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Anderson RD, Nayyar S, Masse S, Lambiase PD, Nanthakumar K. Wave tail mapping to guide ablation therapy for ventricular arrhythmias. Heart Rhythm 2023; 20:461-470. [PMID: 36756940 DOI: 10.1016/j.hrthm.2022.10.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/13/2022] [Accepted: 10/24/2022] [Indexed: 12/23/2022]
Affiliation(s)
- Robert D Anderson
- Hull Family Cardiac Fibrillation Management Laboratory, Division of Cardiology, University Health Network, Toronto General Hospital, Toronto, Ontario, Canada
| | - Sachin Nayyar
- Department of Cardiology, Townsville University Hospital, James Cook University, Douglas, Queensland, Australia
| | - Stephane Masse
- Hull Family Cardiac Fibrillation Management Laboratory, Division of Cardiology, University Health Network, Toronto General Hospital, Toronto, Ontario, Canada
| | - Pier D Lambiase
- Barts Heart Centre, Barts Health National Health Service Trust, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Kumaraswamy Nanthakumar
- Hull Family Cardiac Fibrillation Management Laboratory, Division of Cardiology, University Health Network, Toronto General Hospital, Toronto, Ontario, Canada.
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2
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Liu CH, Chen YC, Lu YY, Lin YK, Higa S, Chen SA, Chen YJ. Gender Difference in Lithium-Induced Sodium Current Dysregulation and Ventricular Arrhythmogenesis in Right Ventricular Outflow Tract Cardiomyocytes. Biomedicines 2022; 10:biomedicines10112727. [PMID: 36359250 PMCID: PMC9687181 DOI: 10.3390/biomedicines10112727] [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: 09/19/2022] [Revised: 10/23/2022] [Accepted: 10/25/2022] [Indexed: 11/16/2022] Open
Abstract
Lithium intoxication induces Brugada-pattern ECG, ventricular arrhythmia, and sudden death with the predominant preference for the male over the female gender. This study investigated the mechanisms of gender difference in lithium-induced arrhythmogenesis. The ECG parameters were recorded in male and female rabbits before and after the intravenous administration of lithium chloride (LiCl) (1, 3, 10 mmol/kg). Patch clamps were used to study the sodium current (INa) and late sodium current (INa-late) in the isolated single male and female right ventricular outflow tract (RVOT) cardiomyocytes before and after LiCl. Male rabbits (n = 9) were more prone to developing lithium-induced Brugada-pattern ECG changes (incomplete right bundle branch block, ST elevation and QRS widening) with fatal arrhythmia (66.7% vs. 0%, p = 0.002) than in female (n = 7) rabbits at 10 mmol/kg (but not 1 or 3 mmol/kg). Compared to those in the female RVOT cardiomyocytes, LiCl (100 μM) reduced INa to a greater extent and increased INa-late in the male RVOT cardiomyocytes. Moreover, in the presence of ranolazine (the INa-late inhibitor, 3.6 mg/kg iv loading, followed by a second iv bolus 6.0 mg/kg administered 30 min later, n = 5), LiCl (10 mmol/kg) did not induce Brugada-pattern ECG changes (p < 0.005). The male gender is much predisposed to lithium-induced Brugada-pattern ECG changes with a greater impact on INa and INa-late in RVOT cardiomyocytes. Targeting INa-late may be a potential therapeutic strategy for Brugada syndrome-related ventricular tachyarrhythmia.
