Buffalo, State University of New York, Buffalo, NY, 14214, USA.
| | - Heming Wei
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, 169609, Republic of Singapore. .,Cardiovascular & Metabolic Disorders Program, Duke-NUS Medical School Singapore, Singapore, 169857, Republic of Singapore.
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27
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Pesco-Koplowitz L, Gintant G, Ward R, Heon D, Saulnier M, Heilbraun J. Drug-induced cardiac abnormalities in premature infants and neonates. Am Heart J 2018; 195:14-38. [PMID: 29224642 DOI: 10.1016/j.ahj.2017.07.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 07/27/2017] [Indexed: 01/09/2023]
Abstract
The Cardiac Safety Research Consortium (CSRC) is a transparent, public-private partnership that was established in 2005 as a Critical Path Program and formalized in 2006 under a Memorandum of Understanding between the United States Food and Drug Administration and Duke University. Our continuing goal is to advance paradigms for more efficient regulatory science related to the cardiovascular safety of new therapeutics, both in the United States and globally, particularly where such safety questions add burden to innovative research and development. This White Paper provides a summary of discussions by a cardiovascular committee cosponsored by the CSRC and the US Food and Drug Administration (FDA) that initially met in December 2014, and periodically convened at FDA's White Oak headquarters from March 2015 to September 2016. The committee focused on the lack of information concerning the cardiac effects of medications in the premature infant and neonate population compared with that of the older pediatric and adult populations. Key objectives of this paper are as follows: Provide an overview of human developmental cardiac electrophysiology, as well as the electrophysiology of premature infants and neonates; summarize all published juvenile animal models relevant to drug-induced cardiac toxicity; provide a consolidated source for all reported drug-induced cardiac toxicities by therapeutic area as a resource for neonatologists; present drugs that have a known cardiac effect in an adult population, but no reported toxicity in the premature infant and neonate populations; and summarize what is not currently known about drug-induced cardiac toxicity in premature infants and neonates, and what could be done to address this lack of knowledge. This paper presents the views of the authors and should not be construed to represent the views or policies of the FDA or Health Canada.
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28
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Hayashi H, Wu Q, Horie M. The relationship between J waves and contact of lung cancer with the heart. Ann Noninvasive Electrocardiol 2017; 22:e12433. [PMID: 28299892 PMCID: PMC6931450 DOI: 10.1111/anec.12433] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 01/05/2017] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND J waves result mainly from an increased density of transient outward current (Ito ). Mechanical stretch to the heart activates multiple signal transduction pathways, in which Ito may be involved. The purpose of this study was to test the hypothesis that mechanical contact of lung cancer with the heart may manifest J waves. METHODS We reviewed 12-lead electrocardiograms to examine whether J waves were associated with contact of lung cancer with the heart. J waves were defied as an elevation of ≥0.1 mV at the junction between QRS complex and ST segment with either notching or slurring morphology. The locational interaction between lung cancer and the heart was determined by computed tomography image. RESULTS A total of 264 patients (176 men; mean 68.5 ± 10.7 years) with lung cancer were evaluated. The prevalence of J waves was 25.4% in the total population. J waves were present in 40 of 44 (90.9%) patients with the contact. In contrast, J waves were present in 25 of 220 (11.4%) patients without the contact. The sensitivity and specificity of the contact for J waves were 90.9% and 88.6%, respectively. The odds ratio of the contact with the heart to the presence of J waves was 78 (95% confidence interval 25.7-236.4). The appearance of J waves that coincided with the development of lung cancer was observed in 12 patients. CONCLUSION The presence of J waves was associated with the contact of lung cancer with the heart.
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Affiliation(s)
- Hideki Hayashi
- Department of Cardiovascular and Respiratory MedicineShiga University of Medical ScienceOtsu CityShigaJapan
| | - Qi Wu
- Department of Cardiovascular and Respiratory MedicineShiga University of Medical ScienceOtsu CityShigaJapan
| | - Minoru Horie
- Department of Cardiovascular and Respiratory MedicineShiga University of Medical ScienceOtsu CityShigaJapan
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29
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Osadchii OE. Role of abnormal repolarization in the mechanism of cardiac arrhythmia. Acta Physiol (Oxf) 2017; 220 Suppl 712:1-71. [PMID: 28707396 DOI: 10.1111/apha.12902] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In cardiac patients, life-threatening tachyarrhythmia is often precipitated by abnormal changes in ventricular repolarization and refractoriness. Repolarization abnormalities typically evolve as a consequence of impaired function of outward K+ currents in cardiac myocytes, which may be caused by genetic defects or result from various acquired pathophysiological conditions, including electrical remodelling in cardiac disease, ion channel modulation by clinically used pharmacological agents, and systemic electrolyte disorders seen in heart failure, such as hypokalaemia. Cardiac electrical instability attributed to abnormal repolarization relies on the complex interplay between a provocative arrhythmic trigger and vulnerable arrhythmic substrate, with a central role played by the excessive prolongation of ventricular action potential duration, impaired intracellular Ca2+ handling, and slowed impulse conduction. This review outlines the electrical activity of ventricular myocytes in normal conditions and cardiac disease, describes classical electrophysiological mechanisms of cardiac arrhythmia, and provides an update on repolarization-related surrogates currently used to assess arrhythmic propensity, including spatial dispersion of repolarization, activation-repolarization coupling, electrical restitution, TRIaD (triangulation, reverse use dependence, instability, and dispersion), and the electromechanical window. This is followed by a discussion of the mechanisms that account for the dependence of arrhythmic vulnerability on the location of the ventricular pacing site. Finally, the review clarifies the electrophysiological basis for cardiac arrhythmia produced by hypokalaemia, and gives insight into the clinical importance and pathophysiology of drug-induced arrhythmia, with particular focus on class Ia (quinidine, procainamide) and Ic (flecainide) Na+ channel blockers, and class III antiarrhythmic agents that block the delayed rectifier K+ channel (dofetilide).
