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Takase B, Ikeda T, Shimizu W, Abe H, Aiba T, Chinushi M, Koba S, Kusano K, Niwano S, Takahashi N, Takatsuki S, Tanno K, Watanabe E, Yoshioka K, Amino M, Fujino T, Iwasaki YK, Kohno R, Kinoshita T, Kurita Y, Masaki N, Murata H, Shinohara T, Yada H, Yodogawa K, Kimura T, Kurita T, Nogami A, Sumitomo N. JCS/JHRS 2022 Guideline on Diagnosis and Risk Assessment of Arrhythmia. Circ J 2024; 88:1509-1595. [PMID: 37690816 DOI: 10.1253/circj.cj-22-0827] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Affiliation(s)
| | - Takanori Ikeda
- Department of Cardiovascular Medicine, Toho University Faculty of Medicine
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School
| | - Haruhiko Abe
- Department of Heart Rhythm Management, University of Occupational and Environmental Health, Japan
| | - Takeshi Aiba
- Department of Clinical Laboratory Medicine and Genetics, National Cerebral and Cardiovascular Center
| | - Masaomi Chinushi
- School of Health Sciences, Niigata University School of Medicine
| | - Shinji Koba
- Division of Cardiology, Department of Medicine, Showa University School of Medicine
| | - Kengo Kusano
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center
| | - Shinichi Niwano
- Department of Cardiovascular Medicine, Kitasato University School of Medicine
| | - Naohiko Takahashi
- Department of Cardiology and Clinical Examination, Faculty of Medicine, Oita University
| | - Seiji Takatsuki
- Department of Cardiology, Keio University School of Medicine
| | - Kaoru Tanno
- Cardiology Division, Cardiovascular Center, Showa University Koto-Toyosu Hospital
| | - Eiichi Watanabe
- Division of Cardiology, Department of Internal Medicine, Fujita Health University Bantane Hospital
| | | | - Mari Amino
- Department of Cardiology, Tokai University School of Medicine
| | - Tadashi Fujino
- Department of Cardiovascular Medicine, Toho University Faculty of Medicine
| | - Yu-Ki Iwasaki
- Department of Cardiovascular Medicine, Nippon Medical School
| | - Ritsuko Kohno
- Department of Heart Rhythm Management, University of Occupational and Environmental Health, Japan
| | - Toshio Kinoshita
- Department of Cardiovascular Medicine, Toho University Faculty of Medicine
| | - Yasuo Kurita
- Cardiovascular Center, International University of Health and Welfare, Mita Hospital
| | - Nobuyuki Masaki
- Department of Intensive Care Medicine, National Defense Medical College
| | | | - Tetsuji Shinohara
- Department of Cardiology and Clinical Examination, Faculty of Medicine, Oita University
| | - Hirotaka Yada
- Department of Cardiology, International University of Health and Welfare, Mita Hospital
| | - Kenji Yodogawa
- Department of Cardiovascular Medicine, Nippon Medical School
| | - Takeshi Kimura
- Cardiovascular Medicine, Kyoto University Graduate School of Medicine
| | | | - Akihiko Nogami
- Department of Cardiology, Faculty of Medicine, University of Tsukuba
| | - Naokata Sumitomo
- Department of Pediatric Cardiology, Saitama Medical University International Medical Center
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2
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Takase B, Ikeda T, Shimizu W, Abe H, Aiba T, Chinushi M, Koba S, Kusano K, Niwano S, Takahashi N, Takatsuki S, Tanno K, Watanabe E, Yoshioka K, Amino M, Fujino T, Iwasaki Y, Kohno R, Kinoshita T, Kurita Y, Masaki N, Murata H, Shinohara T, Yada H, Yodogawa K, Kimura T, Kurita T, Nogami A, Sumitomo N. JCS/JHRS 2022 Guideline on Diagnosis and Risk Assessment of Arrhythmia. J Arrhythm 2024; 40:655-752. [PMID: 39139890 PMCID: PMC11317726 DOI: 10.1002/joa3.13052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 04/22/2024] [Indexed: 08/15/2024] Open
Affiliation(s)
| | - Takanori Ikeda
- Department of Cardiovascular MedicineToho University Faculty of Medicine
| | - Wataru Shimizu
- Department of Cardiovascular MedicineNippon Medical School
| | - Haruhiko Abe
- Department of Heart Rhythm ManagementUniversity of Occupational and Environmental HealthJapan
| | - Takeshi Aiba
- Department of Clinical Laboratory Medicine and GeneticsNational Cerebral and Cardiovascular Center
| | | | - Shinji Koba
- Division of Cardiology, Department of MedicineShowa University School of Medicine
| | - Kengo Kusano
- Department of Cardiovascular MedicineNational Cerebral and Cardiovascular Center
| | - Shinichi Niwano
- Department of Cardiovascular MedicineKitasato University School of Medicine
| | - Naohiko Takahashi
- Department of Cardiology and Clinical Examination, Faculty of MedicineOita University
| | | | - Kaoru Tanno
- Cardiovascular Center, Cardiology DivisionShowa University Koto‐Toyosu Hospital
| | - Eiichi Watanabe
- Division of Cardiology, Department of Internal MedicineFujita Health University Bantane Hospital
| | | | - Mari Amino
- Department of CardiologyTokai University School of Medicine
| | - Tadashi Fujino
- Department of Cardiovascular MedicineToho University Faculty of Medicine
| | - Yu‐ki Iwasaki
- Department of Cardiovascular MedicineNippon Medical School
| | - Ritsuko Kohno
- Department of Heart Rhythm ManagementUniversity of Occupational and Environmental HealthJapan
| | - Toshio Kinoshita
- Department of Cardiovascular MedicineToho University Faculty of Medicine
| | - Yasuo Kurita
- Cardiovascular Center, Mita HospitalInternational University of Health and Welfare
| | - Nobuyuki Masaki
- Department of Intensive Care MedicineNational Defense Medical College
| | | | - Tetsuji Shinohara
- Department of Cardiology and Clinical Examination, Faculty of MedicineOita University
| | - Hirotaka Yada
- Department of CardiologyInternational University of Health and Welfare Mita Hospital
| | - Kenji Yodogawa
- Department of Cardiovascular MedicineNippon Medical School
| | - Takeshi Kimura
- Cardiovascular MedicineKyoto University Graduate School of Medicine
| | | | - Akihiko Nogami
- Department of Cardiology, Faculty of MedicineUniversity of Tsukuba
| | - Naokata Sumitomo
- Department of Pediatric CardiologySaitama Medical University International Medical Center
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3
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Morgat C, Fressart V, Porretta AP, Neyroud N, Messali A, Temmar Y, Algalarrondo V, Surget E, Bloch A, Leenhardt A, Denjoy I, Extramiana F. Genetic characterization of KCNQ1 variants improves risk stratification in type 1 long QT syndrome patients. Europace 2024; 26:euae136. [PMID: 38825991 PMCID: PMC11203906 DOI: 10.1093/europace/euae136] [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: 03/05/2024] [Accepted: 05/21/2024] [Indexed: 06/04/2024] Open
Abstract
AIMS KCNQ1 mutations cause QTc prolongation increasing life-threatening arrhythmias risks. Heterozygous mutations [type 1 long QT syndrome (LQT1)] are common. Homozygous KCNQ1 mutations cause type 1 Jervell and Lange-Nielsen syndrome (JLNS) with deafness and higher sudden cardiac death risk. KCNQ1 variants causing JLNS or LQT1 might have distinct phenotypic expressions in heterozygous patients. The aim of this study is to evaluate QTc duration and incidence of long QT syndrome-related cardiac events according to genetic presentation. METHODS AND RESULTS We enrolled LQT1 or JLNS patients with class IV/V KCNQ1 variants from our inherited arrhythmia clinic (September 1993 to January 2023). Medical history, ECG, and follow-up were collected. Additionally, we conducted a thorough literature review for JLNS variants. Survival curves were compared between groups, and multivariate Cox regression models identified genetic and clinical risk factors. Among the 789 KCNQ1 variant carriers, 3 groups were identified: 30 JLNS, 161 heterozygous carriers of JLNS variants (HTZ-JLNS), and 550 LQT1 heterozygous carriers of non-JLNS variants (HTZ-Non-JLNS). At diagnosis, mean age was 3.4 ± 4.7 years for JLNS, 26.7 ± 21 years for HTZ-JLNS, and 26 ± 21 years for HTZ-non-JLNS; 55.3% were female; and the mean QTc was 551 ± 54 ms for JLNS, 441 ± 32 ms for HTZ-JLNS, and 467 ± 36 ms for HTZ-Non-JLNS. Patients with heterozygous JLNS mutations (HTZ-JLNS) represented 22% of heterozygous KCNQ1 variant carriers and had a lower risk of cardiac events than heterozygous non-JLNS variant carriers (HTZ-Non-JLNS) [hazard ratio (HR) = 0.34 (0.22-0.54); P < 0.01]. After multivariate analysis, four genetic parameters were independently associated with events: haploinsufficiency [HR = 0.60 (0.37-0.97); P = 0.04], pore localization [HR = 1.61 (1.14-1.2.26); P < 0.01], C-terminal localization [HR = 0.67 (0.46-0.98); P = 0.04], and group [HR = 0.43 (0.27-0.69); P < 0.01]. CONCLUSION Heterozygous carriers of JLNS variants have a lower risk of cardiac arrhythmic events than other LQT1 patients.
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Affiliation(s)
- Charles Morgat
- CNMR Maladies Cardiaques Héréditaires Rares, APHP, Hôpital Bichat, 46 rue Henri Huchard, 75018 Paris, France
| | - Véronique Fressart
- AP-HP, Service de Biochimie Métabolique, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | - Alessandra Pia Porretta
- CNMR Maladies Cardiaques Héréditaires Rares, APHP, Hôpital Bichat, 46 rue Henri Huchard, 75018 Paris, France
- Service of Cardiology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Nathalie Neyroud
- Sorbonne Université, Inserm, Research Unit on Cardiovascular and Metabolic Diseases, UMRS-1166, Paris, France
| | - Anne Messali
- CNMR Maladies Cardiaques Héréditaires Rares, APHP, Hôpital Bichat, 46 rue Henri Huchard, 75018 Paris, France
| | - Yassine Temmar
- AP-HP, Unité Rythmologie, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | - Vincent Algalarrondo
- CNMR Maladies Cardiaques Héréditaires Rares, APHP, Hôpital Bichat, 46 rue Henri Huchard, 75018 Paris, France
| | - Elodie Surget
- CNMR Maladies Cardiaques Héréditaires Rares, APHP, Hôpital Bichat, 46 rue Henri Huchard, 75018 Paris, France
| | - Adrien Bloch
- AP-HP, Service de Biochimie Métabolique, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
| | - Antoine Leenhardt
- CNMR Maladies Cardiaques Héréditaires Rares, APHP, Hôpital Bichat, 46 rue Henri Huchard, 75018 Paris, France
| | - Isabelle Denjoy
- CNMR Maladies Cardiaques Héréditaires Rares, APHP, Hôpital Bichat, 46 rue Henri Huchard, 75018 Paris, France
| | - Fabrice Extramiana
- CNMR Maladies Cardiaques Héréditaires Rares, APHP, Hôpital Bichat, 46 rue Henri Huchard, 75018 Paris, France
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4
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Badura K, Buławska D, Dąbek B, Witkowska A, Lisińska W, Radzioch E, Skwira S, Młynarska E, Rysz J, Franczyk B. Primary Electrical Heart Disease-Principles of Pathophysiology and Genetics. Int J Mol Sci 2024; 25:1826. [PMID: 38339103 PMCID: PMC10855675 DOI: 10.3390/ijms25031826] [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: 12/29/2023] [Revised: 01/27/2024] [Accepted: 01/28/2024] [Indexed: 02/12/2024] Open
Abstract
Primary electrical heart diseases, often considered channelopathies, are inherited genetic abnormalities of cardiomyocyte electrical behavior carrying the risk of malignant arrhythmias leading to sudden cardiac death (SCD). Approximately 54% of sudden, unexpected deaths in individuals under the age of 35 do not exhibit signs of structural heart disease during autopsy, suggesting the potential significance of channelopathies in this group of age. Channelopathies constitute a highly heterogenous group comprising various diseases such as long QT syndrome (LQTS), short QT syndrome (SQTS), idiopathic ventricular fibrillation (IVF), Brugada syndrome (BrS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and early repolarization syndromes (ERS). Although new advances in the diagnostic process of channelopathies have been made, the link between a disease and sudden cardiac death remains not fully explained. Evolving data in electrophysiology and genetic testing suggest previously described diseases as complex with multiple underlying genes and a high variety of factors associated with SCD in channelopathies. This review summarizes available, well-established information about channelopathy pathogenesis, genetic basics, and molecular aspects relative to principles of the pathophysiology of arrhythmia. In addition, general information about diagnostic approaches and management is presented. Analyzing principles of channelopathies and their underlying causes improves the understanding of genetic and molecular basics that may assist general research and improve SCD prevention.
