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Fernández-Morales JC, Toth N, Bayram P, Rienzo T, Morad M. Loss-of-function W4645R mutation in the RyR2-caffeine binding site: implications for synchrony and arrhythmogenesis. Cell Calcium 2024; 123:102925. [PMID: 38908063 DOI: 10.1016/j.ceca.2024.102925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Revised: 06/14/2024] [Accepted: 06/16/2024] [Indexed: 06/24/2024]
Abstract
AIMS Previous studies have identified RyR2 W4645R mutation, located in the caffeine-binding site, to associate with CPVT1 pathology. Caffeine binding to its site is thought to displace the carboxyl-terminal domain to Ca2+-binding, allowing the tryptophan residue (W4645) to regulate Ca2+ sensitivity of RyR2. To gain insights into regulation of RyR2 Ca2+-binding and its interaction with caffeine-binding site, we introduced W4645R-RyR2 point mutation via CRISPR/Cas9 gene-editing in human induced pluripotent stem cell-derived cardiomyocytes (hiPSCCMs) and characterized their Ca2+-signaling phenotype compared to WT hiPSCCMs. METHODS AND RESULTS W4645R-RyR2 cardiomyocytes had: (1) no significant change in ICa magnitude or voltage-dependence; (2) slightly reduced CICR; (3) altered relaxation kinetics of Ca2+-transients with no change in isoproterenol sensitivity; (4) complete loss of caffeine-triggered Ca2+ release; (5) larger SR Ca2+ leak resulting in 40 % lower SR Ca2+ content, as determined by myocytes' response to 4-CmC; (6) lower incidence of calcium sparks and asynchronous spontaneous SR Ca2+ releases. CONCLUSIONS W4645R-RyR2 mutation induces loss of caffeine-triggered SR Ca2+ release and enhances SR Ca2+ leak that underlie asynchronous spontaneous Ca2+ releases, triggering arrhythmia and impairing cardiac function.
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Affiliation(s)
| | - Noemi Toth
- Cardiac Signaling Center of MUSC, USC and Clemson University, Charleston, SC, USA
| | - Pinar Bayram
- Cardiac Signaling Center of MUSC, USC and Clemson University, Charleston, SC, USA
| | - Taylor Rienzo
- Cardiac Signaling Center of MUSC, USC and Clemson University, Charleston, SC, USA
| | - Martin Morad
- Cardiac Signaling Center of MUSC, USC and Clemson University, Charleston, SC, USA; Department of Regenerative Medicine and Cell Biology, MUSC,Charleston, SC, USA.
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Mei JY, Xu L, Nguyen TA. Smartwatch detection of new-onset monomorphic ventricular tachycardia in pregnancy. BMJ Case Rep 2024; 17:e258807. [PMID: 38373812 PMCID: PMC10882298 DOI: 10.1136/bcr-2023-258807] [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] [Indexed: 02/21/2024] Open
Abstract
Smartwatches provide health tracking in various ways and there has been a recent rise in reporting cardiac arrhythmias. While original studies focused on atrial fibrillation, fewer reports have been made on other arrhythmias especially in pregnancy. We report a pregnant patient who presented at 34 weeks' gestation with palpitations. An ECG recorded through her Apple Watch showed ventricular tachycardia. Hospital ECG confirmed monomorphic ventricular tachycardia likely caused by increased sympathetic tone from the gravid state. She was admitted to the cardiac intensive care unit for close monitoring with intravenous anti-arrhythmic agents; however, the rhythm persisted. She underwent a caesarean delivery and the arrhythmia resolved post partum. She later underwent a catheter ablation, after which she discontinued all anti-arrhythmic medications with no recurrence. This case highlights the importance of requesting relevant digital health information, if available, from patients in our modern era. Controlled clinical studies are needed to validate such practices.
