1
|
Li Y, Lang S, Akin I, Zhou X, El-Battrawy I. Brugada Syndrome: Different Experimental Models and the Role of Human Cardiomyocytes From Induced Pluripotent Stem Cells. J Am Heart Assoc 2022; 11:e024410. [PMID: 35322667 PMCID: PMC9075459 DOI: 10.1161/jaha.121.024410] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Brugada syndrome (BrS) is an inherited and rare cardiac arrhythmogenic disease associated with an increased risk of ventricular fibrillation and sudden cardiac death. Different genes have been linked to BrS. The majority of mutations are located in the SCN5A gene, and the typical abnormal ECG is an elevation of the ST segment in the right precordial leads V1 to V3. The pathophysiological mechanisms of BrS were studied in different models, including animal models, heterologous expression systems, and human-induced pluripotent stem cell-derived cardiomyocyte models. Currently, only a few BrS studies have used human-induced pluripotent stem cell-derived cardiomyocytes, most of which have focused on genotype-phenotype correlations and drug screening. The combination of new technologies, such as clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 (CRISPR associated protein 9)-mediated genome editing and 3-dimensional engineered heart tissues, has provided novel insights into the pathophysiological mechanisms of the disease and could offer opportunities to improve the diagnosis and treatment of patients with BrS. This review aimed to compare different models of BrS for a better understanding of the roles of human-induced pluripotent stem cell-derived cardiomyocytes in current BrS research and personalized medicine at a later stage.
Collapse
Affiliation(s)
- Yingrui Li
- First Department of Medicine Medical Faculty Mannheim University Medical Centre Mannheim (UMM)University of Heidelberg Mannheim Germany
| | - Siegfried Lang
- First Department of Medicine Medical Faculty Mannheim University Medical Centre Mannheim (UMM)University of Heidelberg Mannheim Germany.,DZHK (German Center for Cardiovascular Research), Partner Site, Heidelberg-Mannheim Mannheim Germany
| | - Ibrahim Akin
- First Department of Medicine Medical Faculty Mannheim University Medical Centre Mannheim (UMM)University of Heidelberg Mannheim Germany.,DZHK (German Center for Cardiovascular Research), Partner Site, Heidelberg-Mannheim Mannheim Germany
| | - Xiaobo Zhou
- First Department of Medicine Medical Faculty Mannheim University Medical Centre Mannheim (UMM)University of Heidelberg Mannheim Germany.,Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province Institute of Cardiovascular Research Southwest Medical University Luzhou Sichuan China.,DZHK (German Center for Cardiovascular Research), Partner Site, Heidelberg-Mannheim Mannheim Germany
| | - Ibrahim El-Battrawy
- First Department of Medicine Medical Faculty Mannheim University Medical Centre Mannheim (UMM)University of Heidelberg Mannheim Germany.,DZHK (German Center for Cardiovascular Research), Partner Site, Heidelberg-Mannheim Mannheim Germany.,Department of Cardiology and Angiology Bergmannsheil Bochum Medical Clinic II Ruhr University Bochum Germany
| |
Collapse
|
2
|
Approach to inherited arrhythmias in pregnancy. INTERNATIONAL JOURNAL OF CARDIOLOGY CONGENITAL HEART DISEASE 2021. [DOI: 10.1016/j.ijcchd.2021.100264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
3
|
Antzelevitch C, Di Diego JM. J wave syndromes: What's new? Trends Cardiovasc Med 2021; 32:350-363. [PMID: 34256120 PMCID: PMC8743304 DOI: 10.1016/j.tcm.2021.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 07/03/2021] [Accepted: 07/04/2021] [Indexed: 12/19/2022]
Abstract
Among the inherited ion channelopathies associated with potentially life-threatening ventricular arrhythmia syndromes in nominally structurally normal hearts are the J wave syndromes, which include the Brugada (BrS) and early repolarization (ERS) syndromes. These ion channelopathies are responsible for sudden cardiac death (SCD), most often in young adults in the third and fourth decade of life. Our principal goal in this review is to briefly outline the clinical characteristics, as well as the molecular, ionic, cellular, and genetic mechanisms underlying these primary electrical diseases that have challenged the cardiology community over the past two decades. In addition, we discuss our recently developed whole-heart experimental model of BrS, providing compelling evidence in support of the repolarization hypothesis for the BrS phenotype as well as novel findings demonstrating that voltage-gated sodium and transient outward current channels can modulate each other's function via trafficking and gating mechanisms with implications for improved understanding of the genetics of both cardiac and neuronal syndromes.
Collapse
Affiliation(s)
- Charles Antzelevitch
- Distinguished Professor Emeritus and Executive Director, Cardiovascular Research, Lankenau Institute for Medical Research, Wynnewood, PA 19096, USA; Lankenau Institute for Medical Research, Wynnwoddm PA USA; Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia PA, USA.
| | | |
Collapse
|
4
|
Roy S, MainakMukhopadhyay. Ventricular Arrhythmia Risk Based on Ethnicity in COVID-19 Patients on Hydroxychloroquine and Azithromycin Combination: Viewpoint. SN COMPREHENSIVE CLINICAL MEDICINE 2020; 2:1019-1024. [PMID: 32838150 PMCID: PMC7320242 DOI: 10.1007/s42399-020-00370-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Accepted: 06/17/2020] [Indexed: 12/19/2022]
Abstract
There are many reports available now, which are mostly observational or registry trial outcomes having varied results on coronavirus 2019 (COVID-19) patients put on hydroxychloroquine and azithromycin combination. Some are showing increased in-hospital mortality and ventricular arrhythmia increase, while some are showing overall benefit with significant viral RNA load reduction. Everyday things are getting more complicated with the publication of these different outcomes. This needs to be addressed.
Collapse
Affiliation(s)
- Sayak Roy
- Consultant Physician, MedicaSuperspeciality Hospital, Kolkata, India
| | | |
Collapse
|
5
|
Tse G, Li KHC, Li G, Liu T, Bazoukis G, Wong WT, Chan MTV, Wong MCS, Xia Y, Letsas KP, Chan GCP, Chan YS, Wu WKK. Higher Dispersion Measures of Conduction and Repolarization in Type 1 Compared to Non-type 1 Brugada Syndrome Patients: An Electrocardiographic Study From a Single Center. Front Cardiovasc Med 2018; 5:132. [PMID: 30338262 PMCID: PMC6180153 DOI: 10.3389/fcvm.2018.00132] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 09/04/2018] [Indexed: 12/26/2022] Open
Abstract
Background: Brugada syndrome (BrS) is a cardiac ion channelopathy that predisposes affected individuals to sudden cardiac death (SCD). Type 1 BrS is thought to take a more malignant clinical course than non-type 1 BrS. We hypothesized that the degrees of abnormal repolarization and conduction are greater in type 1 subjects and these differences can be detected by electrocardiography (ECG). Methods: Electrocardiographic data from spontaneous type 1 and non-type 1 BrS patients were analyzed. ECG parameters were measured from leads V1 to V3. Values were expressed as median [lower quartile-upper quartile] and compared using Kruskal-Wallis ANOVA. Results: Compared to non-type 1 BrS patients (n = 29), patients with spontaneous type 1 patterns (n = 22) showed similar (P > 0.05) heart rate (73 [64-77] vs. 68 [62-80] bpm), QRS duration (136 [124-161] vs. 127 [117-144] ms), uncorrected QT (418 [393-443] vs. 402 [386-424] ms) and corrected QT intervals (457 [414-474] vs. 430 [417-457] ms), JTpeak intervals (174 [144-183] vs. 174 [150-188] ms), Tpeak- Tend intervals (101 [93-120] vs. 99 [90-105] ms), Tpeak- Tend/QT ratios (0.25 [0.23-0.27] vs. 0.24 [0.22-0.27]), Tpeak- Tend/QRS (0.77 [0.62-0.87] vs. 0.77 [0.69-0.86]), Tpeak- Tend/(QRS × QT) (0.00074 [0.00034-0.00096] vs. 0.00073 [0.00048-0.00012] ms-1), index of Cardiac Electrophysiological Balance (iCEB, QT/QRS, marker of wavelength: 3.14 [2.56-3.35] vs. 3.21 [2.85-3.46]) and corrected iCEB (QTc/QRS: 3.25 [2.91-3.73] vs. 3.49 [2.99-3.78]). Higher QRS dispersion was seen in type 1 subjects (QRSd: 34 [24-66] vs. 24 [12-34] ms) but QT dispersion (QTd: 48 [39-71] vs. 43 [22-94] ms), QTc dispersion (QTcd: 52 [41-79] vs. 46 [23-104] ms), JTpeak dispersion (44 [23-62] vs. 45 [30-62] ms), Tpeak- Tend dispersion (28 [15-34] vs. 29 [22-53] ms) or Tpeak- Tend/QT dispersion (0.06 [0.03-0.08] vs. 0.08 [0.04-0.12]) did not differ between the two groups. Type 1 subjects showed higher (QRSd × Tpeak- Tend)/QRS (25 [19-44] vs. 19 [9-30] ms) but similar iCEB dispersion (0.83 [0.49-1.14] vs. 0.61 [0.34-0.92]) and iCEBc dispersion (0.93 [0.51-1.15] vs. 0.65 [0.39-0.96]). Conclusion: Higher levels of dispersion in conduction and repolarization are found in type 1 than non-type 1 BrS patients, potentially explaining the higher incidence of ventricular arrhythmias in the former group.