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Affiliation(s)
- Krzysztof Badura
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Dominika Buławska
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Bartłomiej Dąbek
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Alicja Witkowska
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Wiktoria Lisińska
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Ewa Radzioch
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Sylwia Skwira
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Ewelina Młynarska
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Jacek Rysz
- Department of Nephrology, Hypertension and Family Medicine, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland
| | - Beata Franczyk
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
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5
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Dubey N, Ubhadiya TJ, Garg VS, Vadnagara H, Sojitra MH, Gandhi SK, Patel P. Unlocking the Potential of Left Cardiac Sympathetic Denervation: A Scoping Review of a Promising Approach for Long QT Syndrome. Cureus 2023; 15:e47306. [PMID: 38021601 PMCID: PMC10656634 DOI: 10.7759/cureus.47306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2023] [Indexed: 12/01/2023] Open
Abstract
Left cardiac sympathetic denervation (LCSD) has emerged as an alternative therapy for individuals diagnosed with long QT syndrome (LQTS), a genetic disorder characterized by abnormal electrical activity in the heart and sudden cardiac death (SCD). This review examines the history and rationale behind LCSD in LQTS treatment, as well as the procedure, its efficacy, and indications along with the adverse effects that may be associated with it. LQTS presents with prolonged QT intervals on an electrocardiogram and can manifest as seizures, fainting, and SCD. Beta-blockers are the primary treatment for LQTS but some patients do not respond well to these medications or experience side effects. Additionally, implantable cardioverter-defibrillators (ICDs) are not always effective in preventing arrhythmias and can lead to complications. LCSD might offer an alternative approach by disrupting sympathetic activity in the heart. In humans, LCSD reduces the release of norepinephrine, normalizes the QT interval, and decreases the likelihood of life-threatening heart rhythms. The procedure does not impair heart rate or cardiac function due to the compensatory effects of the right cardiac sympathetic nerves. The surgical procedure for LCSD involves the removal of the lower half of the stellate ganglion and thoracic ganglia. Complete denervation is essential for optimal outcomes, while incomplete procedures are considered unacceptable. Traditional and minimally invasive approaches, such as video-assisted thoracic surgery (VATS), are available, with VATS offering shorter hospital stays and fewer complications. In conclusion, LCSD provides a viable treatment option for individuals with LQTS who do not respond well to beta-blockers or require additional protection beyond medication or ICDs. Further research and clinical experience are needed to enhance its acceptance and implementation in routine practice.
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Affiliation(s)
- Nidhi Dubey
- Department of Internal Medicine, Civil Hospital Ahmedabad, Ahmedabad, IND
| | - Tyagi J Ubhadiya
- Department of Internal Medicine, Civil Hospital Ahmedabad, Ahmedabad, IND
| | - Vasudha S Garg
- Department of Internal Medicine, Civil Hospital Ahmedabad, Ahmedabad, IND
| | - Harsh Vadnagara
- Department of Internal Medicine, Civil Hospital Ahmedabad, Ahmedabad, IND
| | - Mihir H Sojitra
- Department of Neurology, Civil Hospital Ahmedabad, Ahmedabad, IND
| | - Siddharth Kamal Gandhi
- Department of Internal Medicine, Shri M. P. Shah Government Medical College, Jamnagar, IND
| | - Priyansh Patel
- Department of Internal Medicine, Medical College Baroda, Vadodara, IND
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6
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Remme CA. SCN5A channelopathy: arrhythmia, cardiomyopathy, epilepsy and beyond. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220164. [PMID: 37122208 PMCID: PMC10150216 DOI: 10.1098/rstb.2022.0164] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 12/31/2022] [Indexed: 05/02/2023] Open
Abstract
Influx of sodium ions through voltage-gated sodium channels in cardiomyocytes is essential for proper electrical conduction within the heart. Both acquired conditions associated with sodium channel dysfunction (myocardial ischaemia, heart failure) as well as inherited disorders secondary to mutations in the gene SCN5A encoding for the cardiac sodium channel Nav1.5 are associated with life-threatening arrhythmias. Research in the last decade has uncovered the complex nature of Nav1.5 distribution, function, in particular within distinct subcellular subdomains of cardiomyocytes. Nav1.5-based channels furthermore display previously unrecognized non-electrogenic actions and may impact on cardiac structural integrity, leading to cardiomyopathy. Moreover, SCN5A and Nav1.5 are expressed in cell types other than cardiomyocytes as well as various extracardiac tissues, where their functional role in, e.g. epilepsy, gastrointestinal motility, cancer and the innate immune response is increasingly investigated and recognized. This review provides an overview of these novel insights and how they deepen our mechanistic knowledge on SCN5A channelopathies and Nav1.5 (dys)function. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.
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Affiliation(s)
- Carol Ann Remme
- Department of Experimental Cardiology, Heart Centre, Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam UMC location AMC, University of Amsterdam, Amsterdam, The Netherlands
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7
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Rieder M, Kreifels P, Stuplich J, Ziupa D, Servatius H, Nicolai L, Castiglione A, Zweier C, Asatryan B, Odening KE. Genotype-Specific ECG-Based Risk Stratification Approaches in Patients With Long-QT Syndrome. Front Cardiovasc Med 2022; 9:916036. [PMID: 35911527 PMCID: PMC9329832 DOI: 10.3389/fcvm.2022.916036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 06/13/2022] [Indexed: 11/13/2022] Open
Abstract
Background Congenital long-QT syndrome (LQTS) is a major cause of sudden cardiac death (SCD) in young individuals, calling for sophisticated risk assessment. Risk stratification, however, is challenging as the individual arrhythmic risk varies pronouncedly, even in individuals carrying the same variant. Materials and Methods In this study, we aimed to assess the association of different electrical parameters with the genotype and the symptoms in patients with LQTS. In addition to the heart-rate corrected QT interval (QTc), markers for regional electrical heterogeneity, such as QT dispersion (QTmax-QTmin in all ECG leads) and delta Tpeak/end (Tpeak/end V5 – Tpeak/end V2), were assessed in the 12-lead ECG at rest and during exercise testing. Results QTc at rest was significantly longer in symptomatic than asymptomatic patients with LQT2 (493.4 ms ± 46.5 ms vs. 419.5 ms ± 28.6 ms, p = 0.004), but surprisingly not associated with symptoms in LQT1. In contrast, post-exercise QTc (minute 4 of recovery) was significantly longer in symptomatic than asymptomatic patients with LQT1 (486.5 ms ± 7.0 ms vs. 463.3 ms ± 16.3 ms, p = 0.04), while no such difference was observed in patients with LQT2. Enhanced delta Tpeak/end and QT dispersion were only associated with symptoms in LQT1 (delta Tpeak/end 19.0 ms ± 18.1 ms vs. −4.0 ms ± 4.4 ms, p = 0.02; QT-dispersion: 54.3 ms ± 10.2 ms vs. 31.4 ms ± 10.4 ms, p = 0.01), but not in LQT2. Delta Tpeak/end was particularly discriminative after exercise, where all symptomatic patients with LQT1 had positive and all asymptomatic LQT1 patients had negative values (11.8 ± 7.9 ms vs. −7.5 ± 1.7 ms, p = 0.003). Conclusion Different electrical parameters can distinguish between symptomatic and asymptomatic patients in different genetic forms of LQTS. While the classical “QTc at rest” was only associated with symptoms in LQT2, post-exercise QTc helped distinguish between symptomatic and asymptomatic patients with LQT1. Enhanced regional electrical heterogeneity was only associated with symptoms in LQT1, but not in LQT2. Our findings indicate that genotype-specific risk stratification approaches based on electrical parameters could help to optimize risk assessment in LQTS.
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Affiliation(s)
- Marina Rieder
- Translational Cardiology, Department of Cardiology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Paul Kreifels
- Department of Cardiology and Angiology I, Faculty of Medicine, University Heart Center Freiburg-Bad Krozingen, University of Freiburg, Freiburg, Germany
| | - Judith Stuplich
- Department of Cardiology and Angiology I, Faculty of Medicine, University Heart Center Freiburg-Bad Krozingen, University of Freiburg, Freiburg, Germany
| | - David Ziupa
- Department of Cardiology and Angiology I, Faculty of Medicine, University Heart Center Freiburg-Bad Krozingen, University of Freiburg, Freiburg, Germany
| | - Helge Servatius
- Translational Cardiology, Department of Cardiology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Luisa Nicolai
- Translational Cardiology, Department of Cardiology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Alessandro Castiglione
- Translational Cardiology, Department of Cardiology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Christiane Zweier
- Department of Human Genetics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Babken Asatryan
- Translational Cardiology, Department of Cardiology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Katja E Odening
- Translational Cardiology, Department of Cardiology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
- Department of Physiology, University of Bern, Bern, Switzerland
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8
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Harvey A, Curnier D, Dodin P, Abadir S, Jacquemet V, Caru M. OUP accepted manuscript. Eur J Prev Cardiol 2022; 29:1633-1677. [PMID: 35537006 DOI: 10.1093/eurjpc/zwac081] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 04/15/2022] [Accepted: 04/18/2022] [Indexed: 11/13/2022]
Abstract
Current exercise recommendations make it difficult for long QT syndrome (LQTS) patients to adopt a physically active and/or athletic lifestyle. The purpose of this review is to summarize the current evidence, identify knowledge gaps, and discuss research perspectives in the field of exercise and LQTS. The first aim is to document the influence of exercise training, exercise stress, and postural change interventions on ventricular repolarization in LQTS patients, while the second aim is to describe electrophysiological measurements used to study the above. Studies examining the effects of exercise on congenital or acquired LQTS in human subjects of all ages were included. Systematic searches were performed on 1 October 2021, through PubMed (NLM), Ovid Medline, Ovid All EBM Reviews, Ovid Embase, and ISI Web of Science, and limited to articles written in English or French. A total of 1986 LQTS patients and 2560 controls were included in the 49 studies. Studies were mainly case-control studies (n = 41) and examined exercise stress and/or postural change interventions (n = 48). One study used a 3-month exercise training program. Results suggest that LQTS patients have subtype-specific repolarization responses to sympathetic stress. Measurement methods and quality were found to be very heterogeneous, which makes inter-study comparisons difficult. In the absence of randomized controlled trials, the current recommendations may have long-term risks for LQTS patients who are discouraged from performing physical activity, rendering its associated health benefits out of range. Future research should focus on discovering the most appropriate levels of exercise training that promote ventricular repolarization normalization in LQTS.
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Affiliation(s)
- Audrey Harvey
- Laboratory of Pathophysiology of EXercise (LPEX), School of Kinesiology and Physical Activity Sciences, Faculty of Medicine, University of Montreal, Montreal, Canada
- Sainte-Justine University Health Center, Research Center, Montreal, Canada
| | - Daniel Curnier
- Laboratory of Pathophysiology of EXercise (LPEX), School of Kinesiology and Physical Activity Sciences, Faculty of Medicine, University of Montreal, Montreal, Canada
- Sainte-Justine University Health Center, Research Center, Montreal, Canada
| | - Philippe Dodin
- Sainte-Justine University Health Center, Research Center, Montreal, Canada
| | - Sylvia Abadir
- Department of Pediatric Cardiology, Sainte-Justine University Health Center, Montreal, Canada
| | - Vincent Jacquemet
- Department of Pharmacology and Physiology, Faculty of Medicine, University of Montreal, Montreal, Canada
| | - Maxime Caru
- Sainte-Justine University Health Center, Research Center, Montreal, Canada
- Department of Pediatrics, Pennsylvania State University College of Medicine, Hershey, PA, USA
- Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, PA, USA
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9
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Rivaud MR, Delmar M, Remme CA. Heritable arrhythmia syndromes associated with abnormal cardiac sodium channel function: ionic and non-ionic mechanisms. Cardiovasc Res 2021; 116:1557-1570. [PMID: 32251506 PMCID: PMC7341171 DOI: 10.1093/cvr/cvaa082] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/01/2020] [Accepted: 04/01/2020] [Indexed: 12/19/2022] Open
Abstract
The cardiac sodium channel NaV1.5, encoded by the SCN5A gene, is responsible for the fast upstroke of the action potential. Mutations in SCN5A may cause sodium channel dysfunction by decreasing peak sodium current, which slows conduction and facilitates reentry-based arrhythmias, and by enhancing late sodium current, which prolongs the action potential and sets the stage for early afterdepolarization and arrhythmias. Yet, some NaV1.5-related disorders, in particular structural abnormalities, cannot be directly or solely explained on the basis of defective NaV1.5 expression or biophysics. An emerging concept that may explain the large disease spectrum associated with SCN5A mutations centres around the multifunctionality of the NaV1.5 complex. In this alternative view, alterations in NaV1.5 affect processes that are independent of its canonical ion-conducting role. We here propose a novel classification of NaV1.5 (dys)function, categorized into (i) direct ionic effects of sodium influx through NaV1.5 on membrane potential and consequent action potential generation, (ii) indirect ionic effects of sodium influx on intracellular homeostasis and signalling, and (iii) non-ionic effects of NaV1.5, independent of sodium influx, through interactions with macromolecular complexes within the different microdomains of the cardiomyocyte. These indirect ionic and non-ionic processes may, acting alone or in concert, contribute significantly to arrhythmogenesis. Hence, further exploration of these multifunctional effects of NaV1.5 is essential for the development of novel preventive and therapeutic strategies.