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Affiliation(s)
- Jenny Y Mei
- Obstetrics and Gynecology, University of California Los Angeles David Geffen School of Medicine, Los Angeles, California, USA
| | - Liwen Xu
- Obstetrics and Gynecology, University of California Los Angeles David Geffen School of Medicine, Los Angeles, California, USA
| | - Tina A Nguyen
- Obstetrics and Gynecology, University of California Los Angeles David Geffen School of Medicine, Los Angeles, California, USA
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Iyer KA, Barnakov V, Samsó M. Three-dimensional perspective on ryanodine receptor mutations causing skeletal and cardiac muscle-related diseases. Curr Opin Pharmacol 2023; 68:102327. [PMID: 36516687 PMCID: PMC9908851 DOI: 10.1016/j.coph.2022.102327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/18/2022] [Accepted: 11/12/2022] [Indexed: 12/14/2022]
Abstract
Mutations in RyR alter the cell's Ca2+ homeostasis and can cause serious health problems for which few effective therapies are available. Until recently, there was little structural context for the hundreds of mutations linked to muscular disorders reported for this large channel. Growing knowledge of the three-dimensional structure of RyR starts to illustrate the fine control of Ca2+ release. Current efforts directed towards understanding how disease mutations impinge in such processes will be crucial for future design of novel therapies. In this review article we discuss the up-to-date information about mutations according to their role in the 3D structure, and classified them to provide context from a structural perspective.
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Affiliation(s)
- Kavita A Iyer
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Vadim Barnakov
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Montserrat Samsó
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA.
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Leung J, Lee S, Zhou J, Jeevaratnam K, Lakhani I, Radford D, Coakley-Youngs E, Pay L, Çinier G, Altinsoy M, Behnoush AH, Mahmoudi E, Matusik PT, Bazoukis G, Garcia-Zamora S, Zeng S, Chen Z, Xia Y, Liu T, Tse G. Clinical Characteristics, Genetic Findings and Arrhythmic Outcomes of Patients with Catecholaminergic Polymorphic Ventricular Tachycardia from China: A Systematic Review. LIFE (BASEL, SWITZERLAND) 2022; 12:life12081104. [PMID: 35892906 PMCID: PMC9330865 DOI: 10.3390/life12081104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/12/2022] [Accepted: 07/19/2022] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare inherited cardiac ion channelopathy. The present study aims to examine the clinical characteristics, genetic basis, and arrhythmic outcomes of CPVT patients from China to elucidate the difference between CPVT patients in Asia and Western countries. METHODS PubMed and Embase were systematically searched for case reports or series reporting on CPVT patients from China until 19 February 2022 using the keyword: "Catecholaminergic Polymorphic Ventricular Tachycardia" or "CPVT", with the location limited to: "China" or "Hong Kong" or "Macau" in Embase, with no language or publication-type restriction. Articles that did not state a definite diagnosis of CPVT and articles with duplicate cases found in larger cohorts were excluded. All the included publications in this review were critically appraised based on the Joanna Briggs Institute Critical Appraisal Checklist. Clinical characteristics, genetic findings, and the primary outcome of spontaneous ventricular tachycardia/ventricular fibrillation (VT/VF) were analyzed. RESULTS A total of 58 unique cases from 15 studies (median presentation age: 8 (5.0-11.8) years old) were included. All patients, except one, presented at or before 19 years of age. There were 56 patients (96.6%) who were initially symptomatic. Premature ventricular complexes (PVCs) were present in 44 out of 51 patients (86.3%) and VT in 52 out of 58 patients (89.7%). Genetic tests were performed on 54 patients (93.1%) with a yield of 87%. RyR2, CASQ2, TERCL, and SCN10A mutations were found in 35 (71.4%), 12 (24.5%), 1 (0.02%) patient, and 1 patient (0.02%), respectively. There were 54 patients who were treated with beta-blockers, 8 received flecainide, 5 received amiodarone, 2 received verapamil and 2 received propafenone. Sympathectomy (n = 10), implantable cardioverter-defibrillator implantation (n = 8) and ablation (n = 1) were performed. On follow-up, 13 patients developed VT/VF. CONCLUSION This was the first systematic review of CPVT patients from China. Most patients had symptoms on initial presentation, with syncope as the presenting complaint. RyR2 mutation accounts for more than half of the CPVT cases, followed by CASQ2, TERCL and SCN10A mutations.
