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Ventrella N, Bianchini L, Riva S, Pizzamiglio F, Dessanai MA, Tundo F, Sattin T, De Lio F, Cellucci S, Tondo C. Novel SCN5A gene mutation in a patient affected by multifocal ectopic premature Purkinje-related contractions syndrome. ESC Heart Fail 2024; 11:2399-2404. [PMID: 38504463 PMCID: PMC11287344 DOI: 10.1002/ehf2.14677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 12/10/2023] [Accepted: 12/28/2023] [Indexed: 03/21/2024] Open
Abstract
We report the case of a 36-year-old woman who presented to the emergency department complaining of palpitations and asthenia. Investigations showed frequent ventricular ectopy and severe left ventricular ejection fraction impairment. She was diagnosed with a peculiar condition defined multifocal ectopic premature Purkinje-related contractions syndrome, which in some cases can be associated with a dilated cardiomyopathy phenotype. Genetic testing showed a novel mutation in the SCN5A gene (c.673C > G). In the context of acute left ventricular dysfunction in a young patient, we discuss the clinical presentation of this rare condition and its clinical management, as well as its genetic substrate.
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Affiliation(s)
- Nicoletta Ventrella
- Department of Clinical Electrophysiology and Cardiac PacingCentro Cardiologico Monzino, IRCCSMilanItaly
| | - Lorenzo Bianchini
- Department of Clinical Electrophysiology and Cardiac PacingCentro Cardiologico Monzino, IRCCSMilanItaly
| | - Stefania Riva
- Department of Clinical Electrophysiology and Cardiac PacingCentro Cardiologico Monzino, IRCCSMilanItaly
| | - Francesca Pizzamiglio
- Department of Clinical Electrophysiology and Cardiac PacingCentro Cardiologico Monzino, IRCCSMilanItaly
| | - Maria Antonietta Dessanai
- Department of Clinical Electrophysiology and Cardiac PacingCentro Cardiologico Monzino, IRCCSMilanItaly
| | - Fabrizio Tundo
- Department of Clinical Electrophysiology and Cardiac PacingCentro Cardiologico Monzino, IRCCSMilanItaly
| | - Tommaso Sattin
- Department of Clinical Electrophysiology and Cardiac PacingCentro Cardiologico Monzino, IRCCSMilanItaly
| | - Francesca De Lio
- Department of Clinical Electrophysiology and Cardiac PacingCentro Cardiologico Monzino, IRCCSMilanItaly
| | - Selene Cellucci
- Department of Clinical Electrophysiology and Cardiac PacingCentro Cardiologico Monzino, IRCCSMilanItaly
| | - Claudio Tondo
- Department of Clinical Electrophysiology and Cardiac PacingCentro Cardiologico Monzino, IRCCSMilanItaly
- Department of Biomedical, Surgical and Dental SciencesUniversity of MilanMilanItaly
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de Lima Conceição MR, Teixeira-Fonseca JL, Marques LP, Souza DS, da Silva Alcântara F, Orts DJB, Roman-Campos D. Extracellular acidification reveals the antiarrhythmic properties of amiodarone related to late sodium current-induced atrial arrhythmia. Pharmacol Rep 2024; 76:585-599. [PMID: 38619735 DOI: 10.1007/s43440-024-00597-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 04/05/2024] [Accepted: 04/08/2024] [Indexed: 04/16/2024]
Abstract
BACKGROUND Amiodarone (AMIO) is an antiarrhythmic drug with the pKa in the physiological range. Here, we explored how mild extracellular pH (pHe) changes shape the interaction of AMIO with atrial tissue and impact its pharmacological properties in the classical model of sea anemone sodium channel neurotoxin type 2 (ATX) induced late sodium current (INa-Late) and arrhythmias. METHOD Isolated atrial cardiomyocytes from male Wistar rats and human embryonic kidney cells expressing SCN5A Na+ channels were used for patch-clamp experiments. Isolated right atria (RA) and left atria (LA) tissue were used for bath organ experiments. RESULTS A more acidophilic pHe caused negative inotropic effects on isolated RA and LA atrial tissue, without modification of the pharmacological properties of AMIO. A pHe of 7.0 changed the sodium current (INa) related components of the action potential (AP), which was enhanced in the presence of AMIO. ATXinduced arrhythmias in isolated RA and LA. Also, ATX prolonged the AP duration and enhanced repolarization dispersion in isolated cardiomyocytes in both pHe 7.4 and pHe 7.0. Pre-incubation of the isolated RA and LA and isolated atrial cardiomyocytes with AMIO prevented arrhythmias induced by ATX only at a pHe of 7.0. Moreover, AMIO was able to block INa-Late induced by ATX only at a pHe of 7.0. CONCLUSION The pharmacological properties of AMIO concerning healthy rat atrial tissue are not dependent on pHe. However, the prevention of arrhythmias induced by INa-Late is pHe-dependent. The development of drugs analogous to AMIO with charge stabilization may help to create more effective drugs to treat arrhythmias related to the INa-Late.
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Affiliation(s)
- Michael Ramon de Lima Conceição
- Laboratory of CardioBiology, Department of Biophysics, Paulista School of Medicine, Federal University of Sao Paulo Botucatu Street, 862, Biological Science Building, 7th floor,, São Paulo, Brazil
| | - Jorge Lucas Teixeira-Fonseca
- Laboratory of CardioBiology, Department of Biophysics, Paulista School of Medicine, Federal University of Sao Paulo Botucatu Street, 862, Biological Science Building, 7th floor,, São Paulo, Brazil
| | - Leisiane Pereira Marques
- Laboratory of CardioBiology, Department of Biophysics, Paulista School of Medicine, Federal University of Sao Paulo Botucatu Street, 862, Biological Science Building, 7th floor,, São Paulo, Brazil
| | - Diego Santos Souza
- Department of Physiology, Federal University of Sergipe, São Cristóvão, Brazil
| | - Fabiana da Silva Alcântara
- Laboratory of CardioBiology, Department of Biophysics, Paulista School of Medicine, Federal University of Sao Paulo Botucatu Street, 862, Biological Science Building, 7th floor,, São Paulo, Brazil
| | - Diego Jose Belato Orts
- Laboratory of CardioBiology, Department of Biophysics, Paulista School of Medicine, Federal University of Sao Paulo Botucatu Street, 862, Biological Science Building, 7th floor,, São Paulo, Brazil
| | - Danilo Roman-Campos
- Laboratory of CardioBiology, Department of Biophysics, Paulista School of Medicine, Federal University of Sao Paulo Botucatu Street, 862, Biological Science Building, 7th floor,, São Paulo, Brazil.
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Zhu W, Yuan H, Lv J. Advancements in the diagnosis and management of premature ventricular contractions in pediatric patients. Front Pediatr 2024; 12:1373772. [PMID: 38571703 PMCID: PMC10987820 DOI: 10.3389/fped.2024.1373772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 03/11/2024] [Indexed: 04/05/2024] Open
Abstract
Background Premature ventricular contractions (PVCs) are relatively common arrhythmias in the pediatric population, with implications that range from benign to potentially life-threatening. The management of PVCs in children poses unique challenges, and recent advancements in diagnostic and therapeutic options call for a comprehensive review of current practices. Methods This review synthesizes the latest literature on pediatric PVCs, focusing on publications from the past decade. We evaluate studies addressing the epidemiology, pathophysiology, diagnosis, and treatment of PVCs in children, including pharmacological, non-pharmacological, and invasive strategies. Results The review identifies key advancements in the non-invasive detection of PVCs, the growing understanding of their genetic underpinnings, and the evolving landscape of management options. We discuss the clinical decision-making process, considering the variable significance of PVCs in different pediatric patient subgroups, and highlight the importance of individualized care. Current guidelines and consensus statements are examined, and areas of controversy or limited evidence are identified. Conclusions Our review underscores the need for a nuanced approach to PVCs in children, integrating the latest diagnostic techniques with a tailored therapeutic strategy. We call for further research into long-term outcomes and the development of risk stratification tools to guide treatment. The potential of emerging technologies and the importance of multidisciplinary care are also emphasized to improve prognoses for pediatric patients with PVCs.
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Affiliation(s)
- Wenjing Zhu
- Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Shandong Provincial Clinical Research Center for Children's Health and Disease Office, Jinan, Shandong, China
| | - Hui Yuan
- Department of Pediatric Cardiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Shandong Provincial Clinical Research Center for Children's Health and Disease Office, Jinan, Shandong, China
| | - Jianli Lv
- Department of Pediatric Cardiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Shandong Provincial Clinical Research Center for Children's Health and Disease Office, Jinan, Shandong, China
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Ahamed H, Gopi A. Effect of Flecainide on Multifocal Ectopic Purkinje-Related Premature Contractions in an R814W SCN5A Carrier. JACC Case Rep 2024; 29:102223. [PMID: 38464806 PMCID: PMC10920139 DOI: 10.1016/j.jaccas.2024.102223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 11/21/2023] [Accepted: 01/03/2024] [Indexed: 03/12/2024]
Abstract
Multifocal ectopic Purkinje-related premature contraction (MEPPC) is an autosomal dominant SCN5A channelopathy characterized by frequent multiform premature ventricular contractions originating from the His-Purkinje system. We present a patient with an MEPPC phenotype whose genetic testing identified a pathogenic SCN5A (HGNC:10593) variant amenable to precision antiarrhythmic therapy with flecainide.
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Affiliation(s)
- Hisham Ahamed
- Amrita Institute of Medical Sciences and Research Centre, Edappally, Ernakulam, India
| | - Arun Gopi
- Metromed International Cardiac Centre, Calicut, India
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Schwartzman KH, Nayak HM, Kohli U. Novel Phenotypic Effects of a Rare SCN5A (c.2482C>T) Mutation. JACC Case Rep 2024; 29:102212. [PMID: 38379642 PMCID: PMC10874961 DOI: 10.1016/j.jaccas.2023.102212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 12/04/2023] [Accepted: 12/18/2023] [Indexed: 02/22/2024]
Abstract
In a familial cohort with 8 heterozygous carriers of a rare pathogenic SCN5A mutation (c.2482C>T), 4 female mutation carriers manifested with fetal ventricular tachycardia and 2:1 atrioventricular block. One presented with multifocal ectopic premature Purkinje-related complexes-like phenotype and atrial fibrillation later in life. These novel findings inform the need for robust fetal monitoring of mutation carriers.
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Affiliation(s)
| | - Hemal M. Nayak
- Division of Cardiology, University of Texas Health, San Antonio, Texas, USA
| | - Utkarsh Kohli
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, West Virginia University School of Medicine and West Virginia University Children’s Hospital, Morgantown, West Virginia, USA
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Glazer AM, Yang T, Li B, Page D, Fouda M, Wada Y, Lancaster MC, O’Neill MJ, Muhammad A, Gao X, Ackerman MJ, Sanatani S, Ruben PC, Roden DM. Multifocal Ectopic Purkinje Premature Contractions due to neutralization of an SCN5A negative charge: structural insights into the gating pore hypothesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.13.580021. [PMID: 38405820 PMCID: PMC10888965 DOI: 10.1101/2024.02.13.580021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Background We identified a novel SCN5A variant, E171Q, in a neonate with very frequent ectopy and reduced ejection fraction which normalized after arrhythmia suppression by flecainide. This clinical picture is consistent with multifocal ectopic Purkinje-related premature contractions (MEPPC). Most previous reports of MEPPC have implicated SCN5A variants such as R222Q that neutralize positive charges in the S4 voltage sensor helix of the channel protein NaV1.5 and generate a gating pore current. Methods and Results E171 is a highly conserved negatively-charged residue located in the S2 transmembrane helix of NaV1.5 domain I. E171 is a key component of the Gating Charge Transfer Center, a region thought to be critical for normal movement of the S4 voltage sensor helix. We used heterologous expression, CRISPR-edited induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs), and molecular dynamics simulations to demonstrate that E171Q generates a gating pore current, which was suppressed by a low concentration of flecainide (IC50 = 0.71±0.07 µM). R222Q shifts voltage dependence of activation and inactivation in a negative direction but we observed positive shifts with E171Q. E171Q iPSC-CMs demonstrated abnormal spontaneous activity and prolonged action potentials. Molecular dynamics simulations revealed that both R222Q and E171Q proteins generate a water-filled permeation pathway that underlies generation of the gating pore current. Conclusion Previously identified MEPPC-associated variants that create gating pore currents are located in positively-charged residues in the S4 voltage sensor and generate negative shifts in the voltage dependence of activation and inactivation. We demonstrate that neutralizing a negatively charged S2 helix residue in the Gating Charge Transfer Center generates positive shifts but also create a gating pore pathway. These findings implicate the gating pore pathway as the primary functional and structural determinant of MEPPC and widen the spectrum of variants that are associated with gating pore-related disease in voltage-gated ion channels.