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Affiliation(s)
- O. E. Osadchii
- Department of Health Science and Technology; University of Aalborg; Aalborg Denmark
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30
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Lee MY. T wave. INTERNATIONAL JOURNAL OF ARRHYTHMIA 2017. [DOI: 10.18501/arrhythmia.2017.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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31
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Hegyi B, Horváth B, Váczi K, Gönczi M, Kistamás K, Ruzsnavszky F, Veress R, Izu LT, Chen-Izu Y, Bányász T, Magyar J, Csernoch L, Nánási PP, Szentandrássy N. Ca 2+-activated Cl - current is antiarrhythmic by reducing both spatial and temporal heterogeneity of cardiac repolarization. J Mol Cell Cardiol 2017; 109:27-37. [PMID: 28668303 DOI: 10.1016/j.yjmcc.2017.06.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 06/26/2017] [Accepted: 06/28/2017] [Indexed: 01/26/2023]
Abstract
The role of Ca2+-activated Cl- current (ICl(Ca)) in cardiac arrhythmias is still controversial. It can generate delayed afterdepolarizations in Ca2+-overloaded cells while in other studies incidence of early afterdepolarization (EAD) was reduced by ICl(Ca). Therefore our goal was to examine the role of ICl(Ca) in spatial and temporal heterogeneity of cardiac repolarization and EAD formation. Experiments were performed on isolated canine cardiomyocytes originating from various regions of the left ventricle; subepicardial, midmyocardial and subendocardial cells, as well as apical and basal cells of the midmyocardium. ICl(Ca) was blocked by 0.5mmol/L 9-anthracene carboxylic acid (9-AC). Action potential (AP) changes were tested with sharp microelectrode recording. Whole-cell 9-AC-sensitive current was measured with either square pulse voltage-clamp or AP voltage-clamp (APVC). Protein expression of TMEM16A and Bestrophin-3, ion channel proteins mediating ICl(Ca), was detected by Western blot. 9-AC reduced phase-1 repolarization in every tested cell. 9-AC also increased AP duration in a reverse rate-dependent manner in all cell types except for subepicardial cells. Neither ICl(Ca) density recorded with square pulses nor the normalized expressions of TMEM16A and Bestrophin-3 proteins differed significantly among the examined groups of cells. The early outward component of ICl(Ca) was significantly larger in subepicardial than in subendocardial cells in APVC setting. Applying a typical subepicardial AP as a command pulse resulted in a significantly larger early outward component in both subepicardial and subendocardial cells, compared to experiments when a typical subendocardial AP was applied. Inhibiting ICl(Ca) by 9-AC generated EADs at low stimulation rates and their incidence increased upon beta-adrenergic stimulation. 9-AC increased the short-term variability of repolarization also. We suggest a protective role for ICl(Ca) against risk of arrhythmias by reducing spatial and temporal heterogeneity of cardiac repolarization and EAD formation.
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Affiliation(s)
- Bence Hegyi
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary; Department of Pharmacology, Genome and Biomedical Science Facility, University of California, Davis, 451 Health Sciences Drive, Rm 3503, Davis, CA 95616, USA
| | - Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary; Faculty of Pharmacy, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary
| | - Krisztina Váczi
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary
| | - Mónika Gönczi
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary; MTA-DE Momentum, Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary
| | - Kornél Kistamás
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary
| | - Ferenc Ruzsnavszky
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary
| | - Roland Veress
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary
| | - Leighton T Izu
- Faculty of Pharmacy, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary
| | - Ye Chen-Izu
- Faculty of Pharmacy, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary; Department of Biomedical Engineering, Genome and Biomedical Science Facility, University of California, Davis, 451 Health Sciences Drive, Rm 2303, Davis, CA 95616, USA; Department of Internal Medicine, Division of Cardiology, Genome and Biomedical Science Facility, University of California, Davis, 451 Health Sciences Drive, Rm 6315, Davis, CA 95616, USA
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary; Division of Sport Physiology, Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary
| | - Péter P Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary; Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary.
| | - Norbert Szentandrássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary; Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, Nagyerdei krt 98, P.O. Box 22, H-4012 Debrecen, Hungary
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Aguilar-Sanchez Y, Fainstein D, Mejia-Alvarez R, Escobar AL. Local Field Fluorescence Microscopy: Imaging Cellular Signals in Intact Hearts. J Vis Exp 2017. [PMID: 28362405 DOI: 10.3791/55202] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
In the heart, molecular signaling studies are usually performed in isolated myocytes. However, many pathological situations such as ischemia and arrhythmias can only be fully understood at the whole organ level. Here, we present the spectroscopic technique of local field fluorescence microscopy (LFFM) that allows the measurement of cellular signals in the intact heart. The technique is based on a combination of a Langendorff perfused heart and optical fibers to record fluorescent signals. LFFM has various applications in the field of cardiovascular physiology to study the heart under normal and pathological conditions. Multiple cardiac variables can be monitored using different fluorescent indicators. These include cytosolic [Ca2+], intra-sarcoplasmic reticulum [Ca2+] and membrane potentials. The exogenous fluorescent probes are excited and the emitted fluorescence detected with three different arrangements of LFFM epifluorescence techniques presented in this paper. The central differences among these techniques are the type of light source used for excitation and on the way the excitation light is modulated. The pulsed LFFM (PLFFM) uses laser light pulses while continuous wave LFFM (CLFFM) uses continuous laser light for excitation. Finally, light-emitting diodes (LEDs) were used as a third light source. This non-coherent arrangement is called pulsed LED fluorescence microscopy (PLEDFM).
