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Jiang R, Cheung CC, Garcia-Montero M, Davies B, Cao J, Redfearn D, Laksman ZM, Grondin S, Atallah J, Escudero CA, Cadrin-Tourigny J, Sanatani S, Steinberg C, Joza J, Avram R, Tadros R, Krahn AD. Deep Learning-Augmented ECG Analysis for Screening and Genotype Prediction of Congenital Long QT Syndrome. JAMA Cardiol 2024; 9:377-384. [PMID: 38446445 PMCID: PMC10918571 DOI: 10.1001/jamacardio.2024.0039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 01/07/2024] [Indexed: 03/07/2024]
Abstract
Importance Congenital long QT syndrome (LQTS) is associated with syncope, ventricular arrhythmias, and sudden death. Half of patients with LQTS have a normal or borderline-normal QT interval despite LQTS often being detected by QT prolongation on resting electrocardiography (ECG). Objective To develop a deep learning-based neural network for identification of LQTS and differentiation of genotypes (LQTS1 and LQTS2) using 12-lead ECG. Design, Setting, and Participants This diagnostic accuracy study used ECGs from patients with suspected inherited arrhythmia enrolled in the Hearts in Rhythm Organization Registry (HiRO) from August 2012 to December 2021. The internal dataset was derived at 2 sites and an external validation dataset at 4 sites within the HiRO Registry; an additional cross-sectional validation dataset was from the Montreal Heart Institute. The cohort with LQTS included probands and relatives with pathogenic or likely pathogenic variants in KCNQ1 or KCNH2 genes with normal or prolonged corrected QT (QTc) intervals. Exposures Convolutional neural network (CNN) discrimination between LQTS1, LQTS2, and negative genetic test results. Main Outcomes and Measures The main outcomes were area under the curve (AUC), F1 scores, and sensitivity for detecting LQTS and differentiating genotypes using a CNN method compared with QTc-based detection. Results A total of 4521 ECGs from 990 patients (mean [SD] age, 42 [18] years; 589 [59.5%] female) were analyzed. External validation within the national registry (101 patients) demonstrated the CNN's high diagnostic capacity for LQTS detection (AUC, 0.93; 95% CI, 0.89-0.96) and genotype differentiation (AUC, 0.91; 95% CI, 0.86-0.96). This surpassed expert-measured QTc intervals in detecting LQTS (F1 score, 0.84 [95% CI, 0.78-0.90] vs 0.22 [95% CI, 0.13-0.31]; sensitivity, 0.90 [95% CI, 0.86-0.94] vs 0.36 [95% CI, 0.23-0.47]), including in patients with normal or borderline QTc intervals (F1 score, 0.70 [95% CI, 0.40-1.00]; sensitivity, 0.78 [95% CI, 0.53-0.95]). In further validation in a cross-sectional cohort (406 patients) of high-risk patients and genotype-negative controls, the CNN detected LQTS with an AUC of 0.81 (95% CI, 0.80-0.85), which was better than QTc interval-based detection (AUC, 0.74; 95% CI, 0.69-0.78). Conclusions and Relevance The deep learning model improved detection of congenital LQTS from resting ECGs and allowed for differentiation between the 2 most common genetic subtypes. Broader validation over an unselected general population may support application of this model to patients with suspected LQTS.
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Affiliation(s)
- River Jiang
- Center for Cardiovascular Innovation, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Marta Garcia-Montero
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Brianna Davies
- Center for Cardiovascular Innovation, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jason Cao
- Center for Cardiovascular Innovation, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Damian Redfearn
- Division of Cardiology, Queen’s University, Kingston, Ontario, Canada
| | - Zachary M. Laksman
- Center for Cardiovascular Innovation, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Steffany Grondin
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Joseph Atallah
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | | | - Julia Cadrin-Tourigny
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Shubhayan Sanatani
- Children’s Heart Centre, BC Children’s Hospital, Vancouver, British Columbia, Canada
| | - Christian Steinberg
- Institut Universitaire de Cardiologie et Pneumologie de Quebec, Laval University, Quebec City, Quebec, Canada
| | - Jacqueline Joza
- Division of Cardiology, McGill University Health Centre, Montreal, Quebec, Canada
| | - Robert Avram
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Rafik Tadros
- Montreal Heart Institute, Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Andrew D. Krahn
- Center for Cardiovascular Innovation, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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2
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Suna G, Mellor GJ. Explaining the Unexplained: A Practical Approach to Investigating the Cardiac Arrest Survivor. Arrhythm Electrophysiol Rev 2023; 12:e27. [PMID: 38124802 PMCID: PMC10731537 DOI: 10.15420/aer.2023.06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 10/12/2023] [Indexed: 12/23/2023] Open
Abstract
Sudden cardiac arrest (SCA) is a common cause of death. The majority of SCA is caused by ventricular arrhythmia due to underlying CHD. Aborted SCA with no apparent diagnosis after initial assessment with ECG, echocardiography and coronary assessment is referred to as unexplained cardiac arrest (UCA). Systematic evaluation of such patients may reveal a specific diagnosis in up to half of patients before a diagnosis of idiopathic VF is assigned. Specific diagnoses include inherited cardiac conditions, such as latent cardiomyopathies or inherited primary electrical disease. Identifying the cause of UCA is therefore not only critical for appropriate management of the SCA survivors to prevent recurrence, but also for their family members who may be at risk of the same condition. This review provides a tiered, systematic approach for the investigation of UCA.
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Affiliation(s)
- Gonca Suna
- Cardiology Department, Royal Papworth Hospital NHS Foundation Trust Cambridge, UK
| | - Greg J Mellor
- Cardiology Department, Royal Papworth Hospital NHS Foundation Trust Cambridge, UK
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3
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Abrahams T, Davies B, Laksman Z, Sy RW, Postema PG, Wilde AAM, Krahn AD, Han HC. Provocation testing in congenital long QT syndrome: A practical guide. Heart Rhythm 2023; 20:1570-1582. [PMID: 37481219 DOI: 10.1016/j.hrthm.2023.07.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/01/2023] [Accepted: 07/14/2023] [Indexed: 07/24/2023]
Abstract
Congenital long QT syndrome (LQTS) is a hereditary cardiac channelopathy with an estimated prevalence of 1 in 2500. A prolonged resting QT interval corrected for heart rate (QTc interval) remains a key diagnostic component; however, the QTc value may be normal in up to 40% of patients with genotype-positive LQTS and borderline in a further 30%. Provocation of QTc prolongation and T-wave changes may be pivotal to unmasking the diagnosis and useful in predicting genotype. LQTS provocation testing involves assessment of repolarization during and after exercise, in response to changes in heart rate or autonomic tone, with patients with LQTS exhibiting a maladaptive repolarization response. We review the utility and strengths and limitations of 4 forms of provocation testing-stand-up test, exercise stress test, epinephrine challenge, and mental stress test-in diagnosing LQTS and provide some practical guidance for performing provocation testing. Ultimately, exercise testing, when feasible, is the most useful form of provocation testing when considering diagnostic sensitivity and specificity.
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Affiliation(s)
- Timothy Abrahams
- Victorian Heart Institute & Monash Health Heart, Victorian Heart Hospital, Monash University, Melbourne, Victoria, Australia
| | - Brianna Davies
- Center for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Zachary Laksman
- Center for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Raymond W Sy
- Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Pieter G Postema
- Department of Cardiology, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands; Heart Failure & Arrhythmias, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands; European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart (ERN GUARD-Heart), Academic Medical Center, Amsterdam, The Netherlands
| | - Arthur A M Wilde
- Department of Cardiology, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands; Heart Failure & Arrhythmias, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands; European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart (ERN GUARD-Heart), Academic Medical Center, Amsterdam, The Netherlands
| | - Andrew D Krahn
- Center for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hui-Chen Han
- Victorian Heart Institute & Monash Health Heart, Victorian Heart Hospital, Monash University, Melbourne, Victoria, Australia.
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4
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van Weperen VYH, Ripplinger CM, Vaseghi M. Autonomic control of ventricular function in health and disease: current state of the art. Clin Auton Res 2023; 33:491-517. [PMID: 37166736 PMCID: PMC10173946 DOI: 10.1007/s10286-023-00948-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 04/20/2023] [Indexed: 05/12/2023]
Abstract
PURPOSE Cardiac autonomic dysfunction is one of the main pillars of cardiovascular pathophysiology. The purpose of this review is to provide an overview of the current state of the art on the pathological remodeling that occurs within the autonomic nervous system with cardiac injury and available neuromodulatory therapies for autonomic dysfunction in heart failure. METHODS Data from peer-reviewed publications on autonomic function in health and after cardiac injury are reviewed. The role of and evidence behind various neuromodulatory therapies both in preclinical investigation and in-use in clinical practice are summarized. RESULTS A harmonic interplay between the heart and the autonomic nervous system exists at multiple levels of the neuraxis. This interplay becomes disrupted in the setting of cardiovascular disease, resulting in pathological changes at multiple levels, from subcellular cardiac signaling of neurotransmitters to extra-cardiac, extra-thoracic remodeling. The subsequent detrimental cycle of sympathovagal imbalance, characterized by sympathoexcitation and parasympathetic withdrawal, predisposes to ventricular arrhythmias, progression of heart failure, and cardiac mortality. Knowledge on the etiology and pathophysiology of this condition has increased exponentially over the past few decades, resulting in a number of different neuromodulatory approaches. However, significant knowledge gaps in both sympathetic and parasympathetic interactions and causal factors that mediate progressive sympathoexcitation and parasympathetic dysfunction remain. CONCLUSIONS Although our understanding of autonomic imbalance in cardiovascular diseases has significantly increased, specific, pivotal mediators of this imbalance and the recognition and implementation of available autonomic parameters and neuromodulatory therapies are still lagging.