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Affiliation(s)
- Mathilde R Rivaud
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam UMC (location AMC), University of Amsterdam, Amsterdam Cardiovascular Sciences, Meigberdreef 15, 1105AZ Amsterdam, The Netherlands
| | - Mario Delmar
- The Leon H. Charney Division of Cardiology, New York University School of Medicine, 435 E 30th St, NSB 707, New York, NY 10016, USA
| | - Carol Ann Remme
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam UMC (location AMC), University of Amsterdam, Amsterdam Cardiovascular Sciences, Meigberdreef 15, 1105AZ Amsterdam, The Netherlands
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Bileišienė N, Barysienė J, Mikštienė V, Preikšaitienė E, Marinskis G, Keževičiūtė M, Utkus A, Aidietis A. Aborted Cardiac Arrest in LQT2 Related to Novel KCNH2 ( hERG) Variant Identified in One Lithuanian Family. MEDICINA (KAUNAS, LITHUANIA) 2021; 57:721. [PMID: 34357002 PMCID: PMC8305506 DOI: 10.3390/medicina57070721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/09/2021] [Accepted: 07/13/2021] [Indexed: 11/16/2022]
Abstract
Congenital long QT syndrome (LQTS) is a hereditary ion channelopathy associated with ventricular arrhythmia and sudden cardiac death starting from young age due to prolonged cardiac repolarization, which is represented by QT interval changes in electrocardiogram (ECG). Mutations in human ether-à-go-go related gene (KCNH2 (7q36.1), formerly named hERG) are responsible for Long QT syndrome type 2 (LQT2). LQT2 is the second most common type of LQTS. A resuscitated 31-year-old male with the diagnosis of LQT2 and his family are described. Sequencing analysis of their genomic DNA was performed. Amino acid alteration p.(Ser631Pro) in KCNH2 gene was found. This variant had not been previously described in literature, and it was found in three nuclear family members with different clinical course of the disease. Better understanding of genetic alterations and genotype-phenotype correlations aids in risk stratification and more effective management of these patients, especially when employing a trigger-specific approach to risk-assessment and individually tailored therapy.
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Affiliation(s)
- Neringa Bileišienė
- Clinic of Cardiac and Vascular Diseases, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Santariškių str. 2, LT-08661 Vilnius, Lithuania; (J.B.); (G.M.); (A.A.)
| | - Jūratė Barysienė
- Clinic of Cardiac and Vascular Diseases, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Santariškių str. 2, LT-08661 Vilnius, Lithuania; (J.B.); (G.M.); (A.A.)
| | - Violeta Mikštienė
- Department of Human and Medical Genetics, Institute of Biomedical Sciences, Faculty of Medicine, Vilnius University, Santariskiu g. 2, LT-08661 Vilnius, Lithuania; (V.M.); (E.P.); (A.U.)
| | - Eglė Preikšaitienė
- Department of Human and Medical Genetics, Institute of Biomedical Sciences, Faculty of Medicine, Vilnius University, Santariskiu g. 2, LT-08661 Vilnius, Lithuania; (V.M.); (E.P.); (A.U.)
| | - Germanas Marinskis
- Clinic of Cardiac and Vascular Diseases, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Santariškių str. 2, LT-08661 Vilnius, Lithuania; (J.B.); (G.M.); (A.A.)
| | - Monika Keževičiūtė
- Center of Cardiology and Angiology, Vilnius University Hospital Santaros Klinikos, Santariskiu g. 2, LT-08661 Vilnius, Lithuania;
| | - Algirdas Utkus
- Department of Human and Medical Genetics, Institute of Biomedical Sciences, Faculty of Medicine, Vilnius University, Santariskiu g. 2, LT-08661 Vilnius, Lithuania; (V.M.); (E.P.); (A.U.)
| | - Audrius Aidietis
- Clinic of Cardiac and Vascular Diseases, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Santariškių str. 2, LT-08661 Vilnius, Lithuania; (J.B.); (G.M.); (A.A.)
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Marcellino A, Luchetti J, Raponi M, Falsaperla R, Pirone C, Fares MK, Ventriglia F, Lubrano R. Single-centre retrospective analysis of the best timing for the QTc interval length assessment in neonates. BMJ Paediatr Open 2021; 5:e001026. [PMID: 34079915 PMCID: PMC8137191 DOI: 10.1136/bmjpo-2021-001026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 04/17/2021] [Accepted: 04/19/2021] [Indexed: 12/04/2022] Open
Abstract
Objective To evaluate the best timing for ECG screening in order to diagnose long QT syndrome and lower, at the same time, the false positives. Design We retrospectively evaluated the corrected QT (QTc) interval in the clinical reports of the ECG screening performed, as per internal protocol. Setting An outpatient setting in our Unit of Neonatology and Pediatrics, Santa Maria Goretti Hospital in Latina, Italy. Patients We enrolled 3467 healthy neonates between 14 and 30 days of life. Interventions The newborns with abnormal QTc interval were invited to subsequent revaluation every 21 days, until normalisation or necessity to refer to a tertiary paediatric cardiology centre. Main outcome measures Difference in QTc according to patients' characteristics and number of false positives at second ECG evaluation. Results At first evaluation, 249 (7.2%) newborns had prolonged QTc. We did not find any significant difference in the QTc length according to gestational age (p=0.40) and birth weight (p=0.81). As expected, girls had longer QTc than boys (p=0.01). Only 11 out of 240 (4.6%) and 1 out of 238 infants (0.4%) had persistently prolonged QTc at second and third ECG evaluation, respectively. The QTc decreased significantly at second (p<0.0001) and third evaluation (p=0.0035). Conclusions In our study, we showed that a single screening performed in healthy infants after 60 days of life could reduce the risk of false positives, with a beneficial impact on public national health system and the chance to start early therapy in case of long QT syndrome.
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Affiliation(s)
- Alessia Marcellino
- Pediatrics and Neonatology Unit, Maternal-Child Department, Sapienza University of Rome, Santa Maria Goretti Hospital, Latina, Italy
| | - Jessica Luchetti
- Pediatrics and Neonatology Unit, Maternal-Child Department, Sapienza University of Rome, Santa Maria Goretti Hospital, Latina, Italy
| | - Massimo Raponi
- Cardiology Department, Santa Maria Goretti Hospital, Latina, Italy
| | | | - Carmelo Pirone
- Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Maria Katia Fares
- Pediatrics and Neonatology Unit, Maternal-Child Department, Sapienza University of Rome, Santa Maria Goretti Hospital, Latina, Italy
| | - Flavia Ventriglia
- Pediatrics and Neonatology Unit, Maternal-Child Department, Sapienza University of Rome, Santa Maria Goretti Hospital, Latina, Italy
| | - Riccardo Lubrano
- Pediatrics and Neonatology Unit, Maternal-Child Department, Sapienza University of Rome, Santa Maria Goretti Hospital, Latina, Italy
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Dose response to nadolol in congenital long QT syndrome. Heart Rhythm 2021; 18:1377-1383. [PMID: 33905813 DOI: 10.1016/j.hrthm.2021.04.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 11/20/2022]
Abstract
BACKGROUND Beta-blocker therapy is the cornerstone of treatment for patients with long QT syndrome (LQTS). Few details on the dose to be used are available. As the response is variable between patients, we systematically evaluated the effect of treatment by performing an exercise test. OBJECTIVE The purpose of this study was to explore dose response to nadolol on exercise test in LQTS patients in order to propose a more personalized therapeutic approach. METHODS LQTS patients followed at the Reference Centre for Hereditary Arrhythmic Diseases of Nantes with at least 1 exercise test under nadolol were included retrospectively between 1993 and 2017. All patients underwent gradual cycle exercise tests. Doses adjusted to weight and response to treatment were recorded and evaluated by the percentage of age-predicted maximum heart rate reached on exercise test. RESULTS Ninety-five patients were included in the study, and 337 stress tests under nadolol were analyzed. No correlation existed between dose and percentage of age-predicted maximum heart rate on exercise tests. Twenty-one patients were overresponders, mostly LQTS1, and 20 were underresponders, mainly LQTS2 (P = .0229). Forty-two patients had at least 3 stress tests under nadolol. We found a negative correlation between dose change and percentage of age-predicted maximum heart rate change (P <.0001). We then proposed a table to adapt dose according to exercise test response. CONCLUSION Our study demonstrated a major variability of dose response to nadolol in patients with LQTS, thus underlining the need for a tailored dosage for each patient. Intraindividual analysis showed a relatively constant dose-response relationship, allowing guided dose adaptation after the first exercise test.
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13
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Cox KO, Wang BX. Long QT syndrome type 2: mechanism-based therapies. Future Cardiol 2021; 17:1453-1463. [PMID: 33739161 DOI: 10.2217/fca-2020-0234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Long QT syndrome type 2 is a life-threatening disorder of cardiac electrophysiology. It can lead to sudden cardiac death as a result of QT prolongation and can remain undetected until it presents clinically in the form of life-threatening cardiac arrythmias. Current treatment relies on symptom management largely through the use of β-adrenergic blockade and presently no mechanism-based therapies exist to treat the dysfunction in the hERG channels responsible for the rapid delayed rectifier K+ current which is the pathological source of long QT syndrome type 2. We review the pathophysiology, diagnosis and current management of this life-threatening condition and also analyze some promising potential mechanism-based therapies.
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Affiliation(s)
- Kofi Oliver Cox
- Department of Medicine, St George's, University of London, London, UK
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Yoo HS, Medina N, von Wulffen MA, Ciampi N, Paolucci A, Garro HA, Principato MB, Acunzo RS, Carbajales J. A novel KCNH2 frameshift mutation (c.46delG) associated with high risk of sudden death in a family with congenital long QT syndrome type 2. INTERNATIONAL JOURNAL OF ARRHYTHMIA 2021. [DOI: 10.1186/s42444-020-00029-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Abstract
Background
The congenital long QT syndrome type 2 is caused by mutations in KCNH2 gene that encodes the alpha subunit of potassium channel Kv11.1. The carriers of the pathogenic variant of KCNH2 gene manifest a phenotype characterized by prolongation of QT interval and increased risk of sudden cardiac death due to life-threatening ventricular tachyarrhythmias.
Results
A family composed of 17 members with a family history of sudden death and recurrent syncopes was studied. The DNA of proband with clinical manifestations of long QT syndrome was analyzed using a massive DNA sequencer that included the following genes: KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2, ANK2, KCNJ2, CACNA1, CAV3, SCN1B, SCN4B, AKAP9, SNTA1, CALM1, KCNJ5, RYR2 and TRDN. DNA sequencing of proband identified a novel pathogenic variant of KCNH2 gene produced by a heterozygous frameshift mutation c.46delG, pAsp16Thrfs*44 resulting in the synthesis of a truncated alpha subunit of the Kv11.1 ion channel. Eight family members manifested the phenotype of long QT syndrome. The study of family segregation using Sanger sequencing revealed the identical variant in several members of the family with a positive phenotype.
Conclusions
The clinical and genetic findings of this family demonstrate that the novel frameshift mutation causing haploinsufficiency can result in a congenital long QT syndrome with a severe phenotypic manifestation and an elevated risk of sudden cardiac death.