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Affiliation(s)
| | - Tao Yang
- Vanderbilt University Medical Center, Nashville, TN, USA
| | - Bian Li
- Vanderbilt University Medical Center, Nashville, TN, USA
- Current address: Regeneron Pharmaceuticals Inc., Tarrytown NY, USA. Bian Li contributed to this article as an employee of Vanderbilt University Medical Center and the views expressed do not necessarily represent the views of Regeneron Pharmaceuticals Inc
| | - Dana Page
- Simon Fraser University, Burnaby, BC, Canada
| | | | - Yuko Wada
- Vanderbilt University Medical Center, Nashville, TN, USA
| | | | | | | | - Xiaozhi Gao
- Mayo Clinic College of Medicine and Science, Mayo Foundation, Rochester, MN, USA
| | - Michael J. Ackerman
- Mayo Clinic College of Medicine and Science, Mayo Foundation, Rochester, MN, USA
| | | | | | - Dan M. Roden
- Vanderbilt University Medical Center, Nashville, TN, USA
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Deuis JR, Kumble S, Keramidas A, Ragnarsson L, Simons C, Pais L, White SM, Vetter I. Erythromelalgia caused by the missense mutation p.Arg220Pro in an alternatively spliced exon of SCN9A (NaV1.7). Hum Mol Genet 2024; 33:103-109. [PMID: 37721535 PMCID: PMC10772039 DOI: 10.1093/hmg/ddad152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/06/2023] [Accepted: 09/11/2023] [Indexed: 09/19/2023] Open
Abstract
Erythromelalgia (EM), is a familial pain syndrome characterized by episodic 'burning' pain, warmth, and erythema. EM is caused by monoallelic variants in SCN9A, which encodes the voltage-gated sodium channel (NaV) NaV1.7. Over 25 different SCN9A mutations attributed to EM have been described to date, all identified in the SCN9A transcript utilizing exon 6N. Here we report a novel SCN9A missense variant identified in seven related individuals with stereotypic episodes of bilateral lower limb pain presenting in childhood. The variant, XM_011511617.3:c.659G>C;p.(Arg220Pro), resides in the exon 6A of SCN9A, an exon previously shown to be selectively incorporated by developmentally regulated alternative splicing. The mutation is located in the voltage-sensing S4 segment of domain I, which is important for regulating channel activation. Functional analysis showed the p.Arg220Pro mutation altered voltage-dependent activation and delayed channel inactivation, consistent with a NaV1.7 gain-of-function molecular phenotype. These results demonstrate that alternatively spliced isoforms of SCN9A should be included in all genomic testing of EM.
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Affiliation(s)
- Jennifer R Deuis
- Institute for Molecular Bioscience, 306 Carmody Road, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Smitha Kumble
- Murdoch Children's Research Institute, 50 Flemington Road, Royal Children’s Hospital, Parkville, VIC 3052, Australia
- Department of Paediatrics, The University of Melbourne, 50 Flemington Road, Parkville, VIC 3052, Australia
| | - Angelo Keramidas
- Institute for Molecular Bioscience, 306 Carmody Road, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Lotten Ragnarsson
- Institute for Molecular Bioscience, 306 Carmody Road, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Cas Simons
- Murdoch Children's Research Institute, 50 Flemington Road, Royal Children’s Hospital, Parkville, VIC 3052, Australia
| | - Lynn Pais
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, MA 02142, United States
| | - Susan M White
- Department of Paediatrics, The University of Melbourne, 50 Flemington Road, Parkville, VIC 3052, Australia
- Victorian Clinical Genetics Services, Royal Children's Hospital, 50 Flemington Road, Parkville, VIC 3052, Australia
| | - Irina Vetter
- Institute for Molecular Bioscience, 306 Carmody Road, The University of Queensland, St Lucia, QLD 4072, Australia
- School of Pharmacy, 20 Cornwall Street, The University of Queensland, Woolloongabba, QLD 4102, Australia
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Li W, Wu CX, Hou JW, Sun J, Wang QS, Zhang PP, Yu Y, Yang M, Chen M, Mo BF, Wang YP, Li YG. Higher Sodium Channel Excitability in Cardiac Purkinje Fibers: Implications for Multifocal Ectopic Purkinje-Related Premature Contractions. JACC Clin Electrophysiol 2023; 9:2477-2490. [PMID: 37831033 DOI: 10.1016/j.jacep.2023.08.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 07/24/2023] [Accepted: 08/22/2023] [Indexed: 10/14/2023]
Abstract
BACKGROUND Multifocal ectopic Purkinje-related premature contractions (MEPPCs) are associated with SCN5A variants. However, it is not well understood why Purkinje fibers, but not ventricular myocardium, play a predominant role in arrhythmogenesis. OBJECTIVES This study sought to explore the underlying mechanisms of MEPPC. METHODS Whole-cell patch-clamp and molecular biology techniques were used in the present study. RESULTS Clinical data from one patient with R814W variant showed MEPPC syndrome, which is well responsive to amiodarone. Compared with canine ventricular myocytes, Purkinje cells (PCs) had significantly larger sodium current (INa), leftward shift of INa activation and inactivation curves, suggesting higher sodium channel excitability in PCs. Real-time polymerase chain reaction and Western blot analysis showed that the mRNA and protein expression of NaVβ1 and NaVβ3 was higher in canine Purkinje fibers than in ventricular myocardium. INa in heterologous Chinese hamster ovary cell expression system co-expressing NaV1.5 and NaVβ1/NaVβ3 exhibited similar biophysical properties of INa in PCs. R814W variant shifted INa activation in a hyperdepolarized direction, caused a larger window current, and generated an outward-gating pore current at depolarized voltages. Coexpression of NaVβ1/NaVβ3 with Nav1.5-R814W further left-shifted INa activation and caused an even larger window current and gating pore current, suggesting higher susceptibility of Purkinje fibers to R814W variant. Amiodarone inhibited INa, shifted its inactivation to more negative voltages, and significantly decreased the window current. CONCLUSIONS A higher expression of β1 and β3 subunits contributes to higher sodium channel excitability in cardiac Purkinje fibers, making them more susceptible to MEPPC.
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Affiliation(s)
- Wei Li
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chun-Xuan Wu
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jian-Wen Hou
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jian Sun
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qun-Shan Wang
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Peng-Pai Zhang
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi Yu
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mei Yang
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mu Chen
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bin-Feng Mo
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yue-Peng Wang
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi-Gang Li
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Wauchop M, Rafatian N, Zhao Y, Chen W, Gagliardi M, Massé S, Cox BJ, Lai P, Liang T, Landau S, Protze S, Gao XD, Wang EY, Tung KC, Laksman Z, Lu RXZ, Keller G, Nanthakumar K, Radisic M, Backx PH. Maturation of iPSC-derived cardiomyocytes in a heart-on-a-chip device enables modeling of dilated cardiomyopathy caused by R222Q-SCN5A mutation. Biomaterials 2023; 301:122255. [PMID: 37651922 PMCID: PMC10942743 DOI: 10.1016/j.biomaterials.2023.122255] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/17/2023] [Accepted: 07/23/2023] [Indexed: 09/02/2023]
Abstract
To better understand sodium channel (SCN5A)-related cardiomyopathies, we generated ventricular cardiomyocytes from induced pluripotent stem cells obtained from a dilated cardiomyopathy patient harbouring the R222Q mutation, which is only expressed in adult SCN5A isoforms. Because the adult SCN5A isoform was poorly expressed, without functional differences between R222Q and control in both embryoid bodies and cell sheet preparations (cultured for 29-35 days), we created heart-on-a-chip biowires which promote myocardial maturation. Indeed, biowires expressed primarily adult SCN5A with R222Q preparations displaying (arrhythmogenic) short action potentials, altered Na+ channel biophysical properties and lower contractility compared to corrected controls. Comprehensive RNA sequencing revealed differential gene regulation between R222Q and control biowires in cellular pathways related to sarcoplasmic reticulum and dystroglycan complex as well as biological processes related to calcium ion regulation and action potential. Additionally, R222Q biowires had marked reductions in actin expression accompanied by profound sarcoplasmic disarray, without differences in cell composition (fibroblast, endothelial cells, and cardiomyocytes) compared to corrected biowires. In conclusion, we demonstrate that in addition to altering cardiac electrophysiology and Na+ current, the R222Q mutation also causes profound sarcomere disruptions and mechanical destabilization. Possible mechanisms for these observations are discussed.
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Affiliation(s)
- Marianne Wauchop
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Naimeh Rafatian
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada
| | - Yimu Zhao
- Toronto General Hospital Research Institute, Toronto, ON, M5G 2C4, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Wenliang Chen
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada; Department of Biology, York University, Toronto, ON, M3J 1P3, Canada
| | - Mark Gagliardi
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, M5G 1L7, Canada
| | - Stéphane Massé
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada; Toronto General Hospital Research Institute, Toronto, ON, M5G 2C4, Canada; The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, ON, M5G 2C4, Canada
| | - Brian J Cox
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada; Department of Obstetrics and Gynaecology, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Patrick Lai
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada; Toronto General Hospital Research Institute, Toronto, ON, M5G 2C4, Canada; The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, ON, M5G 2C4, Canada
| | - Timothy Liang
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada; Toronto General Hospital Research Institute, Toronto, ON, M5G 2C4, Canada; The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, ON, M5G 2C4, Canada
| | - Shira Landau
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Stephanie Protze
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, M5G 1L7, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Xiao Dong Gao
- Department of Biology, York University, Toronto, ON, M3J 1P3, Canada
| | - Erika Yan Wang
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Kelvin Chan Tung
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, M5G 1L7, Canada
| | - Zachary Laksman
- Department of Medicine, University of British Columbia, Vancouver, BC, V6E 1M7, Canada
| | - Rick Xing Ze Lu
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Gordon Keller
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, M5G 1L7, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, M5G 1L7, Canada
| | - Kumaraswamy Nanthakumar
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada; Toronto General Hospital Research Institute, Toronto, ON, M5G 2C4, Canada; The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, ON, M5G 2C4, Canada.
| | - Milica Radisic
- Toronto General Hospital Research Institute, Toronto, ON, M5G 2C4, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada, M5S 3E5.
| | - Peter H Backx
- Division of Cardiology and Peter Munk Cardiac Center, University Health Network, Toronto, ON, M5G 1L7, Canada; Department of Biology, York University, Toronto, ON, M3J 1P3, Canada; Terrence Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada.
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Calloe K, Magnusson HBD, Lildballe DL, Christiansen MK, Jensen HK. Multifocal ectopic purkinje-related premature contractions and related cardiomyopathy. Front Cardiovasc Med 2023; 10:1179018. [PMID: 37600057 PMCID: PMC10436533 DOI: 10.3389/fcvm.2023.1179018] [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: 03/03/2023] [Accepted: 07/24/2023] [Indexed: 08/22/2023] Open
Abstract
In the past 20 years, genetic variants in SCN5A encoding the cardiac voltage-gated sodium channel Nav1.5 have been linked to a range of inherited cardiac arrhythmias: variants resulting in loss-of-function of Nav1.5 have been linked to sick sinus syndrome, atrial stand still, atrial fibrillation (AF) impaired pulse generation, progressive and non-progressive conduction defects, the Brugada Syndrome (BrS), and sudden cardiac death. SCN5A variants causing increased sodium current during the plateau phase of the cardiac action potential is associated with Long QT Syndrome type 3 (LQTS3), Torsade de Pointes ventricular tachycardia and SCD. Recently, gain-of-function variants have been linked to complex electrical phenotypes, such as the Multifocal Ectopic Purkinje-related Premature Contractions (MEPPC) syndrome. MEPPC is a rare condition characterized by a high burden of premature atrial contractions (PACs) and/or premature ventricular contractions (PVCs) often accompanied by dilated cardiomyopathy (DCM). MEPPC is inherited in an autosomal dominant fashion with an almost complete penetrance. The onset is often in childhood. The link between SCN5A variants, MEPPC and DCM is currently not well understood, but amino acid substitutions resulting in gain-of-function of Nav1.5 or introduction of gating pore currents potentially play an important role. DCM patients with a MEPPC phenotype respond relatively poorly to standard heart failure medical therapy and catheter ablation as the PVCs originate from all parts of the fascicular Purkinje fiber network. Class 1c sodium channel inhibitors, notably flecainide, have a remarkable positive effect on the ectopic burden and the associated cardiomyopathy. This highlights the importance of genetic screening of DCM patients to identify patients with SCN5A variants associated with MEPPC. Here we review the MEPPC phenotype, MEPPC-SCN5A associated variants, and pathogenesis as well as treatment options.
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Affiliation(s)
- Kirstine Calloe
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Helena B. D. Magnusson
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | | | - Henrik Kjærulf Jensen
- Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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Young ML, Kilinc O, Benhayon D. Multifocal ectopic premature Purkinje-related complexes syndrome in children. HeartRhythm Case Rep 2023; 9:545-550. [PMID: 37614396 PMCID: PMC10444558 DOI: 10.1016/j.hrcr.2023.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2023] Open
Affiliation(s)
| | - Orhan Kilinc
- Joe DiMaggio Children’s Hospital, Hollywood, Florida
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12
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Hu X, Kong J, Niu T, Chen L, Yang J. Single coronary artery presenting dilated cardiomyopathy and hyperlipidemia with the SCN5A and APOA5 gene mutation: A case report and review of the literature. Front Cardiovasc Med 2023; 10:1113886. [PMID: 37288251 PMCID: PMC10242075 DOI: 10.3389/fcvm.2023.1113886] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 03/23/2023] [Indexed: 06/09/2023] Open
Abstract
We present a 55-year-old man with chest tightness and dyspnoea after activity lasting for 2 months who was diagnosed with single coronary artery (SCA) and presented with dilated cardiomyopathy (DCM) with the c.1858C > T mutation in the SCN5A gene. The computed tomography coronary angiogram (CTCA) showed congenital absence of the right coronary artery (RCA), and the right heart was nourished by the left coronary artery branch with no apparent stenosis. Transthoracic echocardiography (TTE) revealed enlargement of the left heart and cardiomyopathy. Cardiac magnetic resonance imaging (CMR) revealed DCM. Genetic testing showed that the c.1858C > T variant of the SCN5A gene could lead to Brugada syndrome and DCM. SCA is a rare congenital anomaly of the coronary anatomy, and this case reported as SCA accompanied by DCM is even rarer. We present a rare case of a 55-year-old man with DCM with the c.1858C > T (p. Arg620Cys)/c.1008G > A (p.(Pro336=) variant of the SCN5A gene, congenital absence of RCA, and c.990_993delAACA (p. Asp332Valfs*5) variant of the APOA5 gene. To our knowledge, this is the first report of DCM combined with the SCN5A gene mutation in SCA after searching the PubMed, CNKI and Wanfang databases.