Collapse
Affiliation(s)
- Gary Tse
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
- Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | - Ka Hou Christien Li
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
- Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
- Faculty of Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Guangping Li
- 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
| | - 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
| | - George Bazoukis
- Laboratory of Cardiac Electrophysiology, Second Department of Cardiology, Evangelismos General Hospital of Athens, Athens, Greece
| | - Wing Tak Wong
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Matthew T. V. Chan
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Martin C. S. Wong
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Yunlong Xia
- Department of Cardiology, First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Konstantinos P. Letsas
- Laboratory of Cardiac Electrophysiology, Second Department of Cardiology, Evangelismos General Hospital of Athens, Athens, Greece
| | - Gary Chin Pang Chan
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | - Yat Sun Chan
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | - William K. K. Wu
- Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong, China
| |
Collapse
|
6
|
Asvestas D, Tse G, Baranchuk A, Bazoukis G, Liu T, Saplaouras A, Korantzopoulos P, Goga C, Efremidis M, Sideris A, Letsas KP. High risk electrocardiographic markers in Brugada syndrome. IJC HEART & VASCULATURE 2018; 18:58-64. [PMID: 29876505 PMCID: PMC5988483 DOI: 10.1016/j.ijcha.2018.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 12/19/2022]
Abstract
Several clinical, electrocardiographic (ECG) and electrophysiological markers have been proposed to provide optimal risk stratification in patients with Brugada syndrome (BrS). Of the different markers, only a spontaneous type 1 ECG pattern has clearly shown a sufficiently high predictive value. This review article highlights specific ECG markers based on depolarization and/or repolarization that have been associated with an increased risk of arrhythmic events in patients with BrS.
Collapse
Affiliation(s)
- Dimitrios Asvestas
- Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Greece
| | - Gary Tse
- Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong, SAR, PR China
- Li Ka Shing Institute of Health Sciences, 30-32 Ngan Shing St, Chinese University of Hong Kong, Hong Kong, SAR, PR China
| | - Adrian Baranchuk
- Division of Cardiology, Queen's University, Kingston General Hospital, Kingston, Ontario, Canada
| | - George Bazoukis
- Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Greece
| | - Tong Liu
- Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, PR China
| | - Athanasios Saplaouras
- Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Greece
| | | | - Christina Goga
- Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Greece
| | - Michael Efremidis
- Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Greece
| | - Antonios Sideris
- Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Greece
| | - Konstantinos P. Letsas
- Laboratory of Cardiac Electrophysiology, Evangelismos General Hospital of Athens, Greece
| |
Collapse
|
7
|
Abstract
Brugada syndrome (BrS) is a cardiac disease caused by an inherited ion channelopathy associated with a propensity to develop ventricular fibrillation. Implantable cardioverter defibrillator implantation is recommended in BrS, based on the clinical presentation in the presence of diagnostic ECG criteria. Implantable cardioverter defibrillator implantation is not always indicated or sufficient in BrS, and is associated with a high device complication rate. Pharmacological therapy aimed at rebalancing the membrane action potential can prevent arrhythmogenesis in BrS. Quinidine, a class 1A antiarrhythmic drug with significant Ito blocking properties, is the most extensively used drug for the prevention of arrhythmias in BrS. The present review provides contemporary data gathered on all drugs effective in the therapy of BrS, and on ineffective or contraindicated antiarrhythmic drugs.
Collapse
Key Words
- Brugada syndrome,
- arrhythmia,
- bepridil,
- cilostazol,
- denopamine,
- disopyramide,
- isoproterenol,
- orciprenaline,
- pharmacology,
- quinidine,
- quinine
Collapse
Affiliation(s)
- Oholi Tovia Brodie
- University of Miami Miller School of Medicine Miami, USA.,Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University Tel-Aviv, Israel
| | - Yoav Michowitz
- Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University Tel-Aviv, Israel
| | - Bernard Belhassen
- Tel-Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel-Aviv University Tel-Aviv, Israel
| |
Collapse
|
8
|
Ben-Johny M, Dick IE, Sang L, Limpitikul WB, Kang PW, Niu J, Banerjee R, Yang W, Babich JS, Issa JB, Lee SR, Namkung H, Li J, Zhang M, Yang PS, Bazzazi H, Adams PJ, Joshi-Mukherjee R, Yue DN, Yue DT. Towards a Unified Theory of Calmodulin Regulation (Calmodulation) of Voltage-Gated Calcium and Sodium Channels. Curr Mol Pharmacol 2016; 8:188-205. [PMID: 25966688 DOI: 10.2174/1874467208666150507110359] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 01/29/2015] [Accepted: 04/20/2015] [Indexed: 12/13/2022]
Abstract
Voltage-gated Na and Ca(2+) channels represent two major ion channel families that enable myriad biological functions including the generation of action potentials and the coupling of electrical and chemical signaling in cells. Calmodulin regulation (calmodulation) of these ion channels comprises a vital feedback mechanism with distinct physiological implications. Though long-sought, a shared understanding of the channel families remained elusive for two decades as the functional manifestations and the structural underpinnings of this modulation often appeared to diverge. Here, we review recent advancements in the understanding of calmodulation of Ca(2+) and Na channels that suggest a remarkable similarity in their regulatory scheme. This interrelation between the two channel families now paves the way towards a unified mechanistic framework to understand vital calmodulin-dependent feedback and offers shared principles to approach related channelopathic diseases. An exciting era of synergistic study now looms.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - David T Yue
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Ross Building, Room 713, 720 Rutland Avenue, Baltimore, MD 21205, USA.
| |
Collapse
|
9
|
García-Molina E, Sabater-Molina M, Muñoz C, Ruiz-Espejo F, Gimeno JR. An R1632C variant in the SCN5A gene causing Brugada syndrome. Mol Med Rep 2016; 13:4677-80. [PMID: 27082542 DOI: 10.3892/mmr.2016.5100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 07/10/2015] [Indexed: 11/05/2022] Open
Abstract
Brugada syndrome (BS) is an electrical disease, inherited in an autosomal dominant manner. BS is caused by mutations in up to 13 different genes. SCN5A is the gene most frequently mutated in BS, although this presents an incomplete penetrance. The present case study investigated the SCN5A gene in a family exhibiting BS. Direct sequencing of the SCN5A gene was performed to identify mutations and a familial investigation was performed. A novel variant was identified in the voltage‑sensing domain of the SCN5A protein. This familial investigation revealed one novel asymptomatic carrier in the family. Genetic investigations are useful to classify individuals who require more frequent clinical monitoring and to stratify the risk of developing the disease.