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Affiliation(s)
- Valerie Y H van Weperen
- Division of Cardiology, Department of Medicine, UCLA Cardiac Arrythmia Center, University of California, 100 Medical Plaza, Suite 660, Los Angeles, CA, 90095, USA
| | | | - Marmar Vaseghi
- Division of Cardiology, Department of Medicine, UCLA Cardiac Arrythmia Center, University of California, 100 Medical Plaza, Suite 660, Los Angeles, CA, 90095, USA.
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5
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Wilde AAM, Semsarian C, Márquez MF, Shamloo AS, Ackerman MJ, Ashley EA, Sternick EB, Barajas-Martinez H, Behr ER, Bezzina CR, Breckpot J, Charron P, Chockalingam P, Crotti L, Gollob MH, Lubitz S, Makita N, Ohno S, Ortiz-Genga M, Sacilotto L, Schulze-Bahr E, Shimizu W, Sotoodehnia N, Tadros R, Ware JS, Winlaw DS, Kaufman ES. European Heart Rhythm Association (EHRA)/Heart Rhythm Society (HRS)/Asia Pacific Heart Rhythm Society (APHRS)/Latin American Heart Rhythm Society (LAHRS) Expert Consensus Statement on the state of genetic testing for cardiac diseases. Europace 2022; 24:1307-1367. [PMID: 35373836 PMCID: PMC9435643 DOI: 10.1093/europace/euac030] [Citation(s) in RCA: 98] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Arthur A M Wilde
- Heart Centre, Department of Cardiology, Amsterdam Universitair Medische
Centra, Amsterdam, location AMC, The Netherlands
| | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute,
University of Sydney, Sydney, Australia
| | - Manlio F Márquez
- Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de
México, Mexico
- Member of the Latin American Heart Rhythm Society (LAHRS)
| | | | - Michael J Ackerman
- Departments of Cardiovascular Medicine, Pediatric and Adolescent Medicine,
and Molecular Pharmacology & Experimental Therapeutics; Divisions of Heart Rhythm
Services and Pediatric Cardiology; Windland Smith Rice Genetic Heart Rhythm Clinic and
Windland Smith Rice Sudden Death Genomics Laboratory, Mayo
Clinic, Rochester, MN, USA
| | - Euan A Ashley
- Department of Cardiovascular Medicine, Stanford University,
Stanford, California, USA
| | - Eduardo Back Sternick
- Arrhythmia and Electrophysiology Unit, Biocor Institute,
Minas Gerais, Brazil; and
Member of the Latin American Heart Rhythm Society (LAHRS)
| | - Héctor Barajas-Martinez
- Cardiovascular Research, Lankenau Institute of Medical
Research, Wynnewood, PA, USA; and Member of the Latin American Heart Rhythm Society (LAHRS)
| | - Elijah R Behr
- Cardiovascular Clinical Academic Group, Institute of Molecular and Clinical
Sciences, St. George’s, University of London; St. George’s University Hospitals NHS
Foundation Trust, London, UK; Mayo Clinic Healthcare, London
| | - Connie R Bezzina
- Amsterdam UMC Heart Center, Department of Experimental
Cardiology, Amsterdam, The
Netherlands
| | - Jeroen Breckpot
- Center for Human Genetics, University Hospitals Leuven,
Leuven, Belgium
| | - Philippe Charron
- Sorbonne Université, APHP, Centre de Référence des Maladies Cardiaques
Héréditaires, ICAN, Inserm UMR1166, Hôpital
Pitié-Salpêtrière, Paris, France
| | | | - Lia Crotti
- Center for Cardiac Arrhythmias of Genetic Origin,
Istituto Auxologico Italiano, IRCCS, Milan, Italy
- Cardiomyopathy Unit and Cardiac Rehabilitation Unit, San Luca Hospital,
Istituto Auxologico Italiano, IRCCS, Milan,
Italy
- Department of Medicine and Surgery, University of
Milano-Bicocca, Milan, Italy
| | - Michael H Gollob
- Inherited Arrhythmia and Cardiomyopathy Program, Division of Cardiology,
University of Toronto, Toronto, ON, Canada
| | - Steven Lubitz
- Cardiac Arrhythmia Service, Massachusetts General Hospital and Harvard
Medical School, Boston, MA, USA
| | - Naomasa Makita
- National Cerebral and Cardiovascular Center, Research
Institute, Suita, Japan
| | - Seiko Ohno
- Department of Bioscience and Genetics, National Cerebral and Cardiovascular
Center, Suita, Japan
| | - Martín Ortiz-Genga
- Clinical Department, Health in Code, A
Coruña, Spain; and Member of the Latin
American Heart Rhythm Society (LAHRS)
| | - Luciana Sacilotto
- Arrhythmia Unit, Instituto do Coracao, Hospital das Clinicas HCFMUSP,
Faculdade de Medicina, Universidade de Sao Paulo, Sao
Paulo, Brazil; and Member of the Latin
American Heart Rhythm Society (LAHRS)
| | - Eric Schulze-Bahr
- Institute for Genetics of Heart Diseases, University Hospital
Münster, Münster, Germany
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Graduate School of Medicine, Nippon
Medical School, Bunkyo-ku, Tokyo, Japan
| | - Nona Sotoodehnia
- Cardiovascular Health Research Unit, Division of Cardiology, Department of
Medicine, University of Washington, Seattle, WA,
USA
| | - Rafik Tadros
- Cardiovascular Genetics Center, Department of Medicine, Montreal Heart
Institute, Université de Montréal, Montreal,
Canada
| | - James S Ware
- National Heart and Lung Institute and MRC London Institute of Medical
Sciences, Imperial College London, London,
UK
- Royal Brompton & Harefield Hospitals, Guy’s
and St. Thomas’ NHS Foundation Trust, London, UK
| | - David S Winlaw
- Cincinnati Children's Hospital Medical Centre, University of
Cincinnati, Cincinnati, OH, USA
| | - Elizabeth S Kaufman
- Metrohealth Medical Center, Case Western Reserve University,
Cleveland, OH, USA
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6
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Wilde AAM, Semsarian C, Márquez MF, Sepehri Shamloo A, Ackerman MJ, Ashley EA, Sternick Eduardo B, Barajas‐Martinez H, Behr ER, Bezzina CR, Breckpot J, Charron P, Chockalingam P, Crotti L, Gollob MH, Lubitz S, Makita N, Ohno S, Ortiz‐Genga M, Sacilotto L, Schulze‐Bahr E, Shimizu W, Sotoodehnia N, Tadros R, Ware JS, Winlaw DS, Kaufman ES, Aiba T, Bollmann A, Choi J, Dalal A, Darrieux F, Giudicessi J, Guerchicoff M, Hong K, Krahn AD, Mac Intyre C, Mackall JA, Mont L, Napolitano C, Ochoa Juan P, Peichl P, Pereira AC, Schwartz PJ, Skinner J, Stellbrink C, Tfelt‐Hansen J, Deneke T. European Heart Rhythm Association (EHRA)/Heart Rhythm Society (HRS)/Asia Pacific Heart Rhythm Society (APHRS)/Latin American Heart Rhythm Society (LAHRS) Expert Consensus Statement on the state of genetic testing for cardiac diseases. J Arrhythm 2022; 38:491-553. [PMID: 35936045 PMCID: PMC9347209 DOI: 10.1002/joa3.12717] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Arthur A. M. Wilde
- Heart Centre, Department of Cardiology, Amsterdam Universitair Medische CentraAmsterdamThe Netherlands
| | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology at Centenary InstituteUniversity of SydneySydneyAustralia
| | - Manlio F. Márquez
- Instituto Nacional de Cardiología Ignacio ChávezCiudad de MéxicoMexico
| | | | - Michael J. Ackerman
- Departments of Cardiovascular Medicine, Pediatric and Adolescent Medicine, and Molecular Pharmacology & Experimental Therapeutics; Divisions of Heart Rhythm Services and Pediatric Cardiology; Windland Smith Rice Genetic Heart Rhythm Clinic and Windland Smith Rice Sudden Death Genomics Laboratory, Mayo ClinicRochesterMNUSA
| | - Euan A. Ashley
- Department of Cardiovascular MedicineStanford UniversityStanfordCAUSA
| | | | | | - Elijah R. Behr
- Cardiovascular Clinical Academic Group, Institute of Molecular and Clinical Sciences, St. George’sUniversity of London; St. George’s University Hospitals NHS Foundation TrustLondonUKMayo Clinic HealthcareLondon