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Dahlberg P, Diamant UB, Gilljam T, Rydberg A, Bergfeldt L. QT correction using Bazett's formula remains preferable in long QT syndrome type 1 and 2. Ann Noninvasive Electrocardiol 2020; 26:e12804. [PMID: 33070409 PMCID: PMC7816807 DOI: 10.1111/anec.12804] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 08/27/2020] [Accepted: 08/31/2020] [Indexed: 11/28/2022] Open
Abstract
Background The heart rate (HR) corrected QT interval (QTc) is crucial for diagnosis and risk stratification in the long QT syndrome (LQTS). Although its use has been questioned in some contexts, Bazett's formula has been applied in most diagnostic and prognostic studies in LQTS patients. However, studies on which formula eliminates the inverse relation between QT and HR are lacking in LQTS patients. We therefore determined which QT correction formula is most appropriate in LQTS patients including the effect of beta blocker therapy and an evaluation of the agreement of the formulae when applying specific QTc limits for diagnostic and prognostic purposes. Methods Automated measurements from routine 12‐lead ECGs from 200 genetically confirmed LQTS patients from two Swedish regions were included (167 LQT1, 33 LQT2). QT correction was performed using the Bazett, Framingham, Fridericia, and Hodges formulae. Linear regression was used to compare the formulae in all patients, and before and after the initiation of beta blocking therapy in a subgroup (n = 44). Concordance analysis was performed for QTc ≥ 480 ms (diagnosis) and ≥500 ms (prognosis). Results The median age was 32 years (range 0.1–78), 123 (62%) were female and 52 (26%) were children ≤16 years. Bazett's formula was the only method resulting in a QTc without relation with HR. Initiation of beta blocking therapy did not alter the result. Concordance analyses showed clinically significant differences (Cohen's kappa 0.629–0.469) for diagnosis and prognosis in individual patients. Conclusion Bazett's formula remains preferable for diagnosis and prognosis in LQT1 and 2 patients.
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Affiliation(s)
- Pia Dahlberg
- Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Region Västra Götaland, Department of Cardiology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Ulla-Britt Diamant
- Department of Public Health and Clinical Medicine, Heart Centre, Umeå University, Umeå, Sweden
| | - Thomas Gilljam
- Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Region Västra Götaland, Department of Cardiology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Annika Rydberg
- Department of Clinical Sciences, Pediatrics, Umeå University, Umeå, Sweden
| | - Lennart Bergfeldt
- Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Region Västra Götaland, Department of Cardiology, Sahlgrenska University Hospital, Gothenburg, Sweden
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16
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Abstract
The main inherited cardiac arrhythmias are long QT syndrome, short QT syndrome, catecholaminergic polymorphic ventricular tachycardia and Brugada syndrome. These rare diseases are often the underlying cause of sudden cardiac death in young individuals and result from mutations in several genes encoding ion channels or proteins involved in their regulation. The genetic defects lead to alterations in the ionic currents that determine the morphology and duration of the cardiac action potential, and individuals with these disorders often present with syncope or a life-threatening arrhythmic episode. The diagnosis is based on clinical presentation and history, the characteristics of the electrocardiographic recording at rest and during exercise and genetic analyses. Management relies on pharmacological therapy, mostly β-adrenergic receptor blockers (specifically, propranolol and nadolol) and sodium and transient outward current blockers (such as quinidine), or surgical interventions, including left cardiac sympathetic denervation and implantation of a cardioverter-defibrillator. All these arrhythmias are potentially life-threatening and have substantial negative effects on the quality of life of patients. Future research should focus on the identification of genes associated with the diseases and other risk factors, improved risk stratification and, in particular for Brugada syndrome, effective therapies.
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17
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Pensel MC, Nass RD, Taubøll E, Aurlien D, Surges R. Prevention of sudden unexpected death in epilepsy: current status and future perspectives. Expert Rev Neurother 2020; 20:497-508. [PMID: 32270723 DOI: 10.1080/14737175.2020.1754195] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Introduction: Sudden unexpected death in epilepsy (SUDEP) affects about 1 in 1000 people with epilepsy, and even more in medically refractory epilepsy. As most people are between 20 and 40 years when dying suddenly, SUDEP leads to a considerable loss of potential life years. The most important risk factors are nocturnal and tonic-clonic seizures, underscoring that supervision and effective seizure control are key elements for SUDEP prevention. The question of whether specific antiepileptic drugs are linked to SUDEP is still controversially discussed. Knowledge and education about SUDEP among health-care professionals, patients, and relatives are of outstanding importance for preventive measures to be taken, but still poor and widely neglected.Areas covered: This article reviews epidemiology, pathophysiology, risk factors, assessment of individual SUDEP risk and available measures for SUDEP prevention. Literature search was done using Medline and Pubmed in October 2019.Expert opinion: Significant advances in the understanding of SUDEP were made in the last decade which allow testing of novel strategies to prevent SUDEP. Promising current strategies target neuronal mechanisms of brain stem dysfunction, cardiac susceptibility for fatal arrhythmias, and reliable detection of tonic-clonic seizures using mobile health technologies.Abbreviations: AED, antiepileptic drug; CBZ, carbamazepine; cLQTS, congenital long QT syndrome; EMU, epilepsy monitoring unit; FBTCS, focal to bilateral tonic-clonic seizures; GTCS, generalized tonic-clonic seizures; ICA, ictal central apnea; LTG, lamotrigine; PCCA, postconvulsive central apnea; PGES, postictal generalized EEG suppression; SRI, serotonin reuptake inhibitor; SUDEP, sudden unexpected death in epilepsy; TCS, tonic-clonic seizures.
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Affiliation(s)
| | | | - Erik Taubøll
- Department of Neurology, Oslo University Hospital, Nydalen, Norway.,Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Dag Aurlien
- Neuroscience Research Group and Department of Neurology, Stavanger University Hospital, Stavanger, Norway
| | - Rainer Surges
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
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Rowe MK, Roberts JD. The evolution of gene-guided management of inherited arrhythmia syndromes: Peering beyond monogenic paradigms towards comprehensive genomic risk scores. J Cardiovasc Electrophysiol 2020; 31:2998-3008. [PMID: 32107815 DOI: 10.1111/jce.14415] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/06/2020] [Accepted: 02/21/2020] [Indexed: 12/19/2022]
Abstract
Inherited arrhythmia syndromes have traditionally been viewed as monogenic forms of disease whose pathophysiology is driven by a single highly penetrant rare genetic variant. Although an accurate depiction of a proportion of genetic variants, the variable penetrance frequently noted in genotype positive families and the presence of sporadic genotype negative cases have long highlighted a more nuanced truth being operative. Coupled with our more recent recognition that many rare variants implicated in inherited arrhythmia syndromes possess unexpectedly high allele frequencies within the general population, these observations have contributed to the realization that a spectrum of pathogenicity exists among clinically relevant genetic variants. Notably, variable mutation pathogenicity and corresponding variable degrees of penetrance emphasize a limitation of contemporary guidelines, which attempt to dichotomize genetic variants as pathogenic or benign. Recognition of the existence of low and intermediate penetrant variants insufficient to be causative for disease in isolation has served to emphasize the importance of additional genetic, clinical, and environmental factors in the pathogenesis of rare inherited arrhythmia syndromes. Despite being rare, it has also become increasingly evident that common genetic variants play critical roles in both heritable channelopathies and cardiomyopathies and in aggregate may even be the primary drivers in certain instances, such as genotype negative Brugada syndrome. Our growing realization that the genetic substrates of inherited arrhythmia syndromes have intricacies that extend beyond traditionally perceived monogenic paradigms has highlighted a potential value of leveraging more comprehensive genomic risk scores for predicting disease development and arrhythmic risk.
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Affiliation(s)
- Matthew K Rowe
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, Ontario, Canada
| | - Jason D Roberts
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, Ontario, Canada
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19
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Hammami Bomholtz S, Refaat M, Buur Steffensen A, David J, Espinosa K, Nussbaum R, Wojciak J, Hjorth Bentzen B, Scheinman M, Schmitt N. Functional phenotype variations of two novel K
V
7.1 mutations identified in patients with Long QT syndrome. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2020; 43:210-216. [DOI: 10.1111/pace.13870] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/20/2019] [Accepted: 12/29/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Sofia Hammami Bomholtz
- Danish National Research Foundation Centre for Cardiac ArrhythmiaUniversity of Copenhagen Copenhagen Denmark
- Department of Biomedical SciencesUniversity of Copenhagen Copenhagen Denmark
| | - Marwan Refaat
- Department of Internal Medicine, Division of CardiologyAmerican University of Beirut Medical Center Beirut Lebanon
- Department of Biochemistry and Molecular GeneticsAmerican University of Beirut Beirut Lebanon
| | - Annette Buur Steffensen
- Danish National Research Foundation Centre for Cardiac ArrhythmiaUniversity of Copenhagen Copenhagen Denmark
- Department of Biomedical SciencesUniversity of Copenhagen Copenhagen Denmark
| | - Jens‐Peter David
- Danish National Research Foundation Centre for Cardiac ArrhythmiaUniversity of Copenhagen Copenhagen Denmark
- Department of Biomedical SciencesUniversity of Copenhagen Copenhagen Denmark
| | - Karin Espinosa
- Danish National Research Foundation Centre for Cardiac ArrhythmiaUniversity of Copenhagen Copenhagen Denmark
- Department of Biomedical SciencesUniversity of Copenhagen Copenhagen Denmark
| | - Robert Nussbaum
- Department of MedicineUniversity of California, San Francisco San Francisco California
| | - Julianne Wojciak
- Department of MedicineUniversity of California, San Francisco San Francisco California
| | - Bo Hjorth Bentzen
- Danish National Research Foundation Centre for Cardiac ArrhythmiaUniversity of Copenhagen Copenhagen Denmark
- Department of Biomedical SciencesUniversity of Copenhagen Copenhagen Denmark
| | - Melvin Scheinman
- Department of MedicineUniversity of California, San Francisco San Francisco California
| | - Nicole Schmitt
- Danish National Research Foundation Centre for Cardiac ArrhythmiaUniversity of Copenhagen Copenhagen Denmark
- Department of Biomedical SciencesUniversity of Copenhagen Copenhagen Denmark
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Sudhakaran S, Yazdani L, Wheelan KR, Rao PK. The ketogenic diet and the QT interval. Proc (Bayl Univ Med Cent) 2019; 33:77-79. [PMID: 32063779 DOI: 10.1080/08998280.2019.1664220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/26/2019] [Accepted: 08/29/2019] [Indexed: 12/12/2022] Open
Abstract
Long QT syndrome is a disorder of ventricular myocardial repolarization associated with an increased risk of life-threatening cardiac arrhythmias and sudden cardiac death. This report highlights a case of QT prolongation with torsades de pointes in a patient with baseline congenital long QT syndrome, believed to be precipitated by metabolic changes associated with the "ketogenic diet."
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Affiliation(s)
- Sivakumar Sudhakaran
- Department of Internal Medicine, Baylor University Medical Center and Baylor Jack and Jane Hamilton Heart and Vascular HospitalDallasTexas
| | - Laila Yazdani
- Department of Internal Medicine, Baylor University Medical Center and Baylor Jack and Jane Hamilton Heart and Vascular HospitalDallasTexas
| | - Kevin R Wheelan
- Department of Internal Medicine, Baylor University Medical Center and Baylor Jack and Jane Hamilton Heart and Vascular HospitalDallasTexas
| | - Praveen K Rao
- Department of Internal Medicine, Baylor University Medical Center and Baylor Jack and Jane Hamilton Heart and Vascular HospitalDallasTexas
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21
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Janzen M, Cheung CC, Steinberg C, Lam PY, Krahn AD. Changes on the electrocardiogram in anorexia nervosa: A case control study. J Electrocardiol 2019; 56:64-69. [PMID: 31319227 DOI: 10.1016/j.jelectrocard.2019.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/02/2019] [Accepted: 07/07/2019] [Indexed: 11/30/2022]
Abstract
PURPOSE Anorexia nervosa is a complex psychiatric condition with increased mortality. The electrocardiogram (ECG) may show repolarization changes which may associate with an increased risk of sudden death. Up to 80% of patients may be prescribed psychopharmacotherapies which alter the ECG, potentially compounding arrhythmic risk. This study aimed to describe and improve understanding of ECG changes in eating disorders and assess the effect of psychopharmacotherapies. METHODS Adolescent patients diagnosed with anorexia nervosa were reviewed. ECGs were reviewed by blinded expert reviewers, and repolarization parameters were compared to healthy controls. Patients on and off psychopharmacotherapies were compared. RESULTS Thirty-eight anorexia nervosa patients off psychopharmacotherapies were age matched to 53 healthy controls. Heart rate was lower in anorexia nervosa patients (56 vs. 74 bpm, p < 0.001). The absolute QT interval was longer in patients compared to controls (408 vs. 383 ms, p < 0.001), but the QTc by Hodges' formula was similar between groups (401 vs. 408 ms, p = 0.16). The prevalence of T-wave flattening and inversion was also similar between groups (13% vs. 4%, p = 0.12) and T-peak to T-end interval (Tpe) was shorter in patients compared to controls (p < 0.01). ECG parameters were similar between patients on and off psychopharmacotherapies aside from off-drug patients showing lower HR (56 vs. 65, p = 0.04). CONCLUSIONS Autonomic and repolarization changes are evident on the ECG of anorexia nervosa patients, though the QTc interval was in fact similar between groups. Changes in T-wave morphology and duration may be promising metrics of repolarization effects of anorexia nervosa.