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Affiliation(s)
- Ching-Han Liu
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Armed Forces General Hospital, Kaohsiung 80284, Taiwan
- Division of Cardiology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
- Heart Rhythm Center, Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Cardiovascular Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei 11490, Taiwan
| | - Yen-Yu Lu
- Division of Cardiology, Sijhih Cathay General Hospital, Sijhih, New Taipei City 22174, Taiwan
- School of Medicine, Fu-Jen Catholic University, New Taipei City 24257, Taiwan
| | - Yung-Kuo Lin
- Cardiovascular Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11042, Taiwan
| | - Satoshi Higa
- Cardiac Electrophysiology and Pacing Laboratory, Division of Cardiovascular Medicine, Makiminato Central Hospital, Urasoe 901-2131, Okinawa, Japan
| | - Shih-Ann Chen
- Heart Rhythm Center, Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Cardiovascular Center, Taichung Veterans General Hospital, Taichung 40705, Taiwan
- Department of Post-Baccalaureate Medicine, College of Medicine, National Chung Hsing University, Taichung 40227, Taiwan
- Correspondence: (S.-A.C.); (Y.-J.C.)
| | - Yi-Jen Chen
- Cardiovascular Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11042, Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11042, Taiwan
- Correspondence: (S.-A.C.); (Y.-J.C.)
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Chung CT, Bazoukis G, Radford D, Coakley-Youngs E, Rajan R, Matusik PT, Liu T, Letsas K, Lee S, Tse G. Predictive risk models for forecasting arrhythmic outcomes in Brugada syndrome: A focused review. J Electrocardiol 2022; 72:28-34. [PMID: 35287003 DOI: 10.1016/j.jelectrocard.2022.02.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 02/19/2022] [Accepted: 02/20/2022] [Indexed: 12/20/2022]
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4
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Mascia G, Bona RD, Ameri P, Canepa M, Porto I, Parati G, Crotti L, Brignole M. Brugada syndrome and syncope: a practical approach for diagnosis and treatment. Europace 2021; 23:996-1002. [PMID: 33367713 DOI: 10.1093/europace/euaa370] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/17/2020] [Indexed: 11/13/2022] Open
Abstract
Syncope in patients with Brugada electrocardiogram pattern may represent a conundrum in the decision algorithm because incidental benign forms, especially neurally mediated syncope, are very frequent in this syndrome similarly to the general population. Arrhythmic syncope in Brugada syndrome typically results from a self-terminating sustained ventricular tachycardia or paroxysmal ventricular fibrillation, potentially leading to sudden cardiac death. Distinguishing syncope due to malignant arrhythmias from a benign form is often difficult unless an electrocardiogram is recorded during the episode. We performed a review of the existing literature and propose a practical approach for diagnosis and treatment of the patients with Brugada syndrome and syncope.
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Affiliation(s)
- Giuseppe Mascia
- Cardiovascular Disease Unit, IRCCS Ospedale Policlinico San Martino, Genova, Italy.,Department of Internal Medicine, University of Genoa, Genova, Italy
| | - Roberta Della Bona
- Cardiovascular Disease Unit, IRCCS Ospedale Policlinico San Martino, Genova, Italy.,Department of Internal Medicine, University of Genoa, Genova, Italy
| | - Pietro Ameri
- Cardiovascular Disease Unit, IRCCS Ospedale Policlinico San Martino, Genova, Italy.,Department of Internal Medicine, University of Genoa, Genova, Italy
| | - Marco Canepa
- Cardiovascular Disease Unit, IRCCS Ospedale Policlinico San Martino, Genova, Italy.,Department of Internal Medicine, University of Genoa, Genova, Italy
| | - Italo Porto
- Cardiovascular Disease Unit, IRCCS Ospedale Policlinico San Martino, Genova, Italy.,Department of Internal Medicine, University of Genoa, Genova, Italy
| | - Gianfranco Parati
- Department of Cardiovascular, Neural and Metabolic Sciences, Istituto Auxologico Italiano, IRCCS, San Luca Hospital, Milan, Italy.,Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
| | - Lia Crotti
- Department of Cardiovascular, Neural and Metabolic Sciences, Istituto Auxologico Italiano, IRCCS, San Luca Hospital, Milan, Italy.,Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy.,Department of Cardiovascular, Neural and Metabolic Sciences, Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin, Milan, Italy