| | - Connie R. Bezzina
- Amsterdam UMC Heart Center, Department of Experimental CardiologyAmsterdamThe Netherlands
| | - Jeroen Breckpot
- Center for Human GeneticsUniversity Hospitals LeuvenLeuvenBelgium
| | | | | | - Lia Crotti
- Center for Cardiac Arrhythmias of Genetic Origin, Istituto Auxologico Italiano, IRCCSMilanItaly
- Cardiomyopathy Unit and Cardiac Rehabilitation Unit, San Luca Hospital, Istituto Auxologico Italiano, IRCCSMilanItaly
- Department of Medicine and SurgeryUniversity of Milano‐BicoccaMilanItaly
| | - Michael H. Gollob
- Inherited Arrhythmia and Cardiomyopathy Program, Division of CardiologyUniversity of TorontoTorontoONCanada
| | - Steven Lubitz
- Cardiac Arrhythmia ServiceMassachusetts General Hospital and Harvard Medical SchoolBostonMAUSA
| | - Naomasa Makita
- National Cerebral and Cardiovascular CenterResearch InstituteSuitaJapan
| | - Seiko Ohno
- Department of Bioscience and Genetics, National Cerebral and Cardiovascular CenterSuitaJapan
| | | | - Luciana Sacilotto
- Arrhythmia Unit, Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao PauloBrazil
| | - Eric Schulze‐Bahr
- Institute for Genetics of Heart DiseasesUniversity Hospital MünsterMünsterGermany
| | - Wataru Shimizu
- Department of Cardiovascular MedicineGraduate School of MedicineTokyoJapan
| | - Nona Sotoodehnia
- Cardiovascular Health Research Unit, Division of Cardiology, Department of MedicineUniversity of WashingtonSeattleWAUSA
| | - Rafik Tadros
- Cardiovascular Genetics Center, Department of Medicine, Montreal Heart InstituteUniversité de MontréalMontrealCanada
| | - James S. Ware
- National Heart and Lung Institute and MRC London Institute of Medical SciencesImperial College LondonLondonUK
- Royal Brompton & Harefield Hospitals, Guy’s and St. Thomas’ NHS Foundation TrustLondonUK
| | - David S. Winlaw
- Cincinnati Children's Hospital Medical CentreUniversity of CincinnatiCincinnatiOHUSA
| | | | - Takeshi Aiba
- Department of Clinical Laboratory Medicine and Genetics, National Cerebral and Cardiovascular Center, SuitaOsakaJapan
| | - Andreas Bollmann
- Department of ElectrophysiologyHeart Center Leipzig at University of LeipzigLeipzigGermany
- Leipzig Heart InstituteLeipzigGermany
| | - Jong‐Il Choi
- Division of Cardiology, Department of Internal Medicine, Korea University Anam HospitalKorea University College of MedicineSeoulRepublic of Korea
| | - Aarti Dalal
- Department of Pediatrics, Division of CardiologyVanderbilt University School of MedicineNashvilleTNUSA
| | - Francisco Darrieux
- Arrhythmia Unit, Instituto do Coração, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São PauloSão PauloBrazil
| | - John Giudicessi
- Department of Cardiovascular Medicine (Divisions of Heart Rhythm Services and Circulatory Failure and the Windland Smith Rice Genetic Heart Rhythm Clinic), Mayo ClinicRochesterMNUSA
| | - Mariana Guerchicoff
- Division of Pediatric Arrhythmia and Electrophysiology, Italian Hospital of Buenos AiresBuenos AiresArgentina
| | - Kui Hong
- Department of Cardiovascular MedicineThe Second Affiliated Hospital of Nanchang UniversityNanchangChina
| | - Andrew D. Krahn
- Division of CardiologyUniversity of British ColumbiaVancouverCanada
| | - Ciorsti Mac Intyre
- Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo ClinicRochesterMNUSA
| | - Judith A. Mackall
- Center for Cardiac Electrophysiology and Pacing, University Hospitals Cleveland Medical CenterCase Western Reserve University School of MedicineClevelandOHUSA
| | - Lluís Mont
- Institut d’Investigacions Biomèdiques August Pi Sunyer (IDIBAPS). Barcelona, Spain; Centro de Investigacion Biomedica en Red en Enfermedades Cardiovasculares (CIBERCV), MadridSpain
| | - Carlo Napolitano
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCSPaviaItaly
- Department of Molecular MedicineUniversity of PaviaPaviaItaly
| | - Pablo Ochoa Juan
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), MadridSpain
- Heart Failure and Inherited Cardiac Diseases Unit, Department of Cardiology, Hospital Universitario Puerta de HierroMadridSpain
- Centro de Investigacion Biomedica en Red en Enfermedades Cariovasculares (CIBERCV), MadridSpain
| | - Petr Peichl
- Department of CardiologyInstitute for Clinical and Experimental MedicinePragueCzech Republic
| | - Alexandre C. Pereira
- Laboratory of Genetics and Molecular Cardiology, Heart InstituteUniversity of São Paulo Medical SchoolSão PauloBrazil
- Hipercol Brasil ProgramSão PauloBrazil
| | - Peter J. Schwartz
- Center for Cardiac Arrhythmias of Genetic Origin, Istituto Auxologico Italiano, IRCCSMilanItaly
| | - Jon Skinner
- Sydney Childrens Hospital NetworkUniversity of SydneySydneyAustralia
| | - Christoph Stellbrink
- Department of Cardiology and Intensive Care MedicineUniversity Hospital Campus Klinikum BielefeldBielefeldGermany
| | - Jacob Tfelt‐Hansen
- The Department of Cardiology, the Heart Centre, Copenhagen University Hospital, Rigshopitalet, Copenhagen, Denmark; Section of genetics, Department of Forensic Medicine, Faculty of Medical SciencesUniversity of CopenhagenDenmark
| | - Thomas Deneke
- Heart Center Bad NeustadtBad Neustadt a.d. SaaleGermany
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7
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Yang Y, Lv T, Li S, Liu P, Gao Q, Zhang P. Utility of Provocative Testing in the Diagnosis and Genotyping of Congenital Long QT Syndrome: A Systematic Review and Meta-Analysis. J Am Heart Assoc 2022; 11:e025246. [PMID: 35861842 PMCID: PMC9707831 DOI: 10.1161/jaha.122.025246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 04/27/2022] [Indexed: 11/16/2022]
Abstract
Background Diagnosis is particularly challenging in concealed or asymptomatic long QT syndrome (LQTS). Provocative testing, unmasking the characterization of LQTS, is a promising alternative method for the diagnosis of LQTS, but without uniform standards. Methods and Results A comprehensive search was conducted in PubMed, Embase, and the Cochrane Library through October 14, 2021. The fixed effects model was used to assess the effect of the provocative testing on QTc interval. A total of 22 studies with 1137 patients with LQTS were included. At baseline, QTc interval was 40 ms longer in patients with LQTS than in controls (mean difference [MD], 40.54 [95% CI, 37.43-43.65]; P<0.001). Compared with the control group, patients with LQTS had 28 ms longer ΔQTc upon standing (MD, 28.82 [95% CI, 23.05-34.58]; P<0.001), nearly 30 ms longer both at peak exercise (MD, 27.31 [95% CI, 21.51-33.11]; P<0.001) and recovery 4 to 5 minutes (MD, 29.85 [95% CI, 24.36-35.35]; P<0.001). With epinephrine infusion, QTc interval was prolonged both in controls and patients with QTS, most obviously in LQT1 (MD, 68.26 [95% CI, 58.91-77.60]; P<0.001) and LQT2 (MD, 60.17 [95% CI, 50.18-70.16]; P<0.001). Subgroup analysis showed QTc interval response to abrupt stand testing and exercise testing varied between LQT1, LQT2, and LQT3, named Type Ⅰ, Type Ⅱ, and Type Ⅲ. Conclusions QTc trend Type Ⅰ and Type Ⅲ during abrupt stand testing and exercise testing can be used to propose a prospective evaluation of LQT1 and LQT3, respectively. Type Ⅱ QTc trend combined epinephrine infusion testing could distinguish LQT2 from control. A preliminary diagnostic workflow was proposed but deserves further evaluation.