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Affiliation(s)
- Justin Leung
- Cardiac Electrophysiology Unit, Cardiovascular Analytics Group, China-UK Collaboration, Hong Kong, China; (J.L.); (S.L.); (I.L.)
| | - Sharen Lee
- Cardiac Electrophysiology Unit, Cardiovascular Analytics Group, China-UK Collaboration, Hong Kong, China; (J.L.); (S.L.); (I.L.)
| | - Jiandong Zhou
- School of Data Science, City University of Hong Kong, Hong Kong, China;
| | - Kamalan Jeevaratnam
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK;
| | - Ishan Lakhani
- Cardiac Electrophysiology Unit, Cardiovascular Analytics Group, China-UK Collaboration, Hong Kong, China; (J.L.); (S.L.); (I.L.)
| | - Danny Radford
- Kent and Medway Medical School, Canterbury CT2 7FS, UK; (D.R.); (E.C.-Y.)
| | | | - Levent Pay
- Department of Cardiology, Dr Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital, Istanbul 34147, Turkey; (L.P.); (G.Ç.)
| | - Göksel Çinier
- Department of Cardiology, Dr Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital, Istanbul 34147, Turkey; (L.P.); (G.Ç.)
| | - Meltem Altinsoy
- Department of Cardiology, University of Health Sciences, Diskapi Yildirim Beyazit Training and Research Hospital, Ankara 06145, Turkey;
| | - Amir Hossein Behnoush
- Universal Scientific Education and Research Network (USERN), Tehran University of Medical Sciences, Tehran 1416643931, Iran; (A.H.B.); (E.M.)
| | - Elham Mahmoudi
- Universal Scientific Education and Research Network (USERN), Tehran University of Medical Sciences, Tehran 1416643931, Iran; (A.H.B.); (E.M.)
| | - Paweł T. Matusik
- Department of Electrocardiology, Institute of Cardiology, Jagiellonian University Medical College, John Paul II Hospital, 31-202 Kraków, Poland;
| | - George Bazoukis
- Department of Cardiology, Larnaca General Hospital, Larnaca 6301, Cyprus;
- Medical School, University of Nicosia, Nicosia 2408, Cyprus
| | - Sebastian Garcia-Zamora
- Cardiac Intensive Care Unit, Department of Cardiology, Delta Clinic, Rosario S2000, Argentina;
| | - Shaoying Zeng
- Department of Pediatric Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China;
| | - Ziliang Chen
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China;
| | - Yunlong Xia
- Department of Cardiology, First Affiliated Hospital of Dalian Medical University, Dalian 116014, China;
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China;
- Correspondence: (T.L.); or or (G.T.)
| | - Gary Tse
- Cardiac Electrophysiology Unit, Cardiovascular Analytics Group, China-UK Collaboration, Hong Kong, China; (J.L.); (S.L.); (I.L.)
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK;
- Kent and Medway Medical School, Canterbury CT2 7FS, UK; (D.R.); (E.C.-Y.)
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, China;
- Department of Cardiology, First Affiliated Hospital of Dalian Medical University, Dalian 116014, China;
- Correspondence: (T.L.); or or (G.T.)
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Woll KA, Van Petegem F. Calcium Release Channels: Structure and Function of IP3 Receptors and Ryanodine Receptors. Physiol Rev 2021; 102:209-268. [PMID: 34280054 DOI: 10.1152/physrev.00033.2020] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Ca2+-release channels are giant membrane proteins that control the release of Ca2+ from the endoplasmic and sarcoplasmic reticulum. The two members, ryanodine receptors (RyRs) and inositol-1,4,5-trisphosphate Receptors (IP3Rs), are evolutionarily related and are both activated by cytosolic Ca2+. They share a common architecture, but RyRs have evolved additional modules in the cytosolic region. Their massive size allows for the regulation by tens of proteins and small molecules, which can affect the opening and closing of the channels. In addition to Ca2+, other major triggers include IP3 for the IP3Rs, and depolarization of the plasma membrane for a particular RyR subtype. Their size has made them popular targets for study via electron microscopic methods, with current structures culminating near 3Å. The available structures have provided many new mechanistic insights int the binding of auxiliary proteins and small molecules, how these can regulate channel opening, and the mechanisms of disease-associated mutations. They also help scrutinize previously proposed binding sites, as some of these are now incompatible with the structures. Many questions remain around the structural effects of post-translational modifications, additional binding partners, and the higher-order complexes these channels can make in situ. This review summarizes our current knowledge about the structures of Ca2+-release channels and how this informs on their function.