Collapse
Affiliation(s)
- Esperanza García-Molina
- Department of Clinical Analysis, Virgen de la Arrixaca University Hospital, El Palmar, 30120 Murcia, Spain
| | - María Sabater-Molina
- Department of Clinical Analysis, Virgen de la Arrixaca University Hospital, El Palmar, 30120 Murcia, Spain
| | - Carmen Muñoz
- Department of Cardiology, Virgen de la Arrixaca University Hospital, El Palmar, 30120 Murcia, Spain
| | - Francisco Ruiz-Espejo
- Department of Clinical Analysis, Virgen de la Arrixaca University Hospital, El Palmar, 30120 Murcia, Spain
| | - Juan R Gimeno
- Department of Cardiology, Virgen de la Arrixaca University Hospital, El Palmar, 30120 Murcia, Spain
| |
Collapse
|
10
|
Tse G, Tse V, Yeo JM, Sun B. Atrial Anti-Arrhythmic Effects of Heptanol in Langendorff-Perfused Mouse Hearts. PLoS One 2016; 11:e0148858. [PMID: 26872148 PMCID: PMC4752503 DOI: 10.1371/journal.pone.0148858] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 01/24/2016] [Indexed: 12/24/2022] Open
Abstract
Acute effects of heptanol (0.1 to 2 mM) on atrial electrophysiology were explored in Langendorff-perfused mouse hearts. Left atrial bipolar electrogram or monophasic action potential recordings were obtained during right atrial stimulation. Regular pacing at 8 Hz elicited atrial activity in 11 out of 11 hearts without inducing atrial arrhythmias. Programmed electrical stimulation using a S1S2 protocol provoked atrial tachy-arrhythmias in 9 of 17 hearts. In the initially arrhythmic group, 2 mM heptanol exerted anti-arrhythmic effects (Fisher’s exact test, P < 0.05) and increased atrial effective refractory period (ERP) from 26.0 ± 1.9 to 57.1 ± 2.5 ms (ANOVA, P < 0.001) despite increasing activation latency from 18.7 ± 1.1 to 28.9 ± 2.1 ms (P < 0.001) and leaving action potential duration at 90% repolarization (APD90) unaltered (25.6 ± 1.2 vs. 27.2 ± 1.2 ms; P > 0.05), which led to increases in ERP/latency ratio from 1.4 ± 0.1 to 2.1 ± 0.2 and ERP/APD90 ratio from 1.0 ± 0.1 to 2.1 ± 0.2 (P < 0.001). In contrast, in the initially non-arrhythmic group, heptanol did not alter arrhythmogenicity, increased AERP from 47.3 ± 5.3 to 54.5 ± 3.1 ms (P < 0.05) and activation latency from 23.7 ± 2.2 to 31.3 ± 2.5 ms and did not alter APD90 (24.1 ± 1.2 vs. 25.0 ± 2.3 ms; P > 0.05), leaving both AERP/latency ratio (2.1 ± 0.3 vs. 1.9 ± 0.2; P > 0.05) and ERP/APD90 ratio (2.0 ± 0.2 vs. 2.1 ± 0.1; P > 0.05) unaltered. Lower heptanol concentrations (0.1, 0.5 and 1 mM) did not alter arrhythmogenicity or the above parameters. The present findings contrast with known ventricular pro-arrhythmic effects of heptanol associated with decreased ERP/latency ratio, despite increased ERP/APD ratio observed in both the atria and ventricles.
Collapse
Affiliation(s)
- Gary Tse
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong S.A.R., China
| | - Vivian Tse
- Department of Physiology, McGill University, Montreal, Canada
| | - Jie Ming Yeo
- Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Bing Sun
- Department of Cardiology, Tongji University Affiliated Tongji Hospital, Shanghai, China
- * E-mail:
| |
Collapse
|
11
|
Dick IE, Limpitikul WB, Niu J, Banerjee R, Issa JB, Ben-Johny M, Adams PJ, Kang PW, Lee SR, Sang L, Yang W, Babich J, Zhang M, Bazazzi H, Yue NC, Tomaselli GF. A rendezvous with the queen of ion channels: Three decades of ion channel research by David T Yue and his Calcium Signals Laboratory. Channels (Austin) 2015; 10:20-32. [PMID: 26176690 DOI: 10.1080/19336950.2015.1051272] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
David T. Yue was a renowned biophysicist who dedicated his life to the study of Ca(2+) signaling in cells. In the wake of his passing, we are left not only with a feeling of great loss, but with a tremendous and impactful body of work contributed by a remarkable man. David's research spanned the spectrum from atomic structure to organ systems, with a quantitative rigor aimed at understanding the fundamental mechanisms underlying biological function. Along the way he developed new tools and approaches, enabling not only his own research but that of his contemporaries and those who will come after him. While we cannot hope to replicate the eloquence and style we are accustomed to in David's writing, we nonetheless undertake a review of David's chosen field of study with a focus on many of his contributions to the calcium channel field.
Collapse
Affiliation(s)
- Ivy E Dick
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - Worawan B Limpitikul
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - Jacqueline Niu
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - Rahul Banerjee
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - John B Issa
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - Manu Ben-Johny
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - Paul J Adams
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA.,b Kwantlen Polytechnic University ; Surrey , BC Canada
| | - Po Wei Kang
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - Shin Rong Lee
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - Lingjie Sang
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - Wanjun Yang
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - Jennifer Babich
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - Manning Zhang
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - Hojjat Bazazzi
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - Nancy C Yue
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| | - Gordon F Tomaselli
- a Calcium Signals Laboratory; Department of Biomedical Engineering ; Johns Hopkins University School of Medicine ; Baltimore , MD USA.,c Division of Cardiology; Department of Medicine ; Johns Hopkins University School of Medicine ; Baltimore , MD USA
| |
Collapse
|
12
|
Martin CA, Huang CLH, Matthews GDK. Recent Developments in the Management of Patients at Risk for Sudden Cardiac Death. Postgrad Med 2015; 123:84-94. [DOI: 10.3810/pgm.2011.03.2266] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
13
|
Qu Z, Weiss JN. Mechanisms of ventricular arrhythmias: from molecular fluctuations to electrical turbulence. Annu Rev Physiol 2014; 77:29-55. [PMID: 25340965 DOI: 10.1146/annurev-physiol-021014-071622] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Ventricular arrhythmias have complex causes and mechanisms. Despite extensive investigation involving many clinical, experimental, and computational studies, effective biological therapeutics are still very limited. In this article, we review our current understanding of the mechanisms of ventricular arrhythmias by summarizing the state of knowledge spanning from the molecular scale to electrical wave behavior at the tissue and organ scales and how the complex nonlinear interactions integrate into the dynamics of arrhythmias in the heart. We discuss the challenges that we face in synthesizing these dynamics to develop safe and effective novel therapeutic approaches.