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Affiliation(s)
- Ying Yang
- School of Clinical MedicineTsinghua UniversityBeijingChina
| | - Ting‐ting Lv
- Department of CardiologySchool of Clinical MedicineBeijing Tsinghua Changgung HospitalTsinghua UniversityBeijingChina
| | - Si‐yuan Li
- Department of CardiologySchool of Clinical MedicineBeijing Tsinghua Changgung HospitalTsinghua UniversityBeijingChina
| | - Peng Liu
- School of Clinical MedicineTsinghua UniversityBeijingChina
| | - Qing‐gele Gao
- School of Clinical MedicineTsinghua UniversityBeijingChina
| | - Ping Zhang
- School of Clinical MedicineTsinghua UniversityBeijingChina
- Department of CardiologySchool of Clinical MedicineBeijing Tsinghua Changgung HospitalTsinghua UniversityBeijingChina
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8
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Wilde AAM, Semsarian C, Márquez MF, Sepehri Shamloo A, Ackerman MJ, Ashley EA, Sternick EB, Barajas-Martinez H, Behr ER, Bezzina CR, Breckpot J, Charron P, Chockalingam P, Crotti L, Gollob MH, Lubitz S, Makita N, Ohno S, Ortiz-Genga M, Sacilotto L, Schulze-Bahr E, Shimizu W, Sotoodehnia N, Tadros R, Ware JS, Winlaw DS, Kaufman ES, Aiba T, Bollmann A, Choi JI, Dalal A, Darrieux F, Giudicessi J, Guerchicoff M, Hong K, Krahn AD, MacIntyre C, Mackall JA, Mont L, Napolitano C, Ochoa JP, Peichl P, Pereira AC, Schwartz PJ, Skinner J, Stellbrink C, Tfelt-Hansen J, Deneke T. European Heart Rhythm Association (EHRA)/Heart Rhythm Society (HRS)/Asia Pacific Heart Rhythm Society (APHRS)/Latin American Heart Rhythm Society (LAHRS) Expert Consensus Statement on the State of Genetic Testing for Cardiac Diseases. Heart Rhythm 2022; 19:e1-e60. [PMID: 35390533 DOI: 10.1016/j.hrthm.2022.03.1225] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 03/25/2022] [Indexed: 12/12/2022]
Affiliation(s)
- Arthur A M Wilde
- Heart Centre, Department of Cardiology, Amsterdam Universitair Medische Centra, Amsterdam, location AMC, The Netherlands.
| | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, University of Sydney, Sydney, Australia.
| | - Manlio F Márquez
- Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, Mexico; and Member of the Latin American Heart Rhythm Society (LAHRS).
| | | | - Michael J Ackerman
- Departments of Cardiovascular Medicine, Pediatric and Adolescent Medicine, and Molecular Pharmacology & Experimental Therapeutics; Divisions of Heart Rhythm Services and Pediatric Cardiology; Windland Smith Rice Genetic Heart Rhythm Clinic and Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN, USA
| | - Euan A Ashley
- Department of Cardiovascular Medicine, Stanford University, Stanford, CA, USA
| | - Eduardo Back Sternick
- Arrhythmia and Electrophysiology Unit, Biocor Institute, Minas Gerais, Brazil; and Member of the Latin American Heart Rhythm Society (LAHRS)
| | | | - Elijah R Behr
- Cardiovascular Clinical Academic Group, Institute of Molecular and Clinical Sciences, St. George's, University of London; St. George's University Hospitals NHS Foundation Trust, London, UK; Mayo Clinic Healthcare, London
| | - Connie R Bezzina
- Amsterdam UMC Heart Center, Department of Experimental Cardiology, Amsterdam, The Netherlands
| | - Jeroen Breckpot
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Philippe Charron
- Sorbonne Université, APHP, Centre de Référence des Maladies Cardiaques Héréditaires, ICAN, Inserm UMR1166, Hôpital Pitié-Salpêtrière, Paris, France
| | | | - Lia Crotti
- Center for Cardiac Arrhythmias of Genetic Origin, Istituto Auxologico Italiano, IRCCS, Milan, Italy; Cardiomyopathy Unit and Cardiac Rehabilitation Unit, San Luca Hospital, Istituto Auxologico Italiano, IRCCS, Milan, Italy; Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
| | - Michael H Gollob
- Inherited Arrhythmia and Cardiomyopathy Program, Division of Cardiology, University of Toronto, Toronto, ON, Canada
| | - Steven Lubitz
- Cardiac Arrhythmia Service, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Naomasa Makita
- National Cerebral and Cardiovascular Center, Research Institute, Suita, Japan
| | - Seiko Ohno
- Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Martín Ortiz-Genga
- Clinical Department, Health in Code, A Coruña, Spain; and Member of the Latin American Heart Rhythm Society (LAHRS)
| | - Luciana Sacilotto
- Arrhythmia Unit, Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil; and Member of the Latin American Heart Rhythm Society (LAHRS)
| | - Eric Schulze-Bahr
- Institute for Genetics of Heart Diseases, University Hospital Münster, Münster, Germany
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Graduate School of Medicine, Nippon Medical School, Bunkyo-ku, Tokyo, Japan
| | - Nona Sotoodehnia
- Cardiovascular Health Research Unit, Division of Cardiology, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Rafik Tadros
- Cardiovascular Genetics Center, Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, Canada
| | - James S Ware
- National Heart and Lung Institute and MRC London Institute of Medical Sciences, Imperial College London, London, UK; Royal Brompton & Harefield Hospitals, Guy's and St. Thomas' NHS Foundation Trust, London, UK
| | - David S Winlaw
- Cincinnati Children's Hospital Medical Centre, University of Cincinnati, Cincinnati, OH, USA
| | - Elizabeth S Kaufman
- Metrohealth Medical Center, Case Western Reserve University, Cleveland, OH, USA.
| | - Takeshi Aiba
- Department of Clinical Laboratory Medicine and Genetics, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - Andreas Bollmann
- Department of Electrophysiology, Heart Center Leipzig at University of Leipzig, Leipzig, Germany; Leipzig Heart Institute, Leipzig Heart Digital, Leipzig, Germany
| | - Jong-Il Choi
- Division of Cardiology, Department of Internal Medicine, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Republic of Korea
| | - Aarti Dalal
- Department of Pediatrics, Division of Cardiology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Francisco Darrieux
- Arrhythmia Unit, Instituto do Coração, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - John Giudicessi
- Department of Cardiovascular Medicine (Divisions of Heart Rhythm Services and Circulatory Failure and the Windland Smith Rice Genetic Heart Rhythm Clinic), Mayo Clinic, Rochester, MN, USA
| | - Mariana Guerchicoff
- Division of Pediatric Arrhythmia and Electrophysiology, Italian Hospital of Buenos Aires, Buenos Aires, Argentina
| | - Kui Hong
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Andrew D Krahn
- Division of Cardiology, University of British Columbia, Vancouver, Canada
| | - Ciorsti MacIntyre
- Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, MN, USA
| | - Judith A Mackall
- Center for Cardiac Electrophysiology and Pacing, University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Lluís Mont
- Institut d'Investigacions Biomèdiques August Pi Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigacion Biomedica en Red en Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Carlo Napolitano
- Molecular Cardiology, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy; Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Juan Pablo Ochoa
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain; Heart Failure and Inherited Cardiac Diseases Unit, Department of Cardiology, Hospital Universitario Puerta de Hierro, Madrid, Spain; Centro de Investigacion Biomedica en Red en Enfermedades Cariovasculares (CIBERCV), Madrid, Spain
| | - Petr Peichl
- Department of Cardiology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Alexandre C Pereira
- Laboratory of Genetics and Molecular Cardiology, Heart Institute, University of São Paulo Medical School, São Paulo 05403-000, Brazil; Hipercol Brasil Program, São Paulo, Brazil
| | - Peter J Schwartz
- Center for Cardiac Arrhythmias of Genetic Origin, Istituto Auxologico Italiano, IRCCS, Milan, Italy
| | - Jon Skinner
- Sydney Childrens Hospital Network, University of Sydney, Sydney, Australia
| | - Christoph Stellbrink
- Department of Cardiology and Intensive Care Medicine, University Hospital Campus Klinikum Bielefeld, Bielefeld, Germany
| | - Jacob Tfelt-Hansen
- The Department of Cardiology, the Heart Centre, Copenhagen University Hospital, Rigshopitalet, Copenhagen, Denmark; Section of Genetics, Department of Forensic Medicine, Faculty of Medical Sciences, University of Copenhagen, Denmark
| | - Thomas Deneke
- Heart Center Bad Neustadt, Bad Neustadt a.d. Saale, Germany
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9
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Krahn AD, Laksman Z, Sy RW, Postema PG, Ackerman MJ, Wilde AAM, Han HC. Congenital Long QT Syndrome. JACC Clin Electrophysiol 2022; 8:687-706. [PMID: 35589186 DOI: 10.1016/j.jacep.2022.02.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 02/16/2022] [Accepted: 02/16/2022] [Indexed: 12/14/2022]
Abstract
Congenital long QT syndrome (LQTS) encompasses a group of heritable conditions that are associated with cardiac repolarization dysfunction. Since its initial description in 1957, our understanding of LQTS has increased dramatically. The prevalence of LQTS is estimated to be ∼1:2,000, with a slight female predominance. The diagnosis of LQTS is based on clinical, electrocardiogram, and genetic factors. Risk stratification of patients with LQTS aims to identify those who are at increased risk of cardiac arrest or sudden cardiac death. Factors including age, sex, QTc interval, and genetic background all contribute to current risk stratification paradigms. The management of LQTS involves conservative measures such as the avoidance of QT-prolonging drugs, pharmacologic measures with nonselective β-blockers, and interventional approaches such as device therapy or left cardiac sympathetic denervation. In general, most forms of exercise are considered safe in adequately treated patients, and implantable cardioverter-defibrillator therapy is reserved for those at the highest risk. This review summarizes our current understanding of LQTS and provides clinicians with a practical approach to diagnosis and management.