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Affiliation(s)
- Mikyla Janzen
- Heart Rhythm Services, Division of Cardiology, Department of Medicine, University of British Columbia, 220-1033 Davie St, Vancouver, British Columbia V6E 1M5, Canada.
| | - Christopher C Cheung
- Heart Rhythm Services, Division of Cardiology, Department of Medicine, University of British Columbia, 220-1033 Davie St, Vancouver, British Columbia V6E 1M5, Canada.
| | - Christian Steinberg
- Heart Rhythm Services, Division of Cardiology, Department of Medicine, University of British Columbia, 220-1033 Davie St, Vancouver, British Columbia V6E 1M5, Canada.
| | - Pei-Yoong Lam
- Department of Pediatrics, University of British Columbia, 4480 Oak St, Vancouver, British Columbia V6H 3N1, Canada.
| | - Andrew D Krahn
- Heart Rhythm Services, Division of Cardiology, Department of Medicine, University of British Columbia, 220-1033 Davie St, Vancouver, British Columbia V6E 1M5, Canada.
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Singh M, Morin DP, Link MS. Sudden cardiac death in Long QT syndrome (LQTS), Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia (CPVT). Prog Cardiovasc Dis 2019; 62:227-234. [DOI: 10.1016/j.pcad.2019.05.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 05/06/2019] [Indexed: 10/26/2022]
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Abstract
The discovery of the human genome has ushered in a new era of molecular testing, advancing our knowledge and ability to identify cardiac channelopathies. Genetic variations can affect the opening and closing of the potassium, sodium, and calcium channels, resulting in arrhythmias and sudden death. Cardiac arrhythmias caused by disorders of ion channels are known as cardiac channelopathies. Nurses are important members of many interdisciplinary teams and must have a general understanding of the pathophysiology of the most commonly encountered cardiac channelopathies, electrocardiogram characteristics, approaches to treatment, and care for patients and their families. This article provides an overview of cardiac channelopathies that nurses might encounter in an array of clinical and research settings, focusing on the clinically relevant features of long QT syndrome, short QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, and arrhythmogenic right ventricular dysplasia/cardiomyopathy.
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Affiliation(s)
- Kathleen T Hickey
- Kathleen T. Hickey is Professor of Nursing, Columbia University Medical Center, 622 W 168th St, New York, NY 10032 . Amir Elzomor is a premedical student at the Albert Dorman Honors College at the New Jersey Institute of Technology, Newark, New Jersey
| | - Amir Elzomor
- Kathleen T. Hickey is Professor of Nursing, Columbia University Medical Center, 622 W 168th St, New York, NY 10032 . Amir Elzomor is a premedical student at the Albert Dorman Honors College at the New Jersey Institute of Technology, Newark, New Jersey
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24
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Verkerk AO, Amin AS, Remme CA. Disease Modifiers of Inherited SCN5A Channelopathy. Front Cardiovasc Med 2018; 5:137. [PMID: 30327767 PMCID: PMC6174200 DOI: 10.3389/fcvm.2018.00137] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 09/10/2018] [Indexed: 12/19/2022] Open
Abstract
To date, a large number of mutations in SCN5A, the gene encoding the pore-forming α-subunit of the primary cardiac Na+ channel (NaV1.5), have been found in patients presenting with a wide range of ECG abnormalities and cardiac syndromes. Although these mutations all affect the same NaV1.5 channel, the associated cardiac syndromes each display distinct phenotypical and biophysical characteristics. Variable disease expressivity has also been reported, where one particular mutation in SCN5A may lead to either one particular symptom, a range of various clinical signs, or no symptoms at all, even within one single family. Additionally, disease severity may vary considerably between patients carrying the same mutation. The exact reasons are unknown, but evidence is increasing that various cardiac and non-cardiac conditions can influence the expressivity and severity of inherited SCN5A channelopathies. In this review, we provide a summary of identified disease entities caused by SCN5A mutations, and give an overview of co-morbidities and other (non)-genetic factors which may modify SCN5A channelopathies. A comprehensive knowledge of these modulatory factors is not only essential for a complete understanding of the diverse clinical phenotypes associated with SCN5A mutations, but also for successful development of effective risk stratification and (alternative) treatment paradigms.
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Affiliation(s)
- Arie O Verkerk
- Department of Clinical and Experimental Cardiology, Heart Centre, Academic Medical Center, Amsterdam, Netherlands.,Department of Medical Biology, Academic Medical Center, Amsterdam, Netherlands
| | - Ahmad S Amin
- Department of Clinical and Experimental Cardiology, Heart Centre, Academic Medical Center, Amsterdam, Netherlands
| | - Carol Ann Remme
- Department of Clinical and Experimental Cardiology, Heart Centre, Academic Medical Center, Amsterdam, Netherlands
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25
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Joutsiniemi T, Ekblad U, Rosén KG, Timonen S. Waveform analysis of the fetal ECG in labor in patients with intrahepatic cholestasis of pregnancy. J Obstet Gynaecol Res 2018; 45:306-312. [PMID: 30203501 DOI: 10.1111/jog.13812] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 08/10/2018] [Indexed: 12/27/2022]
Abstract
AIM Intrahepatic cholestasis of pregnancy (ICP) is reported to be associated with an increased risk of sudden fetal death. The possible mechanism is thought to be cardiac arrhythmia. Prolonged QT interval of the electrocardiogram (ECG) is associated with arrhytmogenic events. The aim of the study was to compare the fetal ECG QT interval during labor in pregnancies complicated with ICP to healthy controls. METHODS The fetal ECG and QT interval was reviewed retrospectively. The intrapartum QT interval was measured in 61 fetuses born to mothers with ICP and in a control group of similar size. The corrected QT interval (QTc) was calculated using Bazett's formula: QT/√RR. The occurrence of ST segment depression was also included in the analysis. RESULTS The groups were similar regarding to maternal age, parity, BMI, gestational age and smoking habits. The rate of labor induction was significantly higher in ICP patients (P < 0.001). The QTc at the beginning and the end of recording was analyzed and there were no significant differences in these values between the ICP patients and healthy controls (P = 0.467). Most ICP patients used ursodeoxycholic acid (UDCA) for mediation. We analyzed separately patients who had elevated liver enzymes before labor. No significant differences in the QTc were noted in these patients either. Nor were there any significant ST depressions in ICP patients. CONCLUSIONS The etiology of adverse perinatal outcome and even sudden fetal death in ICP is still controversial. No differences in QTc intervals and ST waveforms during labor were found in our study material.
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Affiliation(s)
- Titta Joutsiniemi
- Department of Obstetrics and Gynecology, Turku University Hospital, Turku, Finland
| | - Ulla Ekblad
- Department of Obstetrics and Gynecology, Turku University Hospital, Turku, Finland
| | - Karl G Rosén
- Faculty of Caring Science, University of Borås, Borås, Sweden
| | - Susanna Timonen
- Department of Obstetrics and Gynecology, Turku University Hospital, Turku, Finland
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26
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Bomba M, Tremolizzo L, Corbetta F, Nicosia F, Lanfranconi F, Poggioli G, Goulene K, Stramba-Badiale M, Conti E, Neri F, Nacinovich R. QT interval and dispersion in drug-free anorexia nervosa adolescents: a case control study. Eur Child Adolesc Psychiatry 2018; 27:861-866. [PMID: 29147785 DOI: 10.1007/s00787-017-1080-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 11/06/2017] [Indexed: 12/20/2022]
Abstract
Long QT values have been reported in patients with anorexia nervosa of the restricting type (ANr) potentially increasing the risk of fatal arrhythmia, especially if psychotropic drug treatment is required. Nevertheless, the previous studies on this topic are biased by drug exposure, long disease durations, and small sample sizes. This study is aimed at assessing QTc and QTcd values in ANr adolescents with recent onset and drug free, as compared to subjects affected by psychiatric disorders other than ANr. We evaluated QTc and its dispersion (QTcd) in a population of 77 drug-free ANr female adolescents and compared to an equal number of healthy controls (H-CTRL) and pathological controls (P-CTRL, mixed psychiatric disorders). The QT determination was performed on a standard simultaneous 12-lead ECG in blind by a single experienced investigator. QTc was calculated by the Bazett's formula and QTcd was determined as the difference between the maximum and minimum QTc intervals in different leads. Only for ANr patients, clinico-demographic data, hormones, and electrolytes were obtained. QTc was slightly reduced in ANr patients (27.7 ms, < 10%, p < 0.0003) vs. controls, while QTcd was increased in P-CTRL (30%, p < 0.0003). Heart rate was significantly lower in ANr patients vs. controls (25%; p < 0.003). Tyroid hormones and serum potassium showed weak although significant positive correlations with QTc in ANr patients. QTcd displayed a weak negative correlation with the BMI percentile (r = - 0.262, p = 0.03). We reject the hypothesis that QTc and QTcd are increased in drug-free ANr adolescents with a relatively short-disease duration. Further studies are needed to understand if the previously reported increase might be related to other associated chronic disorders, such as hormonal or electrolyte imbalance.
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Affiliation(s)
- Monica Bomba
- Child and Adolescent Mental Health, University of Milano-Bicocca, Milan, Italy. .,Child and Adolescent Mental Health Department, "San Gerardo" Hospital, Via Pergolesi 33, 20900, Monza, Italy.
| | - Lucio Tremolizzo
- Neurology, ASST of Monza, University of Milano-Bicocca, Milan, Italy.,School of Medicine and Surgery and Milan-Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Milan, Italy
| | - Fabiola Corbetta
- Child and Adolescent Mental Health, University of Milano-Bicocca, Milan, Italy.,Child and Adolescent Mental Health Department, "San Gerardo" Hospital, Via Pergolesi 33, 20900, Monza, Italy
| | - Franco Nicosia
- Geriatric Unit, Spedali Civili, Department of Medical and Surgery Sciences, University of Brescia, Brescia, Italy
| | - Francesca Lanfranconi
- School of Medicine and Surgery and Milan-Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Milan, Italy
| | - Gianni Poggioli
- Sport Medicine, "Papa Giovanni XXIII" Hospital, Bergamo, Italy
| | - Karine Goulene
- Pediatric Arrhythmias Center, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | | | - Elisa Conti
- School of Medicine and Surgery and Milan-Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Milan, Italy
| | - Francesca Neri
- Child and Adolescent Mental Health, University of Milano-Bicocca, Milan, Italy.,School of Medicine and Surgery and Milan-Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Milan, Italy.,Child and Adolescent Mental Health Department, "San Gerardo" Hospital, Via Pergolesi 33, 20900, Monza, Italy
| | - Renata Nacinovich
- Child and Adolescent Mental Health, University of Milano-Bicocca, Milan, Italy.,School of Medicine and Surgery and Milan-Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Milan, Italy.,Child and Adolescent Mental Health Department, "San Gerardo" Hospital, Via Pergolesi 33, 20900, Monza, Italy
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27
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Marino BS, Tabbutt S, MacLaren G, Hazinski MF, Adatia I, Atkins DL, Checchia PA, DeCaen A, Fink EL, Hoffman GM, Jefferies JL, Kleinman M, Krawczeski CD, Licht DJ, Macrae D, Ravishankar C, Samson RA, Thiagarajan RR, Toms R, Tweddell J, Laussen PC. Cardiopulmonary Resuscitation in Infants and Children With Cardiac Disease: A Scientific Statement From the American Heart Association. Circulation 2018; 137:e691-e782. [PMID: 29685887 DOI: 10.1161/cir.0000000000000524] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cardiac arrest occurs at a higher rate in children with heart disease than in healthy children. Pediatric basic life support and advanced life support guidelines focus on delivering high-quality resuscitation in children with normal hearts. The complexity and variability in pediatric heart disease pose unique challenges during resuscitation. A writing group appointed by the American Heart Association reviewed the literature addressing resuscitation in children with heart disease. MEDLINE and Google Scholar databases were searched from 1966 to 2015, cross-referencing pediatric heart disease with pertinent resuscitation search terms. The American College of Cardiology/American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. The recommendations in this statement concur with the critical components of the 2015 American Heart Association pediatric basic life support and pediatric advanced life support guidelines and are meant to serve as a resuscitation supplement. This statement is meant for caregivers of children with heart disease in the prehospital and in-hospital settings. Understanding the anatomy and physiology of the high-risk pediatric cardiac population will promote early recognition and treatment of decompensation to prevent cardiac arrest, increase survival from cardiac arrest by providing high-quality resuscitations, and improve outcomes with postresuscitation care.