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Affiliation(s)
- Kellie A Woll
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
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Ogawa H, Kurebayashi N, Yamazawa T, Murayama T. Regulatory mechanisms of ryanodine receptor/Ca 2+ release channel revealed by recent advancements in structural studies. J Muscle Res Cell Motil 2020; 42:291-304. [PMID: 32040690 PMCID: PMC8332584 DOI: 10.1007/s10974-020-09575-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 02/05/2020] [Indexed: 02/07/2023]
Abstract
Ryanodine receptors (RyRs) are huge homotetrameric Ca2+ release channels localized to the sarcoplasmic reticulum. RyRs are responsible for the release of Ca2+ from the SR during excitation–contraction coupling in striated muscle cells. Recent revolutionary advancements in cryo-electron microscopy have provided a number of near-atomic structures of RyRs, which have enabled us to better understand the architecture of RyRs. Thus, we are now in a new era understanding the gating, regulatory and disease-causing mechanisms of RyRs. Here we review recent advances in the elucidation of the structures of RyRs, especially RyR1 in skeletal muscle, and their mechanisms of regulation by small molecules, associated proteins and disease-causing mutations.
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Affiliation(s)
- Haruo Ogawa
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.
| | - Nagomi Kurebayashi
- Department of Pharmacology, Juntendo University School of Medicine, Tokyo, 113-8421, Japan
| | - Toshiko Yamazawa
- Department of Molecular Physiology, The Jikei University School of Medicine, Tokyo, 105-8461, Japan
| | - Takashi Murayama
- Department of Pharmacology, Juntendo University School of Medicine, Tokyo, 113-8421, Japan
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7
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Murayama T, Ogawa H, Kurebayashi N, Ohno S, Horie M, Sakurai T. A tryptophan residue in the caffeine-binding site of the ryanodine receptor regulates Ca 2+ sensitivity. Commun Biol 2018; 1:98. [PMID: 30271978 PMCID: PMC6123685 DOI: 10.1038/s42003-018-0103-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 07/02/2018] [Indexed: 11/11/2022] Open
Abstract
Ryanodine receptors (RyRs) are Ca2+ release channels in the sarcoplasmic reticulum of skeletal and cardiac muscles and are essential for muscle contraction. Mutations in genes encoding RyRs cause various muscle and arrhythmogenic heart diseases. Although RyR channels are activated by Ca2+, the actual mechanism of Ca2+ binding remains largely unknown. Here, we report the molecular basis of Ca2+ binding to RyRs for channel activation and discuss its implications in disease states. RyR1 and RyR2 carrying mutations in putative Ca2+ and caffeine-binding sites were functionally analysed. The results were interpreted with respect to recent near-atomic resolution RyR1 structures in various ligand states. We demonstrate that a tryptophan residue in the caffeine-binding site controls the structure of the Ca2+-binding site to regulate the Ca2+ sensitivity. Our results reveal the initial step of RyR channel activation by Ca2+ and explain the molecular mechanism of Ca2+ sensitization by caffeine and disease-causing mutations. Takashi Murayama et al. report the molecular basis of calcium binding to ryanodine receptors, a process essential for muscle contraction. They find that a tryptophan residue in the caffeine binding site controls the structure of the calcium binding site, affecting calcium sensitivity.
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Affiliation(s)
- Takashi Murayama
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan.
| | - Haruo Ogawa
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan
| | - Nagomi Kurebayashi
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
| | - Seiko Ohno
- Department of Cardiovascular Medicine, Shiga University of Medical Science, Otsu, Shiga, 520-2192, Japan.,Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center, Suita, Osaka, 565-8565, Japan
| | - Minoru Horie
- Department of Cardiovascular Medicine, Shiga University of Medical Science, Otsu, Shiga, 520-2192, Japan
| | - Takashi Sakurai
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan
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Using Simulation-Based Learning to Prepare for a Potential Cardiac Emergency on the Labor Unit. Nurs Womens Health 2017; 21:20-27. [PMID: 28187836 DOI: 10.1016/j.nwh.2016.12.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/16/2016] [Indexed: 11/21/2022]
Abstract
Cardiac arrest on the labor unit is a rare event, but it can have significant effects on a woman and her fetus, as well as on the clinicians providing health care. Our labor team was challenged to provide care for a woman with a rare cardiac condition that can cause a wide range of events, from fainting to cardiac arrest. This article describes our use of simulation-based learning to prepare for potential scenarios.