Collapse
Affiliation(s)
- Zhilin Qu
- Departments of 1Medicine (Cardiology) and
| | | |
Collapse
|
14
|
García-Molina E, Lacunza J, Ruiz-Espejo F, Sabater M, García-Alberola A, Gimeno JR, Cañizares F, García A, Martínez P, Valdés M, Tovar I. A study of the SCN5A gene in a cohort of 76 patients with Brugada syndrome. Clin Genet 2012; 83:530-8. [PMID: 22984773 DOI: 10.1111/cge.12017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 09/11/2012] [Accepted: 09/11/2012] [Indexed: 11/29/2022]
Abstract
We aim to study the SCN5A gene in a cohort of Brugada syndrome (BS) patients and evaluate the genotype-phenotype correlation. BS is caused by mutations in up to 10 different genes, SCN5A being the most frequently involved. Large genomic rearrangements in SCN5A have been associated with conduction disease, but its prevalence in BS is unknown. Seventy-six non-related patients with BS were studied. Clinical characteristics and family risk profile were recorded. Direct sequencing and multiplex ligation-dependent probe amplification (MLPA) of the SCN5A gene for identification of mutations and larger rearrangements were performed, respectively. Eight patients (10.5%) had point mutations (R27H, E901K, G1743R (detected in three families), V728I, N1443S and E1152X). Patients with mutations had a trend toward a higher proportion of spontaneous type I Brugada electrocardiogram (ECG) (87.5% vs 52.9%, p = 0.06) and had evidence of familial disease (62.5%, vs 23.5%, p = 0.03). The symptoms and risk profile of the carriers were not different from wild-type probands. There were non-significant differences in the prevalence of type I ECG, syncope and history of arrhythmia in carriers of selected polymorphisms. None of the patients had any deletion/duplication in the SCN5A gene. In conclusion, 10.5% of our patients had mutations in the SCN5A gene. Patients with mutations seemed to have more spontaneous type I ECG, but no differences in syncope or arrhythmic events compared with patients without mutations. Larger studies are needed to evaluate the role of polymorphisms in the SCN5A in the expression of the phenotype and prognosis. Large rearrangements were not identified in the SCN5A gene using the MLPA technique.
Collapse
Affiliation(s)
- E García-Molina
- Department of Clinical Analysis, Virgen de la Arrixaca University Hospital, Murcia, Spain.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Abstract
T-wave alternans, a manifestation of repolarization alternans at the cellular level, is associated with lethal cardiac arrhythmias and sudden cardiac death. At the cellular level, several mechanisms can produce repolarization alternans, including: (1) electrical restitution resulting from collective ion channel recovery, which usually occurs at fast heart rates but can also occur at normal heart rates when action potential is prolonged resulting in a short diastolic interval; (2) the transient outward current, which tends to occur at normal or slow heart rates; (3) the dynamics of early after depolarizations, which tends to occur during bradycardia; and (4) intracellular calcium cycling alternans through its interaction with membrane voltage. In this review, we summarize the cellular mechanisms of alternans arising from these different mechanisms, and discuss their roles in arrhythmogenesis in the setting of cardiac disease.
Collapse
Affiliation(s)
- Zhilin Qu
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, California, USA.
| | | | | | | |
Collapse
|
16
|
|
17
|
Abstract
Sudden cardiac death stemming from ventricular arrhythmogenesis is one of the major causes of mortality in the developed world. Congenital and acquired forms of long QT syndrome (LQTS) are in turn associated with life threatening arrhythmias. Over the past decade our understanding of arrhythmogenic mechanisms in the setting of these diseases has increased greatly due to the creation of a number of animal models. Of these, the genetically amenable mouse has proved to be a particularly powerful tool. This review summarizes the congenital and acquired LQTS and describes the various mouse models that have been created to further probe arrhythmogenic mechanisms.
Collapse
Affiliation(s)
- M J Killeen
- Physiological Laboratory, University of Cambridge, Cambridge, UK.
| | | | | | | | | |
Collapse
|
18
|
Ten Tusscher KHWJ, Panfilov AV. Cell model for efficient simulation of wave propagation in human ventricular tissue under normal and pathological conditions. Phys Med Biol 2006; 51:6141-56. [PMID: 17110776 DOI: 10.1088/0031-9155/51/23/014] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In this paper, we formulate a model for human ventricular cells that is efficient enough for whole organ arrhythmia simulations yet detailed enough to capture the effects of cell level processes such as current blocks and channelopathies. The model is obtained from our detailed human ventricular cell model by using mathematical techniques to reduce the number of variables from 19 to nine. We carefully compare our full and reduced model at the single cell, cable and 2D tissue level and show that the reduced model has a very similar behaviour. Importantly, the new model correctly produces the effects of current blocks and channelopathies on AP and spiral wave behaviour, processes at the core of current day arrhythmia research. The new model is well over four times more efficient than the full model. We conclude that the new model can be used for efficient simulations of the effects of current changes on arrhythmias in the human heart.
Collapse
Affiliation(s)
- K H W J Ten Tusscher
- Department of Theoretical Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
| | | |
Collapse
|
19
|
Xia L, Zhang Y, Zhang H, Wei Q, Liu F, Crozier S. Simulation of Brugada syndrome using cellular and three-dimensional whole-heart modeling approaches. Physiol Meas 2006; 27:1125-42. [PMID: 17028406 DOI: 10.1088/0967-3334/27/11/006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Brugada syndrome (BS) is a genetic disease identified by an abnormal electrocardiogram (ECG) (mainly abnormal ECGs associated with right bundle branch block and ST-elevation in right precordial leads). BS can lead to increased risk of sudden cardiac death. Experimental studies on human ventricular myocardium with BS have been limited due to difficulties in obtaining data. Thus, the use of computer simulation is an important alternative. Most previous BS simulations were based on animal heart cell models. However, due to species differences, the use of human heart cell models, especially a model with three-dimensional whole-heart anatomical structure, is needed. In this study, we developed a model of the human ventricular action potential (AP) based on refining the ten Tusscher et al (2004 Am. J. Physiol. Heart Circ. Physiol. 286 H1573-89) model to incorporate newly available experimental data of some major ionic currents of human ventricular myocytes. These modified channels include the L-type calcium current (I(CaL)), fast sodium current (I(Na)), transient outward potassium current (I(to)), rapidly and slowly delayed rectifier potassium currents (I(Kr) and I(Ks)) and inward rectifier potassium current (I(Ki)). Transmural heterogeneity of APs for epicardial, endocardial and mid-myocardial (M) cells was simulated by varying the maximum conductance of I(Ks) and I(to). The modified AP models were then used to simulate the effects of BS on cellular AP and body surface potentials using a three-dimensional dynamic heart-torso model. Our main findings are as follows. (1) BS has little effect on the AP of endocardial or mid-myocardial cells, but has a large impact on the AP of epicardial cells. (2) A likely region of BS with abnormal cell AP is near the right ventricular outflow track, and the resulting ST-segment elevation is located in the median precordium area. These simulation results are consistent with experimental findings reported in the literature. The model can reproduce a variety of electrophysiological behaviors and provides a good basis for understanding the genesis of abnormal ECG under the condition of BS disease.
Collapse
Affiliation(s)
- Ling Xia
- Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China.
| | | | | | | | | | | |
Collapse
|
20
|
Flaim SN, Giles WR, McCulloch AD. Contributions of sustained INa and IKv43 to transmural heterogeneity of early repolarization and arrhythmogenesis in canine left ventricular myocytes. Am J Physiol Heart Circ Physiol 2006; 291:H2617-29. [PMID: 16829642 DOI: 10.1152/ajpheart.00350.2006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The roles of sustained components of I(Na) and I(Kv43) in shaping the action potentials (AP) of myocytes isolated from the canine left ventricle (LV) have not been studied in detail. Here we investigate the hypothesis that these two currents can contribute substantially to heterogeneity of early repolarization and arrhythmic risk. Quantitative data from voltage-clamp and expression profiling experiments were used to complete meaningful modifications to an existing "local control" model of canine midmyocardial myocyte excitation-contraction coupling for epicardial and endocardial cells. We include 1) heterogeneous I(Kv43), I(Ks), and I(SERCA) density; 2) modulation of I(Kv43) by Kv channel interacting protein type 2 (KChIP2) channel subunits; 3) a possible Ca(2+)-dependent open-state inactivation of I(Kv43); and 4) a sustained component of the inward Na(+) current, I(NaL). The resulting simulations illustrate ways in which KChIP2- and Ca(2+)-dependent control of I(Kv43) can result in a sustained outward current that can neutralize I(NaL) in a rate- and myocyte subtype-dependent manner. Both these currents appear to play significant roles in modulating AP duration and rate dependence in midmyocardial myocytes. Furthermore, an increased ratio of I(Kv43) to I(NaL) is capable of protecting epicardial myocytes from the early afterdepolarizations resulting from the SCN5A-I1768V mutation-induced increase in I(NaL). Experimentally observed transmural differences in Ca(2+) handling, including greater sarcoplasmic reticulum Ca(2+) content and faster Ca(2+) transient decay rates on the epicardium, were recapitulated in our simulations. By design, these models allow upward integration into organ models or may be used as a basis for further investigations into cellular heterogeneities.