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Affiliation(s)
- Xiaoxia Hu
- Department of Cardiology, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Jing Kong
- Department of Cardiology, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Tingting Niu
- Department of Medical Technology, Jinan Vocational College of Nursing, Jinan, Shandong, China
| | - Liang Chen
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Jingjing Yang
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan, Shandong, China
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Enokizono K, Nagase S, Ishibashi K, Miyamoto K, Aiba T, Kusano K. Combination of low-dose quinidine and verapamil for multifocal ectopic Purkinje-related premature contractions in a patient with SCN5A mutation. HeartRhythm Case Rep 2023. [DOI: 10.1016/j.hrcr.2023.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
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14
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Wright CA, Taylor JW, Cochran M, Lawlor JMJ, Moyers BA, Amaral MD, Bonnstetter ZT, Carter P, Solomon V, Myers RM, Love MN, Geldmacher DS, Cooper SJ, Roberson ED, Cochran JN. Contributions of rare and common variation to early-onset and atypical dementia risk. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.02.06.23285383. [PMID: 36798301 PMCID: PMC9934786 DOI: 10.1101/2023.02.06.23285383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
We collected and analyzed genomic sequencing data from individuals with clinician- diagnosed early-onset or atypical dementia. Thirty-two patients were previously described, with sixty-eight newly described in this report. Of those sixty-eight, sixty-two patients reported Caucasian, non-Hispanic ethnicity and six reported as African American, non-Hispanic. Fifty-three percent of patients had a returnable variant. Five patients harbored a pathogenic variant as defined by the American College of Medical Genetics criteria for pathogenicity. A polygenic risk score was calculated for Alzheimer's patients in the total cohort and compared to the scores of a late-onset Alzheimer's cohort and a control set. Patients with early-onset Alzheimer's had higher non- APOE polygenic risk scores than patients with late onset Alzheimer's, supporting the conclusion that both rare and common genetic variation associate with early-onset neurodegenerative disease risk.
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Affiliation(s)
- Carter A Wright
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama 35806, USA
- University of Alabama in Huntsville, Huntsville, Alabama 35899, USA
| | - Jared W Taylor
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama 35806, USA
| | - Meagan Cochran
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama 35806, USA
| | - James M J Lawlor
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama 35806, USA
| | - Belle A Moyers
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama 35806, USA
| | - Michelle D Amaral
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama 35806, USA
| | | | - Princess Carter
- Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Veronika Solomon
- Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Richard M Myers
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama 35806, USA
| | - Marissa Natelson Love
- Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - David S Geldmacher
- Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Sara J Cooper
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama 35806, USA
| | - Erik D Roberson
- Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - J Nicholas Cochran
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama 35806, USA
- Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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Calloe K, Geryk M, Freude K, Treat JA, Vold VA, Frederiksen HRS, Broendberg AK, Frederiksen TC, Jensen HK, Cordeiro JM. The G213D variant in Nav1.5 alters sodium current and causes an arrhythmogenic phenotype resulting in a multifocal ectopic Purkinje-related premature contraction phenotype in human-induced pluripotent stem cell-derived cardiomyocytes. Europace 2022; 24:2015-2027. [PMID: 35726875 DOI: 10.1093/europace/euac090] [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: 12/01/2021] [Accepted: 05/12/2022] [Indexed: 12/14/2022] Open
Abstract
AIMS Variants in SCN5A encoding Nav1.5 are associated with cardiac arrhythmias. We aimed to determine the mechanism by which c.638G>A in SCNA5 resulting in p.Gly213Asp (G213D) in Nav1.5 altered Na+ channel function and how flecainide corrected the defect in a family with multifocal ectopic Purkinje-related premature contractions (MEPPC)-like syndrome. METHODS AND RESULTS Five patients carrying the G213D variant were treated with flecainide. Gating pore currents were evaluated in Xenopus laevis oocytes. The 638G>A SCN5A variant was introduced to human-induced pluripotent stem cell (hiPSC) by CRISPR-Cas9 gene editing and subsequently differentiated to cardiomyocytes (hiPSC-CM). Action potentials and sodium currents were measured in the absence and presence of flecainide. Ca2+ transients were measured by confocal microscopy. The five patients exhibited premature atrial and ventricular contractions which were suppressed by flecainide treatment. G213D induced gating pore current at potentials negative to -50 mV. Voltage-clamp analysis in hiPSC-CM revealed the activation threshold of INa was shifted in the hyperpolarizing direction resulting in a larger INa window current. The G213D hiPSC-CMs had faster beating rates compared with wild-type and frequently showed Ca2+ waves and alternans. Flecainide applied to G213D hiPSC-CMs decreased window current by shifting the steady-state inactivation curve and slowed the beating rate. CONCLUSION The G213D variant in Nav1.5 induced gating pore currents and increased window current. The changes in INa resulted in a faster beating rate and Ca2+ transient dysfunction. Flecainide decreased window current and inhibited INa, which is likely responsible for the therapeutic effectiveness of flecainide in MEPPC patients carrying the G213D variant.
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Affiliation(s)
- Kirstine Calloe
- Section for Pathobiological Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Dyrlaegevej 100 DK-1870 Frederiksberg, Denmark
| | - Michelle Geryk
- Section for Pathobiological Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Dyrlaegevej 100 DK-1870 Frederiksberg, Denmark
| | - Kristine Freude
- Section for Pathobiological Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Dyrlaegevej 100 DK-1870 Frederiksberg, Denmark
| | - Jacqueline A Treat
- Department of Experimental Cardiology, Masonic Medical Research Institute, 2150 Bleecker Street, Utica, NY 13501, USA
| | - Victoria A Vold
- Section for Pathobiological Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Dyrlaegevej 100 DK-1870 Frederiksberg, Denmark
| | - Henriette Reventlow S Frederiksen
- Section for Pathobiological Sciences, Department of Veterinary and Animal Sciences, University of Copenhagen, Dyrlaegevej 100 DK-1870 Frederiksberg, Denmark
| | | | - Tanja Charlotte Frederiksen
- Department of Cardiology, Aarhus University Hospital, DK-8200 Aarhus N, Denmark.,Department of Clinical Medicine, Aarhus University, DK-8200 Aarhus N, Denmark
| | - Henrik K Jensen
- Department of Cardiology, Aarhus University Hospital, DK-8200 Aarhus N, Denmark.,Department of Clinical Medicine, Aarhus University, DK-8200 Aarhus N, Denmark
| | - Jonathan M Cordeiro
- Department of Experimental Cardiology, Masonic Medical Research Institute, 2150 Bleecker Street, Utica, NY 13501, USA
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16
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Zeppenfeld K, Tfelt-Hansen J, de Riva M, Winkel BG, Behr ER, Blom NA, Charron P, Corrado D, Dagres N, de Chillou C, Eckardt L, Friede T, Haugaa KH, Hocini M, Lambiase PD, Marijon E, Merino JL, Peichl P, Priori SG, Reichlin T, Schulz-Menger J, Sticherling C, Tzeis S, Verstrael A, Volterrani M. 2022 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death. Eur Heart J 2022; 43:3997-4126. [PMID: 36017572 DOI: 10.1093/eurheartj/ehac262] [Citation(s) in RCA: 859] [Impact Index Per Article: 429.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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17
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Peters S, Thompson BA, Perrin M, James P, Zentner D, Kalman JM, Vandenberg JI, Fatkin D. Arrhythmic Phenotypes Are a Defining Feature of Dilated Cardiomyopathy-Associated SCN5A Variants: A Systematic Review. CIRCULATION. GENOMIC AND PRECISION MEDICINE 2022; 15:e003432. [PMID: 34949099 DOI: 10.1161/circgen.121.003432] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Variants in the SCN5A gene, that encodes the cardiac sodium channel, Nav1.5, are associated with a highly arrhythmogenic form of dilated cardiomyopathy (DCM). Our aim was to review the phenotypes, natural history, functional effects, and treatment outcomes of DCM-associated rare SCN5A variants. METHODS A systematic review of reported DCM-associated rare SCN5A variants was undertaken using PubMed and Embase. RESULTS Eighteen SCN5A rare variants in 29 families with DCM (173 affected individuals) were identified. Eleven variants had undergone experimental evaluation, with 7 of these resulting in increased sustained current flow during the action potential (eg, increased window current) and at resting membrane potentials (eg, creation of a new gating pore current). These variants were located in transmembrane voltage-sensing domains and had a consistent phenotype characterized by frequent multifocal narrow and broad complex ventricular premature beats (VPB; 72% of affected relatives), ventricular arrhythmias (33%), atrial arrhythmias (32%), sudden cardiac death (13%), and DCM (56%). This VPB-predominant phenotype was not seen with 1 variant that increased late sodium current, or with variants that reduced peak current density or had mixed effects. In the latter groups, affected individuals mainly showed sinus node dysfunction, conduction defects, and atrial arrhythmias, with infrequent VPB and ventricular arrhythmias. DCM did not occur in the absence of arrhythmias for any variant. Twelve studies (23 total patients) reported treatment success in the VPB-predominant cardiomyopathy using sodium channel-blocking drug therapy. CONCLUSIONS SCN5A variants can present with a diverse spectrum of primary arrhythmic features. A majority of DCM-associated variants cause a multifocal VPB-predominant cardiomyopathy that is reversible with sodium channel blocking drug therapy. Early recognition of the distinctive phenotype and prompt genetic testing to identify variant carriers are needed. Our findings have implications for interpretation and management of SCN5A variants found in DCM patients with and without arrhythmias.
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Affiliation(s)
- Stacey Peters
- Department of Cardiology (S.P., M.P., D.Z., J.M.K.), Royal Melbourne Hospital
- Department of Genomic Medicine (S.P., B.A.T., M.P., P.J., D.Z.), Royal Melbourne Hospital
- Department of Medicine, University of Melbourne (S.P., P.J., D.Z., J.M.K.)
| | - Bryony A Thompson
- Department of Genomic Medicine (S.P., B.A.T., M.P., P.J., D.Z.), Royal Melbourne Hospital
- Department of Pathology (B.A.T.), Royal Melbourne Hospital
| | - Mark Perrin
- Department of Genomic Medicine (S.P., B.A.T., M.P., P.J., D.Z.), Royal Melbourne Hospital
| | - Paul James
- Department of Genomic Medicine (S.P., B.A.T., M.P., P.J., D.Z.), Royal Melbourne Hospital
- Department of Medicine, University of Melbourne (S.P., P.J., D.Z., J.M.K.)
- Familial Cancer Centre, Peter MacCallum Centre, Melbourne, Victoria (P.J.)
| | - Dominica Zentner
- Department of Genomic Medicine (S.P., B.A.T., M.P., P.J., D.Z.), Royal Melbourne Hospital
- Department of Medicine, University of Melbourne (S.P., P.J., D.Z., J.M.K.)
| | - Jonathan M Kalman
- Department of Medicine, University of Melbourne (S.P., P.J., D.Z., J.M.K.)
| | - Jamie I Vandenberg
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute (J.I.V., D.F.)
- St. Vincent's Clinical School, Faculty of Medicine, UNSW Sydney (J.I.V., D.F.)
| | - Diane Fatkin
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute (J.I.V., D.F.)
- St. Vincent's Clinical School, Faculty of Medicine, UNSW Sydney (J.I.V., D.F.)
- Cardiology Department, St. Vincent's Hospital, Sydney, New South Wales, Australia (D.F.)
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18
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Gao X, Ye D, Zhou W, Tester DJ, Ackerman MJ, Giudicessi JR. A novel functional variant residing outside the SCN5A-encoded Nav1.5 voltage-sensing domain causes multifocal ectopic Purkinje-related premature contractions. HeartRhythm Case Rep 2022; 8:54-59. [PMID: 35070709 PMCID: PMC8767173 DOI: 10.1016/j.hrcr.2021.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Affiliation(s)
- Xiaozhi Gao
- Departments of Cardiovascular Medicine (Division of Heart Rhythm Services), Pediatric and Adolescent Medicine (Division of Pediatric Cardiology and the Windland Smith Rice Genetic Heart Rhythm Clinic), and Molecular Pharmacology & Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, Minnesota
| | - Dan Ye
- Departments of Cardiovascular Medicine (Division of Heart Rhythm Services), Pediatric and Adolescent Medicine (Division of Pediatric Cardiology and the Windland Smith Rice Genetic Heart Rhythm Clinic), and Molecular Pharmacology & Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, Minnesota
| | - Wei Zhou
- Departments of Cardiovascular Medicine (Division of Heart Rhythm Services), Pediatric and Adolescent Medicine (Division of Pediatric Cardiology and the Windland Smith Rice Genetic Heart Rhythm Clinic), and Molecular Pharmacology & Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, Minnesota
| | - David J. Tester
- Departments of Cardiovascular Medicine (Division of Heart Rhythm Services), Pediatric and Adolescent Medicine (Division of Pediatric Cardiology and the Windland Smith Rice Genetic Heart Rhythm Clinic), and Molecular Pharmacology & Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, Minnesota
| | - Michael J. Ackerman
- Departments of Cardiovascular Medicine (Division of Heart Rhythm Services), Pediatric and Adolescent Medicine (Division of Pediatric Cardiology and the Windland Smith Rice Genetic Heart Rhythm Clinic), and Molecular Pharmacology & Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, Minnesota
| | - John R. Giudicessi
- Departments of Cardiovascular Medicine (Division of Heart Rhythm Services), Pediatric and Adolescent Medicine (Division of Pediatric Cardiology and the Windland Smith Rice Genetic Heart Rhythm Clinic), and Molecular Pharmacology & Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, Minnesota
- Department of Cardiovascular Medicine (Division of Circulatory Failure), Mayo Clinic, Rochester, Minnesota
- Address reprint requests and correspondence: Dr John R. Giudicessi, Department of Cardiovascular Medicine (Divisions of Heart Rhythm Services and Circulatory Failure), Mayo Clinic, Rochester, MN 55905.