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9
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Abstract
Cardiac arrhythmias can follow disruption of the normal cellular electrophysiological processes underlying excitable activity and their tissue propagation as coherent wavefronts from the primary sinoatrial node pacemaker, through the atria, conducting structures and ventricular myocardium. These physiological events are driven by interacting, voltage-dependent, processes of activation, inactivation, and recovery in the ion channels present in cardiomyocyte membranes. Generation and conduction of these events are further modulated by intracellular Ca2+ homeostasis, and metabolic and structural change. This review describes experimental studies on murine models for known clinical arrhythmic conditions in which these mechanisms were modified by genetic, physiological, or pharmacological manipulation. These exemplars yielded molecular, physiological, and structural phenotypes often directly translatable to their corresponding clinical conditions, which could be investigated at the molecular, cellular, tissue, organ, and whole animal levels. Arrhythmogenesis could be explored during normal pacing activity, regular stimulation, following imposed extra-stimuli, or during progressively incremented steady pacing frequencies. Arrhythmic substrate was identified with temporal and spatial functional heterogeneities predisposing to reentrant excitation phenomena. These could arise from abnormalities in cardiac pacing function, tissue electrical connectivity, and cellular excitation and recovery. Triggering events during or following recovery from action potential excitation could thereby lead to sustained arrhythmia. These surface membrane processes were modified by alterations in cellular Ca2+ homeostasis and energetics, as well as cellular and tissue structural change. Study of murine systems thus offers major insights into both our understanding of normal cardiac activity and its propagation, and their relationship to mechanisms generating clinical arrhythmias.
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Affiliation(s)
- Christopher L-H Huang
- Physiological Laboratory and the Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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10
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Abstract
BACKGROUND Catecholaminergic polymorphic ventricular tachycardia is a genetic disorder in which ventricular tachycardia occurs in the absence of structural heart disease or a prolonged QT interval. If untreated, there is a high incidence of sudden cardiac death. Management of this cardiac condition during pregnancy merits a multidisciplinary approach. CASE A nulliparous woman with catecholaminergic polymorphic ventricular tachycardia presented at 15 weeks of gestation. Her care involved a multidisciplinary team including cardiology, maternal-fetal medicine, obstetric nursing, cardiac nursing, and anesthesia. A simulation scenario was designed to prepare for cardiac events during labor. A term intrapartum cesarean delivery was performed for fetal indications. CONCLUSION A multidisciplinary approach to the antepartum, intrapartum, and postpartum care of women with catecholaminergic polymorphic ventricular tachycardia is critical to a team-based successful pregnancy outcome.
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11
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Leong IUS, Sucich J, Prosser DO, Skinner JR, Crawford JR, Higgins C, Love DR. Array comparative genomic hybridization identifies a heterozygous deletion of exon 3 of the RYR2 gene. Ups J Med Sci 2015; 120:190-7. [PMID: 25835811 PMCID: PMC4526874 DOI: 10.3109/03009734.2015.1029101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a heritable cardiac disorder characterized by life-threatening ventricular tachycardia caused by exercise or acute emotional stress. The standard diagnostic screening involves Sanger-based sequencing of 45 of the 105 translated exons of the RYR2 gene, and copy number changes of a limited number of exons that are detected using multiplex ligation-dependent probe amplification (MLPA). METHODS In the current study, a previously validated bespoke array comparative genomic hybridization (aCGH) technique was used to detect copy number changes in the RYR2 gene in a 43-year-old woman clinically diagnosed with CPVT. RESULTS The CGH array detected a 1.1 kb deletion encompassing exon 3 of the RYR2 gene. This is the first report using the aCGH technique to screen for mutations causing CPVT. CONCLUSIONS The aCGH method offers significant advantages over MLPA in genetic screening for heritable cardiac disorders.