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Affiliation(s)
- Andrew D Krahn
- Center for Cardiovascular Innovation, Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, BC, Canada.
| | - Zachary Laksman
- Center for Cardiovascular Innovation, Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, BC, Canada
| | - Raymond W Sy
- Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Pieter G Postema
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Michael J Ackerman
- Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, Minnesota, USA; Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minnesota, USA; Departments of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota, USA
| | - Arthur A M Wilde
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam University Medical Centers, Amsterdam, the Netherlands; European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (ERN GUARD-Heart), Academic University Medical Center, Amsterdam, the Netherlands
| | - Hui-Chen Han
- Center for Cardiovascular Innovation, Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, BC, Canada; Victorian Heart Institute, Monash University, Clayton, VIC, Australia
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10
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Kashiwa A, Hosaka Y, Takahashi K, Ohno S, Wada Y, Makiyama T, Oda H, Horie M. Pueraria mirifica, an estrogenic tropical herb, unveiled the severity of Type 1 LQTS caused by KCNQ1-T587M. J Arrhythm 2021; 37:1114-1116. [PMID: 34386142 PMCID: PMC8339079 DOI: 10.1002/joa3.12576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 05/07/2021] [Accepted: 05/22/2021] [Indexed: 11/09/2022] Open
Abstract
After taking an estrogen-containing supplement derived from a tropical plant Pueraria mirifica, a 24-year-old woman presented marked QT prolongation and repetitive torsade de pointes. The patient was found to carry a heterozygous KCNQ1-T587M mutation. This is the first report on Pueraria mirifica-related acquired long QT syndrome.
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Affiliation(s)
- Asami Kashiwa
- Department of Cardiovascular MedicineKyoto University Graduate School of MedicineKyotoJapan
- Department of Cardiovascular MedicineNiigata City General HospitalNiigataJapan
| | - Yukio Hosaka
- Department of Cardiovascular MedicineNiigata City General HospitalNiigataJapan
| | - Kazuyoshi Takahashi
- Department of Cardiovascular MedicineNiigata City General HospitalNiigataJapan
| | - Seiko Ohno
- Department of Bioscience and GeneticsNational Cerebral and Cardiovascular CenterOsakaJapan
| | - Yuko Wada
- Vanderbilt Center for Arrhythmia Research and TherapeuticsDivision of Clinical PharmacologyDepartment of MedicineVanderbilt University Medical CenterNashvilleTNUSA
- Department of Cardiovascular MedicineShiga University of Medical ScienceShigaJapan
| | - Takeru Makiyama
- Department of Cardiovascular MedicineKyoto University Graduate School of MedicineKyotoJapan
| | - Hirotaka Oda
- Department of Cardiovascular MedicineNiigata City General HospitalNiigataJapan
| | - Minoru Horie
- Department of Cardiovascular MedicineShiga University of Medical ScienceShigaJapan
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11
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Abstract
Long QT syndrome (LQTS) is a cardiovascular disorder characterized by an abnormality in cardiac repolarization leading to a prolonged QT interval and T-wave irregularities on the surface electrocardiogram. It is commonly associated with syncope, seizures, susceptibility to torsades de pointes, and risk for sudden death. LQTS is a rare genetic disorder and a major preventable cause of sudden cardiac death in the young. The availability of therapy for this lethal disease emphasizes the importance of early and accurate diagnosis. Additionally, understanding of the molecular mechanisms underlying LQTS could help to optimize genotype-specific treatments to prevent deaths in LQTS patients. In this review, we briefly summarize current knowledge regarding molecular underpinning of LQTS, in particular focusing on LQT1, LQT2, and LQT3, and discuss novel strategies to study ion channel dysfunction and drug-specific therapies in LQT1, LQT2, and LQT3 syndromes.
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Affiliation(s)
| | - Isabelle Deschênes
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio
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12
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Boulay E, Troncy E, Accardi MV, Pugsley MK, Downey AM, Miraucourt L, Huang H, Menard A, Tan W, Dubuc-Mageau M, Sanfacon A, Guerrier M, Authier S. Confounders and Pharmacological Characterization When Using the QT, JTp, and Tpe Intervals in Beagle Dogs. Int J Toxicol 2020; 39:530-541. [PMID: 33063577 DOI: 10.1177/1091581820954865] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Corrected QT (QTc) interval is an essential proarrhythmic risk biomarker, but recent data have identified limitations to its use. The J to T-peak (JTp) interval is an alternative biomarker for evaluating drug-induced proarrhythmic risk. The aim of this study was to evaluate pharmacological effects using spatial magnitude leads and DII electrocardiogram (ECG) leads and common ECG confounders (ie, stress and body temperature changes) on covariate adjusted QT (QTca), covariate adjusted JTp (JTpca), and covariate adjusted T-peak to T-end (Tpeca) intervals. METHODS Beagle dogs were exposed to body hyper- (42 °C) or hypothermic (33 °C) conditions or were administered epinephrine to assess confounding effects on heart rate corrected QTca, JTpca, and Tpeca intervals. Dofetilide (0.1, 0.3, 1.0 mg/kg), ranolazine (100, 140, 200 mg/kg), and verapamil (7, 15, 30, 43, 62.5 mg/kg) were administered to evaluate pharmacological effects. RESULTS Covariate adjusted QT (slope -12.57 ms/°C) and JTpca (-14.79 ms/°C) were negatively correlated with body temperature but Tpeca was minimally affected. Epinephrine was associated with QTca and JTpca shortening, which could be related to undercorrection in the presence of tachycardia, while minimal effects were observed for Tpeca. There were no significant ECG change following ranolazine administration. Verapamil decreased QTca and JTpca intervals and increased Tpeca, whereas dofetilide increased QTca and JTpca intervals but had inconsistent effects on Tpeca. CONCLUSION Results highlight potential confounders on QTc interval, but also on JTpca and Tpeca intervals in nonclinical studies. These potential confounding effects may be relevant to the interpretation of ECG data obtained from nonclinical drug safety studies with Beagle dogs.
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Affiliation(s)
- Emmanuel Boulay
- Charles River Laboratories, Laval, Quebec, Canada.,70354Faculté de médecine vétérinaire, Université de Montréal, Québec, Canada
| | - Eric Troncy
- 70354Faculté de médecine vétérinaire, Université de Montréal, Québec, Canada
| | | | | | | | | | - Hai Huang
- Charles River Laboratories, Laval, Quebec, Canada
| | | | - Wendy Tan
- 70354Faculté de médecine vétérinaire, Université de Montréal, Québec, Canada
| | | | - Audrey Sanfacon
- 70354Faculté de médecine vétérinaire, Université de Montréal, Québec, Canada
| | - Mireille Guerrier
- 70354Faculté de médecine vétérinaire, Université de Montréal, Québec, Canada
| | - Simon Authier
- Charles River Laboratories, Laval, Quebec, Canada.,70354Faculté de médecine vétérinaire, Université de Montréal, Québec, Canada
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13
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Vasospastic angina and overlapping cardiac disorders in patients resuscitated from cardiac arrest. Heart Vessels 2020; 36:321-329. [PMID: 32990791 DOI: 10.1007/s00380-020-01705-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 09/18/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Vasospastic angina (VSA) reportedly accounts for one form of sudden cardiac arrest (SCA). Intracoronary acetylcholine (ACh) testing is useful for diagnosing VSA although invasive provocation testing after SCA is a clinical challenge. In addition, even if the ACh test is positive, any causal relationship between VSA and SCA is often unclear because patients with VSA may have other underlying cardiac disorders. METHODS A total of 20 patients without overt structural heart disease who had been fully resuscitated from SCA were included. All patients underwent the ACh provocation test and scrutiny such as cardiac computed tomography or magnetic resonance imaging. Patients were followed up for all-cause death or recurrent SCA including appropriate implantable cardioverter defibrillator therapy. RESULTS An ACh provocation test was performed 20 ± 17 days after cardiac arrest. Fifteen out of 20 (75.0%) patients had a positive ACh test and 2 (10.0%) had adverse events such as ventricular tachycardia and transient cardiogenic shock during the test. In patients with a positive ACh test, 6 of 15 (40.0%) patients had other overlapping cardiac disorders such as long QT syndrome, Brugada syndrome, cardiac sarcoidosis, myocarditis, or cardiomyopathy. Long-term prognosis was not different regardless of a positive ACh test or the presence of other cardiac disorders overlapping with VSA. CONCLUSIONS Three-quarters of the patients who had been resuscitated from SCA had a positive ACh test. Further examinations revealed other overlapping cardiac disorders in addition to VSA in 40% of patients with a positive ACh test.