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Cardiomyopathies: An Overview. Int J Mol Sci 2021; 22:ijms22147722. [PMID: 34299342 PMCID: PMC8303989 DOI: 10.3390/ijms22147722] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/04/2021] [Accepted: 07/14/2021] [Indexed: 12/15/2022] Open
Abstract
Background: Cardiomyopathies are a heterogeneous group of pathologies characterized by structural and functional alterations of the heart. Aims: The purpose of this narrative review is to focus on the most important cardiomyopathies and their epidemiology, diagnosis, and management. Methods: Clinical trials were identified by Pubmed until 30 March 2021. The search keywords were “cardiomyopathies, sudden cardiac arrest, dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), restrictive cardiomyopathy, arrhythmogenic cardiomyopathy (ARCV), takotsubo syndrome”. Results: Hypertrophic cardiomyopathy (HCM) is the most common primary cardiomyopathy, with a prevalence of 1:500 persons. Dilated cardiomyopathy (DCM) has a prevalence of 1:2500 and is the leading indication for heart transplantation. Restrictive cardiomyopathy (RCM) is the least common of the major cardiomyopathies, representing 2% to 5% of cases. Arrhythmogenic cardiomyopathy (ARCV) is a pathology characterized by the substitution of the myocardium by fibrofatty tissue. Takotsubo cardiomyopathy is defined as an abrupt onset of left ventricular dysfunction in response to severe emotional or physiologic stress. Conclusion: In particular, it has been reported that HCM is the most important cause of sudden death on the athletic field in the United States. It is needless to say how important it is to know which changes in the heart due to physical activity are normal, and when they are pathological.
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Leventopoulos G, Perperis A, Karelas D, Almpanis G. You cannot ablate the Lernaean Hydra: SCN5A mutation in a patient with multifocal ectopic Purkinje-related premature contractions syndrome treated with Flecainide and an implant of a subcutaneous defibrillator—a case report. Eur Heart J Case Rep 2021; 5:ytab158. [PMID: 33959699 PMCID: PMC8086419 DOI: 10.1093/ehjcr/ytab158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/28/2020] [Accepted: 04/12/2021] [Indexed: 12/19/2022]
Abstract
Background SCN5A mutations may present with different clinical phenotypes such as Brugada syndrome, long QT3 syndrome, sick sinus syndrome, atrial fibrillation, dilated cardiomyopathy, and the least known multifocal ectopic Purkinje-related premature contractions syndrome. Case summary We report a case of a 29-year-old woman with palpitations due to multifocal premature ventricular complexes (PVCs) and a family history of sudden death. The previous electrophysiological study had shown that PVCs arose from Purkinje fibres but catheter ablation was unsuccessful. Cardiac magnetic resonance (CMR) imaging demonstrated non-ischaemic areas of subendocardial fibrosis at multiple left ventricular (LV) segments with concomitant dilatation and mild systolic impairment. Amiodarone suppressed the ectopy but caused hyperthyroidism. Due to recent pregnancy, she received no antiarrhythmics which resulted in PVC burden increase and further deterioration of the ejection fraction (EF). After gestation, amiodarone was reinitiated and switched to flecainide after implantation of a subcutaneous defibrillator as a safety net. At follow-up, LV function had almost normalized. Genetic analysis confirmed an SCN5A mutation. Discussion Multifocal ectopic Purkinje-related premature contractions syndrome is associated with SCN5A mutation which in our case (R222Q) is the most common described. Flecainide can be an appropriate treatment option when ablation is ineffective. Defibrillator—even a subcutaneous type—could be implanted in cases of LV dysfunction or scar. PVCs suppression by flecainide and restoration of EF implies an arrhythmia—induced mechanism of LV impairment.
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Zakrzewska-Koperska J, Bilińska ZT, Truszkowska GT, Franaszczyk M, Elikowski W, Warmiński G, Kalin K, Urbanek P, Bodalski R, Orczykowski M, Szumowski Ł, Płoski R, Bilińska M. A combination of quinidine/mexiletine reduces arrhythmia in dilated cardiomyopathy in two patients with R814W SCN5A mutation. ESC Heart Fail 2020; 7:4326-4335. [PMID: 33084224 PMCID: PMC7754730 DOI: 10.1002/ehf2.12993] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 08/03/2020] [Accepted: 08/17/2020] [Indexed: 12/13/2022] Open
Abstract
SCN5A gene mutations are described in 2% of patients with dilated cardiomyopathy (DCM) and different rhythm disturbances, including multifocal ectopic Purkinje‐related premature contractions. Recent data indicate that sodium channel blockers are particularly effective monotherapy in carriers of the R222Q SCN5A variant. Our purpose is to describe the effectiveness of antiarrhythmic treatment in a family with genetically determined arrhythmogenic DCM associated with the R814W variant in the SCN5A gene. We examined a family with arrhythmogenic DCM (multifocal ectopic Purkinje‐related premature contractions phenotype, atrial tachyarrhythmias, automatism, and conduction disorders) and described antiarrhythmic treatment efficacy in heart failure symptoms reduction and myocardial function improvement. We found a heterozygotic mutation R814W in SCN5A by whole exome sequencing in the proband and confirmed its presence in all affected subjects. There were two sudden cardiac deaths and one heart transplantation among first‐degree relatives. The 58‐year‐old father and his 37‐year‐old daughter had full spectrum of symptoms associated with R814W SCN5A mutation. Both had implanted cardioverter defibrillator. In the father, adding mexiletine to quinidine therapy reduced ventricular arrhythmia (50–60% → 6–8% of whole rhythm) and reverted long‐standing atrial fibrillation to sinus rhythm. In the daughter, mexiletine and overdrive pacing were effective in ventricular arrhythmia reduction (25% → 0.01%). Because of a growing number of atrial fibrillation recurrences, a reduced dose of quinidine (subsequently flecainide) was added, resulting in arrhythmia significant reduction. In both cases, antiarrhythmic effectiveness correlated with clinical improvement. In SCN5A R814W‐associated DCM, a combination of Class I antiarrhythmics and overdrive pacing is an effective treatment of severe ventricular and atrial arrhythmias.
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Affiliation(s)
| | - Zofia T Bilińska
- Unit for Screening Studies in Inherited Cardiovascular Diseases, National Institute of Cardiology, ul. Alpejska 42, Warsaw, 04-628, Poland
| | - Grażyna T Truszkowska
- Molecular Biology Laboratory, Department of Medical Biology, National Institute of Cardiology, Warsaw, Poland
| | - Maria Franaszczyk
- Molecular Biology Laboratory, Department of Medical Biology, National Institute of Cardiology, Warsaw, Poland
| | | | - Grzegorz Warmiński
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
| | - Katarzyna Kalin
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
| | - Piotr Urbanek
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
| | - Robert Bodalski
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
| | - Michał Orczykowski
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
| | - Łukasz Szumowski
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
| | - Rafał Płoski
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Maria Bilińska
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
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Beserra SS, Santos-Miranda A, Sarmento JO, Miranda VM, Roman-Campos D. Effects of amiodarone on rodent ventricular cardiomyocytes: Novel perspectives from a cellular model of Long QT Syndrome Type 3. Life Sci 2020; 255:117814. [PMID: 32439300 DOI: 10.1016/j.lfs.2020.117814] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/04/2020] [Accepted: 05/15/2020] [Indexed: 10/24/2022]
Abstract
AIMS Amiodarone (AMIO) is currently used in medical practice to reverse ventricular tachycardia. Here we determine the effects of AMIO in the electromechanical properties of isolated left ventricle myocyte (LVM) from mice and guinea pig and in a cellular model of Long QT Syndrome Type 3 (LQTS-3) using anemone neurotoxin 2 (ATX II), which induces increase of late sodium current in LVM. MAIN METHODS AND KEY FINDINGS Using patch-clamp technique, fluorescence imaging to detect cellular Ca2+ transient and sarcomere detection systems we evaluate the effect of AMIO in healthy LVM. AMIO produced a significant reduction in the percentage of sarcomere shortening (0.1, 1 and 10 μM) in a range of pacing frequencies, however, without significant attenuation of Ca2+ transient. Also, 10 μM of AMIO caused the opposite effect on action potential repolarization of mouse and guinea pig LVM. When LVM from mouse and guinea pig were paced in a range of pacing frequencies and exposed to ATX (10 nM), AMIO (10 μM) was only able to abrogate electromechanical arrhythmias in LVM from guinea pig at lower pacing frequency. SIGNIFICANCE AMIO has negative inotropic effect with opposite effect on action potential waveform in mouse and guinea pig LVM. Furthermore, the antiarrhythmic action of AMIO in LQTS-3 is species and frequency-dependent, which indicates that AMIO may be beneficial for some types of arrhythmias related to late sodium current.
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Affiliation(s)
- Samuel Santos Beserra
- Laboratory of CardioBiology, Department of Biophysics, Paulista School of Medicina, Federal University of Sao Paulo, Brazil
| | - Artur Santos-Miranda
- Laboratory of CardioBiology, Department of Biophysics, Paulista School of Medicina, Federal University of Sao Paulo, Brazil
| | - Jaqueline Oliveira Sarmento
- Laboratory of CardioBiology, Department of Biophysics, Paulista School of Medicina, Federal University of Sao Paulo, Brazil
| | - Victor Martins Miranda
- Laboratory of CardioBiology, Department of Biophysics, Paulista School of Medicina, Federal University of Sao Paulo, Brazil
| | - Danilo Roman-Campos
- Laboratory of CardioBiology, Department of Biophysics, Paulista School of Medicina, Federal University of Sao Paulo, Brazil.
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23
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Luo Q, Wu T, Wu W, Chen G, Luo X, Jiang L, Tao H, Rong M, Kang S, Deng M. The Functional Role of Voltage-Gated Sodium Channel Nav1.5 in Metastatic Breast Cancer. Front Pharmacol 2020; 11:1111. [PMID: 32792949 PMCID: PMC7393602 DOI: 10.3389/fphar.2020.01111] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 07/08/2020] [Indexed: 12/12/2022] Open
Abstract
Voltage-gated sodium channels (VGSCs), which are abnormally expressed in various types of cancers such as breast cancer, prostate cancer, lung cancer, and cervical cancer, are involved in the metastatic process of invasion and migration. Nav1.5 is a pore-forming α subunit of VGSC encoded by SCN5A. Various studies have demonstrated that Nav1.5, often as its neonatal splice form, is highly expressed in metastatic breast cancer cells. Abnormal activation and expression of Nav1.5 trigger a variety of cellular mechanisms, including changing H+ efflux, promoting epithelial-to-mesenchymal transition (EMT) and the expression of cysteine cathepsin, to potentiate the metastasis and invasiveness of breast cancer cells in vitro and in vivo. Here, we systematically review the latest available data on the pro-metastatic effect of Nav1.5 and its underlying mechanisms in breast cancer. We summarize the factors affecting Nav1.5 expression in breast cancer cells, and discuss the potential of Nav1.5 blockers serving as candidates for breast cancer treatment.
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Affiliation(s)
- Qianxuan Luo
- Department of Biochemistry and Molecular Biology & Hunan Province Key Laboratory of Basic and Applied Hematology, School of Life Sciences, Central South University, Changsha, China
- Hunan Key Laboratory of Animal Models for Human Diseases & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Ting Wu
- Department of Biochemistry and Molecular Biology & Hunan Province Key Laboratory of Basic and Applied Hematology, School of Life Sciences, Central South University, Changsha, China
- Xiangya School of Medicine, Central South University, Changsha, China
| | - Wenfang Wu
- Department of Biochemistry and Molecular Biology & Hunan Province Key Laboratory of Basic and Applied Hematology, School of Life Sciences, Central South University, Changsha, China
| | - Gong Chen
- Department of Biochemistry and Molecular Biology & Hunan Province Key Laboratory of Basic and Applied Hematology, School of Life Sciences, Central South University, Changsha, China
| | - Xuan Luo
- Department of Biochemistry and Molecular Biology, Hunan Normal University, Changsha, China
| | - Liping Jiang
- Xiangya School of Medicine, Central South University, Changsha, China
| | - Huai Tao
- Department of Biochemistry and Molecular Biology, Hunan University of Chinese Medicine, Changsha, China
| | - Mingqiang Rong
- Department of Biochemistry and Molecular Biology, Hunan Normal University, Changsha, China
| | - Shuntong Kang
- Department of Biochemistry and Molecular Biology & Hunan Province Key Laboratory of Basic and Applied Hematology, School of Life Sciences, Central South University, Changsha, China
- Xiangya School of Medicine, Central South University, Changsha, China
| | - Meichun Deng
- Department of Biochemistry and Molecular Biology & Hunan Province Key Laboratory of Basic and Applied Hematology, School of Life Sciences, Central South University, Changsha, China
- Hunan Key Laboratory of Animal Models for Human Diseases & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China
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24
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Barake W, Giudicessi JR, Asirvatham SJ, Ackerman MJ. Purkinje system hyperexcitability and ventricular arrhythmia risk in type 3 long QT syndrome. Heart Rhythm 2020; 17:1768-1776. [PMID: 32454217 DOI: 10.1016/j.hrthm.2020.05.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/01/2020] [Accepted: 05/11/2020] [Indexed: 01/20/2023]
Abstract
BACKGROUND Gain-of-function variants in the SCN5A-encoded Nav1.5 sodium channel cause type 3 long QT syndrome (LQT3) and multifocal ectopic Purkinje-related premature contractions. Although the Purkinje system is uniquely sensitive to the action potential-prolonging effects of LQT3-causative variants, the existence of additional Purkinje phenotype(s) in LQT3 is unknown. OBJECTIVE The purpose of this study was to determine the prevalence and clinical implications of frequent fascicular/Purkinje-related premature ventricular contractions (PVCs) and short-coupled ventricular arrhythmias (VAs), suggestive of Purkinje system hyperexcitability (PSH), in a single-center LQT3 cohort. METHODS A retrospective analysis of 177 SCN5A-positive patients was performed to identify individuals with a LQT3 phenotype. Available electrocardiographic, electrophysiology study, device, and genetic data from 91 individuals with LQT3 were reviewed for evidence of presumed fascicular PVCs and short-coupled VAs. The relationship between PSH and ventricular fibrillation events was assessed by Kaplan-Meier and Cox regression analyses. RESULTS Overall, 30 of 91 patients with LQT3 (33%) exhibited evidence of presumed PSH (fascicular PVCs 30 of 30 [100%]; short-coupled VAs 17 of 30 [56%]). Kaplan-Meier and Cox regression analyses demonstrated an increased risk of ventricular fibrillation events in individuals with LQT3 and PSH (log-rank, P < .03; hazard ratio 3.95; 95% confidence interval 1.15-15.7; P = .03). Interestingly, variants in the voltage-sensing domain regions of Nav1.5 were more frequently observed in patients with LQT3 and PSH than those without (19 of 30 [63%] vs 9 of 61 [15%]; P < .0001). CONCLUSION This study demonstrates that a discernible Purkinje phenotype is present in one-third of LQT3 cases and increases the risk of potentially lethal VAs. Further study is needed to determine whether a distinct cellular electrophysiology phenotype underlies this phenomenon.