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Affiliation(s)
- Ivone U. S. Leong
- Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland 1142, New Zealand
| | - Jennifer Sucich
- Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland 1142, New Zealand
| | - Debra O. Prosser
- Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland 1142, New Zealand
| | - Jonathan R. Skinner
- Greenlane Paediatric and Congenital Cardiac Service, Starship Children’s Hospital, Grafton Auckland, Private Bag 92024, New Zealand
- Cardiac Inherited Disease Group, Auckland City Hospital, Auckland, New Zealand
- Department of Child Health, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Jackie R. Crawford
- Greenlane Paediatric and Congenital Cardiac Service, Starship Children’s Hospital, Grafton Auckland, Private Bag 92024, New Zealand
- Cardiac Inherited Disease Group, Auckland City Hospital, Auckland, New Zealand
| | - Colleen Higgins
- School of Applied Sciences, Auckland University of Technology, Private Bag 92006, Auckland, New Zealand
| | - Donald R. Love
- Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland 1142, New Zealand
- Cardiac Inherited Disease Group, Auckland City Hospital, Auckland, New Zealand
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Forensische Molekularpathologie. Rechtsmedizin (Berl) 2014. [DOI: 10.1007/s00194-014-0975-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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13
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Arakawa J, Hamabe A, Aiba T, Nagai T, Yoshida M, Touya T, Ishigami N, Hisadome H, Katsushika S, Tabata H, Miyamoto Y, Shimizu W. A novel cardiac ryanodine receptor gene (RyR2) mutation in an athlete with aborted sudden cardiac death: a case of adult-onset catecholaminergic polymorphic ventricular tachycardia. Heart Vessels 2014; 30:835-40. [PMID: 25092222 DOI: 10.1007/s00380-014-0555-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 07/11/2014] [Indexed: 12/26/2022]
Abstract
Sudden cardiac death (SCD) in athletes <35 years of age are mostly due to congenital or acquired cardiac malformations or hypertrophic cardiomyopathy. However, ion channelopathies such as catecholaminergic polymorphic ventricular tachycardia (CPVT) or long-QT syndromes, which are less frequently observed, are also potential pathogenesis of SCD in young athletes. CPVT is an inherited arrhythmia that is induced by physical or emotional stress and may lead to ventricular fibrillation syncope or SCD. Here, we report a case of athlete woman with adult-onset CPVT and aborted SCD who has a novel missense mutation (K4392R) in the cardiac RyR2 gene.
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Affiliation(s)
- Junko Arakawa
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan.
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan.
| | - Akira Hamabe
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Takeshi Aiba
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Tomoo Nagai
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Mikoto Yoshida
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Takumi Touya
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Norio Ishigami
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Hideki Hisadome
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Shuichi Katsushika
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Hirotsugu Tabata
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Yoshihiro Miyamoto
- Laboratory of Molecular Genetics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
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Campuzano O, Allegue C, Brugada R. [Genetics of sudden unexplained death]. Med Clin (Barc) 2013; 142:265-9. [PMID: 24018251 DOI: 10.1016/j.medcli.2013.06.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 06/17/2013] [Accepted: 06/20/2013] [Indexed: 10/26/2022]
Abstract
Sudden unexplained death is defined by death without a conclusive diagnosis after autopsy and it is responsible for a large percentage of sudden deaths. The progressive interaction between genetics and forensics in post-mortem studies has identified inheritable alterations responsible for pathologies associated with arrhythmic sudden death. The genetic diagnosis of the deceased enables the undertaking of preventive measures in family members, many of them asymptomatic but at risk. The implications of this multidisciplinary translational medical approach are complex, requiring the dedication of a specialized team.
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Affiliation(s)
- Oscar Campuzano
- Centro de Genética Cardiovascular, IdIBGi-Universitat de Girona, Girona, España
| | - Catarina Allegue
- Centro de Genética Cardiovascular, IdIBGi-Universitat de Girona, Girona, España
| | - Ramon Brugada
- Centro de Genética Cardiovascular, IdIBGi-Universitat de Girona, Girona, España.