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14
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Takahashi K, Shimizu W, Makita N, Nakayashiro M. Dynamic QT response to cold-water face immersion in long-QT syndrome type 3. Pediatr Int 2020; 62:899-906. [PMID: 32449227 PMCID: PMC7496693 DOI: 10.1111/ped.14319] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 05/03/2020] [Accepted: 05/18/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Abnormal dynamics of QT intervals in response to sympathetic nervous system stimulation are used to diagnose long-QT syndrome (LQTS). We hypothesized that parasympathetic stimulation with cold-water face immersion following exercise would influence QT dynamics in patients with LQTS type 3 (LQT3). METHODS Study participants (n = 42; mean age = 11.2 years) comprised 20 genotyped LQTS children and 22 healthy children. The LQTS group was divided into LQT3 (n = 12) and non-LQT3 (n = 8) subgroups. Provocative testing for assessing QT dynamics comprised a treadmill exercise followed by cold-water face immersion. The QT intervals were automatically measured at rest and during exercise, recovery, and cold-water face immersion. The QT/heart rate (HR) relationship was visualized by plotting beat-to-beat confluence of the data. RESULTS The QT/HR slopes, determined by linear regression analysis, were steeper in the LQTS group than in the control group during exercise and immersion tests: -2.16 ± 0.63 versus -1.21 ± 0.28, P < 0.0001, and -2.02 ± 0.76 vs -0.75 ± 0.24, P < 0.0001, respectively. The LQT3 patients had steeper slopes in the immersion test than did non-LQT3 and control individuals: -2.42 ± 0.52 vs -1.40 ± 0.65, P < 0.0001, and vs -0.75 ± 0.24, P < 0.0001. CONCLUSIONS The QT dynamics of LQT3 patients differ from those of other LQTS subtypes during the post-exercise cold-water face immersion test in this study. Abnormal QT dynamics during the parasympathetic provocative test are concordant with the fact that cardiac events occur when HRs are lower or during sleep in LQT3 patients.
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Affiliation(s)
- Kazuhiro Takahashi
- Department of Pediatric CardiologyOkinawa Nanbu and Children’s Medical CenterOkinawaJapan
| | | | - Naomasa Makita
- National Cerebral and Cardiovascular CenterResearch InstituteOsakaJapan
| | - Mami Nakayashiro
- Department of Pediatric CardiologyOkinawa Nanbu and Children’s Medical CenterOkinawaJapan
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15
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Saadeh K, Shivkumar K, Jeevaratnam K. Targeting the β-adrenergic receptor in the clinical management of congenital long QT syndrome. Ann N Y Acad Sci 2020; 1474:27-46. [PMID: 32901453 DOI: 10.1111/nyas.14425] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/10/2020] [Accepted: 06/09/2020] [Indexed: 01/01/2023]
Abstract
The long QT syndrome (LQTS) is largely treated pharmacologically with β-blockers, despite the role of sympathetic activity in LQTS being poorly understood. Using the trigger-substrate model of cardiac arrhythmias in this review, we amalgamate current experimental and clinical data from both animal and human studies to explain the mechanism of adrenergic stimulation and blockade on LQT arrhythmic risk and hence assess the efficacy of β-adrenoceptor blockade in the management of LQTS. In LQTS1 and LQTS2, sympathetic stimulation increases arrhythmic risk by enhancing early afterdepolarizations and transmural dispersion of repolarization. β-Blockers successfully reduce cardiac events by reducing these triggers and substrates; however, these effects are less marked in LQTS2 compared with LQTS1. In LQTS3, clinical and experimental investigations of the effects of sympathetic stimulation and β-blocker use have produced contradictory findings, resulting in significant clinical uncertainty. We offer explanations for these contradicting results relating to study sample size, the dose of the β-blocker administered associated with its off-target Na+ channel effects, as well as the type of β-blocker used. We conclude that the antiarrhythmic efficacy of β-blockers is a genotype-specific phenomenon, and hence the use of β-blockers in clinical practice should be genotype dependent.
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Affiliation(s)
- Khalil Saadeh
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Centre, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
| | - Kamalan Jeevaratnam
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
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16
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Piccirillo G, Moscucci F, Fabietti M, Parrotta I, Mastropietri F, Di Iorio C, Sabatino T, Crapanzano D, Vespignani G, Mariani MV, Salvi N, Magrì D. Arrhythmic Risk in Elderly Patients Candidates to Transcatheter Aortic Valve Replacement: Predictive Role of Repolarization Temporal Dispersion. Front Physiol 2019; 10:991. [PMID: 31447689 PMCID: PMC6691061 DOI: 10.3389/fphys.2019.00991] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 07/18/2019] [Indexed: 12/30/2022] Open
Abstract
Background/Aim Degenerative aortic valve stenosis (AS) is associated to ventricular arrhythmias and sudden cardiac death, as well as mental stress in specific patients. In such a context, substrate, autonomic imbalance as well as repolarization dispersion abnormalities play an undoubted role. Aim of the study was to evaluate the increase of premature ventricular contractions (PVC) and complex ventricular arrhythmias during mental stress in elderly patients candidate to the transcatheter aortic valve replacement (TAVR). Methods In eighty-one elderly patients with AS we calculated several short-period RR- and QT-derived variables at rest, during controlled breathing and during mild mental stress, the latter being represented by a mini-mental state evaluation (MMSE). Results All the myocardial repolarization dispersion markers worsened during mental stress (p < 0.05). Furthermore, during MMSE, low frequency component of the RR variability increased significantly both as absolute power (LFRR) and normalized units (LFRRN U) (p < 0.05) as well as the low-high frequency ratio (LFRR/HFRR) (p < 0.05). Eventually, twenty-four (30%) and twelve (15%) patients increased significantly PVC and, respectively, complex ventricular arrhythmias during the MMSE administration. At multivariate logistic regression analysis, the standard deviation of QTend (QTesd), obtained at rest, was predictive of increased PVC (odd ratio: 1.54, 95% CI 1.14-2.08; p = 0.005) and complex ventricular arrhythmias (odd ratio: 2.31, 95% CI 1.40-3.83; p = 0.001) during MMSE. The QTesd showed the widest sensitive-specificity area under the curve for the increase of PVC (AUC: 0.699, 95% CI: 0.576-0.822, p < 0.05) and complex ventricular arrhythmias (AUC: 0.801, 95% CI: 0.648-0.954, p < 0.05). Conclusion In elderly with AS ventricular arrhythmias worsened during a simple cognitive assessment, this events being a possible further burden on the outcome of TAVR. QTesd might be useful to identify those patients with the highest risk of ventricular arrhythmias. Whether the TAVR could led to a QTesd reduction and, hence, to a reduction of the arrhythmic burden in this setting of patients is worthy to be investigated.