Collapse
Affiliation(s)
- Sarah N Flaim
- University of California, San Diego, La Jolla, CA 92093-0412, USA
| | | | | |
Collapse
|
21
|
Abstract
A variety of inherited human disorders affecting skeletal muscle contraction, heart rhythm, and nervous system function have been traced to mutations in genes encoding voltage-gated sodium channels. Clinical severity among these conditions ranges from mild or even latent disease to life-threatening or incapacitating conditions. The sodium channelopathies were among the first recognized ion channel diseases and continue to attract widespread clinical and scientific interest. An expanding knowledge base has substantially advanced our understanding of structure-function and genotype-phenotype relationships for voltage-gated sodium channels and provided new insights into the pathophysiological basis for common diseases such as cardiac arrhythmias and epilepsy.
Collapse
Affiliation(s)
- Alfred L George
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University, Nashville, Tennessee 37232-0275, USA.
| |
Collapse
|
22
|
Inamura M, Okamoto H, Kuroiwa M, Hoka S. General anesthesia for patients with Brugada syndrome. A report of six cases. Can J Anaesth 2005; 52:409-12. [PMID: 15814757 DOI: 10.1007/bf03016285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
PURPOSE To review six cases of Brugada syndrome presenting for insertion of a cardioverter-defibrillator under general anesthesia. CLINICAL FEATURES All patients had a history of syncope, ST segment elevation in the right precordial lead of the electrocardiogram (ECG) which became prominent after a pilsicainide challenge test. Routine monitors, right precordial lead of the ECG and an external defibrillator were installed prior to anesthesia. We administered propofol/midazolam for induction, and propofol/sevoflurane combined with fentanyl for maintenance of anesthesia. Atropine and ephedrine were administered to decrease vagal tone. No ECG change or arrhythmia was observed perioperatively. After the successful implantation of the defibrillator, all patients were discharged without any adverse event. CONCLUSION By avoiding agents or conditions that may exacerbate Brugada syndrome during anesthesia, we were able to manage the patients uneventfully for implantation of a cardioverter-defibrillator.
Collapse
Affiliation(s)
- Mihoko Inamura
- Department of Anesthesiology, Kitasato University Hospital, 1-15-1, Kitasato, Sagamihara, Kanagawa, 228-8555 Japan
| | | | | | | |
Collapse
|
23
|
Towbin JA, Vatta M, Wang Z, Bowles NE, Li H. Emerging targets in the long QT syndromes and Brugada syndrome. ACTA ACUST UNITED AC 2005. [DOI: 10.1517/14728222.3.3.423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
24
|
Abstract
This article outlines the up-to-date understanding of the molecular basis of disorders that cause sudden death. Several arrhythmic disorders that cause sudden death have been well-described at the molecular level, including the long QT syndromes and Brugada syndrome; this article reviews the current scientific knowledge of these diseases. Hypertrophic cardiomyopathy, a myocardial disorder that causes sudden death also has been well-studied. Finally, a disorder in which myocardial abnormalities and rhythm abnormalities coexist, arrhythmogenic right ventricular dysplasia, is described.
Collapse
MESH Headings
- Arrhythmias, Cardiac/genetics
- Arrhythmias, Cardiac/physiopathology
- Arrhythmogenic Right Ventricular Dysplasia/genetics
- Arrhythmogenic Right Ventricular Dysplasia/physiopathology
- Cardiomyopathy, Hypertrophic, Familial/genetics
- Cardiomyopathy, Hypertrophic, Familial/physiopathology
- Child
- Death, Sudden, Cardiac/etiology
- ERG1 Potassium Channel
- Ether-A-Go-Go Potassium Channels
- Humans
- KCNQ Potassium Channels
- KCNQ1 Potassium Channel
- Long QT Syndrome/complications
- Long QT Syndrome/genetics
- Long QT Syndrome/therapy
- NAV1.5 Voltage-Gated Sodium Channel
- Potassium Channels/physiology
- Potassium Channels, Voltage-Gated
- Sodium Channels/physiology
- Syndrome
- Tachycardia, Ventricular/genetics
- Wolff-Parkinson-White Syndrome/physiopathology
Collapse
Affiliation(s)
- Jeffrey A Towbin
- Department of Pediatrics (Cardiology), Texas Children's Hospital and Baylor College of Medicine, 6621 Fannin Street, FC. 430.09, Houston, TX 77030, USA.
| |
Collapse
|
25
|
Abstract
Findings on standard 12-lead electrocardiogram in patients with hypothermia include sinus bradycardia, prolonged QT and PR interval, wide QRS complex, supraventricular and ventricular arrhythmia, and the most striking electrocardiographic abnormality, the J wave. Although characteristic of hypothermia, J wave also occurs in other conditions. The electro-physiologic basis of J wave in hypothermia has been recently elucidated. We present a case of giant J wave due to accidental hypothermia and in addition discuss the features, mechanism, and significance of J wave in hypothermia.
Collapse
Affiliation(s)
- Balavenkatesh Kanna
- Lincoln Medical and Mental Health Center, New York (Affiliated with Weill Medical College of Cornell University, New York), 10451, USA.
| | | |
Collapse
|
26
|
Kimura M, Kobayashi T, Owada S, Ashikaga K, Higuma T, Sasaki S, Iwasa A, Motomura S, Okumura K. Mechanism of ST Elevation and Ventricular Arrhythmias in an Experimental Brugada Syndrome Model. Circulation 2004; 109:125-31. [PMID: 14662710 DOI: 10.1161/01.cir.0000105762.94855.46] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Although phase 2 reentry is said to be responsible for initiation of ventricular tachycardia (VT) in Brugada syndrome, information about the activation sequence during VT is limited. METHODS AND RESULTS We developed an experimental Brugada syndrome model using a canine isolated right ventricular preparation cross-circulated with arterial blood of a supporter dog and examined the VT mechanism. Two plaque electrodes (35x30 mm) containing 96 bipolar electrodes were attached to the endocardium and epicardium. Saddleback and coved types of ST elevation in transmural ECG were induced by pilsicainide, a pure sodium channel blocker, and pinacidil, a KATP channel opener. Eighteen polymorphic VT episodes were recorded in 9 of the 12 preparations associated with ST elevation. Fourteen episodes spontaneously developed in 5 preparations after an extrasystole during basic drive pacing. Analysis of local recovery times revealed increased dispersion especially in epicardium, and the extrasystole originated from a site with a short recovery time, suggesting that phase 2 reentry was its mechanism. The other 4 VTs in 4 preparations were induced by premature stimulation. Analysis of the activation sequences during VT revealed reentry between epicardium and endocardium or reentry around an arc of a functional block confined to epicardium or endocardium with bystander activation of the other. CONCLUSIONS Electrical heterogeneity in the recovery phase was induced in this experimental Brugada syndrome model, which can be a substrate for the development of phase 2 reentry and the subsequent reentry around an arc of the functional block, resulting in sustained VT.