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28
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Landaw J, Qu Z. Memory-induced nonlinear dynamics of excitation in cardiac diseases. Phys Rev E 2018; 97:042414. [PMID: 29758700 PMCID: PMC6542282 DOI: 10.1103/physreve.97.042414] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Indexed: 11/07/2022]
Abstract
Excitable cells, such as cardiac myocytes, exhibit short-term memory, i.e., the state of the cell depends on its history of excitation. Memory can originate from slow recovery of membrane ion channels or from accumulation of intracellular ion concentrations, such as calcium ion or sodium ion concentration accumulation. Here we examine the effects of memory on excitation dynamics in cardiac myocytes under two diseased conditions, early repolarization and reduced repolarization reserve, each with memory from two different sources: slow recovery of a potassium ion channel and slow accumulation of the intracellular calcium ion concentration. We first carry out computer simulations of action potential models described by differential equations to demonstrate complex excitation dynamics, such as chaos. We then develop iterated map models that incorporate memory, which accurately capture the complex excitation dynamics and bifurcations of the action potential models. Finally, we carry out theoretical analyses of the iterated map models to reveal the underlying mechanisms of memory-induced nonlinear dynamics. Our study demonstrates that the memory effect can be unmasked or greatly exacerbated under certain diseased conditions, which promotes complex excitation dynamics, such as chaos. The iterated map models reveal that memory converts a monotonic iterated map function into a nonmonotonic one to promote the bifurcations leading to high periodicity and chaos.
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Affiliation(s)
- Julian Landaw
- Department of Medicine (Cardiology), University of California, Los Angeles, California 90095, USA and Department of Biomathematics, University of California, Los Angeles, California 90095, USA
| | - Zhilin Qu
- Department of Medicine (Cardiology), University of California, Los Angeles, California 90095, USA and Department of Biomathematics, University of California, Los Angeles, California 90095, USA
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29
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Abstract
INTRODUCTION AND OBJECTIVES The importance of sodium channels for the normal electrical activity of the heart is emphasized by the fact that mutations (inherited or de novo) in genes that encode for these channels or their associated proteins cause arrhythmogenic syndromes such as the Brugada syndrome and the long QT syndrome (LQTS). The aim of this study is to conduct a review of the literature on the mutations in the sodium channel complex responsible for heart disease and the implications of a close relationship between genetics and the clinical aspects of the main cardiac channelopathies, namely at the level of diagnosis, risk stratification, prognosis, screening of family members and treatment. METHODS The online Pubmed® database was used to search for articles published in this field in indexed journals. The MeSH database was used to define the following query: "Mutation [Mesh] AND Sodium Channels [Mesh] AND Heart Diseases [Mesh]", and articles published in the last 15 years, written in English or Portuguese and referring to research in human beings were included. CONCLUSIONS In the past few years, significant advances have been made to clarify the genetic and molecular basis of these syndromes. A greater understanding of the underlying pathophysiological mechanisms showed the importance of the relationship between genotype and phenotype and led to progress in the clinical approach to these patients. However, it is still necessary to improve diagnostic capacity, optimize risk stratification, and develop new specific treatments according to the genotype-phenotype binomial.
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30
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A Conceptual Framework Encompassing the Psychoneuroimmunoendocrinological Influences of Listening to Music in Patients With Heart Failure. Holist Nurs Pract 2018; 32:81-89. [DOI: 10.1097/hnp.0000000000000253] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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31
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Fonseca DJ, Vaz da Silva MJ. Cardiac channelopathies: The role of sodium channel mutations. REVISTA PORTUGUESA DE CARDIOLOGIA (ENGLISH EDITION) 2018. [DOI: 10.1016/j.repce.2017.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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32
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Mascia G, Arbelo E, Solimene F, Giaccardi M, Brugada R, Brugada J. The long-QT syndrome and exercise practice: The never-ending debate. J Cardiovasc Electrophysiol 2018; 29:489-496. [DOI: 10.1111/jce.13410] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 12/14/2017] [Accepted: 12/18/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Giuseppe Mascia
- Electrophysiology Unit; Clinica Montevergine; Mercogliano Italy
| | - Elena Arbelo
- Arrhythmia Section, Cardiology Department, Hospital Clínic, IDIBAPS; University of Barcelona; Barcelona Spain
| | | | - Marzia Giaccardi
- Cardiology and Electrophysiology Unit, Department of Internal Medicine; Santa Maria Nuova Hospital; Florence Italy
| | - Ramon Brugada
- Cardiovascular Genetics Center, Institut d'Investigació Biomèdica Girona (IDIBGI); University of Girona; Girona Spain
| | - Josep Brugada
- Arrhythmia Section, Cardiology Department, Hospital Clínic, IDIBAPS; University of Barcelona; Barcelona Spain
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33
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34
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Animal toxins for channelopathy treatment. Neuropharmacology 2017; 132:83-97. [PMID: 29080794 DOI: 10.1016/j.neuropharm.2017.10.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 10/09/2017] [Accepted: 10/24/2017] [Indexed: 12/18/2022]
Abstract
Ion channels are transmembrane proteins that allow passive flow of ions inside and/or outside of cells or cell organelles. Except mutations lead to nonfunctional protein production or abolished receptor entrance on the membrane surface an altered channel may have two principal conditions that can be corrected. The channel may conduct fewer ions through (loss-of-function mutations) or too many ions (gain-of-function mutations) compared to a normal channel. Toxins from animal venoms are specialised molecules that are generally oriented toward interactions with ion channels. This is a result of long coevolution between predators and their prey. On the molecular level, toxins activate or inhibit ion channels, so they are ideal molecules for restoring conductance in mutated channels. Another aspect of this long coevolution is that a broad variety of toxins have been fine tuned to recognize the channels of different species, keeping many amino acids substitution among sequences. Many peptide ligands with high selectivity to specific receptor subtypes have been isolated from animal venoms, some of which are absolutely non-toxic to humans and mammalians. It is expected that molecules that are selective to each known receptor can be found in animal venoms, but the pool of toxins currently does not override all receptors described as being involved in channelopathies. Modern investigating methods have enhanced the search process for selective ligands. One prominent method is a site-directed mutagenesis of existing toxins to change the selectivity or/and affinity to the selected receptor, which has shown positive results. This article is part of the Special Issue entitled 'Channelopathies.'
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35
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Kauferstein S, Herz N, Scheiper S, Biel S, Jenewein T, Kunis M, Erkapic D, Beckmann BM, Neumann T. Relevance of molecular testing in patients with a family history of sudden death. Forensic Sci Int 2017; 276:18-23. [PMID: 28472724 DOI: 10.1016/j.forsciint.2017.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 02/23/2017] [Accepted: 04/04/2017] [Indexed: 12/19/2022]
Abstract
Sudden cardiac death (SCD) is a major cause of death in industrial countries. Although SCD occurs mainly in adults, it may also affect young persons, where genetic cardiac disorders comprise at least half of these cases. This includes primary arrhythmogenic disorders such as long QT syndrome and inherited cardiomyopathies. However, in many cases, postmortem examinations provide no conclusive results explaining the cause of death. Since family members of the deceased may eventually have inherited the same disease, they are at risk of SCD. In the present study, 28 patients with a family history of sudden unexplained death (SUD), of survived cardiac arrest and with a clinical diagnosis of an inherited cardiac disease were screened using phenotype-guided molecular analysis of genes associated with arrhythmogenic cardiac diseases. In 64% of the cases, gene variants with potentially pathogenic cardiac effects were detected suggesting that an arrhythmia syndrome may have caused the death of the deceased family member. Therefore, we recommend that relatives of SUD victims should undergo extended cardiac examination and, depending on the clinical diagnosis, a targeted genetic analysis should follow, which is crucial to identify family members at risk.
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Affiliation(s)
- Silke Kauferstein
- Institute of Legal Medicine, University of Frankfurt, Kennedyallee 104, 60596 Frankfurt/Main, Germany.
| | - Nadine Herz
- Institute of Legal Medicine, University of Frankfurt, Kennedyallee 104, 60596 Frankfurt/Main, Germany; Bundeskriminalamt, D-65173 Wiesbaden, Germany
| | - Stefanie Scheiper
- Institute of Legal Medicine, University of Frankfurt, Kennedyallee 104, 60596 Frankfurt/Main, Germany
| | - Stephanie Biel
- Institute of Legal Medicine, University of Frankfurt, Kennedyallee 104, 60596 Frankfurt/Main, Germany
| | - Tina Jenewein
- Institute of Legal Medicine, University of Frankfurt, Kennedyallee 104, 60596 Frankfurt/Main, Germany
| | - Malte Kunis
- Kerckhoff Heart and Thorax Center, Benekestraße 2, 61231 Bad Nauheim, Germany
| | - Damir Erkapic
- Kerckhoff Heart and Thorax Center, Benekestraße 2, 61231 Bad Nauheim, Germany; Medical Clinic I, University Hospital Giessen and Marburg GmbH, Giessen, Germany
| | - Britt-Maria Beckmann
- Medical Clinic I, Hospital Grosshadern, Ludwig-Maximilians University, München, Germany
| | - Thomas Neumann
- Kerckhoff Heart and Thorax Center, Benekestraße 2, 61231 Bad Nauheim, Germany
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36
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Hurtado-Sierra D, Rivera-Rodríguez L. Anomalía de Ebstein y síndrome de QT largo congénito. A propósito de un caso. ARCHIVOS DE CARDIOLOGIA DE MEXICO 2017; 87:178-180. [DOI: 10.1016/j.acmx.2016.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 11/24/2022] Open
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Fernández-Falgueras A, Sarquella-Brugada G, Brugada J, Brugada R, Campuzano O. Cardiac Channelopathies and Sudden Death: Recent Clinical and Genetic Advances. BIOLOGY 2017; 6:biology6010007. [PMID: 28146053 PMCID: PMC5372000 DOI: 10.3390/biology6010007] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/17/2017] [Accepted: 01/20/2017] [Indexed: 12/19/2022]
Abstract
Sudden cardiac death poses a unique challenge to clinicians because it may be the only symptom of an inherited heart condition. Indeed, inherited heart diseases can cause sudden cardiac death in older and younger individuals. Two groups of familial diseases are responsible for sudden cardiac death: cardiomyopathies (mainly hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic cardiomyopathy) and channelopathies (mainly long QT syndrome, Brugada syndrome, short QT syndrome, and catecholaminergic polymorphic ventricular tachycardia). This review focuses on cardiac channelopathies, which are characterized by lethal arrhythmias in the structurally normal heart, incomplete penetrance, and variable expressivity. Arrhythmias in these diseases result from pathogenic variants in genes encoding cardiac ion channels or associated proteins. Due to a lack of gross structural changes in the heart, channelopathies are often considered as potential causes of death in otherwise unexplained forensic autopsies. The asymptomatic nature of channelopathies is cause for concern in family members who may be carrying genetic risk factors, making the identification of these genetic factors of significant clinical importance.
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Affiliation(s)
| | | | - Josep Brugada
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, Barcelona 08950, Spain.
| | - Ramon Brugada
- Cardiovascular Genetics Center, IDIBGI, Girona 17190, Spain.
- Medical Sciences Department, School of Medicine, University of Girona, Girona 17071, Spain.
- Familial Cardiomyopathies Unit, Hospital Josep Trueta, Girona 17007, Spain.
| | - Oscar Campuzano
- Cardiovascular Genetics Center, IDIBGI, Girona 17190, Spain.
- Medical Sciences Department, School of Medicine, University of Girona, Girona 17071, Spain.