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Affiliation(s)
| | - Diego Fainstein
- Centro de Investigaciones Cardiovasculares, Universidad de la Plata and Conicet; Facultad de Ingenieria, Universidad Nacional de Entre Rios
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Ion currents of cardiomyocytes in different regions of the Göttingen minipig heart. J Pharmacol Toxicol Methods 2017; 86:12-18. [PMID: 28254506 DOI: 10.1016/j.vascn.2017.02.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 01/18/2017] [Accepted: 02/20/2017] [Indexed: 01/25/2023]
Abstract
INTRODUCTION The Göttingen minipig is a promising model for pharmacological safety assessment and for translational research in cardiology. We have examined the main ion currents in cardiomyocytes of the minipig heart. METHODS Cardiac cells were isolated from different cardiac regions (endo-, mid- and epicardial left ventricle and right ventricle) from Göttingen minipigs and examined using the whole cell patch clamp technique combined with pharmacological interventions. RESULTS The inward rectifier (IK1), the delayed rectifier (IK), with the rapid and slow components, (IKr, IKs) and the L-type Ca2+ channel (ICa,L) were identified in the different regions of the heart, whereas the Ca2+-independent transient outward current (Ito1) was observed in only a few cells. IK1 was similar in the cardiac regions with a slightly lower value in the epicardial cells. IKs was smaller in epi- and endo-cardial regions. DISCUSSION The equivalents of the main human cardiac ion currents are present in the minipig cardiomyocytes with the exception of the Ca2+-independent Ito1. The study provides further evidence that the minipig is a valid model for investigating cardiovascular pharmacology.
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Corsi C, Cortesi M, Callisesi G, De Bie J, Napolitano C, Santoro A, Mortara D, Severi S. Noninvasive quantification of blood potassium concentration from ECG in hemodialysis patients. Sci Rep 2017; 7:42492. [PMID: 28198403 PMCID: PMC5309791 DOI: 10.1038/srep42492] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 01/11/2017] [Indexed: 11/29/2022] Open
Abstract
Blood potassium concentration ([K+]) influences the electrocardiogram (ECG), particularly T-wave morphology. We developed a new method to quantify [K+] from T-wave analysis and tested its clinical applicability on data from dialysis patients, in whom [K+] varies significantly during the therapy. To elucidate the mechanism linking [K+] and T-wave, we also analysed data from long QT syndrome type 2 (LQT2) patients, testing the hypothesis that our method would have underestimated [K+] in these patients. Moreover, a computational model was used to explore the physiological processes underlying our estimator at the cellular level. We analysed 12-lead ECGs from 45 haemodialysis and 12 LQT2 patients. T-wave amplitude and downslope were calculated from the first two eigenleads. The T-wave slope-to-amplitude ratio (TS/A) was used as starting point for an ECG-based [K+] estimate (KECG). Leave-one-out cross-validation was performed. Agreement between KECG and reference [K+] from blood samples was promising (error: −0.09 ± 0.59 mM, absolute error: 0.46 ± 0.39 mM). The analysis on LQT2 patients, also supported by the outcome of computational analysis, reinforces our interpretation that, at the cellular level, delayed-rectifier potassium current is a main contributor of KECG correlation to blood [K+]. Following a comprehensive validation, this method could be effectively applied to monitor patients at risk for hyper/hypokalemia.
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Affiliation(s)
- Cristiana Corsi
- Department of Electrical, Electronic and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena, Italy.,Health Sciences and Technology Interdepartmental Center for Industrial Research, University of Bologna, Cesena, Italy
| | - Marilisa Cortesi
- Department of Electrical, Electronic and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena, Italy
| | - Giulia Callisesi
- Department of Electrical, Electronic and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena, Italy
| | | | - Carlo Napolitano
- Molecular Cardiology, IRCCS Fondazione Salvatore Maugeri, Pavia, Italy
| | - Antonio Santoro
- Nephrology Dialysis, Hypertension Unit, Hospital Policlinico S.Orsola-Malpighi, Bologna, Italy
| | | | - Stefano Severi
- Department of Electrical, Electronic and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena, Italy.,Health Sciences and Technology Interdepartmental Center for Industrial Research, University of Bologna, Cesena, Italy
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Finlay M, Harmer SC, Tinker A. The control of cardiac ventricular excitability by autonomic pathways. Pharmacol Ther 2017; 174:97-111. [PMID: 28223225 DOI: 10.1016/j.pharmthera.2017.02.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Central to the genesis of ventricular cardiac arrhythmia are variations in determinants of excitability. These involve individual ionic channels and transporters in cardiac myocytes but also tissue factors such as variable conduction of the excitation wave, fibrosis and source-sink mismatch. It is also known that in certain diseases and particularly the channelopathies critical events occur with specific stressors. For example, in hereditary long QT syndrome due to mutations in KCNQ1 arrhythmic episodes are provoked by exercise and in particular swimming. Thus not only is the static substrate important but also how this is modified by dynamic signalling events associated with common physiological responses. In this review, we examine the regulation of ventricular excitability by signalling pathways from a cellular and tissue perspective in an effort to identify key processes, effectors and potential therapeutic approaches. We specifically focus on the autonomic nervous system and related signalling pathways.