Collapse
Affiliation(s)
- Masaomi Kimura
- Second Department of Internal Medicine, Hirosaki University School of Medicine, Zaifu-cho 5, Hirosaki 036-8562, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Abstract
Until recently, sudden cardiac death in a young person often remained an unexplained tragedy. However, in the last decade there have been dramatic advances in medical knowledge regarding inheritable dysrhythmias that increase the risk of SCD in otherwise healthy young individuals. The primary mechanism in this group of dysrhythmias appears to be an alteration of cardiac repolarization. In some diseases, the specific genes affected and even precise cellular mechanisms have been identified. The information about these diseases is often complex and rapidly evolving, challenging both healthcare providers and the families who must make important decisions based on emerging and incomplete information. The purpose of this article is to describe current understanding of the repolarization-related dysrhythmias and discuss the clinical implications for advanced practice nurses.
Collapse
Affiliation(s)
- Sarah S Leroy
- University of Michigan Congenital Heart Center, Ann Arbor, MI 48109-0204, USA.
| | | |
Collapse
|
28
|
Chahine M. To the Editor:. J Cardiovasc Electrophysiol 2003; 14:1257-8; author reply 1258. [PMID: 14678148 DOI: 10.1046/j.1540-8167.2003.03328.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
29
|
Takagi A, Nakazawa K, Sakurai T, Nanke T, Miyake F. Prolongation of LAS40 (duration of the low amplitude electric potential component (<40 microV) of the terminal portion of the QRS) induced by isoproterenol in 11 patients with Brugada syndrome. Circ J 2002; 66:1101-4. [PMID: 12499613 DOI: 10.1253/circj.66.1101] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The electrophysiological mechanism of Brugada syndrome is unclear, but transmural dispersion of repolarization in the right ventricle is believed to be the most likely mechanism. On the other hand, the presence of a conduction delay region is considered to be related to the occurrence of ventricular fibrillation; that is, a relationship between the presence of a ventricular late potential (LP) and arrhythmogenic right ventricular cardiomyopathy. In this study, the LP from signal-averaged electrocardiography during isoproterenol (ISP) administration in patients with Brugada syndrome is discussed. The subjects were 11 patients with Brugada syndrome and 6 healthy individuals. In all subjects, the total filtered QRS duration (fQRS), root mean square voltage of the 40 ms terminal portion of the QRS (RMS(40)), duration of the low amplitude electric potential component (40 microV) of the terminal portion of the QRS (LAS(40)), and time duration of the fQRS-LAS(40) difference were compared between when ISP was prescribed and when it was not. During ISP administration, a peculiar response, which resulted in an LAS(40) prolongation, was observed in the patients with Brugada syndrome. With ISP, the fQRS remained unchanged, but the RMS(40) and the fQRS-LAS(40) decreased. Consequently another 3 patients with a positive LP were diagnosed using the ordinary standard because of the administration of ISP. We believe that the low-amplitude component was unmasked by shortening of the high-amplitude component. In patients with Brugada syndrome, a conduction delay in the ventricle may be present and may be related to the occurrence of ventricular fibrillation.
Collapse
Affiliation(s)
- Akihiko Takagi
- Division of Cardiology, Department of Internal Medicine, St Marianna University School of Medicine, Kawasaki, Japan
| | | | | | | | | |
Collapse
|
30
|
Masaki R, Watanabe I, Nakai T, Kondo K, Oshikawa N, Sugimura H, Okubo K, Kojima T, Saito S, Ozawa Y, Kanmatsuse K. Role of signal-averaged electrocardiograms for predicting the inducibility of ventricular fibrillation in the syndrome consisting of right bundle branch block and ST segment elevation in leads V1-V3. JAPANESE HEART JOURNAL 2002; 43:367-78. [PMID: 12227712 DOI: 10.1536/jhj.43.367] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Right bundle branch block and ST segment elevation (RBBB-STE) in the right precordial leads have been reported as a distinct clinical and electrocardiographic syndrome in patients prone to ventricular fibrillation (VF) in the absence of structural heart disease (Brugada syndrome). The purpose of the study was to investigate the role of signal averaged electrocardiogram (SAECG) in identifying patients at high risk among asymptomatic RBBB-STE patients. Thirteen patients with the RBBB-STE ECG were identified. Symptoms were: syncope (n=3, cases 1, 3, and 11), atypical chest pain (n=3, cases 4, 10, and 12) and palpitations (n=2, cases 6, and 7). The other 5 patients were asymptomatic. SAECG and programmed electrical stimulation (PES) were conducted in all patients. Body surface late potentials (LPs) were present in 7 of 13 patients before PES. Vf was induced in 6 of 7 LP positive patients. Vf was induced in 3 of 6 LP negative patients, but LP became positive in 2 of 3 patients in whom Vf was induced. One patient with syncope due to VF (case 1), 1 patient without symptoms who died suddenly during follow up (case 2), and 1 asymptomatic patient (case 9) showed reproducibly positive LP. In a patient (case 9) with positive LP at baseline, LP transiently became negative during follow up. In RBBB-STE patients, reproducibly positive LP is at risk for malignant ventricular arrhythmias and sudden death. Repeated SAECG recording may be useful for screening high-risk patients who should receive electrophysiological study among asymptomatic RBBB-STE patients.
Collapse
Affiliation(s)
- Riko Masaki
- Second Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Vatta M, Dumaine R, Antzelevitch C, Brugada R, Li H, Bowles NE, Nademanee K, Brugada J, Brugada P, Towbin JA. Novel mutations in domain I of SCN5A cause Brugada syndrome. Mol Genet Metab 2002; 75:317-24. [PMID: 12051963 DOI: 10.1016/s1096-7192(02)00006-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Brugada syndrome, an autosomal dominantly inherited form of ventricular fibrillation characterized by ST-segment elevation in leads V1-V3 and right bundle-branch block on surface electrocardiogram, is caused by mutations in the cardiac sodium channel gene SCN5A. Patients with Brugada syndrome were studied using single-strand conformation polymorphism analysis, denaturing high-performance liquid chromatography, and DNA sequencing of SCN5A. Mutations were identified in SCN5A in two families and one sporadic case. In one family, a missense mutation leading to a glycine to valine substitution (G351V) in the pore region between the DIS5 and DIS6 transmembrane segments was detected. Biophysical analysis demonstrated that this mutation caused significant current reduction. In the other family, a 20-bp deletion of the exon 5 splice acceptor site was identified; as exon 5 encodes part of the intracellular loop between DIS2 and DIS3, this portion of the channel is disrupted. In the sporadic patient, a missense mutation resulting in the substitution of lysine by glutamic acid (K126E) in the intracellular loop at the boundary with DIS1 was identified. These three new SCN5A mutations in Brugada syndrome patients are all located within domain I of SCN5A, a region not previously considered important in the development of ventricular arrhythmias.
Collapse
Affiliation(s)
- Matteo Vatta
- Department of Pediatrics (Cardiology), Baylor College of Medicine, Houston, TX, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Abstract
The Brugada syndrome describes a subgroup of patients at risk for the occurrence of ventricular fibrillation who have no definable structural heart disease associated with a right bundle branch block conduction pattern and ST-segment elevation in the right precordial leads. This syndrome is caused by genetic defects in the alpha subunit of the sodium channel. This defect causes a reduction in the sodium channel current, which accentuates the epicardial action potential notch leading to ST-segment elevation. Sodium channel blockers can potentiate these findings and screen for patients with intermittent baseline electrocardiographic findings. Because of the poor prognosis of such patients, symptomatic patients should be treated with an implantable cardioverter-defibrillator.