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Affiliation(s)
- Gianfranco Piccirillo
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Geriatriche, Anestesiologiche e Nefrologiche, Policlinico Umberto I, "La Sapienza" University of Rome, Rome, Italy
| | - Federica Moscucci
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Geriatriche, Anestesiologiche e Nefrologiche, Policlinico Umberto I, "La Sapienza" University of Rome, Rome, Italy
| | - Marcella Fabietti
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Geriatriche, Anestesiologiche e Nefrologiche, Policlinico Umberto I, "La Sapienza" University of Rome, Rome, Italy
| | - Ilaria Parrotta
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Geriatriche, Anestesiologiche e Nefrologiche, Policlinico Umberto I, "La Sapienza" University of Rome, Rome, Italy
| | - Fabiola Mastropietri
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Geriatriche, Anestesiologiche e Nefrologiche, Policlinico Umberto I, "La Sapienza" University of Rome, Rome, Italy
| | - Claudia Di Iorio
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Geriatriche, Anestesiologiche e Nefrologiche, Policlinico Umberto I, "La Sapienza" University of Rome, Rome, Italy
| | - Teresa Sabatino
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Geriatriche, Anestesiologiche e Nefrologiche, Policlinico Umberto I, "La Sapienza" University of Rome, Rome, Italy
| | - Davide Crapanzano
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Geriatriche, Anestesiologiche e Nefrologiche, Policlinico Umberto I, "La Sapienza" University of Rome, Rome, Italy
| | - Giulia Vespignani
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Geriatriche, Anestesiologiche e Nefrologiche, Policlinico Umberto I, "La Sapienza" University of Rome, Rome, Italy
| | - Marco Valerio Mariani
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Geriatriche, Anestesiologiche e Nefrologiche, Policlinico Umberto I, "La Sapienza" University of Rome, Rome, Italy
| | - Nicolò Salvi
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Geriatriche, Anestesiologiche e Nefrologiche, Policlinico Umberto I, "La Sapienza" University of Rome, Rome, Italy
| | - Damiano Magrì
- Dipartimento di Medicina Clinica e Molecolare, S. Andrea Hospital, "Sapienza" University of Rome, Rome, Italy
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Deif B, Roberts JD. Diagnostic evaluation and arrhythmia mechanisms in survivors of unexplained cardiac arrest. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2019; 42:1320-1330. [DOI: 10.1111/pace.13780] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/16/2019] [Accepted: 08/11/2019] [Indexed: 12/25/2022]
Affiliation(s)
- Bishoy Deif
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of MedicineWestern University London Ontario
| | - Jason D. Roberts
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of MedicineWestern University London Ontario
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18
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Churet M, Luttoo K, Hocini M, Haïssaguerre M, Sacher F, Duchateau J. Diagnostic reproducibility of epinephrine drug challenge interpretation in suspected long QT syndrome. J Cardiovasc Electrophysiol 2019; 30:896-901. [DOI: 10.1111/jce.13926] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 03/06/2019] [Accepted: 03/09/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Maxime Churet
- Department of Cardiology‐Cardiac Electrophysiology and PacingBordeaux University HospitalBordeaux France
| | - Khaled Luttoo
- Department of Cardiology‐Cardiac Electrophysiology and PacingBordeaux University HospitalBordeaux France
| | - Mélèze Hocini
- Department of Cardiology‐Cardiac Electrophysiology and PacingBordeaux University HospitalBordeaux France
| | - Michel Haïssaguerre
- Department of Cardiology‐Cardiac Electrophysiology and PacingBordeaux University HospitalBordeaux France
| | - Frédéric Sacher
- Department of Cardiology‐Cardiac Electrophysiology and PacingBordeaux University HospitalBordeaux France
| | - Josselin Duchateau
- Department of Cardiology‐Cardiac Electrophysiology and PacingBordeaux University HospitalBordeaux France
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19
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Guess J, Hubel K, Wiggins A, Madigan CG, Bunin J. Recurrent Torsades with Refractory QT Prolongation in a 54-Year-Old Man. AMERICAN JOURNAL OF CASE REPORTS 2018; 19:1515-1518. [PMID: 30568157 PMCID: PMC6322060 DOI: 10.12659/ajcr.912326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND QT prolongation is a common, easily overlooked clinical problem with potentially dire consequences. Drug-induced and congenital forms are not mutually exclusive, but are treated differently. Here, we present a case of cryptogenic underlying congenital long QT syndrome (cLQTS) successfully treated with isoproterenol, a drug contraindicated in most congenital forms of this condition. CASE REPORT We present the case of a 54-year-old man who experienced severe QT prolongation after drug administration followed by recurrent episodes of torsade de pointes (TdP) with subsequent ventricular fibrillation (VF) arrest unresponsive to typical therapy. After failing electrolyte repletion, magnesium, amiodarone, and lidocaine, the patient was started on an isoproterenol drip to achieve a heart rate of at least 90 beats per minute (bpm). Isoproterenol resulted in an immediate near-normalization of his QT interval and cessation of his recurrent TdP. The patient was subsequently found to have a mutation of undetermined significance in the KCNQ1 gene, which is implicated in long QT syndrome type 1 (LQT1). Although isoproterenol is contraindicated in LQT1, our patient had an astonishingly therapeutic benefit. CONCLUSIONS After reviewing the electrophysiology of the delayed rectifier potassium current as it relates to long QT syndrome, we propose a mechanism by which our patient's specific mutation may have allowed him to derive benefit from isoproterenol treatment. We believe that there are patients with variants of LQT1 who can be safely treated with isoproterenol.
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Affiliation(s)
- Joel Guess
- Department of Internal Medicine, Tripler Army Medical Center, Honolulu, HI, USA
| | - Kinsley Hubel
- Department of Medicine, Tripler Army Medical Center, Honolulu, HI, USA
| | - Amanda Wiggins
- Department of Medicine, Tripler Army Medical Center, Honolulu, HI, USA
| | - Cory G Madigan
- Department of Cradiology, San Antonio Military Medical Center, San Antonio, TX, USA
| | - Jessica Bunin
- Critical Care Services, Tripler Army Medical Center, Honolulu, HI, USA
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20
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Ozawa J, Ohno S, Fujii Y, Makiyama T, Suzuki H, Saitoh A, Horie M. Differential Diagnosis Between Catecholaminergic Polymorphic Ventricular Tachycardia and Long QT Syndrome Type 1 ― Modified Schwartz Score ―. Circ J 2018; 82:2269-2276. [DOI: 10.1253/circj.cj-17-1032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Junichi Ozawa
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science
- Department of Pediatrics, Niigata University Graduate School of Medical and Dental Sciences
| | - Seiko Ohno
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science
- Center for Epidemiologic Research in Asia, Shiga University of Medical Science
- Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center
| | - Yusuke Fujii
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science
| | - Takeru Makiyama
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine
| | - Hiroshi Suzuki
- Department of Pediatrics, Niigata University Graduate School of Medical and Dental Sciences
| | - Akihiko Saitoh
- Department of Pediatrics, Niigata University Graduate School of Medical and Dental Sciences
| | - Minoru Horie
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science
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21
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Etienne P, Huchet F, Gaborit N, Barc J, Thollet A, Kyndt F, Guyomarch B, Le Marec H, Charpentier F, Schott JJ, Redon R, Probst V, Gourraud JB. Mental stress test: a rapid, simple, and efficient test to unmask long QT syndrome. Europace 2018; 20:2014-2020. [DOI: 10.1093/europace/euy078] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 03/20/2018] [Indexed: 11/14/2022] Open
Affiliation(s)
- Pauline Etienne
- l’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Boulevard Jacques Monod, Nantes, France
| | - François Huchet
- l’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Boulevard Jacques Monod, Nantes, France
| | | | - Julien Barc
- l’institut du thorax, INSERM, CNRS, UNIV Nantes, Nantes, France
| | - Aurélie Thollet
- l’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Boulevard Jacques Monod, Nantes, France
| | - Florence Kyndt
- l’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Boulevard Jacques Monod, Nantes, France
| | - Béatrice Guyomarch
- l’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Boulevard Jacques Monod, Nantes, France
| | - Hervé Le Marec
- l’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Boulevard Jacques Monod, Nantes, France
| | - Flavien Charpentier
- l’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Boulevard Jacques Monod, Nantes, France
| | - Jean-Jacques Schott
- l’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Boulevard Jacques Monod, Nantes, France
| | - Richard Redon
- l’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Boulevard Jacques Monod, Nantes, France
| | - Vincent Probst
- l’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Boulevard Jacques Monod, Nantes, France
| | - Jean-Baptiste Gourraud
- l’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU de Nantes, Boulevard Jacques Monod, Nantes, France
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22
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Horie M. Long QT syndrome presents not only as QT prolongation but also as abnormal T-wave morphology. Heart Rhythm 2017; 14:1171-1172. [DOI: 10.1016/j.hrthm.2017.04.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Indexed: 11/24/2022]
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23
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Balla C, Ali H, Cappato R. Ventricular tachycardia as the first manifestation of disease: an element with different clinical settings. J Cardiovasc Med (Hagerstown) 2017; 18 Suppl 1:e77-e82. [PMID: 28151771 DOI: 10.2459/jcm.0000000000000452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Cristina Balla
- aArrhythmia and Electrophysiology Research Center, IRCCS Humanitas Research Hospital, Rozzano, Milan bArrhythmia and Electrophysiology Unit II, Humanitas Gavazzeni Clinics, Bergamo cDepartment of Cardiology, SS. ma Annunziata Hospital, Azienda Unità Sanitaria Locale Ferrara, Cento, Ferrara, Italy
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24
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Abstract
Long QT syndrome (LQTS) exhibits great phenotype variability among family members carrying the same mutation, which can be partially attributed to genetic factors. We functionally analyzed the KCNH2 (encoding for Kv11.1 or hERG channels) and TBX20 (encoding for the transcription factor Tbx20) variants found by next-generation sequencing in two siblings with LQTS in a Spanish family of African ancestry. Affected relatives harbor a heterozygous mutation in KCNH2 that encodes for p.T152HfsX180 Kv11.1 (hERG). This peptide, by itself, failed to generate any current when transfected into Chinese hamster ovary (CHO) cells but, surprisingly, exerted "chaperone-like" effects over native hERG channels in both CHO cells and mouse atrial-derived HL-1 cells. Therefore, heterozygous transfection of native (WT) and p.T152HfsX180 hERG channels generated a current that was indistinguishable from that generated by WT channels alone. Some affected relatives also harbor the p.R311C mutation in Tbx20. In human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), Tbx20 enhanced human KCNH2 gene expression and hERG currents (IhERG) and shortened action-potential duration (APD). However, Tbx20 did not modify the expression or activity of any other channel involved in ventricular repolarization. Conversely, p.R311C Tbx20 did not increase KCNH2 expression in hiPSC-CMs, which led to decreased IhERG and increased APD. Our results suggest that Tbx20 controls the expression of hERG channels responsible for the rapid component of the delayed rectifier current. On the contrary, p.R311C Tbx20 specifically disables the Tbx20 protranscriptional activity over KCNH2 Therefore, TBX20 can be considered a KCNH2-modifying gene.