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Affiliation(s)
- Walid Barake
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota
| | - John R Giudicessi
- Clinician Investigator Training Program, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota; Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota
| | - Samuel J Asirvatham
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota; Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota
| | - Michael J Ackerman
- Division of Heart Rhythm Services, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota; Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota; Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota.
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25
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Doisne N, Waldmann V, Redheuil A, Waintraub X, Fressart V, Ader F, Fossé L, Hidden-Lucet F, Gandjbakhch E, Neyroud N. A novel gain-of-function mutation in SCN5A responsible for multifocal ectopic Purkinje-related premature contractions. Hum Mutat 2020; 41:850-859. [PMID: 31930659 DOI: 10.1002/humu.23981] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 12/13/2019] [Accepted: 01/02/2020] [Indexed: 12/19/2022]
Abstract
Recently, four SCN5A mutations have been associated with Multifocal Ectopic Purkinje-related Premature Contractions (MEPPC), a rare cardiac syndrome combining polymorphic ventricular arrhythmia with dilated cardiomyopathy (DCM). Here, we identified a novel heterozygous mutation in SCN5A (c.611C>A, pAla204Glu) in a young woman presenting with polymorphic premature ventricular contractions (PVCs) and DCM. After failure of antiarrhythmic drugs and an attempt of radiofrequency catheter ablation showing three exit-sites of PVCs, all with presystolic Purkinje potentials, a treatment by hydroquinidine was tried, leading to an immediate and spectacular disappearance of all PVCs and normalization of cardiac function. Electrophysiological studies showed that Nav 1.5-A204E mutant channels exhibited a significant leftward shift of 8 mV of the activation curve, leading to a larger hyperpolarized window current when compared to wild-type. Action potential modeling using Purkinje fiber and ventricular cell models predicted an arrhythmogenic effect predominant in Purkinje fibers for the A204E mutation. Comparison with other MEPPC-associated Nav 1.5 mutations revealed a common electrophysiological pattern of abnormal voltage-dependence of activation leading to a larger hyperpolarized window current as a shared biophysical mechanism of this syndrome. These features of the mutant sodium channels are likely to be responsible for the hyperexcitability of the fascicular-Purkinje system observed in patients with MEPPC.
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Affiliation(s)
- Nicolas Doisne
- Faculté de Médecine, Sorbonne Université, Paris, France.,INSERM, UMR_S1166, Hôpital Pitié-Salpêtrière, Paris, France.,ICAN, Institute of Cardiometabolism and Nutrition, Paris, France
| | - Victor Waldmann
- Département de Cardiologie, Hôpital Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Alban Redheuil
- Faculté de Médecine, Sorbonne Université, Paris, France.,ICAN, Institute of Cardiometabolism and Nutrition, Paris, France.,Département d'Imagerie Cardiovasculaire, Hôpital Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Xavier Waintraub
- ICAN, Institute of Cardiometabolism and Nutrition, Paris, France.,Département de Cardiologie, Hôpital Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Véronique Fressart
- Faculté de Médecine, Sorbonne Université, Paris, France.,INSERM, UMR_S1166, Hôpital Pitié-Salpêtrière, Paris, France.,ICAN, Institute of Cardiometabolism and Nutrition, Paris, France.,Département de Biochimie métabolique, Cardiogénétique, Hôpital Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Flavie Ader
- Faculté de Médecine, Sorbonne Université, Paris, France.,INSERM, UMR_S1166, Hôpital Pitié-Salpêtrière, Paris, France.,ICAN, Institute of Cardiometabolism and Nutrition, Paris, France.,Département de Biochimie métabolique, Cardiogénétique, Hôpital Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Lucie Fossé
- Faculté de Médecine, Sorbonne Université, Paris, France.,INSERM, UMR_S1166, Hôpital Pitié-Salpêtrière, Paris, France
| | - Françoise Hidden-Lucet
- ICAN, Institute of Cardiometabolism and Nutrition, Paris, France.,Département de Cardiologie, Hôpital Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Estelle Gandjbakhch
- Faculté de Médecine, Sorbonne Université, Paris, France.,INSERM, UMR_S1166, Hôpital Pitié-Salpêtrière, Paris, France.,ICAN, Institute of Cardiometabolism and Nutrition, Paris, France.,Département de Cardiologie, Hôpital Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Nathalie Neyroud
- Faculté de Médecine, Sorbonne Université, Paris, France.,INSERM, UMR_S1166, Hôpital Pitié-Salpêtrière, Paris, France.,ICAN, Institute of Cardiometabolism and Nutrition, Paris, France
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26
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Pang PD, Alsina KM, Cao S, Koushik AB, Wehrens XHT, Cooper TA. CRISPR -Mediated Expression of the Fetal Scn5a Isoform in Adult Mice Causes Conduction Defects and Arrhythmias. J Am Heart Assoc 2019; 7:e010393. [PMID: 30371314 PMCID: PMC6404881 DOI: 10.1161/jaha.118.010393] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Background The sodium channel, Nav1.5, encoded by SCN5A, undergoes developmentally regulated splicing from inclusion of exon 6A in the fetal heart to exon 6B in adults. These mutually exclusive exons differ in 7 amino acids altering the electrophysiological properties of the Nav1.5 channel. In myotonic dystrophy type 1, SCN5A is mis‐spliced such that the fetal pattern of exon 6A inclusion is detected in adult hearts. Cardiac manifestations of myotonic dystrophy type 1 include conduction defects and arrhythmias and are the second‐leading cause of death. Methods and Results This work aimed to determine the impact of SCN5A mis‐splicing on cardiac function. We used clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR‐associated protein 9 (Cas9) to delete Scn5a exon 6B in mice, thereby redirecting splicing toward exon 6A. These mice exhibit prolonged PR and QRS intervals, slowed conduction velocity, extended action potential duration, and are highly susceptible to arrhythmias. Conclusions Our findings highlight a nonmutational pathological mechanism of arrhythmias and conduction defects as a result of mis‐splicing of the predominant cardiac sodium channel. Animals homozygous for the deleted exon express only the fetal isoform and have more‐severe phenotypes than heterozygotes that also express the adult isoform. This observation is directly relevant to myotonic dystrophy type 1, and possibly pathological arrhythmias, in which individuals differ with regard to the ratios of the isoforms expressed.
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Affiliation(s)
- Paul D Pang
- 1 Department of Molecular Physiology & Biophysics Baylor College of Medicine Houston TX.,2 Department of Pathology & Immunology Baylor College of Medicine Houston TX.,3 Integrative Molecular and Biomedical Sciences Program Baylor College of Medicine Houston TX
| | - Katherina M Alsina
- 1 Department of Molecular Physiology & Biophysics Baylor College of Medicine Houston TX.,3 Integrative Molecular and Biomedical Sciences Program Baylor College of Medicine Houston TX
| | - Shuyi Cao
- 1 Department of Molecular Physiology & Biophysics Baylor College of Medicine Houston TX
| | - Amrita B Koushik
- 2 Department of Pathology & Immunology Baylor College of Medicine Houston TX
| | - Xander H T Wehrens
- 1 Department of Molecular Physiology & Biophysics Baylor College of Medicine Houston TX.,3 Integrative Molecular and Biomedical Sciences Program Baylor College of Medicine Houston TX.,5 Department of Medicine Baylor College of Medicine Houston TX.,6 Department of Pediatrics Baylor College of Medicine Houston TX.,7 Center for Space Medicine Baylor College of Medicine Houston TX.,8 Cardiovascular Research Institute Baylor College of Medicine Houston TX
| | - Thomas A Cooper
- 1 Department of Molecular Physiology & Biophysics Baylor College of Medicine Houston TX.,2 Department of Pathology & Immunology Baylor College of Medicine Houston TX.,3 Integrative Molecular and Biomedical Sciences Program Baylor College of Medicine Houston TX.,4 Department of Molecular & Cellular Biology Baylor College of Medicine Houston TX.,8 Cardiovascular Research Institute Baylor College of Medicine Houston TX
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27
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Daniel LL, Yang T, Kroncke B, Hall L, Stroud D, Roden DM. SCN5A variant R222Q generated abnormal changes in cardiac sodium current and action potentials in murine myocytes and Purkinje cells. Heart Rhythm 2019; 16:1676-1685. [PMID: 31125670 PMCID: PMC6825529 DOI: 10.1016/j.hrthm.2019.05.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND The cardiac sodium channel (SCN5A) mutation R222Q neutralizes a positive charge in the domain I voltage sensor. Mutation carriers display very frequent ectopy and dilated cardiomyopathy. OBJECTIVES To describe the effect of SCN5A R222Q on murine myocyte and Purkinje fiber electrophysiology, and identify underlying mechanisms. METHODS We generated mice carrying humanized wild-type (H) and mutant (RQ) SCN5A channels. We characterized whole-heart and isolated ventricular and Purkinje myocyte properties. RESULTS RQ/RQ mice were not viable. INa from RQ/H ventricular myocytes displayed increased "window current" and hyperpolarizing shifts in both inactivation and activation compared to H/H, as previously reported in heterologous expression systems. Surprisingly, action potentials were markedly abbreviated in RQ/H myocytes (action potential durations at 90% repolarization: 12.6 ± 1.3 ms vs 29.1 ± 1.0 ms in H/H, P < .01, n = 10 each). We identified a large [K+]o-dependent outward gating pore current in RQ/H but not H/H myocytes, and decreasing [K+]o elicited early afterdepolarizations (EADs) and triggered activity in isolated myocytes and ectopic beats in whole hearts. Further, RQ/H Purkinje cells displayed striking, consistent low-voltage EADs. In vivo, however, RQ/H mice displayed little ectopy and contractile function was normal. CONCLUSION While SCN5A R222Q increases plateau inward sodium current, action potentials were unexpectedly shortened, likely reflecting an outward gating-pore current. Low extracellular potassium increased this pore current, and was arrhythmogenic in vitro and ex vivo.
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Affiliation(s)
- Laura L Daniel
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Tao Yang
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Brett Kroncke
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Lynn Hall
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Dina Stroud
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Dan M Roden
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, Tennessee.
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28
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Cerrone M, Remme CA, Tadros R, Bezzina CR, Delmar M. Beyond the One Gene-One Disease Paradigm: Complex Genetics and Pleiotropy in Inheritable Cardiac Disorders. Circulation 2019; 140:595-610. [PMID: 31403841 DOI: 10.1161/circulationaha.118.035954] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Inheritable cardiac disorders, which may be associated with cardiomyopathic changes, are often associated with increased risk of sudden death in the young. Early linkage analysis studies in Mendelian forms of these diseases, such as hypertrophic cardiomyopathy and long-QT syndrome, uncovered large-effect genetic variants that contribute to the phenotype. In more recent years, through genotype-phenotype studies and methodological advances in genetics, it has become evident that most inheritable cardiac disorders are not monogenic but, rather, have a complex genetic basis wherein multiple genetic variants contribute (oligogenic or polygenic inheritance). Conversely, studies on genes underlying these disorders uncovered pleiotropic effects, with a single gene affecting multiple and apparently unrelated phenotypes. In this review, we explore these 2 phenomena: on the one hand, the evidence that variants in multiple genes converge to generate one clinical phenotype, and, on the other, the evidence that variants in one gene can lead to apparently unrelated phenotypes. Although multiple conditions are addressed to illustrate these concepts, the experience obtained in the study of long-QT syndrome, Brugada syndrome, and arrhythmogenic cardiomyopathy, and in the study of functions related to SCN5A (the gene coding for the α-subunit of the most abundant sodium channel in the heart) and PKP2 (the gene coding for the desmosomal protein plakophilin-2), as well, is discussed in more detail.