Collapse
Affiliation(s)
- Gerald V Naccarelli
- Division of Cardiology, Cardiovascular Center, Penn State University College of Medicine, Hershey, Pennsylvania 17033, USA
| | | | | | | |
Collapse
|
33
|
Abstract
In this review, the up-to-date understanding of the molecular basis of disorders causing sudden death will be described. Two arrhythmic disorders causing sudden death have recently been well described at the molecular level, the long QT syndromes (LQTS) and Brugada syndrome, and in this article we will review the current scientific knowledge of each disease. A third disorder, hypertrophic cardiomyopathy (HCM), a myocardial disorder causing sudden death, has also been well studied. Finally, a disorder in which both myocardial abnormalities and rhythm abnormalities coexist, arrhythmogenic right ventricular dysplasia (ARVD) will also be described. The role of the pathologist in these studies will be highlighted.
Collapse
MESH Headings
- Animals
- Arrhythmogenic Right Ventricular Dysplasia/genetics
- Arrhythmogenic Right Ventricular Dysplasia/pathology
- Arrhythmogenic Right Ventricular Dysplasia/physiopathology
- Cardiomyopathy, Hypertrophic, Familial/genetics
- Cardiomyopathy, Hypertrophic, Familial/pathology
- Cardiomyopathy, Hypertrophic, Familial/physiopathology
- Death, Sudden, Cardiac/etiology
- Death, Sudden, Cardiac/pathology
- Dogs
- Genetic Predisposition to Disease
- Humans
- Ion Channels
- Long QT Syndrome/genetics
- Long QT Syndrome/pathology
- Long QT Syndrome/physiopathology
- Molecular Biology
- Ventricular Fibrillation/genetics
- Ventricular Fibrillation/pathology
- Ventricular Fibrillation/physiopathology
Collapse
Affiliation(s)
- J A Towbin
- Department of Pediatrics (Cardiology), Texas Children's Hospital and Baylor College of Medicine, One Baylor Plaza, Room 333E, Houston, TX 77030, USA.
| |
Collapse
|
34
|
Rivolta I, Abriel H, Tateyama M, Liu H, Memmi M, Vardas P, Napolitano C, Priori SG, Kass RS. Inherited Brugada and long QT-3 syndrome mutations of a single residue of the cardiac sodium channel confer distinct channel and clinical phenotypes. J Biol Chem 2001; 276:30623-30. [PMID: 11410597 DOI: 10.1074/jbc.m104471200] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Defects of the SCN5A gene encoding the cardiac sodium channel alpha-subunit are associated with both the long QT-3 (LQT-3) subtype of long-QT syndrome and Brugada syndrome (BrS). One previously described SCN5A mutation (1795insD) in the C terminus results in a clinical phenotype combining QT prolongation and ST segment elevation, indicating a close interrelationship between the two disorders. Here we provide additional evidence that these two disorders are closely related. We report the analysis of two novel mutations on the same codon, Y1795C (LQT-3) and Y1795H (BrS), expressed in HEK 293 cells and characterized using whole-cell patch clamp procedures. We find marked and opposing effects on channel gating consistent with activity associated with the cellular basis of each clinical disorder. Y1795H speeds and Y1795C slows the onset of inactivation. The Y1795H, but not the Y1795C, mutation causes a marked negative shift in the voltage dependence of inactivation, and neither mutation affects the kinetics of the recovery from inactivation. Interestingly, both mutations increase the expression of sustained Na+ channel activity compared with wild type (WT) channels, although this effect is most pronounced for the Y1795C mutation, and both mutations promote entrance into an intermediate or a slowly developing inactivated state. These data confirm the key role of the C-terminal tail of the cardiac Na+ channel in the control of channel gating, illustrate how subtle changes in channel biophysics can have significant and distinct effects in human disease, and, additionally, provide further evidence of the close interrelationship between BrS and LQT-3 at the molecular level.
Collapse
Affiliation(s)
- I Rivolta
- Department of Pharmacology, College of Physicians and Surgeons of Columbia University, New York, New York 10032, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Oudit GY, Kassiri Z, Sah R, Ramirez RJ, Zobel C, Backx PH. The molecular physiology of the cardiac transient outward potassium current (I(to)) in normal and diseased myocardium. J Mol Cell Cardiol 2001; 33:851-72. [PMID: 11343410 DOI: 10.1006/jmcc.2001.1376] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
G. Y. Oudit, Z. Kassiri, R. Sah, R. J. Ramirez, C. Zobel and P. H. Backx. The Molecular Physiology of the Cardiac Transient Outward Potassium Current (I(to)) in Normal and Diseased Myocardium. Journal of Molecular and Cellular Cardiology (2001) 33, 851-872. The Ca(2+)-independent transient outward potassium current (I(to)) plays an important role in early repolarization of the cardiac action potential. I(to)has been clearly demonstrated in myocytes from different cardiac regions and species. Two kinetic variants of cardiac I(to)have been identified: fast I(to), called I(to,f), and slow I(to), called I(to,s). Recent findings suggest that I(to,f)is formed by assembly of K(v4.2)and/or K(v4.3)alpha pore-forming voltage-gated subunits while I(to,s)is comprised of K(v1.4)and possibly K(v1.7)subunits. In addition, several regulatory subunits and pathways modulating the level and biophysical properties of cardiac I(to)have been identified. Experimental findings and data from computer modeling of cardiac action potentials have conclusively established an important physiological role of I(to)in rodents, with its role in large mammals being less well defined due to complex interplay between a multitude of cardiac ionic currents. A central and consistent electrophysiological change in cardiac disease is the reduction in I(to)density with a loss of heterogeneity of I(to)expression and associated action potential prolongation. Alterations of I(to)in rodent cardiac disease have been linked to repolarization abnormalities and alterations in intracellular Ca(2+)homeostasis, while in larger mammals the link with functional changes is far less certain. We review the current literature on the molecular basis for cardiac I(to)and the functional consequences of changes in I(to)that occur in cardiovascular disease.
Collapse
Affiliation(s)
- G Y Oudit
- Department of Medicine and Physiology, Toronto General Hospital, 101 College Street, Toronto, M5G 2C4, Canada
| | | | | | | | | | | |
Collapse
|
36
|
Antzelevitch C, Yan GX. Cellular and ionic mechanisms responsible for the Brugada syndrome. J Electrocardiol 2001; 33 Suppl:33-9. [PMID: 11265734 DOI: 10.1054/jelc.2000.20321] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Brugada syndrome is characterized by ST-segment elevation in the right precordial leads, V1-V3 (unrelated to ischemia or structural disease), normal QT intervals, RBBB pattern, and sudden cardiac death, particularly in men of Asian origin. An autosomal dominant mode of inheritance with variable penetrance is generally observed. The only gene mutations thus far linked to the Brugada Syndrome appear in the alpha subunit of the gene that encodes for the cardiac sodium channel, SCN5A. An outward shift in the balance of currents contributing to phase 1 of the right ventricular action potential is thought to underline to electrocardiographic manifestation of the syndrome. Strong sodium channel block, among other modalities, can accentuate the action potential notch in right ventricular epicardial cells, eventually leading to loss of the action potential dome. This results in the development of a large dispersion of repolarization within epicardium as well as between epicardium and endocardium, providing the substrate for the development of phase 2 and cirus movement reentry, which underline VT/VF. Therapy is directed at restoring the balance of current via inhibition of the transient outward current, Ito, and/or stimulation of inward calcium using beta adrenergic agonists, among several strategies.