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38
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Chiamvimonvat N, Chen-Izu Y, Clancy CE, Deschenes I, Dobrev D, Heijman J, Izu L, Qu Z, Ripplinger CM, Vandenberg JI, Weiss JN, Koren G, Banyasz T, Grandi E, Sanguinetti MC, Bers DM, Nerbonne JM. Potassium currents in the heart: functional roles in repolarization, arrhythmia and therapeutics. J Physiol 2017; 595:2229-2252. [PMID: 27808412 DOI: 10.1113/jp272883] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 10/11/2016] [Indexed: 12/19/2022] Open
Abstract
This is the second of the two White Papers from the fourth UC Davis Cardiovascular Symposium Systems Approach to Understanding Cardiac Excitation-Contraction Coupling and Arrhythmias (3-4 March 2016), a biennial event that brings together leading experts in different fields of cardiovascular research. The theme of the 2016 symposium was 'K+ channels and regulation', and the objectives of the conference were severalfold: (1) to identify current knowledge gaps; (2) to understand what may go wrong in the diseased heart and why; (3) to identify possible novel therapeutic targets; and (4) to further the development of systems biology approaches to decipher the molecular mechanisms and treatment of cardiac arrhythmias. The sessions of the Symposium focusing on the functional roles of the cardiac K+ channel in health and disease, as well as K+ channels as therapeutic targets, were contributed by Ye Chen-Izu, Gideon Koren, James Weiss, David Paterson, David Christini, Dobromir Dobrev, Jordi Heijman, Thomas O'Hara, Crystal Ripplinger, Zhilin Qu, Jamie Vandenberg, Colleen Clancy, Isabelle Deschenes, Leighton Izu, Tamas Banyasz, Andras Varro, Heike Wulff, Eleonora Grandi, Michael Sanguinetti, Donald Bers, Jeanne Nerbonne and Nipavan Chiamvimonvat as speakers and panel discussants. This article summarizes state-of-the-art knowledge and controversies on the functional roles of cardiac K+ channels in normal and diseased heart. We endeavour to integrate current knowledge at multiple scales, from the single cell to the whole organ levels, and from both experimental and computational studies.
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Affiliation(s)
- Nipavan Chiamvimonvat
- Department of Internal Medicine, University of California, Davis, Genome and Biomedical Science Facility, Rm 6315, Davis, CA, 95616, USA.,Department of Veterans Affairs, Northern California Health Care System, Mather, CA, 95655, USA
| | - Ye Chen-Izu
- Department of Internal Medicine, University of California, Davis, Genome and Biomedical Science Facility, Rm 6315, Davis, CA, 95616, USA.,Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA.,Department of Biomedical Engineering, University of California, Davis, Genome and Biomedical Science Facility, Rm 2303, Davis, CA, 95616, USA
| | - Colleen E Clancy
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Isabelle Deschenes
- Department of Physiology and Biophysics, and Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44109, USA.,Heart and Vascular Research Center, MetroHealth Medical Center, Cleveland, OH, 44109, USA
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Hufelandstrasse 55, 45122, Essen, Germany
| | - Jordi Heijman
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Leighton Izu
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Zhilin Qu
- Division of Cardiology, Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, 3645 MRL, Los Angeles, CA, 90095, USA
| | - Crystal M Ripplinger
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Jamie I Vandenberg
- Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, NSW, 2010, Australia
| | - James N Weiss
- Division of Cardiology, Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, 3645 MRL, Los Angeles, CA, 90095, USA
| | - Gideon Koren
- Cardiovascular Research Center, Rhode Island Hospital and the Cardiovascular Institute, The Warren Alpert Medical School of Brown University, Providence, RI, 02903, USA
| | - Tamas Banyasz
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Eleonora Grandi
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Michael C Sanguinetti
- Department of Internal Medicine, University of Utah, Nora Eccles Harrison Cardiovascular Research & Training Institute, Salt Lake City, UT, 84112, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Jeanne M Nerbonne
- Departments of Developmental Biology and Internal Medicine, Cardiovascular Division, Washington University Medical School, St Louis, MO, 63110, USA
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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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Aurlien D, Gjerstad L, Taubøll E. The role of antiepileptic drugs in sudden unexpected death in epilepsy. Seizure 2016; 43:56-60. [PMID: 27886630 DOI: 10.1016/j.seizure.2016.11.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 10/26/2016] [Accepted: 11/05/2016] [Indexed: 01/30/2023] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) primarily affects young adults and is the leading cause of death related directly to seizures. High frequency of generalized tonic-clonic seizures is the most important risk factor, and effective seizure protection is probably the most important measure to prevent these tragic deaths. For several years a potential role of antiepileptic drugs (AEDs) has been discussed, but at present there is wide agreement that choice of AED therapy does not influence the risk. However, although it is well known that the efficacy and safety profiles of AEDs may differ significantly when used in the treatment of genetic epilepsy compared to symptomatic or cryptogenic epilepsy, this has generally been overlooked in epidemiologic studies of possible relationships between AEDs and SUDEP. Consequently important information about drug safety may have been lost. This review challenges the current view that no AED can increase the risk of SUDEP.
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Affiliation(s)
- Dag Aurlien
- Neuroscience Research Group and Department of Neurology, Stavanger University Hospital, Stavanger, Norway.
| | - Leif Gjerstad
- Department of Neurology, Oslo University Hospital and Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Erik Taubøll
- Department of Neurology, Oslo University Hospital and Faculty of Medicine, University of Oslo, Oslo, Norway
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Huang X, Kim TY, Koren G, Choi BR, Qu Z. Spontaneous initiation of premature ventricular complexes and arrhythmias in type 2 long QT syndrome. Am J Physiol Heart Circ Physiol 2016; 311:H1470-H1484. [PMID: 27765749 DOI: 10.1152/ajpheart.00500.2016] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 10/03/2016] [Indexed: 02/07/2023]
Abstract
The occurrence of early afterdepolarizations (EADs) and increased dispersion of repolarization are two known factors for arrhythmogenesis in long QT syndrome. However, increased dispersion of repolarization tends to suppress EADs due to the source-sink effect, and thus how the two competing factors cause initiation of arrhythmias remains incompletely understood. Here we used optical mapping and computer simulation to investigate the mechanisms underlying spontaneous initiation of arrhythmias in type 2 long QT (LQT2) syndrome. In optical mapping experiments of transgenic LQT2 rabbit hearts under isoproterenol, premature ventricular complexes (PVCs) were observed to originate from the steep spatial repolarization gradient (RG) regions and propagated unidirectionally. The same PVC behaviors were demonstrated in computer simulations of tissue models of rabbits. Depending on the heterogeneities, these PVCs could lead to either repetitive focal excitations or reentry without requiring an additional vulnerable substrate. Systematic simulations showed that cellular phase 2 EADs were either suppressed or confined to the long action potential region due to the source-sink effect. Tissue-scale phase 3 EADs and PVCs occurred due to tissue-scale dynamical instabilities caused by RG and enhanced L-type calcium current (ICa,L), occurring under both large and small RG. Presence of cellular EADs was not required but potentiated PVCs when RG was small. We also investigated how other factors affect the dynamical instabilities causing PVCs. Our main conclusion is that tissue-scale dynamical instabilities caused by RG and enhanced ICa,L give rise to both the trigger and the vulnerable substrate simultaneously for spontaneous initiation of arrhythmias in LQT2 syndrome.
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Affiliation(s)
- Xiaodong Huang
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, California.,Department of Physics, South China University of Technology, Guangzhou, China; and
| | - Tae Yun Kim
- Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Gideon Koren
- Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Bum-Rak Choi
- Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Zhilin Qu
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, California; .,Department of Biomathematics, David Geffen School of Medicine, University of California, Los Angeles, California
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Hofman N, Wilde AAM. Role of Genetic Testing in Patients with Ventricular Arrhythmias in Apparently Normal Hearts. Card Electrophysiol Clin 2016; 8:515-523. [PMID: 27521086 DOI: 10.1016/j.ccep.2016.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Ventricular arrhythmias without structural heart disease are responsible for ∼35% of patients who have sudden cardiac death before the age of 40 years. Molecular autopsy and/or cardiological investigation of nearby family members often reveals the diagnosis and genetic testing can be helpful in family screening and risk stratification in disease carriers. Extended gene panels can be screened in a short period of time at low cost. A multidisciplinary team of (genetically) specialized clinicians is necessary to judge all the available details and to decide on the significance of the variant and further strategies.
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Affiliation(s)
- Nynke Hofman
- Department of Clinical Genetics, Academic Medical Center, M0-229, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands
| | - Arthur A M Wilde
- Department of Cardiology, Academic Medical Center, B2-239, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands.
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Samol A, Gönes M, Zumhagen S, Bruns HJ, Paul M, Vahlhaus C, Waltenberger J, Schulze-Bahr E, Eckardt L, Mönnig G. Improved Clinical Risk Stratification in Patients with Long QT Syndrome? Novel Insights from Multi-Channel ECGs. PLoS One 2016; 11:e0158085. [PMID: 27379800 PMCID: PMC4933388 DOI: 10.1371/journal.pone.0158085] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 06/09/2016] [Indexed: 11/19/2022] Open
Abstract
Background We investigated whether multichannel ECG-recordings are useful to risk-stratify patients with congenital long-QT syndrome (LQTS) for risk of sudden cardiac death under optimized medical treatment. Methods In 34 LQTS-patients (11 male; age 31±13 years, QTc 478±51ms; LQT1 n = 8, LQT2 n = 15) we performed a standard 12-channel ECG and a 120-channel body surface potential mapping. The occurrence of clinical events (CE; syncope, torsade de pointes (TdP), sudden cardiac arrest (SCA)) was documented and correlated with different ECG-parameters in all lead positions. Results Seven patients developed TdP, four survived SCA and 12 experienced syncope. 12/34 had at least one CE. CE was associated with a longer QTc-interval (519±43ms vs. 458±42ms; p = 0.001), a lower T-wave integral (TWI) on the left upper chest (-1.2±74.4mV*ms vs. 63.0±29.7mV*ms; p = 0.001), a lower range of T-wave amplitude (TWA) in the region of chest lead V8 (0.10±0.08mV vs. 0.18±0.07mV; p = 0.008) and a longer T-peak-T-end time (TpTe) in lead V1 (98±23ms vs. 78±26ms; p = 0.04). Receiver-operating-characteristic (ROC) analyses revealed a sensitivity of 96% and a specificity of 75% (area under curve (AUC) 0.89±0.06, p = 0.001) at a cut-off value of 26.8mV*ms for prediction of CE by TWI, a sensitivity of 86% and a specificity of 83% at a cut-off value of 0.11mV (AUC 0.83±0.09, p = 0.002) for prediction of CE by TWA and a sensitivity of 83% and a specificity of 73% at a cut-off value of 87ms (AUC 0.80±0.07, p = 0.005) for prediction of CE by TpTe. Conclusions Occurrence of CE in LQTS-patients seems to be associated with a prolonged, low-amplitude T-wave.
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Affiliation(s)
- Alexander Samol
- Division of Cardiology, Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
- * E-mail:
| | - Mehmet Gönes
- Division of Electrophysiology, Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Sven Zumhagen
- Division of Electrophysiology, Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Hans-Jürgen Bruns
- Division of Cardiology, Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Matthias Paul
- Division of Cardiology, Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Christian Vahlhaus
- Division of Cardiology, Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Johannes Waltenberger
- Division of Cardiology, Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Eric Schulze-Bahr
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Lars Eckardt
- Division of Electrophysiology, Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
| | - Gerold Mönnig
- Division of Electrophysiology, Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany
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Hayashi K, Konno T, Fujino N, Itoh H, Fujii Y, Imi-Hashida Y, Tada H, Tsuda T, Tanaka Y, Saito T, Ino H, Kawashiri MA, Ohta K, Horie M, Yamagishi M. Impact of Updated Diagnostic Criteria for Long QT Syndrome on Clinical Detection of Diseased Patients: Results From a Study of Patients Carrying Gene Mutations. JACC Clin Electrophysiol 2016; 2:279-287. [PMID: 29766885 DOI: 10.1016/j.jacep.2016.01.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 12/11/2015] [Accepted: 01/07/2016] [Indexed: 01/01/2023]
Abstract
OBJECTIVES In this study, we scored patients with long QT syndrome (LQTS) according to the different Schwartz diagnostic criteria from 1993, 2006, and 2011, and to examine the validation of the criteria in relevance to the frequency of LQTS-related gene mutation. BACKGROUND Although updated diagnostic criteria have been used in clinical settings, few data exist regarding their impact on the diagnosis of LQTS. METHODS We used a cohort of 132 patients who presented with prolonged QTc intervals and/or abnormal clinical history in cardiac screening and who underwent exercise stress testing. LQTS scores of ≥3.5 points according to the 2006 and the 2011 criteria were considered to indicate a high probability of LQTS, as opposed to the 4 points used by the 1993 criteria. The 2011 criteria were updated by adding the evaluation of the recovery phase of exercise. RESULTS The 2011 criteria significantly increased the number of high probability patients (n = 62) compared with the 1993 criteria (n = 32; p = 0.0002) or the 2006 criteria (n = 36; p = 0.0014). The percentage of mutation carriers in those with an intermediate score, which was rather high using the 1993 (53%) and 2006 criteria (53%), was greatly reduced with the 2011 criteria (15%, p = 0.0014 vs. the 1993 criteria, and p = 0.0013 vs. the 2006 criteria). Among 54 mutation carriers, the 1993, the 2006, and the 2011 criteria identified a high probability of carriers in 25 patients (46% sensitivity and 91% specificity), 27 patients (50% sensitivity and 88% specificity), and 48 patients (89% sensitivity and 82% specificity), respectively. CONCLUSIONS The use of the 2011 criteria will facilitate the diagnosis of LQTS and will decrease the number of false negative results.