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Affiliation(s)
- Malcolm Finlay
- The Heart Centre, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Charterhouse Square, London EC1M6BQ, UK
| | - Stephen C Harmer
- The Heart Centre, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Charterhouse Square, London EC1M6BQ, UK
| | - Andrew Tinker
- The Heart Centre, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Charterhouse Square, London EC1M6BQ, UK.
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Seo J, Park J, Oh J, Uhm JS, Sung JH, Kim JY, Pak HN, Lee MH, Joung B. High Prevalence and Clinical Implication of Myocardial Bridging in Patients with Early Repolarization. Yonsei Med J 2017; 58:67-74. [PMID: 27873497 PMCID: PMC5122654 DOI: 10.3349/ymj.2017.58.1.67] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 05/30/2016] [Accepted: 05/30/2016] [Indexed: 01/29/2023] Open
Abstract
PURPOSE Recent evidence suggests that early repolarization (ER) is related with myocardial ischemia. Compression of coronary artery by a myocardial bridging (MB) can be associated with clinical manifestations of myocardial ischemia. This study aimed to evaluate the associations of MB in patients with ER. MATERIALS AND METHODS In consecutive patients (n=1303, age, 61±12 years) who had undergone coronary angiography, we assessed the prevalence and prognostic implication of MB in those with ER (n=142) and those without ER (n=1161). RESULTS MB was observed in 54 (38%) and 196 (17%) patients in ER and no-ER groups (p<0.001). In multivariate analysis, MB was independently associated with ER (odd ratio: 2.9, 95% confidence interval: 1.98-4.24, p<0.001). Notched type ER was more frequently observed in MB involving the mid portion of left anterior descending coronary artery (LAD) (69.8% vs. 30.2%, p=0.03). Cardiac event was observed in nine (6.3%) and 22 (1.9%) subjects with and without ER, respectively. MB was more frequently observed in sudden death patients with ER (2 out of 9, 22%) than in those without ER (0 out of 22). CONCLUSION MB was independently associated with ER in patients without out structural heart disease who underwent coronary angiography. Notched type ER was closely related with MB involving the mid portion of the LAD. Among patients who had experienced cardiac events, a higher prevalence of MB was observed in patients with ER than those without ER. Further prospective studies on the prognosis of MB in ER patients are required.
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Affiliation(s)
- Jiwon Seo
- Department of Internal Medicine, Division of Cardiology, Yonsei University College of Medicine, Seoul, Korea
| | - Junbeom Park
- Department of Internal Medicine, Division of Cardiology, Ewha Womans University, Seoul, Korea
| | - Jaewon Oh
- Department of Internal Medicine, Division of Cardiology, Yonsei University College of Medicine, Seoul, Korea
| | - Jae Sun Uhm
- Department of Internal Medicine, Division of Cardiology, Yonsei University College of Medicine, Seoul, Korea
| | - Jung Hoon Sung
- Department of Internal Medicine, Division of Cardiology, Bundang CHA Medical Center, CHA University, Seongnam, Korea
| | - Jong Youn Kim
- Department of Internal Medicine, Division of Cardiology, Yonsei University College of Medicine, Seoul, Korea
| | - Hui Nam Pak
- Department of Internal Medicine, Division of Cardiology, Yonsei University College of Medicine, Seoul, Korea
| | - Moon Hyoung Lee
- Department of Internal Medicine, Division of Cardiology, Yonsei University College of Medicine, Seoul, Korea
| | - Boyoung Joung
- Department of Internal Medicine, Division of Cardiology, Yonsei University College of Medicine, Seoul, Korea.
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Cohen IS, Mathias RT. The renin-angiotensin system regulates transmural electrical remodeling in response to mechanical load. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 122:187-201. [PMID: 27645328 PMCID: PMC5161618 DOI: 10.1016/j.pbiomolbio.2016.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 09/13/2016] [Indexed: 06/06/2023]
Affiliation(s)
- Ira S Cohen
- Department of Physiology & Biophysics, Institute for Molecular Cardiology, Stony Brook University, United States.
| | - Richard T Mathias
- Department of Physiology & Biophysics, Institute for Molecular Cardiology, Stony Brook University, United States
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McKinnon D, Rosati B. Transmural gradients in ion channel and auxiliary subunit expression. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 122:165-186. [PMID: 27702655 DOI: 10.1016/j.pbiomolbio.2016.09.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 09/30/2016] [Indexed: 12/11/2022]
Abstract
Evolution has acted to shape the action potential in different regions of the heart in order to produce a maximally stable and efficient pump. This has been achieved by creating regional differences in ion channel expression levels within the heart as well as differences between equivalent cardiac tissues in different species. These region- and species-dependent differences in channel expression are established by regulatory evolution, evolution of the regulatory mechanisms that control channel expression levels. Ion channel auxiliary subunits are obvious targets for regulatory evolution, in order to change channel expression levels and/or modify channel function. This review focuses on the transmural gradients of ion channel expression in the heart and the role that regulation of auxiliary subunit expression plays in generating and shaping these gradients.
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Affiliation(s)
- David McKinnon
- Department of Veterans Affairs Medical Center, Northport, NY, USA; Institute of Molecular Cardiology, Stony Brook University, Stony Brook, NY, USA; Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Barbara Rosati
- Department of Veterans Affairs Medical Center, Northport, NY, USA; Institute of Molecular Cardiology, Stony Brook University, Stony Brook, NY, USA; Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, 11794, USA.