Collapse
Affiliation(s)
- C Antzelevitch
- Masonic Medical Research Laboratory, Utica, NY 13501, USA.
| | | |
Collapse
|
37
|
Abstract
The Brugada syndrome is an arrhythmic syndrome characterized by a right bundle branch block pattern and ST segment elevation in the right precordial leads of the electrocardiogram in conjunction with a high incidence of sudden death secondary to ventricular tachyarrhythmias. No evidence of structural heart disease is noted during diagnostic evaluation of these patients. In 25% of families, there appears to be an autosomal dominant mode of transmission with variable expression of the abnormal gene. Mutations have been identified in the gene that encodes the alpha subunit of the sodium channel (SCN5A) on chromosome 3. This genetic defect causes a reduction in the density of the sodium current and explains the worsening of the above electrocardiographic abnormalities when patients are treated with sodium channel blocking antiarrhythmic agents, which further diminish the already reduced sodium current. The prognosis is poor with up to a 10% per year mortality. Antiarrhythmic drugs including beta-blockers and amiodarone have no benefit in prolonging survival. The treatment of choice is the insertion of an implantable cardioverter-defibrillator.
Collapse
Affiliation(s)
- G V Naccarelli
- Division of Cardiology, Cardiovascular Center, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
| | | |
Collapse
|
38
|
Nemec J, Shen WK. Congenital long QT syndromes and Brugada syndrome: the arrhythmogenic ion channel disorders. Expert Opin Pharmacother 2001; 2:773-97. [PMID: 11336622 DOI: 10.1517/14656566.2.5.773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Congenital long QT syndromes (LQTS) and Brugada syndrome are hereditary disorders of cardiac ion channels which result in life-threatening cardiac arrhythmias or sudden cardiac death in patients with anatomically normal hearts. The pathogenesis of these dramatic events has been partially elucidated with the identification of the individual ion channels involved and understanding of the effect of some disease-causing mutations on the membrane currents and action potential. The clinical spectrum of congenital LQTS is broader than previously thought and involves certain patients previously diagnosed with idiosyncratic drug-induced proarrhythmia. The initial treatment for congenital LQTS patients involves beta-blockers in most cases. Indications for implantable cardioverter-defibrillator (ICD) or pace-maker (PM) implantation in selected individuals continue to evolve.
Collapse
Affiliation(s)
- J Nemec
- Department of Cardiology, Institute of Clinical and Experimental Medicine, Vídenská 800, Prague, Czech Republic
| | | |
Collapse
|
39
|
Towbin JA, Vatta M, Li H. Genetics of brugada, long QT, and arrhythmogenic right ventricular dysplasia syndromes. J Electrocardiol 2001; 33 Suppl:11-22. [PMID: 11265709 DOI: 10.1054/jelc.2000.20361] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This article outlines the up-to-date understanding of the molecular basis of primary ventricular arrhythmias. Two disorders have recently been well described at the molecular level, the long QT syndromes and Brugada syndrome, and this article reviews the current scientific knowledge of each disease. A third disorder, arrhythmogenic right ventricular dysplasia, which is on the cusp of understanding, will also be described.
Collapse
Affiliation(s)
- J A Towbin
- Department of Pediatrics (Cardiology), Texas Children's Hospital and Baylor College of Medicine, Houston 77030, USA.
| | | | | |
Collapse
|
40
|
Abstract
The mechanisms responsible for active cardiac arrhythmias are generally divided into two major categories: (1) enhanced or abnormal impulse formation and (2) reentry. Reentry can be subdivided into three subcategories: (1) circus movement, (2) reflection, and (3) Phase 2 reentry. Reentry occurs when a propagating impulse fails to die out after normal activation of the heart and persists to re-excite the heart after expiration of the refractory period. Evidence implicating reentry as a mechanism of cardiac arrhythmias stems back to the turn of the century. Amplification of intrinsic electrical heterogeneities provides the substrate responsible for developing Phase 2 and circus movement reentry, which underlie ventricular tachycardia in the long QT and Brugada syndromes.
Collapse
Affiliation(s)
- C Antzelevitch
- Masonic Medical Research Laboratory, Utica, New York, USA. ca.mmrl.edu
| |
Collapse
|
41
|
Wang DW, Makita N, Kitabatake A, Balser JR, George AL. Enhanced Na(+) channel intermediate inactivation in Brugada syndrome. Circ Res 2000; 87:E37-43. [PMID: 11029409 DOI: 10.1161/01.res.87.8.e37] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Brugada syndrome is an inherited cardiac disease that causes sudden death related to idiopathic ventricular fibrillation in a structurally normal heart. The disease is characterized by ST-segment elevation in the right precordial ECG leads and is frequently accompanied by an apparent right bundle-branch block. The biophysical properties of the SCN5A mutation T1620M associated with Brugada syndrome were examined for defects in intermediate inactivation (I:(M)), a gating process in Na(+) channels with kinetic features intermediate between fast and slow inactivation. Cultured mammalian cells expressing T1620M Na(+) channels in the presence of the human beta(1) subunit exhibit enhanced intermediate inactivation at both 22 degrees C and 32 degrees C compared with wild-type recombinant human heart Na(+) channels (WT-hH1). Our findings support the hypothesis that Brugada syndrome is caused, in part, by functionally reduced Na(+) current in the myocardium due to an increased proportion of Na(+) channels that enter the I:(M) state. This phenomenon may contribute significantly to arrhythmogenesis in patients with Brugada syndrome. The full text of this article is available at http://www.circresaha.org.
Collapse
Affiliation(s)
- D W Wang
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | | | | | | | | |
Collapse
|
42
|
Wehrens XH, Abriel H, Cabo C, Benhorin J, Kass RS. Arrhythmogenic mechanism of an LQT-3 mutation of the human heart Na(+) channel alpha-subunit: A computational analysis. Circulation 2000; 102:584-90. [PMID: 10920073 DOI: 10.1161/01.cir.102.5.584] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND D1790G, a mutation of SCN5A, the gene that encodes the human Na(+) channel alpha-subunit, is linked to 1 form of the congenital long-QT syndrome (LQT-3). In contrast to other LQT-3-linked SCN5A mutations, D1790G does not promote sustained Na(+) channel activity but instead alters the kinetics and voltage-dependence of the inactivated state. METHODS AND RESULTS We modeled the cardiac ventricular action potential (AP) using parameters and techniques described by Luo and Rudy as our control. On this background, we modified only the properties of the voltage-gated Na(+) channel according to our patch-clamp analysis of D1790G channels. Our results indicate that D1790G-induced changes in Na(+) channel activity prolong APs in a steeply heart rate-dependent manner not directly due to changes in Na(+) entry through mutant channels but instead to alterations in the balance of net plateau currents by modulation of calcium-sensitive exchange and ion channel currents. CONCLUSIONS We conclude that the D1790G mutation of the Na(+) channel alpha-subunit can prolong the cardiac ventricular AP despite the absence of mutation-induced sustained Na(+) channel current. This prolongation is calcium-dependent, is enhanced at slow heart rates, and at sufficiently slow heart rate triggers arrhythmogenic early afterdepolarizations.
Collapse
Affiliation(s)
- X H Wehrens
- Department of Pharmacology, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
| | | | | | | | | |
Collapse
|
43
|
Abriel H, Motoike H, Kass RS. KChAP: a novel chaperone for specific K(+) channels key to repolarization of the cardiac action potential. Focus on "KChAP as a chaperone for specific K(+) channels". Am J Physiol Cell Physiol 2000; 278:C863-4. [PMID: 10794658 DOI: 10.1152/ajpcell.2000.278.5.c863] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
44
|
Abstract
In this review, the up-to-date understanding of the molecular basis of primary ventricular arrhythmias will be outlined. Two disorders have recently been well described at the molecular level, the long QT syndromes and Brugada syndrome, and in this paper we review the current scientific knowledge of each disease.
Collapse
Affiliation(s)
- M Vatta
- Department of Pediatrics (Cardiology), Texas Children's Hospital, Houston, USA
| | | | | |
Collapse
|