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Affiliation(s)
- Marina Cerrone
- Leon H. Charney Division of Cardiology (M.C., M.D.), NYU School of Medicine, New York.,Inherited Arrhythmias Clinic and Heart Rhythm Center, Leon H. Charney Division of Cardiology (M.C.), NYU School of Medicine, New York
| | - Carol Ann Remme
- Inherited Arrhythmias Clinic and Heart Rhythm Center, Leon H. Charney Division of Cardiology (M.C.), NYU School of Medicine, New York
| | - Rafik Tadros
- Amsterdam UMC, University of Amsterdam, Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, AMC Heart Center, The Netherlands (C.A.R., C.R.B.)
| | - Connie R Bezzina
- Inherited Arrhythmias Clinic and Heart Rhythm Center, Leon H. Charney Division of Cardiology (M.C.), NYU School of Medicine, New York
| | - Mario Delmar
- Leon H. Charney Division of Cardiology (M.C., M.D.), NYU School of Medicine, New York
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Asatryan B. Cardiac Sodium Channel Dysfunction and Dilated Cardiomyopathy: A Contemporary Reappraisal of Pathophysiological Concepts. J Clin Med 2019; 8:jcm8071029. [PMID: 31336969 PMCID: PMC6678327 DOI: 10.3390/jcm8071029] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/07/2019] [Accepted: 07/09/2019] [Indexed: 12/19/2022] Open
Abstract
A key emerging theme in translational cardiovascular medicine is the need to identify specific causes of arrhythmias and heart failure, defined by phenotype and/or genotype that will respond to a particular intervention. Unlike other genes implicated in hereditary arrhythmias and cardiomyopathies, pathogenic/likely pathogenic variants in the cardiac sodium channel alpha subunit gene (SCN5A) produce a remarkably diverse set of electrical and structural phenotypes, one of them being dilated cardiomyopathy. There has been debate about whether left ventricular remodeling is a bona fide phenotypic feature of cardiac sodium channel dysfunction, or a consequence of tachyarrhythmias or conduction disturbances. In light of recent findings, a critical digest of the available experimental and medical literature is necessary. This paper provides a critical appraisal of the evidence linking a dysfunctional cardiac sodium channel to ventricular dysfunction, and discusses the potential mechanisms involved in shaping this phenotype along with implications for precision therapy.
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Affiliation(s)
- Babken Asatryan
- Department of Cardiology, Inselspital, Bern University Hospital, Freiburgstrasse 10, 3010 Bern, Switzerland.
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30
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Wilde AA, Garan H, Boyden PA. Role of the Purkinje system in heritable arrhythmias. Heart Rhythm 2019; 16:1121-1126. [DOI: 10.1016/j.hrthm.2019.01.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Indexed: 12/28/2022]
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31
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Towbin JA, McKenna WJ, Abrams DJ, Ackerman MJ, Calkins H, Darrieux FCC, Daubert JP, de Chillou C, DePasquale EC, Desai MY, Estes NAM, Hua W, Indik JH, Ingles J, James CA, John RM, Judge DP, Keegan R, Krahn AD, Link MS, Marcus FI, McLeod CJ, Mestroni L, Priori SG, Saffitz JE, Sanatani S, Shimizu W, van Tintelen JP, Wilde AAM, Zareba W. 2019 HRS expert consensus statement on evaluation, risk stratification, and management of arrhythmogenic cardiomyopathy. Heart Rhythm 2019; 16:e301-e372. [PMID: 31078652 DOI: 10.1016/j.hrthm.2019.05.007] [Citation(s) in RCA: 436] [Impact Index Per Article: 87.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Indexed: 02/08/2023]
Abstract
Arrhythmogenic cardiomyopathy (ACM) is an arrhythmogenic disorder of the myocardium not secondary to ischemic, hypertensive, or valvular heart disease. ACM incorporates a broad spectrum of genetic, systemic, infectious, and inflammatory disorders. This designation includes, but is not limited to, arrhythmogenic right/left ventricular cardiomyopathy, cardiac amyloidosis, sarcoidosis, Chagas disease, and left ventricular noncompaction. The ACM phenotype overlaps with other cardiomyopathies, particularly dilated cardiomyopathy with arrhythmia presentation that may be associated with ventricular dilatation and/or impaired systolic function. This expert consensus statement provides the clinician with guidance on evaluation and management of ACM and includes clinically relevant information on genetics and disease mechanisms. PICO questions were utilized to evaluate contemporary evidence and provide clinical guidance related to exercise in arrhythmogenic right ventricular cardiomyopathy. Recommendations were developed and approved by an expert writing group, after a systematic literature search with evidence tables, and discussion of their own clinical experience, to present the current knowledge in the field. Each recommendation is presented using the Class of Recommendation and Level of Evidence system formulated by the American College of Cardiology and the American Heart Association and is accompanied by references and explanatory text to provide essential context. The ongoing recognition of the genetic basis of ACM provides the opportunity to examine the diverse triggers and potential common pathway for the development of disease and arrhythmia.
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Affiliation(s)
- Jeffrey A Towbin
- Le Bonheur Children's Hospital, Memphis, Tennessee; University of Tennessee Health Science Center, Memphis, Tennessee
| | - William J McKenna
- University College London, Institute of Cardiovascular Science, London, United Kingdom
| | | | | | | | | | | | | | | | | | - N A Mark Estes
- University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Wei Hua
- Fu Wai Hospital, Beijing, China
| | - Julia H Indik
- University of Arizona, Sarver Heart Center, Tucson, Arizona
| | - Jodie Ingles
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney, Australia
| | | | - Roy M John
- Vanderbilt University Medical Center, Nashville, Tennessee
| | - Daniel P Judge
- Medical University of South Carolina, Charleston, South Carolina
| | - Roberto Keegan
- Hospital Privado Del Sur, Buenos Aires, Argentina; Hospital Español, Bahia Blanca, Argentina
| | | | - Mark S Link
- UT Southwestern Medical Center, Dallas, Texas
| | - Frank I Marcus
- University of Arizona, Sarver Heart Center, Tucson, Arizona
| | | | - Luisa Mestroni
- University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Silvia G Priori
- University of Pavia, Pavia, Italy; European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (ERN GUARD-Heart); ICS Maugeri, IRCCS, Pavia, Italy
| | | | | | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
| | - J Peter van Tintelen
- University of Amsterdam, Academic Medical Center, Amsterdam, the Netherlands; Utrecht University Medical Center Utrecht, University of Utrecht, Department of Genetics, Utrecht, the Netherlands
| | - Arthur A M Wilde
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (ERN GUARD-Heart); University of Amsterdam, Academic Medical Center, Amsterdam, the Netherlands; Department of Medicine, Columbia University Irving Medical Center, New York, New York
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Han D, Tan H, Sun C, Li G. Amiodarone-induced life-threatening torsade de pointes in an end-stage lung cancer patient receiving gefitinib. Oxf Med Case Reports 2019; 2019:omy122. [PMID: 30697438 PMCID: PMC6345081 DOI: 10.1093/omcr/omy122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/25/2018] [Accepted: 11/07/2018] [Indexed: 12/19/2022] Open
Abstract
The risk factors of acquired long QT syndrome (aLQTS) are sometimes overlooked in clinics. Drugs, hypokalemia, age and female sex are well-known risk factors of QT prolongation-dependent torsade de pointes (TdP), which explains the high incidence of sudden cardiac death in LQT patients. Here, we report a case of an elderly female patient with lung cancer who was in poor condition, for whom amiodarone was mistakenly prescribed to rectify premature ventricular contractions. QT prolongation-dependent TdP immediately followed intravenous injection of amiodarone. Fortunately, the patient survived aborted sudden cardiac arrest after effective cardio-pulmonary resuscitation and electric defibrillation. Upon reviewing the clinical information, several pre-existing risk factors of aLQTS and TdP were identified. The mistaken prescription of amiodarone provoked TdP after these risk factors were overlooked in this case and thus predisposed this patient to a high susceptibility of drug-induced TdP.
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Affiliation(s)
- Dan Han
- Department of Cardiovascular Medicine, First Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, China
| | - Hui Tan
- Department of Respiratory Medicine, First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, China
| | - Chaofeng Sun
- Department of Cardiovascular Medicine, First Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, China
| | - Guoliang Li
- Department of Cardiovascular Medicine, First Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, China
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A leaky voltage sensor domain of cardiac sodium channels causes arrhythmias associated with dilated cardiomyopathy. Sci Rep 2018; 8:13804. [PMID: 30218094 PMCID: PMC6138662 DOI: 10.1038/s41598-018-31772-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 08/21/2018] [Indexed: 11/18/2022] Open
Abstract
Dilated cardiomyopathy (DCM) is a structural heart disease that causes dilatation of cardiac chambers and impairs cardiac contractility. The SCN5A gene encodes Nav1.5, the predominant cardiac sodium channel alpha subunit. SCN5A mutations have been identified in patients with arrhythmic disorders associated with DCM. The characterization of Nav1.5 mutations located in the voltage sensor domain (VSD) and associated with DCM revealed divergent biophysical defects that do not fully explain the pathologies observed in these patients. The purpose of this study was to characterize the pathological consequences of a gating pore in the heart arising from the Nav1.5/R219H mutation in a patient with complex cardiac arrhythmias and DCM. We report its properties using cardiomyocytes derived from patient-specific human induced pluripotent stem cells. We showed that this mutation generates a proton leak (called gating pore current). We also described disrupted ionic homeostasis, altered cellular morphology, electrical properties, and contractile function, most probably linked to the proton leak. We thus propose a novel link between SCN5A mutation and the complex pathogenesis of cardiac arrhythmias and DCM. Furthermore, we suggest that leaky channels would constitute a common pathological mechanism underlying several neuronal, neuromuscular, and cardiac pathologies.
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Bondue A, Arbustini E, Bianco A, Ciccarelli M, Dawson D, De Rosa M, Hamdani N, Hilfiker-Kleiner D, Meder B, Leite-Moreira AF, Thum T, Tocchetti CG, Varricchi G, Van der Velden J, Walsh R, Heymans S. Complex roads from genotype to phenotype in dilated cardiomyopathy: scientific update from the Working Group of Myocardial Function of the European Society of Cardiology. Cardiovasc Res 2018; 114:1287-1303. [PMID: 29800419 PMCID: PMC6054212 DOI: 10.1093/cvr/cvy122] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 05/05/2018] [Accepted: 05/16/2018] [Indexed: 12/14/2022] Open
Abstract
Dilated cardiomyopathy (DCM) frequently affects relatively young, economically, and socially active adults, and is an important cause of heart failure and transplantation. DCM is a complex disease and its pathological architecture encounters many genetic determinants interacting with environmental factors. The old perspective that every pathogenic gene mutation would lead to a diseased heart, is now being replaced by the novel observation that the phenotype depends not only on the penetrance-malignancy of the mutated gene-but also on epigenetics, age, toxic factors, pregnancy, and a diversity of acquired diseases. This review discusses how gene mutations will result in mutation-specific molecular alterations in the heart including increased mitochondrial oxidation (sarcomeric gene e.g. TTN), decreased calcium sensitivity (sarcomeric genes), fibrosis (e.g. LMNA and TTN), or inflammation. Therefore, getting a complete picture of the DCM patient will include genomic data, molecular assessment by preference from cardiac samples, stratification according to co-morbidities, and phenotypic description. Those data will help to better guide the heart failure and anti-arrhythmic treatment, predict response to therapy, develop novel siRNA-based gene silencing for malignant gene mutations, or intervene with mutation-specific altered gene pathways in the heart.This article is part of the Mini Review Series from the Varenna 2017 meeting of the Working Group of Myocardial Function of the European Society of Cardiology.
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Affiliation(s)
- Antoine Bondue
- Department of Cardiology, CUB Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
| | - Eloisa Arbustini
- Centre for Inherited Cardiovascular Diseases, IRCCS Foundation, University Hospital Policlinico San Matteo, Pavia, Italy
| | - Anna Bianco
- Department of Translational Medical Sciences, Federico II University, Naples, Italy
- Department of Cardiology, Maastricht University Medical Center & CARIM, Maastricht University, Maastricht, The Netherlands
| | - Michele Ciccarelli
- School of Medicine, Surgery and Dentistry, University of Salerno, Salerno, Italy
| | - Dana Dawson
- School of Medicine and Dentistry, University of Aberdeen, Aberdeen, UK
| | - Matteo De Rosa
- School of Medicine, Surgery and Dentistry, University of Salerno, Salerno, Italy
| | - Nazha Hamdani
- Department of Systems Physiology, Ruhr University Bochum, Bochum, Germany
| | - Denise Hilfiker-Kleiner
- Molecular Cardiology, Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany
| | - Benjamin Meder
- Department of Cardiology, Heidelberg University, Heidelberg, Germany
- Department of Genetics, Stanford University School of Medicine, Genome Technology Center, Palo Alto, CA, USA
| | - Adelino F Leite-Moreira
- Cardiovascular R&D Unit, Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
- Department of Cardiothoracic Surgery, Hospital of S. João, Porto, Portugal
| | - Thomas Thum
- Institute of Molecular and Translational Therapeutic Strategies, Hannover Medical School, Hannover, Germany
| | - Carlo G Tocchetti
- Department of Translational Medical Sciences, Federico II University, Naples, Italy
| | - Gilda Varricchi
- Department of Translational Medical Sciences, Federico II University, Naples, Italy
| | - Jolanda Van der Velden
- Department of Physiology, VU University Medical Centre, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
- Netherlands Heart Institute, Utrecht, The Netherlands
| | - Roddy Walsh
- Cardiovascular Research Center, Royal Brompton and Harefield NHS Foundation Trust and Imperial College London, London, UK
| | - Stephane Heymans
- Department of Cardiology, Maastricht University Medical Center & CARIM, Maastricht University, Maastricht, The Netherlands
- Netherlands Heart Institute, Utrecht, The Netherlands
- Department of Cardiovascular Sciences, Leuven University, Leuven, Belgium
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Beauty and the beat: A complicated case of multifocal ectopic Purkinje-related premature contractions. HeartRhythm Case Rep 2018; 4:429-433. [PMID: 30228971 PMCID: PMC6140614 DOI: 10.1016/j.hrcr.2018.05.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Han D, Tan H, Sun C, Li G. Dysfunctional Nav1.5 channels due to SCN5A mutations. Exp Biol Med (Maywood) 2018; 243:852-863. [PMID: 29806494 DOI: 10.1177/1535370218777972] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The voltage-gated sodium channel 1.5 (Nav1.5), encoded by the SCN5A gene, is responsible for the rising phase of the action potential of cardiomyocytes. The sodium current mediated by Nav1.5 consists of peak and late components (INa-P and INa-L). Mutant Nav1.5 causes alterations in the peak and late sodium current and is associated with an increasingly wide range of congenital arrhythmias. More than 400 mutations have been identified in the SCN5A gene. Although the mechanisms of SCN5A mutations leading to a variety of arrhythmias can be classified according to the alteration of INa-P and INa-L as gain-of-function, loss-of-function and both, few researchers have summarized the mechanisms in this way before. In this review article, we aim to review the mechanisms underlying dysfunctional Nav1.5 due to SCN5A mutations and to provide some new insights into further approaches in the treatment of arrhythmias. Impact statement The field of ion channelopathy caused by dysfunctional Nav1.5 due to SCN5A mutations is rapidly evolving as novel technologies of electrophysiology are introduced and our understanding of the mechanisms of various arrhythmias develops. In this review, we focus on the dysfunctional Nav1.5 related to arrhythmias and the underlying mechanisms. We update SCN5A mutations in a precise way since 2013 and presents novel classifications of SCN5A mutations responsible for the dysfunction of the peak (INa-P) and late (INa-L) sodium channels based on their phenotypes, including loss-, gain-, and coexistence of gain- and loss-of function mutations in INa-P, INa-L, respectively. We hope this review will provide a new comprehensive way to better understand the electrophysiological mechanisms underlying arrhythmias from cell to bedside, promoting the management of various arrhythmias in practice.