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Zhang Y, Matthews GDK, Lei M, Huang CLH. Abnormal Ca(2+) homeostasis, atrial arrhythmogenesis, and sinus node dysfunction in murine hearts modeling RyR2 modification. Front Physiol 2013; 4:150. [PMID: 23805105 PMCID: PMC3691467 DOI: 10.3389/fphys.2013.00150] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Accepted: 06/05/2013] [Indexed: 12/19/2022] Open
Abstract
Ryanodine receptor type 2 (RyR2) mutations are implicated in catecholaminergic polymorphic ventricular tachycardia (CPVT) thought to result from altered myocyte Ca(2+) homeostasis reflecting inappropriate "leakiness" of RyR2-Ca(2+) release channels arising from increases in their basal activity, alterations in their phosphorylation, or defective interactions with other molecules or ions. The latter include calstabin, calsequestrin-2, Mg(2+), and extraluminal or intraluminal Ca(2+). Recent clinical studies additionally associate RyR2 abnormalities with atrial arrhythmias including atrial tachycardia (AT), fibrillation (AF), and standstill, and sinus node dysfunction (SND). Some RyR2 mutations associated with CPVT in mouse models also show such arrhythmias that similarly correlate with altered Ca(2+) homeostasis. Some examples show evidence for increased Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) phosphorylation of RyR2. A homozygotic RyR2-P2328S variant demonstrates potential arrhythmic substrate resulting from reduced conduction velocity (CV) in addition to delayed afterdepolarizations (DADs) and ectopic action potential (AP) firing. Finally, one model with an increased RyR2 activity in the sino-atrial node (SAN) shows decreased automaticity in the presence of Ca(2+)-dependent decreases in I Ca, L and diastolic sarcoplasmic reticular (SR) Ca(2+) depletion.
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Affiliation(s)
- Yanmin Zhang
- Department of Paediatrics, Institute of Shaanxi Province Children's Cardiovascular Diseases, The Shaanxi Provincial People's Hospital of Xi'an Jiaotong UniversityXi'an, PR of China
- Faculty of Medicine and Human Sciences, Institute of Cardiovascular Sciences, University of ManchesterManchester, UK
| | | | - Ming Lei
- Faculty of Medicine and Human Sciences, Institute of Cardiovascular Sciences, University of ManchesterManchester, UK
| | - Christopher L.-H. Huang
- Physiological Laboratory, Faculty of Biology, University of CambridgeCambridge, UK
- Department of Biochemistry, University of CambridgeCambridge, UK
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16
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Shan J, Xie W, Betzenhauser M, Reiken S, Chen BX, Wronska A, Marks AR. Calcium leak through ryanodine receptors leads to atrial fibrillation in 3 mouse models of catecholaminergic polymorphic ventricular tachycardia. Circ Res 2012; 111:708-17. [PMID: 22828895 DOI: 10.1161/circresaha.112.273342] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
RATIONALE Atrial fibrillation (AF) is the most common cardiac arrhythmia, however the mechanism(s) causing AF remain poorly understood and therapy is suboptimal. The ryanodine receptor (RyR2) is the major calcium (Ca2+) release channel on the sarcoplasmic reticulum (SR) required for excitation-contraction coupling in cardiac muscle. OBJECTIVE In the present study, we sought to determine whether intracellular diastolic SR Ca2+ leak via RyR2 plays a role in triggering AF and whether inhibiting this leak can prevent AF. METHODS AND RESULTS We generated 3 knock-in mice with mutations introduced into RyR2 that result in leaky channels and cause exercise induced polymorphic ventricular tachycardia in humans [catecholaminergic polymorphic ventricular tachycardia (CPVT)]. We examined AF susceptibility in these three CPVT mouse models harboring RyR2 mutations to explore the role of diastolic SR Ca2+ leak in AF. AF was stimulated with an intra-esophageal burst pacing protocol in the 3 CPVT mouse models (RyR2-R2474S+/-, 70%; RyR2-N2386I+/-, 60%; RyR2-L433P+/-, 35.71%) but not in wild-type (WT) mice (P<0.05). Consistent with these in vivo results, there was a significant diastolic SR Ca2+ leak in atrial myocytes isolated from the CPVT mouse models. Calstabin2 (FKBP12.6) is an RyR2 subunit that stabilizes the closed state of RyR2 and prevents a Ca2+ leak through the channel. Atrial RyR2 from RyR2-R2474S+/- mice were oxidized, and the RyR2 macromolecular complex was depleted of calstabin2. The Rycal drug S107 stabilizes the closed state of RyR2 by inhibiting the oxidation/phosphorylation induced dissociation of calstabin2 from the channel. S107 reduced the diastolic SR Ca2+ leak in atrial myocytes and decreased burst pacing-induced AF in vivo. S107 did not reduce the increased prevalence of burst pacing-induced AF in calstabin2-deficient mice, confirming that calstabin2 is required for the mechanism of action of the drug. CONCLUSIONS The present study demonstrates that RyR2-mediated diastolic SR Ca2+ leak in atrial myocytes is associated with AF in CPVT mice. Moreover, the Rycal S107 inhibited diastolic SR Ca2+ leak through RyR2 and pacing-induced AF associated with CPVT mutations.