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Colli Franzone P, Pavarino LF, Scacchi S. Joint influence of transmural heterogeneities and wall deformation on cardiac bioelectrical activity: A simulation study. Math Biosci 2016; 280:71-86. [PMID: 27545966 DOI: 10.1016/j.mbs.2016.08.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 05/25/2016] [Accepted: 08/04/2016] [Indexed: 10/21/2022]
Abstract
The aim of this work is to investigate, by means of numerical simulations, the influence of myocardial deformation due to muscle contraction and relaxation on the cardiac repolarization process in presence of transmural intrinsic action potential duration (APD) heterogeneities. The three-dimensional electromechanical model considered consists of the following four coupled components: the quasi-static transversely isotropic finite elasticity equations for the deformation of the cardiac tissue; the active tension model for the intracellular calcium dynamics and cross-bridge binding; the anisotropic Bidomain model for the electrical current flow through the deforming cardiac tissue; the membrane model of ventricular myocytes, including stretch-activated channels. The numerical simulations are based on our finite element parallel solver, which employs Multilevel Additive Schwarz preconditioners for the solution of the discretized Bidomain equations and Newton-Krylov methods for the solution of the discretized non-linear finite elasticity equations. Our findings show that: (i) the presence of intrinsic transmural cellular APD heterogeneities is not fully masked by electrotonic current flow or by the presence of the mechanical deformation; (ii) despite the presence of transmural APD heterogeneities, the recovery process follows the activation sequence and there is no significant transmural repolarization gradient; (iii) with or without transmural APD heterogeneities, epicardial electrograms always display the same wave shape and discordance between the polarity of QRS complex and T-wave; (iv) the main effects of the mechanical deformation are an increase of the dispersion of repolarization time and APD, when computed over the total cardiac domain and over the endo- and epicardial surfaces, while there is a slight decrease along the transmural direction.
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Affiliation(s)
- P Colli Franzone
- Dipartimento di Matematica, Università di Pavia, Via Ferrata 1, Pavia 27100, Italy.
| | - L F Pavarino
- Dipartimento di Matematica, Università di Milano, Via Saldini 50, Milano 20133, Italy.
| | - S Scacchi
- Dipartimento di Matematica, Università di Milano, Via Saldini 50, Milano 20133, Italy.
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Multi-scale Modeling of the Cardiovascular System: Disease Development, Progression, and Clinical Intervention. Ann Biomed Eng 2016; 44:2642-60. [PMID: 27138523 DOI: 10.1007/s10439-016-1628-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 04/22/2016] [Indexed: 12/19/2022]
Abstract
Cardiovascular diseases (CVDs) are the leading cause of death in the western world. With the current development of clinical diagnostics to more accurately measure the extent and specifics of CVDs, a laudable goal is a better understanding of the structure-function relation in the cardiovascular system. Much of this fundamental understanding comes from the development and study of models that integrate biology, medicine, imaging, and biomechanics. Information from these models provides guidance for developing diagnostics, and implementation of these diagnostics to the clinical setting, in turn, provides data for refining the models. In this review, we introduce multi-scale and multi-physical models for understanding disease development, progression, and designing clinical interventions. We begin with multi-scale models of cardiac electrophysiology and mechanics for diagnosis, clinical decision support, personalized and precision medicine in cardiology with examples in arrhythmia and heart failure. We then introduce computational models of vasculature mechanics and associated mechanical forces for understanding vascular disease progression, designing clinical interventions, and elucidating mechanisms that underlie diverse vascular conditions. We conclude with a discussion of barriers that must be overcome to provide enhanced insights, predictions, and decisions in pre-clinical and clinical applications.
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A dual potassium channel activator improves repolarization reserve and normalizes ventricular action potentials. Biochem Pharmacol 2016; 108:36-46. [PMID: 27002181 DOI: 10.1016/j.bcp.2016.03.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 03/17/2016] [Indexed: 11/22/2022]
Abstract
BACKGROUND A loss of repolarization reserve due to downregulation of K(+) currents has been observed in cultured ventricular myocytes. A similar reduction of K(+) currents is well documented under numerous pathophysiological conditions. We examined the extent of K(+) current downregulation in cultured canine cardiac myocytes and determined whether a dual K(+) current activator can normalize K(+) currents and restore action potential (AP) configuration. METHODS AND RESULTS Ventricular myocytes were isolated and cultured for up to 48 h. Current and voltage clamp recordings were made using patch electrodes. Application of NS3623 to coronary-perfused left ventricular wedges resulted in increased phase 1 magnitude, epicardial AP notch and J wave amplitude. Patch clamp measurements of IKr and Ito revealed an increase in the magnitude of both currents. Culturing of Mid ventricular cells resulted in a significant decrease in Ito and IKr density. NS3623 increased Ito from 16.4 ± 2.23 to 31.8 ± 4.5 pA/pF, and IKr from 0.28 ± 0.06 to 0.47 ± 0.09 pA/pF after 2 days in culture. AP recordings from 2 day cultured cells exhibited a reduced phase 1 repolarization, AP prolongation, and early afterdepolarizations (EADs). NS3623 restored the AP notch and was able to suppress EADs. CONCLUSIONS NS3623 is a dual Ito and IKr activator. Application of this compound to cells with a reduced repolarization reserve resulted in an increase in these currents and a shortening of AP duration, increase in phase 1 repolarization and suppression of EADs. Our results suggest a potential benefit of K(+) current activators under conditions of reduced repolarization reserve including heart failure.
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Abstract
Optimal cardiac function depends on proper timing of excitation and contraction in various regions of the heart, as well as on appropriate heart rate. This is accomplished via specialized electrical properties of various components of the system, including the sinoatrial node, atria, atrioventricular node, His-Purkinje system, and ventricles. Here we review the major regionally determined electrical properties of these cardiac regions and present the available data regarding the molecular and ionic bases of regional cardiac function and dysfunction. Understanding these differences is of fundamental importance for the investigation of arrhythmia mechanisms and pharmacotherapy.