| | - Michele Brignole
- Department of Cardiovascular, Neural and Metabolic Sciences, Istituto Auxologico Italiano, IRCCS, San Luca Hospital, Milan, Italy.,Department of Cardiovascular, Neural and Metabolic Sciences, Istituto Auxologico Italiano, IRCCS, Faint & Fall Programme, Ospedale San Luca, Piazzale Brescia 20, 20149 Milan, Italy.,Department of Cardiology, Arrhythmologic Centre, Ospedali del Tigullio, Lavagna, Italy
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Lee S, Wong WT, Wong ICK, Mak C, Mok NS, Liu T, Tse G. Ventricular Tachyarrhythmia Risk in Paediatric/Young vs. Adult Brugada Syndrome Patients: A Territory-Wide Study. Front Cardiovasc Med 2021; 8:671666. [PMID: 34179137 PMCID: PMC8225934 DOI: 10.3389/fcvm.2021.671666] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 05/18/2021] [Indexed: 12/22/2022] Open
Abstract
Introduction: Brugada syndrome (BrS) is a cardiac ion channelopathy with a higher prevalence in Asia compared to the Western populations. The present study compared the differences in clinical and electrocardiographic (ECG) presentation between paediatric/young (≤25 years old) and adult (>25 years) BrS patients. Method: This was a territory-wide retrospective cohort study of consecutive BrS patients presenting to public hospitals in Hong Kong. The primary outcome was spontaneous ventricular tachycardia/ventricular fibrillation (VT/VF). Results: The cohort consists of 550 consecutive patients (median age of initial presentation = 51 ± 23 years; female = 7.3%; follow-up period = 83 ± 80 months), divided into adult (n = 505, mean age of initial presentation = 52 ± 19 years; female = 6.7%; mean follow-up period = 83 ± 80 months) and paediatric/young subgroups (n = 45, mean age of initial presentation = 21 ± 5 years, female = 13.3%, mean follow-up period = 73 ± 83 months). The mean annual VT/VF incidence rate were 17 and 25 cases per 1,000 patient-year, respectively. Multivariate analysis showed that initial presentation of type 1 pattern (HR = 1.80, 95% CI = [1.02, 3.15], p = 0.041), initial asymptomatic presentation (HR = 0.26, 95% CI = [0.07, 0.94], p = 0.040) and increased P-wave axis (HR = 0.98, 95% CI = [0.96, 1.00], p = 0.036) were significant predictors of VT/VF for the adult subgroup. Only initial presentation of VT/VF was predictive (HR = 29.30, 95% CI = [1.75, 492.00], p = 0.019) in the paediatric/young subgroup. Conclusion: Clinical and ECG presentation of BrS vary between the paediatric/young and adult population in BrS. Risk stratification and management strategies for younger patients should take into consideration and adopt an individualised approach.
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Affiliation(s)
- Sharen Lee
- Cardiovascular Analytics Group, Laboratory of Cardiovascular Physiology, Hong Kong, China
| | - Wing Tak Wong
- State Key Laboratory of Agrobiotechnology (CUHK), School of Life Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - Ian Chi Kei Wong
- Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,School of Pharmacy, University College London, London, United Kingdom
| | - Chloe Mak
- Department of Pathology, Hong Kong Children's Hospital, Hong Kong, China
| | - Ngai Shing Mok
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Hong Kong, China
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Gary Tse
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China.,Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,Kent and Medway Medical School, Canterbury, United Kingdom
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Abstract
Brugada syndrome is an inherited cardiac condition characterized by a typical electrocardiogram signature of coved-type ST-segment elevation in the right precordial leads and ventricular arrhythmias leading to sudden cardiac death, in the absence of unequivocal structural heart disease. Brugada syndrome specifically affects the right ventricle, which predisposes to cardiac arrest. Besides medical management with quinidine, emerging data indicate that catheter ablation can help reduce the ventricular arrhythmia burden in these patients. This review explores the mechanisms of ventricular arrhythmia, current approaches and evidence for ablating the epicardial arrhythmogenic substrate in this condition.