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Affiliation(s)
- Jian Shan
- Clyde and Helen Wu Center for Molecular Cardiology, Department of Physiology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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Medeiros-Domingo A, Bhuiyan ZA, Tester DJ, Hofman N, Bikker H, van Tintelen JP, Mannens MM, Wilde AA, Ackerman MJ. The RYR2-encoded ryanodine receptor/calcium release channel in patients diagnosed previously with either catecholaminergic polymorphic ventricular tachycardia or genotype negative, exercise-induced long QT syndrome: a comprehensive open reading frame mutational analysis. J Am Coll Cardiol 2009; 54:2065-74. [PMID: 19926015 PMCID: PMC2880864 DOI: 10.1016/j.jacc.2009.08.022] [Citation(s) in RCA: 203] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 08/28/2009] [Accepted: 08/30/2009] [Indexed: 12/20/2022]
Abstract
OBJECTIVES This study was undertaken to determine the spectrum and prevalence of mutations in the RYR2-encoded cardiac ryanodine receptor in cases with exertional syncope and normal corrected QT interval (QTc). BACKGROUND Mutations in RYR2 cause type 1 catecholaminergic polymorphic ventricular tachycardia (CPVT1), a cardiac channelopathy with increased propensity for lethal ventricular dysrhythmias. Most RYR2 mutational analyses target 3 canonical domains encoded by <40% of the translated exons. The extent of CPVT1-associated mutations localizing outside of these domains remains unknown as RYR2 has not been examined comprehensively in most patient cohorts. METHODS Mutational analysis of all RYR2 exons was performed using polymerase chain reaction, high-performance liquid chromatography, and deoxyribonucleic acid sequencing on 155 unrelated patients (49% females, 96% Caucasian, age at diagnosis 20 +/- 15 years, mean QTc 428 +/- 29 ms), with either clinical diagnosis of CPVT (n = 110) or an initial diagnosis of exercise-induced long QT syndrome but with QTc <480 ms and a subsequent negative long QT syndrome genetic test (n = 45). RESULTS Sixty-three (34 novel) possible CPVT1-associated mutations, absent in 400 reference alleles, were detected in 73 unrelated patients (47%). Thirteen new mutation-containing exons were identified. Two-thirds of the CPVT1-positive patients had mutations that localized to 1 of 16 exons. CONCLUSIONS Possible CPVT1 mutations in RYR2 were identified in nearly one-half of this cohort; 45 of the 105 translated exons are now known to host possible mutations. Considering that approximately 65% of CPVT1-positive cases would be discovered by selective analysis of 16 exons, a tiered targeting strategy for CPVT genetic testing should be considered.
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Affiliation(s)
| | - Zahurul A. Bhuiyan
- Department of Clinical Genetics, Academic Medical Center, University of Amsterdam, Netherlands
| | - David J. Tester
- Department of Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic, Rochester MN USA
| | - Nynke Hofman
- Department of Clinical Genetics, Academic Medical Center, University of Amsterdam, Netherlands
| | - Hennie Bikker
- Department of Clinical Genetics, Academic Medical Center, University of Amsterdam, Netherlands
| | - J Peter van Tintelen
- Department of Genetics, University Medical Center Groningen, University of Groningen, the Netherlands
| | - Marcel M.A.M Mannens
- Department of Clinical Genetics, Academic Medical Center, University of Amsterdam, Netherlands
| | - Arthur A.M. Wilde
- Department of Clinical Genetics, Academic Medical Center, University of Amsterdam, Netherlands
- Department of Cardiology and Heart Failure Research Centre, Academic Medical Center, University of Amsterdam, Netherlands
| | - Michael J. Ackerman
- Department of Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic, Rochester MN USA
- Department of Medicine/Division of Cardiovascular Diseases, Mayo Clinic, Rochester MN USA
- Department of Pediatrics/Division of Pediatric Cardiology, Mayo Clinic, Rochester MN USA
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