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Affiliation(s)
- Kenshi Hayashi
- Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | - Tetsuo Konno
- Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | - Noboru Fujino
- Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | - Hideki Itoh
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan
| | - Yusuke Fujii
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan
| | | | - Hayato Tada
- Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | - Toyonobu Tsuda
- Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | - Yoshihiro Tanaka
- Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | - Takekatsu Saito
- Department of Pediatrics, Kanazawa University, Kanazawa, Japan
| | - Hidekazu Ino
- Department of Cardiovascular Medicine, Komatsu Municipal Hospital, Komatsu, Japan
| | - Masa-Aki Kawashiri
- Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
| | - Kunio Ohta
- Department of Pediatrics, Kanazawa University, Kanazawa, Japan
| | - Minoru Horie
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan
| | - Masakazu Yamagishi
- Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan.
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Detta N, Frisso G, Salvatore F. The multi-faceted aspects of the complex cardiac Nav1.5 protein in membrane function and pathophysiology. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015. [PMID: 26209461 DOI: 10.1016/j.bbapap.2015.07.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The aim of this mini-review is to draw together the main concepts and findings that have emerged from recent studies of the cardiac channel protein Nav1.5. This complex protein is encoded by the SCN5A gene that, in its mutated form, is implicated in various diseases, particularly channelopathies, specifically at cardiac tissue level. Here we describe the structural, and functional aspects of Nav1.5 including post-translational modifications in normal conditions, and the main human channelopathies in which this protein may be the cause or trigger. Lastly, we also briefly discuss interacting proteins that are relevant for these channel functions in normal and disease conditions.
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Affiliation(s)
- Nicola Detta
- CEINGE-Biotecnologie Avanzate s.c.ar.l., Naples, Italy
| | - Giulia Frisso
- CEINGE-Biotecnologie Avanzate s.c.ar.l., Naples, Italy; Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università di Napoli Federico II, Naples, Italy
| | - Francesco Salvatore
- CEINGE-Biotecnologie Avanzate s.c.ar.l., Naples, Italy; IRCCS-Fondazione SDN, Naples, Italy.
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Shamsuzzaman AS, Somers VK, Knilans TK, Ackerman MJ, Wang Y, Amin RS. Obstructive Sleep Apnea in Patients with Congenital Long QT Syndrome: Implications for Increased Risk of Sudden Cardiac Death. Sleep 2015; 38:1113-9. [PMID: 26118557 PMCID: PMC4481019 DOI: 10.5665/sleep.4824] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 01/09/2015] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Congenital long QT syndrome (LQTS) is a familial arrhythmogenic cardiac channelopathy characterized by prolonged ventricular repolarization and increased risk of torsades de pointes-mediated syncope, seizures, and sudden cardiac death (SCD). QT prolongation corrected for heart rate (QTc) is an important diagnostic and prognostic feature in LQTS. Obstructive sleep apnea (OSA) has been increasingly implicated in the pathogenesis of cardiovascular disease, including arrhythmias and SCD. We tested the hypothesis that the presence of concomitant OSA in patients with LQTS is associated with increased QT intervals, both during sleep and while awake. METHODS AND RESULTS Polysomnography with simultaneous overnight 12-lead electrocardiography (ECG) was recorded in 54 patients with congenital LQTS and 67 control subjects. OSA was diagnosed as apnea-hypopnea index (AHI) ≥ 5 events/h for adults and AHI > 1 event/h for children. RR and QT intervals were measured from the 12-lead surface ECG. QTc was determined by the Bazett formula. Respiratory disturbance index, AHI, and arousal index were significantly increased in patients with LQTS and with OSA compared to those without OSA and control subjects. QTc during different sleep stages and while awake was also significantly increased in patients with LQTS and OSA compared to those without OSA. Severity of OSA in patients with LQTS was directly associated with the degree of QTc. CONCLUSIONS The presence and severity of obstructive sleep apnea (OSA) in patients with congenital long QT syndrome (LQTS) is associated with increased QT prolongation corrected for heart rate, which is an important biomarker of sudden cardiac death (SCD). Treatment of OSA in LQTS patients may reduce QT prolongation, thus reducing the risk of LQT-triggered SCD.
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Affiliation(s)
- Abu S. Shamsuzzaman
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH
- Department of Medicine, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
| | - Virend K. Somers
- Department of Medicine, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
| | | | - Michael J. Ackerman
- Department of Medicine, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
- Departments of Pediatrics and Molecular Pharmacology and Experimental Therapeutics; Division of Pediatric Cardiology; Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN
| | - Yu Wang
- Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Raouf S. Amin
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH
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Adler A, Viskin S. Syncope in Hereditary Arrhythmogenic Syndromes. Cardiol Clin 2015; 33:433-40. [PMID: 26115829 DOI: 10.1016/j.ccl.2015.04.011] [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] [Indexed: 11/29/2022]
Abstract
Since the discovery of the first mutation causing long QT syndrome (LQTS) in 1995, the field of hereditary arrhythmogenic syndromes has expanded greatly. Today, these syndromes include LQTS, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, and short QT syndrome. There is also evidence suggesting that the newly described malignant early repolarization syndrome also has a genetic cause.
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Affiliation(s)
- Arnon Adler
- Sackler School of Medicine, Tel Aviv Medical Center, Tel Aviv University, Israel
| | - Sami Viskin
- Sackler School of Medicine, Tel Aviv Medical Center, Tel Aviv University, Israel.
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Phan DQ, Silka MJ, Lan YT, Chang RKR. Comparison of formulas for calculation of the corrected QT interval in infants and young children. J Pediatr 2015; 166:960-4.e1-2. [PMID: 25648293 PMCID: PMC4380641 DOI: 10.1016/j.jpeds.2014.12.037] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 10/27/2014] [Accepted: 12/15/2014] [Indexed: 01/08/2023]
Abstract
OBJECTIVE To compare 4 heart rate correction formulas for calculation of the rate corrected QT (QTc) interval among infants and young children. STUDY DESIGN R-R and QT intervals were measured from digital electrocardiograms. QTc were calculated with the Bazett, Fridericia, Hodges, and Framingham formulas. QTc vs R-R graphs were plotted, and slopes of the regression lines compared. Slopes of QTc-R-R regression lines close to zero indicate consistent QT corrections over the range of heart rates. RESULTS We reviewed electrocardiograms from 702 children, with 233 (33%) <1 year of age and 567 (81%) <2 years. The average heart rate was 122 ± 20 bpm (median 121 bpm). The slopes of the QTc-R-R regression lines for the 4 correction formulas were -0.019 (Bazett); 0.1028 (Fridericia); -0.1241 (Hodges); and 0.2748 (Framingham). With the Bazett formula, a QTc >460 ms was 2 SDs above the mean, compared with "prolonged" QTc values of 414, 443, and 353 ms for the Fridericia, Hodges, and Framingham formulas, respectively. CONCLUSIONS The Bazett formula calculated the most consistent QTc; 460 ms is the best threshold for prolonged QTc. The study supports continued use of the Bazett formula for infants and children and differs from the use of the Fridericia correction during clinical trials of new medications.
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Affiliation(s)
- Derek Q. Phan
- Division of Pediatric Cardiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA
| | - Michael J. Silka
- Division of Cardiology, Children’s Hospital Los Angeles, University of Southern California, Los Angeles, CA
| | - Yueh-Tze Lan
- Division of Pediatric Cardiology, Santa Clara Valley Medical Center, San Jose, CA
| | - Ruey-Kang R. Chang
- Division of Pediatric Cardiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA
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Kim TY, Kunitomo Y, Pfeiffer Z, Patel D, Hwang J, Harrison K, Patel B, Jeng P, Ziv O, Lu Y, Peng X, Qu Z, Koren G, Choi BR. Complex excitation dynamics underlie polymorphic ventricular tachycardia in a transgenic rabbit model of long QT syndrome type 1. Heart Rhythm 2015; 12:220-8. [PMID: 25285647 PMCID: PMC4277941 DOI: 10.1016/j.hrthm.2014.10.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND Long QT syndrome type 1 (LQT1) is a congenital disease arising from a loss of function in the slowly activating delayed potassium current IKs, which causes early afterdepolarizations (EADs) and polymorphic ventricular tachycardia (pVT). OBJECTIVE The purpose of this study was to investigate the mechanisms underlying pVT using a transgenic rabbit model of LQT1. METHODS Hearts were perfused retrogradely, and action potentials were recorded using a voltage-sensitive dye and CMOS cameras. RESULTS Bolus injection of isoproterenol (140 nM) induced pVT initiated by focal excitations from the right ventricle (RV; n = 16 of 18 pVTs). After the pVT was initiated, complex focal excitations occurred in both the RV and the left ventricle, which caused oscillations of the QRS complexes on ECG, consistent with the recent proposal of multiple shifting foci caused by EAD chaos. Moreover, the action potential upstroke in pVT showed a bimodal distribution, demonstrating the coexistence of 2 types of excitation that interacted to produce complex pVT: Na(+) current (INa)-mediated fast conduction and L-type Ca(2+) current (ICa)-mediated slow conduction coexist, manifesting as pVT. Addition of 2 μM tetrodotoxin to reduce INa converted pVT into monomorphic VT. Reducing late INa in computer simulation converted pVT into a single dominant reentry, agreeing with experimental results. CONCLUSION Our study demonstrates that pVT in LQT1 rabbits is initiated by focal excitations from the RV and is maintained by multiple shifting foci in both ventricles. Moreover, wave conduction in pVT exhibits bi-excitability, that is, fast wavefronts driven by INa and slow wavefronts driven by ICa co-exist during pVT.
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Affiliation(s)
- Tae Yun Kim
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Yukiko Kunitomo
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Zachary Pfeiffer
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Divyang Patel
- Cardiovascular Institutes, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jungmin Hwang
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island; Department of Pharmacology, University of Rhode Island, Kingston, Rhode Island
| | - Kathryn Harrison
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Brijesh Patel
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Paul Jeng
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Ohad Ziv
- Case Western Reserve University, School of Medicine, Cleveland, Ohio
| | - Yichun Lu
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Xuwen Peng
- Department of Comparative Medicine, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Zhilin Qu
- Department of Medicine, University of California, Los Angeles, California
| | - Gideon Koren
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Bum-Rak Choi
- Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island.
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50
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Barsheshet A, Dotsenko O, Goldenberg I. Congenital long QT syndromes: prevalence, pathophysiology and management. Paediatr Drugs 2014; 16:447-56. [PMID: 25288402 DOI: 10.1007/s40272-014-0090-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Long QT syndrome is a genetic disorder associated with life threatening ventricular arrhythmias and sudden death. This inherited arrhythmic disorder exhibits genetic heterogeneity, incomplete penetrance, and variable expressivity. During the past two decades there have been major advancements in understanding the genotype-phenotype correlations in LQTS. This genotype-phenotype relationship can lead to improved management of LQTS. However, development of genotype-specific or mutation-specific management strategies is very challenging. This review describes the pathophysiology of LQTS, genotype-phenotype correlations, and focuses on the management of LQTS. In general, the treatment of LQTS consists of lifestyle modifications, medical therapy with beta-blockers, device and surgical therapy. We further summarize current data on the efficacy of pharmacological treatment options for the three most prevalent LQTS variants including beta-blockers in LQT1, LQT2 and LQT3, sodium channel blockers and ranolazine for LQT3, potassium supplementation and spironolactone for LQT2, and possibly sex hormone-based therapy for LQT2.
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Affiliation(s)
- Alon Barsheshet
- Cardiology Department, Rabin Medical Center, Petach Tikva, Israel
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