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Li KHC, Lee S, Yin C, Liu T, Ngarmukos T, Conte G, Yan GX, Sy RW, Letsas KP, Tse G. Brugada syndrome: A comprehensive review of pathophysiological mechanisms and risk stratification strategies. IJC HEART & VASCULATURE 2020; 26:100468. [PMID: 31993492 PMCID: PMC6974766 DOI: 10.1016/j.ijcha.2020.100468] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 01/01/2020] [Accepted: 01/02/2020] [Indexed: 12/17/2022]
Abstract
Brugada syndrome (BrS) is an inherited ion channel channelopathy predisposing to ventricular arrhythmias and sudden cardiac death. Originally believed to be predominantly associated with mutations in SCN5A encoding for the cardiac sodium channel, mutations of 18 genes other than SCN5A have been implicated in the pathogenesis of BrS to date. Diagnosis is based on the presence of a spontaneous or drug-induced coved-type ST segment elevation. The predominant electrophysiological mechanism underlying BrS remains disputed, commonly revolving around the three main hypotheses based on abnormal repolarization, depolarization or current-load match. Evidence from computational modelling, pre-clinical and clinical studies illustrates that molecular abnormalities found in BrS lead to alterations in excitation wavelength (λ), which ultimately elevates arrhythmic risk. A major challenge for clinicians in managing this condition is the difficulty in predicting the subset of patients who will suffer from life-threatening ventricular arrhythmic events. Several repolarization risk markers have been used thus far, but these neglect the contributions of conduction abnormalities in the form of slowing and dispersion. Indices incorporating both repolarization and conduction based on the concept of λ have recently been proposed. These may have better predictive values than the existing markers. Current treatment options include pharmacological therapy to reduce the occurrence of arrhythmic events or to abort these episodes, and interventions such as implantable cardioverter-defibrillator insertion or radiofrequency ablation of abnormal arrhythmic substrate.
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Affiliation(s)
- Ka Hou Christien Li
- Faculty of Medicine, Newcastle University, Newcastle, United Kingdom.,Laboratory of Cardiovascular Physiology, Li Ka Shing Institute of Health Sciences, Hong Kong, SAR, PR China
| | - Sharen Lee
- Laboratory of Cardiovascular Physiology, Li Ka Shing Institute of Health Sciences, Hong Kong, SAR, PR China
| | - Chengye Yin
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, PR China
| | - Tachapong Ngarmukos
- Department of Medicine Faculty of Medicine Ramathibodi Hospital Mahidol University, Bangkok, Thailand
| | - Giulio Conte
- Division of Cardiology, Cardiocentro Ticino, Lugano, Switzerland
| | - Gan-Xin Yan
- Lankenau Institute for Medical Research and Lankenau Medical Center, Wynnewood, PA, USA
| | - Raymond W Sy
- Department of Cardiology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia.,Sydney Medical School, University of Sydney, Camperdown, New South Wales, Australia
| | - Konstantinos P Letsas
- Second Department of Cardiology, Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Athens, Greece
| | - Gary Tse
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, PR China.,Xiamen Cardiovascular Hospital, Xiamen University, Xiamen, China
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8
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Tse G, Lee S, Gong M, Mililis P, Asvestas D, Bazoukis G, Roever L, Jeevaratnam K, Hothi SS, Li KHC, Liu T, Letsas KP. Restitution metrics in Brugada syndrome: a systematic review and meta-analysis. J Interv Card Electrophysiol 2019; 57:319-327. [PMID: 31836966 DOI: 10.1007/s10840-019-00675-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 11/19/2019] [Indexed: 12/15/2022]
Abstract
BACKGROUND Brugada syndrome (BrS) is an ion channelopathy that predisposes affected subjects to ventricular tachycardia/fibrillation (VT/VF) and sudden cardiac death. Restitution analysis has been examined in BrS patients but not all studies have reported significant differences between BrS patients and controls. Therefore, we conducted a systematic review and meta-analysis to investigate the different restitution indices used in BrS. METHODS PubMed and Embase were searched until April 7, 2019, identifying 20 and 27 studies. RESULTS A total of ten studies involving 178 BrS (mean age 38 years old, 63% male) and 102 controls (mean age 31 years old, 42% male) were included in this systematic review. Pacing was carried out at the right ventricular outflow tract (RVOT)/right ventricular apex (RPA) (n = 4), RPA (n = 4), or right atrium (RA) (n = 1). Basic cycle lengths of 400 (n = 4), 500 (n = 2), 600 (n = 6) and 750 ms (n = 1) were used. Recording methods include electrograms (n = 4), monophasic action potentials (n = 5), and electrocardiograms (n = 1). Signals were obtained from the RVOT (n = 8), RVA (n = 3), RA (n = 1), or the body surface (n = 1). The maximum restitution slope for endocardial repolarization at the RVOT was 0.87 for BrS patients (n = 5; 95% confidence interval [CI] 0.68-1.07) compared with 0.74 in control subjects (n = 4; 95% CI 0.42-1.06), with a significant mean difference of 0.40 (n = 4; 95% CI 0.11-0.69; P = 0.007). CONCLUSIONS Steeper endocardial repolarization restitution slopes are found in BrS patients compared with controls at baseline. Restitution analysis can provide important information for risk stratification in BrS.