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Affiliation(s)
- Dan Han
- 1 Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, P.R. China
| | - Hui Tan
- 2 Department of Respiratory Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, P.R. China
| | - Chaofeng Sun
- 1 Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, P.R. China
| | - Guoliang Li
- 1 Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, P.R. China
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37
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Wilde AAM, Amin AS. Clinical Spectrum of SCN5A Mutations: Long QT Syndrome, Brugada Syndrome, and Cardiomyopathy. JACC Clin Electrophysiol 2018; 4:569-579. [PMID: 29798782 DOI: 10.1016/j.jacep.2018.03.006] [Citation(s) in RCA: 188] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 03/02/2018] [Accepted: 03/08/2018] [Indexed: 12/13/2022]
Abstract
SCN5A gene encodes the pore-forming ion-conducting α-subunit of the cardiac sodium channel (Nav1.5), which is responsible for the initiation and propagation of action potentials and thereby determines cardiac excitability and conduction of electrical stimuli through the heart. The importance of Nav1.5 for normal cardiac electricity is reflected by various disease entities that can be caused by mutations in SCN5A. Gain-of-function mutations in SCN5A lead to more sodium influx into cardiomyocytes through aberrant channel gating and cause long QT syndrome, a primary electrical disease of the heart. Loss-of-function mutations in SCN5A lead to lower expression levels of SCN5A or production of defective Nav1.5 proteins and cause Brugada syndrome, an electrical disease with minor structural changes in the heart. In addition, both loss- and gain-of-function mutations may cause dilated cardiomyopathy, which is an arrhythmogenic disease with gross structural defects of the left ventricle (and sometimes both ventricles). Other SCN5A-related diseases are multifocal ectopic premature Purkinje-related complexes (gain-of-function mutations), isolated cardiac conduction defect (loss-of-function mutations), sick sinus syndrome (loss-of-function mutations), atrial fibrillation (loss-of-function or gain-of-function mutations), and overlap syndromes (mutations with both loss-of-function and gain-of-function effects). Growing insights into the role of SCN5A in health and disease has enabled clinicians to lay out gene-specific risk stratification schemes and mutation-specific diagnostic and therapeutic strategies in the management of patients with a SCN5A mutation. This review summarizes currently available knowledge about the pathophysiological mechanisms of SCN5A mutations and describes how this knowledge can be used to manage patients suffering from potentially lethal cardiac diseases.
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Affiliation(s)
- Arthur A M Wilde
- Heart Centre Academic Medical Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands; Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, Jeddah, Kingdom of Saudi Arabia; Department of Medicine, Columbia University Irving Medical Centre, New York, New York.
| | - Ahmad S Amin
- Heart Centre Academic Medical Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
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38
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Multifocal ectopic Purkinje-related premature contractions: Sorting the wheat from the chaff. Int J Cardiol 2018; 257:218-219. [DOI: 10.1016/j.ijcard.2018.01.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 01/10/2018] [Indexed: 11/21/2022]
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39
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Multifocal atrial and ventricular premature contractions with an increased risk of dilated cardiomyopathy caused by a Na v 1.5 gain-of-function mutation (G213D). Int J Cardiol 2018; 257:160-167. [DOI: 10.1016/j.ijcard.2017.11.095] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 10/24/2017] [Accepted: 11/27/2017] [Indexed: 01/14/2023]
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40
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Zhang X, Yoon JY, Morley M, McLendon JM, Mapuskar KA, Gutmann R, Mehdi H, Bloom HL, Dudley SC, Ellinor PT, Shalaby AA, Weiss R, Tang WHW, Moravec CS, Singh M, Taylor AL, Yancy CW, Feldman AM, McNamara DM, Irani K, Spitz DR, Breheny P, Margulies KB, London B, Boudreau RL. A common variant alters SCN5A-miR-24 interaction and associates with heart failure mortality. J Clin Invest 2018; 128:1154-1163. [PMID: 29457789 DOI: 10.1172/jci95710] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 12/12/2017] [Indexed: 12/19/2022] Open
Abstract
SCN5A encodes the voltage-gated Na+ channel NaV1.5 that is responsible for depolarization of the cardiac action potential and rapid intercellular conduction. Mutations disrupting the SCN5A coding sequence cause inherited arrhythmias and cardiomyopathy, and single-nucleotide polymorphisms (SNPs) linked to SCN5A splicing, localization, and function associate with heart failure-related sudden cardiac death. However, the clinical relevance of SNPs that modulate SCN5A expression levels remains understudied. We recently generated a transcriptome-wide map of microRNA (miR) binding sites in human heart, evaluated their overlap with common SNPs, and identified a synonymous SNP (rs1805126) adjacent to a miR-24 site within the SCN5A coding sequence. This SNP was previously shown to reproducibly associate with cardiac electrophysiological parameters, but was not considered to be causal. Here, we show that miR-24 potently suppresses SCN5A expression and that rs1805126 modulates this regulation. We found that the rs1805126 minor allele associates with decreased cardiac SCN5A expression and that heart failure subjects homozygous for the minor allele have decreased ejection fraction and increased mortality, but not increased ventricular tachyarrhythmias. In mice, we identified a potential basis for this in discovering that decreased Scn5a expression leads to accumulation of myocardial reactive oxygen species. Together, these data reiterate the importance of considering the mechanistic significance of synonymous SNPs as they relate to miRs and disease, and highlight a surprising link between SCN5A expression and nonarrhythmic death in heart failure.
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Affiliation(s)
- Xiaoming Zhang
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Jin-Young Yoon
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Michael Morley
- Department of Internal Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jared M McLendon
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Kranti A Mapuskar
- Department of Radiation Oncology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Rebecca Gutmann
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Haider Mehdi
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Heather L Bloom
- Department of Medicine, Emory University Medical Center, Atlanta, Georgia, USA
| | - Samuel C Dudley
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Patrick T Ellinor
- Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Alaa A Shalaby
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Raul Weiss
- Department of Internal Medicine, The Ohio State University Medical Center, Columbus, Ohio, USA
| | - W H Wilson Tang
- Department of Cardiovascular Medicine, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, USA
| | - Christine S Moravec
- Department of Molecular Cardiology, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, USA
| | - Madhurmeet Singh
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Anne L Taylor
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Clyde W Yancy
- Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Arthur M Feldman
- Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Dennis M McNamara
- Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Kaikobad Irani
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Douglas R Spitz
- Department of Radiation Oncology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Patrick Breheny
- Department of Biostatistics, University of Iowa College of Public Heath, Iowa City, Iowa, USA
| | - Kenneth B Margulies
- Department of Internal Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Barry London
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Ryan L Boudreau
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
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Abstract
Voltage-gated sodium channels belong to the superfamily of voltage-gated cation channels. Their structure is based on domains comprising a voltage sensor domain (S1-S4 segments) and a pore domain (S5-S6 segments). Mutations in positively charged residues of the S4 segments may allow protons or cations to pass directly through the gating pore constriction of the voltage sensor domain; these anomalous currents are referred to as gating pore or omega (ω) currents. In the skeletal muscle disorder hypokalemic periodic paralysis, and in arrhythmic dilated cardiomyopathy, inherited mutations of S4 arginine residues promote omega currents that have been shown to be a contributing factor in the pathogenesis of these sodium channel disorders. Characterization of gating pore currents in these channelopathies and with artificial mutations has been possible by measuring the voltage-dependence and selectivity of these leak currents. The basis of gating pore currents and the structural basis of S4 movement through the gating pore has also been studied extensively with molecular dynamics. These simulations have provided valuable insight into the nature of S4 translocation and the physical basis for the effects of mutations that promote permeation of protons or cations through the gating pore.
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Affiliation(s)
- J R Groome
- Department of Biological Sciences, Idaho State University, Pocatello, ID, 83209, USA.
| | - A Moreau
- Institut NeuroMyogene, ENS de Lyon, Site MONOD, Lyon, France
| | - L Delemotte
- Science for Life Laboratory, Department of Physics, KTH Royal Institute of Technology, Box 1031, 171 21, Solna, Sweden
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42
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Prescribing an automated external defibrillator for children at increased risk of sudden arrhythmic death. Cardiol Young 2017; 27:1271-1279. [PMID: 28606196 DOI: 10.1017/s1047951117000026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Automated external defibrillators can be life-saving in out-of-hospital cardiac arrest. OBJECTIVE Our aim was to review our experience of prescribing automated external defibrillators for children at increased risk of sudden arrhythmic death. METHODS We reviewed all automated external defibrillators issued by the Scottish Paediatric Cardiac Electrophysiology Service from 2005 to 2015. All parents were given resuscitation training according to the Paediatric Resuscitation Guidelines, including the use of the automated external defibrillator. RESULTS A total of 36 automated external defibrillators were issued to 36 families for 44 children (27 male). The mean age at issue was 8.8 years. Diagnoses at issue included long QT syndrome (50%), broad complex tachycardia (14%), hypertrophic cardiomyopathy (11%), and catecholaminergic polymorphic ventricular tachycardia (9%). During the study period, the automated external defibrillator was used in four (9%) children, and in all four the automated external defibrillator correctly discriminated between a shockable rhythm - polymorphic ventricular tachycardia/ventricular fibrillation in three patients with one or more shocks delivered - and non-shockable rhythm - sinus rhythm in one patient. Of the three children, two of them who received one or more shocks for ventricular fibrillation/polymorphic ventricular tachycardia survived, but one died as a result of recurrent torsades de pointes. There were no other deaths. CONCLUSION Parents can be taught to recognise cardiac arrest, apply resuscitation skills, and use an automated external defibrillator. Prescribing an automated external defibrillator should be considered for children at increased risk of sudden arrhythmic death, especially where the risk/benefit ratio of an implantable defibrillator is unclear or delay to defibrillator implantation is deemed necessary.
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43
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Weintraub RG, Semsarian C, Macdonald P. Dilated cardiomyopathy. Lancet 2017; 390:400-414. [PMID: 28190577 DOI: 10.1016/s0140-6736(16)31713-5] [Citation(s) in RCA: 385] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 09/09/2016] [Accepted: 09/14/2016] [Indexed: 12/18/2022]
Abstract
Dilated cardiomyopathy is defined by the presence of left ventricular dilatation and contractile dysfunction. Genetic mutations involving genes that encode cytoskeletal, sarcomere, and nuclear envelope proteins, among others, account for up to 35% of cases. Acquired causes include myocarditis and exposure to alcohol, drugs and toxins, and metabolic and endocrine disturbances. The most common presenting symptoms relate to congestive heart failure, but can also include circulatory collapse, arrhythmias, and thromboembolic events. Secondary neurohormonal changes contribute to reverse remodelling and ongoing myocyte damage. The prognosis is worst for individuals with the lowest ejection fractions or severe diastolic dysfunction. Treatment of chronic heart failure comprises medications that improve survival and reduce hospital admission-namely, angiotensin converting enzyme inhibitors and β blockers. Other interventions include enrolment in a multidisciplinary heart failure service, and device therapy for arrhythmia management and sudden death prevention. Patients who are refractory to medical therapy might benefit from mechanical circulatory support and heart transplantation. Treatment of preclinical disease and the potential role of stem-cell therapy are being investigated.