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Affiliation(s)
- Daniel C Bartos
- Department of Pharmacology, University of California Davis, Davis, California, USA
| | - Eleonora Grandi
- Department of Pharmacology, University of California Davis, Davis, California, USA
| | - Crystal M Ripplinger
- Department of Pharmacology, University of California Davis, Davis, California, USA
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Lopez-Perez A, Sebastian R, Ferrero JM. Three-dimensional cardiac computational modelling: methods, features and applications. Biomed Eng Online 2015; 14:35. [PMID: 25928297 PMCID: PMC4424572 DOI: 10.1186/s12938-015-0033-5] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 04/02/2015] [Indexed: 01/19/2023] Open
Abstract
The combination of computational models and biophysical simulations can help to interpret an array of experimental data and contribute to the understanding, diagnosis and treatment of complex diseases such as cardiac arrhythmias. For this reason, three-dimensional (3D) cardiac computational modelling is currently a rising field of research. The advance of medical imaging technology over the last decades has allowed the evolution from generic to patient-specific 3D cardiac models that faithfully represent the anatomy and different cardiac features of a given alive subject. Here we analyse sixty representative 3D cardiac computational models developed and published during the last fifty years, describing their information sources, features, development methods and online availability. This paper also reviews the necessary components to build a 3D computational model of the heart aimed at biophysical simulation, paying especial attention to cardiac electrophysiology (EP), and the existing approaches to incorporate those components. We assess the challenges associated to the different steps of the building process, from the processing of raw clinical or biological data to the final application, including image segmentation, inclusion of substructures and meshing among others. We briefly outline the personalisation approaches that are currently available in 3D cardiac computational modelling. Finally, we present examples of several specific applications, mainly related to cardiac EP simulation and model-based image analysis, showing the potential usefulness of 3D cardiac computational modelling into clinical environments as a tool to aid in the prevention, diagnosis and treatment of cardiac diseases.
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Affiliation(s)
- Alejandro Lopez-Perez
- Centre for Research and Innovation in Bioengineering (Ci2B), Universitat Politècnica de València, València, Spain.
| | - Rafael Sebastian
- Computational Multiscale Physiology Lab (CoMMLab), Universitat de València, València, Spain.
| | - Jose M Ferrero
- Centre for Research and Innovation in Bioengineering (Ci2B), Universitat Politècnica de València, València, Spain.
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Meijer van Putten RME, Mengarelli I, Guan K, Zegers JG, van Ginneken ACG, Verkerk AO, Wilders R. Ion channelopathies in human induced pluripotent stem cell derived cardiomyocytes: a dynamic clamp study with virtual IK1. Front Physiol 2015; 6:7. [PMID: 25691870 PMCID: PMC4315032 DOI: 10.3389/fphys.2015.00007] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 01/07/2015] [Indexed: 12/11/2022] Open
Abstract
Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) are widely used in studying basic mechanisms of cardiac arrhythmias that are caused by ion channelopathies. Unfortunately, the action potential profile of hiPSC-CMs-and consequently the profile of individual membrane currents active during that action potential-differs substantially from that of native human cardiomyocytes, largely due to almost negligible expression of the inward rectifier potassium current (IK1). In the present study, we attempted to "normalize" the action potential profile of our hiPSC-CMs by inserting a voltage dependent in silico IK1 into our hiPSC-CMs, using the dynamic clamp configuration of the patch clamp technique. Recordings were made from single hiPSC-CMs, using the perforated patch clamp technique at physiological temperature. We assessed three different models of IK1, with different degrees of inward rectification, and systematically varied the magnitude of the inserted IK1. Also, we modified the inserted IK1 in order to assess the effects of loss- and gain-of-function mutations in the KCNJ2 gene, which encodes the Kir2.1 protein that is primarily responsible for the IK1 channel in human ventricle. For our experiments, we selected spontaneously beating hiPSC-CMs, with negligible IK1 as demonstrated in separate voltage clamp experiments, which were paced at 1 Hz. Upon addition of in silico IK1 with a peak outward density of 4-6 pA/pF, these hiPSC-CMs showed a ventricular-like action potential morphology with a stable resting membrane potential near -80 mV and a maximum upstroke velocity >150 V/s (n = 9). Proarrhythmic action potential changes were observed upon injection of both loss-of-function and gain-of-function IK1, as associated with Andersen-Tawil syndrome type 1 and short QT syndrome type 3, respectively (n = 6). We conclude that injection of in silico IK1 makes the hiPSC-CM a more reliable model for investigating mechanisms underlying cardiac arrhythmias.