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Affiliation(s)
- Gary Tse
- Xiamen Cardiovascular Hospital Affiliated to Xiamen University, Xiamen, Fujian, People's Republic of China. .,Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, 300211, People's Republic of China.
| | - Sharen Lee
- Laboratory of Cardiovascular Physiology, Li Ka Shing Institute of Health Sciences, Hong Kong, SAR, People's Republic of China
| | - Mengqi Gong
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, 300211, People's Republic of China
| | - Panagiotis Mililis
- Second Department of Cardiology, Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Athens, Greece
| | - Dimitrios Asvestas
- Second Department of Cardiology, Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Athens, Greece
| | - George Bazoukis
- Second Department of Cardiology, Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Athens, Greece
| | - Leonardo Roever
- Department of Clinical Research, Federal University of Uberlândia, Uberlândia, MG, Brazil
| | | | - Sandeep S Hothi
- Heart and Lung Centre, New Cross Hospital, Wolverhampton, UK
| | - Ka Hou Christien Li
- Xiamen Cardiovascular Hospital Affiliated to Xiamen University, Xiamen, Fujian, People's Republic of China.,Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, 300211, People's Republic of China.,Faculty of Medicine, Newcastle University, Newcastle, UK
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, 300211, People's Republic of China
| | - Konstantinos P Letsas
- Second Department of Cardiology, Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Athens, Greece.
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Finlay M, Bhar-Amato J, Ng KE, Santos D, Orini M, Vyas V, Taggart P, Grace AA, Huang CLH, Lambiase PD, Tinker A. Autonomic modulation of the electrical substrate in mice haploinsufficient for cardiac sodium channels: a model of the Brugada syndrome. Am J Physiol Cell Physiol 2019; 317:C576-C583. [PMID: 31291141 DOI: 10.1152/ajpcell.00028.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A murine line haploinsufficient in the cardiac sodium channel has been used to model human Brugada syndrome: a disease causing sudden cardiac death due to lethal ventricular arrhythmias. We explored the effects of cholinergic tone on electrophysiological parameters in wild-type and genetically modified, heterozygous, Scn5a+/- knockout mice. Scn5a+/- ventricular slices showed longer refractory periods than wild-type both at baseline and during isoprenaline challenge. Scn5a+/- hearts also showed lower conduction velocities and increased mean increase in delay than did littermate controls at baseline and blunted responses to isoprenaline challenge. Carbachol exerted limited effects but reversed the effects of isoprenaline with coapplication. Scn5a+/- mice showed a reduction in conduction reserve in that isoprenaline no longer increased conduction velocity, and this was not antagonized by muscarinic agonists.
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Affiliation(s)
- Malcolm Finlay
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Justine Bhar-Amato
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Keat-Eng Ng
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Diogo Santos
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Michele Orini
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Vishal Vyas
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Peter Taggart
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Andrew A Grace
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Christopher L-H Huang
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Pier D Lambiase
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Andrew Tinker
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
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