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Affiliation(s)
- Robert G Weintraub
- Department of Cardiology, Royal Children's Hospital, Melbourne, VIC, Australia; Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia.
| | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology, Centenary Institute and Sydney Medical School, University of Sydney, Sydney, NSW, Australia; Department of Cardiology, Royal Prince Alfred Hospital, Sydney, NSW, Australia
| | - Peter Macdonald
- St Vincent's Hospital, Sydney, NSW, Australia; Victor Chang Cardiac Research Institute, Sydney, NSW, Australia
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44
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CaMKII modulates sodium current in neurons from epileptic Scn2a mutant mice. Proc Natl Acad Sci U S A 2017; 114:1696-1701. [PMID: 28137877 DOI: 10.1073/pnas.1615774114] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Monogenic epilepsies with wide-ranging clinical severity have been associated with mutations in voltage-gated sodium channel genes. In the Scn2aQ54 mouse model of epilepsy, a focal epilepsy phenotype is caused by transgenic expression of an engineered NaV1.2 mutation displaying enhanced persistent sodium current. Seizure frequency and other phenotypic features in Scn2aQ54 mice depend on genetic background. We investigated the neurophysiological and molecular correlates of strain-dependent epilepsy severity in this model. Scn2aQ54 mice on the C57BL/6J background (B6.Q54) exhibit a mild disorder, whereas animals intercrossed with SJL/J mice (F1.Q54) have a severe phenotype. Whole-cell recording revealed that hippocampal pyramidal neurons from B6.Q54 and F1.Q54 animals exhibit spontaneous action potentials, but F1.Q54 neurons exhibited higher firing frequency and greater evoked activity compared with B6.Q54 neurons. These findings correlated with larger persistent sodium current and depolarized inactivation in neurons from F1.Q54 animals. Because calcium/calmodulin protein kinase II (CaMKII) is known to modify persistent current and channel inactivation in the heart, we investigated CaMKII as a plausible modulator of neuronal sodium channels. CaMKII activity in hippocampal protein lysates exhibited a strain-dependence in Scn2aQ54 mice with higher activity in F1.Q54 animals. Heterologously expressed NaV1.2 channels exposed to activated CaMKII had enhanced persistent current and depolarized channel inactivation resembling the properties of F1.Q54 neuronal sodium channels. By contrast, inhibition of CaMKII attenuated persistent current, evoked a hyperpolarized channel inactivation, and suppressed neuronal excitability. We conclude that CaMKII-mediated modulation of neuronal sodium current impacts neuronal excitability in Scn2aQ54 mice and may represent a therapeutic target for the treatment of epilepsy.
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45
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Huang L, Tang S, Chen Y, Zhang L, Yin K, Wu Y, Zheng J, Wu Q, Makielski JC, Cheng J. Molecular pathological study on LRRC10 in sudden unexplained nocturnal death syndrome in the Chinese Han population. Int J Legal Med 2016; 131:621-628. [PMID: 28032242 DOI: 10.1007/s00414-016-1516-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 12/07/2016] [Indexed: 11/28/2022]
Abstract
Sudden unexplained nocturnal death syndrome (SUNDS) is a perplexing disorder to both forensic pathologists and clinic physicians. Clinical features of SUNDS survivors suggested that SUNDS is similar to Brugada syndrome (BrS). Leucine-rich repeat containing 10 (LRRC10) gene was a newly identified gene linked to dilated cardiomyopathy, a disease associated with sudden cardiac death. To investigate the prevalence and spectrum of genetic variants of LRRC10 gene in SUNDS and BrS, the coding regions of LRRC10 were genetically screened in 113 sporadic SUNDS victims (from January 2005 to December 2015, 30.7 ± 7.5 years) and ten BrS patients (during January 2010 to December 2014, 38.7 ± 10.3 years) using direct Sanger sequencing. Afterwards, LRRC10 missense variant carriers were screened for a panel of 80 genes known to be associated with inherited cardiac arrhythmia/cardiomyopathy using target-captured next-generation sequencing. In this study, an in silico-predicted malignant LRRC10 mutation p.E129K was detected in one SUNDS victim without pathogenic rare variant in a panel of 80 arrhythmia/cardiomyopathy-related genes. We also provided evidence to show that rare variant p.P69L might contribute to the genetic cause for one SUNDS victim and two BrS family members. This is the first report of genetic screening of LRRC10 in Chinese SUNDS victims and BrS patients. LRRC10 may be a new susceptible gene for SUNDS, and LRRC10 variant was initially and genetically linked to BrS-associated arrhythmia.
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Affiliation(s)
- Lei Huang
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Shuangbo Tang
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yili Chen
- Department of Cardiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Liyong Zhang
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Kun Yin
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yeda Wu
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jinxiang Zheng
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Qiuping Wu
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jonathan C Makielski
- Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin, Madison, WI, USA
| | - Jianding Cheng
- Department of Forensic Pathology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China.
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46
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Genetic basis of dilated cardiomyopathy. Int J Cardiol 2016; 224:461-472. [PMID: 27736720 DOI: 10.1016/j.ijcard.2016.09.068] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 09/15/2016] [Accepted: 09/17/2016] [Indexed: 01/19/2023]
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47
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Moreau A, Gosselin-Badaroudine P, Chahine M. Gating pore currents, a new pathological mechanism underlying cardiac arrhythmias associated with dilated cardiomyopathy. Channels (Austin) 2016; 9:139-44. [PMID: 26046592 PMCID: PMC4594536 DOI: 10.1080/19336950.2015.1031937] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Voltage-gated ion channels (VGIC) are transmembrane proteins responsible for the generation of electrical signals in excitable cells. VGIC were first described in 1952 by Hodgkin and Huxley,1 and have since been associated with various physiological functions such as propagating nerve impulses, locomotion, and cardiac excitability. VGIC include channels specialized in the selective passage of K+, Ca2+ Na+, or H+. They are composed of 2 main structures: the pore domain (PD) and the voltage sensor domain (VSD). The PD ensures the physiological flow of ions and is typically composed of 8 transmembrane segments (TM). The VSD detects voltage variations and is composed of 4 TM (S1-S4). Given their crucial physiological role, VGIC dysfunctions are associated with diverse pathologies known as ion channelopathies. These dysfunctions usually affect the membrane expression of ion channels or voltage-dependent conformational changes of the pore. However, an increasing number of ion channelopathies, including periodic paralysis, dilated cardiomyopathy (DCM) associated with cardiac arrhythmias, and peripheral nerve hyperexcitability (PNH), have been linked to the appearance of a new pathological mechanism involving the creation of an alternative permeation pathway through the normally non-conductive VSD of VGIC. This permeation pathway is called the gating pore or omega pore.
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Affiliation(s)
- Adrien Moreau
- a Centre de Recherche ; Institut Universitaire en Santé Mentale de Québec ; Quebec City , QC Canada
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48
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Loussouarn G, Sternberg D, Nicole S, Marionneau C, Le Bouffant F, Toumaniantz G, Barc J, Malak OA, Fressart V, Péréon Y, Baró I, Charpentier F. Physiological and Pathophysiological Insights of Nav1.4 and Nav1.5 Comparison. Front Pharmacol 2016; 6:314. [PMID: 26834636 PMCID: PMC4712308 DOI: 10.3389/fphar.2015.00314] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 12/21/2015] [Indexed: 12/19/2022] Open
Abstract
Mutations in Nav1.4 and Nav1.5 α-subunits have been associated with muscular and cardiac channelopathies, respectively. Despite intense research on the structure and function of these channels, a lot of information is still missing to delineate the various physiological and pathophysiological processes underlying their activity at the molecular level. Nav1.4 and Nav1.5 sequences are similar, suggesting structural and functional homologies between the two orthologous channels. This also suggests that any characteristics described for one channel subunit may shed light on the properties of the counterpart channel subunit. In this review article, after a brief clinical description of the muscular and cardiac channelopathies related to Nav1.4 and Nav1.5 mutations, respectively, we compare the knowledge accumulated in different aspects of the expression and function of Nav1.4 and Nav1.5 α-subunits: the regulation of the two encoding genes (SCN4A and SCN5A), the associated/regulatory proteins and at last, the functional effect of the same missense mutations detected in Nav1.4 and Nav1.5. First, it appears that more is known on Nav1.5 expression and accessory proteins. Because of the high homologies of Nav1.5 binding sites and equivalent Nav1.4 sites, Nav1.5-related results may guide future investigations on Nav1.4. Second, the analysis of the same missense mutations in Nav1.4 and Nav1.5 revealed intriguing similarities regarding their effects on membrane excitability and alteration in channel biophysics. We believe that such comparison may bring new cues to the physiopathology of cardiac and muscular diseases.
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Affiliation(s)
- Gildas Loussouarn
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Damien Sternberg
- Institut National de la Santé et de la Recherche Médicale, U1127Paris, France; Sorbonne Universités, Université Pierre-et-Marie-Curie, UMR S1127Paris, France; Centre National de la Recherche Scientifique, UMR 7225Paris, France; Institut du Cerveau et de la Moelle Épinière, ICMParis, France; Assistance Publique - Hôpitaux de Paris (AP-HP), Centres de Référence des Canalopathies Musculaires et des Maladies Neuro-musculaires Paris-EstParis, France; Assistance Publique - Hôpitaux de Paris (AP-HP), Hôpital de la Pitié Salpêtrière, Service de Biochimie Métabolique, Unité de Cardiogénétique et MyogénétiqueParis, France
| | - Sophie Nicole
- Institut National de la Santé et de la Recherche Médicale, U1127Paris, France; Sorbonne Universités, Université Pierre-et-Marie-Curie, UMR S1127Paris, France; Centre National de la Recherche Scientifique, UMR 7225Paris, France; Institut du Cerveau et de la Moelle Épinière, ICMParis, France
| | - Céline Marionneau
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Francoise Le Bouffant
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Gilles Toumaniantz
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Julien Barc
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Olfat A Malak
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Véronique Fressart
- Assistance Publique - Hôpitaux de Paris (AP-HP), Hôpital de la Pitié Salpêtrière, Service de Biochimie Métabolique, Unité de Cardiogénétique et Myogénétique Paris, France
| | - Yann Péréon
- Centre Hospitalier Universitaire de Nantes, Centre de Référence Maladies Neuromusculaires Nantes-AngersNantes, France; Atlantic Gene Therapies - Biotherapy Institute for Rare DiseasesNantes, France
| | - Isabelle Baró
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France
| | - Flavien Charpentier
- Institut National de la Santé et de la Recherche Médicale, UMR 1087, l'Institut du ThoraxNantes, France; Centre National de la Recherche Scientifique, UMR 6291Nantes, France; Université de NantesNantes, France; Centre Hospitalier Universitaire de Nantes, l'Institut du ThoraxNantes, France
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49
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Gopinathannair R, Etheridge SP, Marchlinski FE, Spinale FG, Lakkireddy D, Olshansky B. Arrhythmia-Induced Cardiomyopathies: Mechanisms, Recognition, and Management. J Am Coll Cardiol 2016; 66:1714-28. [PMID: 26449143 DOI: 10.1016/j.jacc.2015.08.038] [Citation(s) in RCA: 206] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 07/28/2015] [Accepted: 08/17/2015] [Indexed: 12/19/2022]
Abstract
Arrhythmia-induced cardiomyopathy (AIC) is a potentially reversible condition in which left ventricular dysfunction is induced or mediated by atrial or ventricular arrhythmias. Cellular and extracellular changes in response to the culprit arrhythmia have been identified, but specific pathophysiological mechanisms remain unclear. Early recognition of AIC and prompt treatment of the culprit arrhythmia using pharmacological or ablative techniques result in symptom resolution and recovery of ventricular function. Although cardiomyopathy in response to an arrhythmia may take months to years to develop, recurrent arrhythmia can result in rapid decline in ventricular function with development of heart failure, suggesting residual ultrastructural abnormalities. Reports of sudden death in patients with normalized left ventricular ejection fraction cast doubt on the complete reversibility of this condition. Several aspects of AIC, including specific pathophysiological mechanisms, predisposing factors, optimal therapeutic strategies to prevent ultrastructural changes, and long-term risk of sudden death remain unresolved and need further research.
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Affiliation(s)
- Rakesh Gopinathannair
- Division of Cardiovascular Medicine, University of Louisville, Louisville, Kentucky.
| | - Susan P Etheridge
- Division of Pediatric Cardiology, University of Utah, Salt Lake City, Utah
| | | | - Francis G Spinale
- Department of Internal Medicine, University of South Carolina, Charleston, South Carolina
| | | | - Brian Olshansky
- Mercy Heart and Vascular Institute, Mercy Medical Center North Iowa, Mason City, Iowa
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50
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Moreau A, Gosselin-Badaroudine P, Boutjdir M, Chahine M. Mutations in the Voltage Sensors of Domains I and II of Nav1.5 that are Associated with Arrhythmias and Dilated Cardiomyopathy Generate Gating Pore Currents. Front Pharmacol 2015; 6:301. [PMID: 26733869 PMCID: PMC4689871 DOI: 10.3389/fphar.2015.00301] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 12/09/2015] [Indexed: 12/19/2022] Open
Abstract
Voltage gated sodium channels (Nav) are transmembrane proteins responsible for action potential initiation. Mutations mainly located in the voltage sensor domain (VSD) of Nav1.5, the cardiac sodium channel, have been associated with the development of arrhythmias combined with dilated cardiomyopathy. Gating pore currents have been observed with three unrelated mutations associated with similar clinical phenotypes. However, gating pores have never been associated with mutations outside the first domain of Nav1.5. The aim of this study was to explore the possibility that gating pore currents might be caused by the Nav1.5 R225P and R814W mutations (R3, S4 in DI and DII, respectively), which are associated with rhythm disturbances and dilated cardiomyopathy. Nav1.5 WT and mutant channels were transiently expressed in tsA201 cells. The biophysical properties of the alpha pore currents and the presence of gating pore currents were investigated using the patch-clamp technique. We confirmed the previously reported gain of function of the alpha pores of the mutant channels, which mainly consisted of increased window currents mostly caused by shifts in the voltage dependence of activation. We also observed gating pore currents associated with the R225P and R814W mutations. This novel permeation pathway was open under depolarized conditions and remained temporarily open at hyperpolarized potentials after depolarization periods. Gating pore currents could represent a molecular basis for the development of uncommon electrical abnormalities and changes in cardiac morphology. We propose that this biophysical defect be routinely evaluated in the case of Nav1.5 mutations on the VSD.
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Affiliation(s)
- Adrien Moreau
- Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec City QC, Canada
| | | | - Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare System, Brooklyn NY, USA
| | - Mohamed Chahine
- Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Quebec CityQC, Canada; Department of Medicine, Université Laval, Quebec CityQC, Canada
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