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Affiliation(s)
- Rosalie M E Meijer van Putten
- Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
| | - Isabella Mengarelli
- Department of Experimental Cardiology, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
| | - Kaomei Guan
- Department of Cardiology and Pneumology, Georg-August-University of Göttingen Göttingen, Germany
| | - Jan G Zegers
- Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
| | - Antoni C G van Ginneken
- Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
| | - Arie O Verkerk
- Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
| | - Ronald Wilders
- Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
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Perrin MJ, Adler A, Green S, Al-Zoughool F, Doroshenko P, Orr N, Uppal S, Healey JS, Birnie D, Sanatani S, Gardner M, Champagne J, Simpson C, Ahmad K, van den Berg MP, Chauhan V, Backx PH, van Tintelen JP, Krahn AD, Gollob MH. Evaluation of genes encoding for the transient outward current (Ito) identifies the KCND2 gene as a cause of J-wave syndrome associated with sudden cardiac death. ACTA ACUST UNITED AC 2014; 7:782-9. [PMID: 25214526 DOI: 10.1161/circgenetics.114.000623] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND J-wave ECG patterns are associated with an increased risk of sudden arrhythmic death, and experimental evidence supports a transient outward current (I(to))-mediated mechanism of J-wave formation. This study aimed to determine the frequency of genetic mutations in genes encoding the I(to) in patients with J waves on ECG. METHODS AND RESULTS Comprehensive mutational analysis was performed on I(to)-encoding KCNA4, KCND2, and KCND3 genes, as well as the previously described J-wave-associated KCNJ8 gene, in 51 unrelated patients with ECG evidence defining a J-wave syndrome. Only patients with a resuscitated cardiac arrest or type 1 Brugada ECG pattern were included for analysis. A rare genetic mutation of the KCND2 gene, p.D612N, was identified in a single patient. Co-expression of mutant and wild-type KCND2 with KChIP2 in HEK293 cells demonstrated a gain-of-function phenotype, including an increase in peak I(to) density of 48% (P<0.05) in the heterozygous state. Using computer modeling, this increase in Ito resulted in loss of the epicardial action potential dome, predicting an increased ventricular transmural Ito gradient. The previously described KCNJ8-S422L mutation was not identified in this cohort of patients with ECG evidence of J-wave syndrome. CONCLUSIONS These findings are the first to implicate the KCND2 gene as a novel cause of J-wave syndrome associated with sudden cardiac arrest. However, genetic defects in I(to)-encoding genes seem to be an uncommon cause of sudden cardiac arrest in patients with apparent J-wave syndromes.
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Affiliation(s)
- Mark J Perrin
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Arnon Adler
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Sharon Green
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Foad Al-Zoughool
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Petro Doroshenko
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Nathan Orr
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Shaheen Uppal
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Jeff S Healey
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - David Birnie
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Shubhayan Sanatani
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Martin Gardner
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Jean Champagne
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Chris Simpson
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Kamran Ahmad
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Maarten P van den Berg
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Vijay Chauhan
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Peter H Backx
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - J Peter van Tintelen
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Andrew D Krahn
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.)
| | - Michael H Gollob
- From the Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa (M.J.P., A.A., S.G., F.A.-Z., P.D., N.O., S.U., D.B.); Population Health Research Institute, McMaster University, Hamilton, ON (J.S.H.); Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC (S.S., A.D.K.); Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, NS (M.G.); Division of Cardiology, Department of Medicine, Laval University, Québec, QC (J.C.); Division of Cardiology, Department of Medicine, Queens University, Kingston (C.S.); Division of Cardiology, St Michael's Hospital, University of Toronto, Toronto, ON, Canada (K.A.); Department of Genetics, University of Groningen, University Medical Center, Groningen, the Netherlands (M.P.v.d.B., J.P.v.T.); Division of Cardiology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada (V.C., P.H.B., M.H.G.).
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Min G, Shaoxin Z, Chang F, Juan L, Guiyi Y, Shuxian Z. Effects of different ventricular pacing modes on ventricular repolarisation in patients undergoing cardiac resynchronisation therapy: a single-centre study. Heart Lung Circ 2014; 23:644-8. [PMID: 24713298 DOI: 10.1016/j.hlc.2014.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 11/20/2013] [Accepted: 02/06/2014] [Indexed: 11/27/2022]
Abstract
AIMS The aims of this study were to compare ventricular repolarisation parameters in patients who underwent cardiac resynchronisation therapy (CRT) at Sun Yat-sen University Memorial Hospital under different ventricular pacing modes and to understand effects of epicardial pacing on ventricular repolarisation. METHODS The study included 55 patients who underwent CRT. During follow-up outpatient visits three months after CRT implantation, the CRT devices were programmed to deliver no pacing (with the exception of patients with third-degree atrioventricular block), biventricular pacing (BivP), right ventricular endocardial pacing (RV-EndoP), and left ventricular epicardial pacing (LV-EpiP). Signals from the standard 12-lead ECG were recorded simultaneously to measure the QT interval, JT interval, and Tp-e interval, from which the heart rate-corrected QTc interval, JTc interval, and Tp-ec interval were determined. RESULTS The JTc interval and Tp-ec interval were prolonged during LV-EpiP and BivP compared with those during spontaneous cardiac rhythm and RV-EndoP. The JTc dispersion and Tp-ec dispersion were not significantly different among the four pacing modes. CONCLUSION Epicardial pacing prolongs myocardial repolarisation time and increases transmural dispersion of repolarisation. Epicardial pacing has no significant effect on the dispersion of regional ventricular repolarisation.
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Affiliation(s)
- Gu Min
- Cardiovascular Medicine, Jiangsu Subei People's Hospital, China
| | - Zheng Shaoxin
- Cardiovascular Medicine, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, China
| | - Fang Chang
- Cardiovascular Medicine, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, China
| | - Lei Juan
- Cardiovascular Medicine, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, China
| | - Yuan Guiyi
- Cardiovascular Medicine, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, China
| | - Zhou Shuxian
- Cardiovascular Medicine, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, China.
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Cummins MA, Dalal PJ, Bugana M, Severi S, Sobie EA. Comprehensive analyses of ventricular myocyte models identify targets exhibiting favorable rate dependence. PLoS Comput Biol 2014; 10:e1003543. [PMID: 24675446 PMCID: PMC3967944 DOI: 10.1371/journal.pcbi.1003543] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 02/13/2014] [Indexed: 12/02/2022] Open
Abstract
Reverse rate dependence is a problematic property of antiarrhythmic drugs that prolong the cardiac action potential (AP). The prolongation caused by reverse rate dependent agents is greater at slow heart rates, resulting in both reduced arrhythmia suppression at fast rates and increased arrhythmia risk at slow rates. The opposite property, forward rate dependence, would theoretically overcome these parallel problems, yet forward rate dependent (FRD) antiarrhythmics remain elusive. Moreover, there is evidence that reverse rate dependence is an intrinsic property of perturbations to the AP. We have addressed the possibility of forward rate dependence by performing a comprehensive analysis of 13 ventricular myocyte models. By simulating populations of myocytes with varying properties and analyzing population results statistically, we simultaneously predicted the rate-dependent effects of changes in multiple model parameters. An average of 40 parameters were tested in each model, and effects on AP duration were assessed at slow (0.2 Hz) and fast (2 Hz) rates. The analysis identified a variety of FRD ionic current perturbations and generated specific predictions regarding their mechanisms. For instance, an increase in L-type calcium current is FRD when this is accompanied by indirect, rate-dependent changes in slow delayed rectifier potassium current. A comparison of predictions across models identified inward rectifier potassium current and the sodium-potassium pump as the two targets most likely to produce FRD AP prolongation. Finally, a statistical analysis of results from the 13 models demonstrated that models displaying minimal rate-dependent changes in AP shape have little capacity for FRD perturbations, whereas models with large shape changes have considerable FRD potential. This can explain differences between species and between ventricular cell types. Overall, this study provides new insights, both specific and general, into the determinants of AP duration rate dependence, and illustrates a strategy for the design of potentially beneficial antiarrhythmic drugs. Several drugs intended to treat cardiac arrhythmias have failed because of unfavorable rate-dependent properties. That is, the drugs fail to alter electrical activity at fast heart rates, where this would be beneficial, but they do affect electrical activity at slow rates, where this is unwanted. In targeted studies, several agents have been shown to exhibit these unfavorable properties, suggesting that these rate-dependent responses may be intrinsic to ventricular muscle. To determine whether drugs with desirable rate-dependent properties could be rationally designed, we performed comprehensive and systematic analyses of several heart cell models. These analyses calculated the rate-dependent properties of changes in any model parameter, thereby generating simultaneously a large number of model predictions. The analyses showed that targets with favorable rate-dependent properties could indeed be identified, and further simulations uncovered the mechanisms underlying these behaviors. Moreover, a quantitative comparison of results obtained in different models provided new insight in why a given drug applied to different species, or to different tissue types, might produce different rate-dependent behaviors. Overall this study shows how a comprehensive and systematic approach to heart cell models can both identify novel targets and produce more general insight into rate-dependent alterations to cardiac electrical activity.
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Affiliation(s)
- Megan A. Cummins
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Pavan J. Dalal
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | | | | | - Eric A. Sobie
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
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Milani-Nejad N, Janssen PML. Small and large animal models in cardiac contraction research: advantages and disadvantages. Pharmacol Ther 2014; 141:235-49. [PMID: 24140081 PMCID: PMC3947198 DOI: 10.1016/j.pharmthera.2013.10.007] [Citation(s) in RCA: 305] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 08/15/2013] [Indexed: 12/22/2022]
Abstract
The mammalian heart is responsible for not only pumping blood throughout the body but also adjusting this pumping activity quickly depending upon sudden changes in the metabolic demands of the body. For the most part, the human heart is capable of performing its duties without complications; however, throughout many decades of use, at some point this system encounters problems. Research into the heart's activities during healthy states and during adverse impacts that occur in disease states is necessary in order to strategize novel treatment options to ultimately prolong and improve patients' lives. Animal models are an important aspect of cardiac research where a variety of cardiac processes and therapeutic targets can be studied. However, there are differences between the heart of a human being and an animal and depending on the specific animal, these differences can become more pronounced and in certain cases limiting. There is no ideal animal model available for cardiac research, the use of each animal model is accompanied with its own set of advantages and disadvantages. In this review, we will discuss these advantages and disadvantages of commonly used laboratory animals including mouse, rat, rabbit, canine, swine, and sheep. Since the goal of cardiac research is to enhance our understanding of human health and disease and help improve clinical outcomes, we will also discuss the role of human cardiac tissue in cardiac research. This review will focus on the cardiac ventricular contractile and relaxation kinetics of humans and animal models in order to illustrate these differences.
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Affiliation(s)
- Nima Milani-Nejad
- Department of Physiology and Cell Biology and D. Davis Heart Lung Institute, College of Medicine, The Ohio State University, OH, USA
| | - Paul M L Janssen
- Department of Physiology and Cell Biology and D. Davis Heart Lung Institute, College of Medicine, The Ohio State University, OH, USA.
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Di Diego JM, Antzelevitch C. Acute myocardial ischemia: cellular mechanisms underlying ST segment elevation. J Electrocardiol 2014; 47:486-90. [PMID: 24742586 DOI: 10.1016/j.jelectrocard.2014.02.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Indexed: 10/25/2022]
Abstract
The electrocardiogram (ECG) is an essential tool for the diagnosis of acute myocardial ischemia in the emergency department, as well as for that of an evolving acute myocardial infarction (AMI). Changes in the surface ECG in leads whose positive poles face the ischemic region are known to be related to injury currents flowing across the boundaries between the ischemic and the surrounding normal myocardium. Although experimental studies have also shown an endocardium to epicardium differential sensitivity to the effect of acute ischemia, the important contribution of this transmural heterogeneous response to the changes observed in the surface ECG is less appreciated by the clinical cardiologist. This review briefly discusses our current knowledge regarding the electrophysiology of the ischemic myocardium focusing primarily on the electrophysiologic changes underlying the ECG alterations observed at the onset of a transmural AMI.
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