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25
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Cho Y. Left cardiac sympathetic denervation: An important treatment option for patients with hereditary ventricular arrhythmias. J Arrhythm 2016; 32:340-343. [PMID: 27761156 PMCID: PMC5063267 DOI: 10.1016/j.joa.2015.08.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 07/14/2015] [Accepted: 08/14/2015] [Indexed: 12/25/2022] Open
Abstract
Medications such as ß-blockers are currently the primary treatment for patients with hereditary arrhythmia syndromes such as long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT). However, these drugs are ineffective in some patients, and the other treatment option, that is implantable cardioverter defibrillator (ICD) implantation, is associated with significant complications in young and active patients. Left cardiac sympathetic denervation (LCSD) may reduce the wide gap between life-long ß-blocker medication and ICD implantation. Although LCSD is highly effective in prevention of cardiac events in patients with LQTS and CPVT, it is rarely used. The recently introduced procedure video-assisted thoracoscopic LCSD is associated with short hospital stays and low morbidity. Thus, LCSD is an important therapeutic option for patients with LQTS and CPVT.
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Affiliation(s)
- Yongkeun Cho
- Department of Internal Medicine, Kyungpook National University Hospital, 130 Dongdeok-ro, Daegu, Republic of Korea
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26
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Liu J, Hakucho A, Liu X, Fujimiya T. Acute restraint stress provokes sudden cardiac death in normotensive rats and enhances susceptibility to arrhythmogenic effects of adrenaline in spontaneously hypertensive rats. Leg Med (Tokyo) 2016; 21:19-28. [PMID: 27497329 DOI: 10.1016/j.legalmed.2016.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 04/15/2016] [Accepted: 05/12/2016] [Indexed: 01/09/2023]
Abstract
BACKGROUND A high incidence of cardiovascular events and sudden cardiac death (SCD) has been reported following unexpected acute psychosocial stress. The possible pathways by which acute restraint stress (ARS), a kind of acute psychosocial stress, leads to SCD were determined. METHODS Using 16-week-old male normotensive Wistar Kyoto rats (WKY, n=24) as controls and spontaneously hypertensive rats (SHR, n=24) as the hypertensive subjects with left ventricular hypertrophy (LVH), we assessed ARS-related incidence of SCD, cardiac and myocardial autonomic nervous system dysfunction, gap junction connexin-43 (Cx43) channel remodeling, and ventricular repolarization abnormality, based on electrocardiography, an adrenaline test, heart rate variability (HRV), and reverse transcriptase polymerase chain reaction analyses. Rats with ARS were introduced into restrainers that allowed head, limb, and tail movement. RESULTS In normotensive hearts without LVH, ARS induced a higher incidence of SCD attributed to lethal bradycardia, increased cardiac and myocardial sympathetic activation, and gap junction Cx43 channel remodeling, as evidenced by the increases in the ratio of low-frequency and high-frequency powers in HRV, the ratio of myocardial neuropeptide Y (NPY) and acetylcholinesterase (AChE) mRNA expressions, and the up-regulation of LV Cx43 mRNA expression; in hypertensive hearts with LVH, ARS enhanced susceptibility to the malignant arrhythmogenic effects of the adrenaline test (a kind of sympathetic stimuli) accompanied by abnormal ventricular repolarization, as evidenced by increased incidence of ventricular tachycardia and/or ventricular fibrillation during the adrenaline test and prolonged QTc immediately after ARS. CONCLUSIONS ARS may trigger cardiac and myocardial sympathetic predominance, and then induce gap junction Cx43 channel remodeling, finally leading to lethal bradycardia in normotensive WKY. ARS-induced abnormal ventricular repolarization may be responsible for ARS-enhanced susceptibility to sympathetic stimulation in SHR with LVH. Expressions of myocardial NPY, AChE, and Cx43 genes, HRV, QTc and LVH measures showed diagnostic and prognostic potential for predicting ARS-induced SCD.
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Affiliation(s)
- Jinyao Liu
- Department of Legal Medicine, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
| | - Ayako Hakucho
- Department of Legal Medicine, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan
| | - Xu Liu
- Department of Legal Medicine, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan
| | - Tatsuya Fujimiya
- Department of Legal Medicine, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan
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27
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Abstract
Context: The congenital long QT syndrome (LQTS) is an inherited channelopathy known for its electrocardiographic manifestations of QT prolongation and its hallmark arrhythmia, torsades de pointes (TdP). TdP can lead to syncope or sudden death and is often precipitated by triggers such as physical exertion or emotional stress. Given that athletes may be at particular risk for adverse outcomes, those suspected of having LQTS should be evaluated, risk stratified, treated, and receive appropriate counseling by providers with sufficient expertise according to the latest guidelines. Evidence Acquisition: The following keywords were used to query MEDLINE and PubMed through 2016: LQTS, LQT1, LQT2, LQT3, long QT, long QTc, prolonged QT, prolonged QTc, QT interval, QTc interval, channelopathy, channelopathies, athletes, torsades de pointes, and sudden cardiac death. Selected articles within this primary search, in addition to relevant references from those articles, were reviewed for relevant information and data. Articles with pertinent information regarding pathophysiology, evaluation, diagnosis, genetic testing, treatment, and guidelines for athletes were included, particularly those published in the prior 2 decades. Study Design: Clinical review. Level of Evidence: Level 3. Results: Diagnosis of LQTS involves eliciting the patient’s family history, clinical history, and evaluation of electrocardiographic findings. Genetic testing for common mutations can confirm suspected cases. β-Blockers represent the mainstay of treatment, though interventions such as implantable cardioverter-defibrillator placement or left cardiac sympathetic denervation may be required. Properly evaluated and treated athletes with LQTS have a low risk of cardiac events. Conclusion: Detection and management of LQTS in the athletic population is crucial given the possibility of adverse outcomes with the stress of athletic participation. Preparticipation screening examinations should include a thorough clinical and family history. Screening electrocardiograms may display key findings consistent with LQTS while genetic testing can confirm the diagnosis. Formerly considered a strict contraindication to athletic participation, LQTS is now an increasingly manageable entity with proper evaluation and treatment by qualified and experienced providers.
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Affiliation(s)
- Andrew T Gomez
- Family Medicine Residency, University of Washington, Seattle, Washington
| | - Jordan M Prutkin
- Center for Sports Cardiology, Division of Cardiology/Electrophysiology, Department of Medicine, University of Washington, Seattle, Washington
| | - Ashwin L Rao
- Primary Care Sports Medicine Fellowship, Family Medicine, Sports Medicine Section, University of Washington, Seattle, Washington
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28
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Takahashi K, Nabeshima T, Nakayashiro M, Ganaha H. QT Dynamics During Exercise in Asymptomatic Children with Long QT Syndrome Type 3. Pediatr Cardiol 2016; 37:860-7. [PMID: 26921063 DOI: 10.1007/s00246-016-1360-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/13/2016] [Indexed: 01/08/2023]
Abstract
Sympathetic provocative testing is commonly used to detect the abnormal QT dynamics in long QT syndrome (LQTS) patients, particularly LQTS type 1 and type 2. However, little is known about LQTS type 3 (LQT3). We investigated QT dynamics during exercise testing in LQTS patients, particularly LQT3. This study included 37 subjects, comprising 16 genotyped LQTS patients and 21 unrelated healthy subjects without QT prolongation. LQTS patients were divided into LQT3 and non-LQT3 groups. During exercise tests using a modified Bruce protocol, 12-lead electrocardiogram monitoring was performed using a novel multifunctional electrocardiograph. QT intervals were automatically measured. The QT/heart rate (HR) relationship was visualized by plotting the beat-to-beat confluence of the recorded data. A linear regression analysis was performed to determine the QT/HR slope and intercept. Estimated QT intervals at HR 60 bpm (QT60) were calculated by the regression line formula. QT/HR slopes were steeper for each LQTS group than for the control group (P < 0.001). QT60 values demonstrated a moderate correlation with QT intervals at rest (P < 0.0001) for both groups. The corrected QT intervals (QTc) at 4 min of recovery after exercise were significantly longer in the non-LQT3 group than in the control group but were not different between the LQT3 and the control groups. Abnormal QT dynamics during exercise testing were observed in both LQT3 patients and other LQTS subtypes. This method may be useful for directing genetic testing in subjects with borderline prolonged QT intervals.
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Affiliation(s)
- Kazuhiro Takahashi
- Department of Pediatric Cardiology, Okinawa Children's Medical Center, 118-1 Arakawa, Haebaru-chou, Okinawa, 901-1193, Japan.
| | - Taisuke Nabeshima
- Department of Pediatric Cardiology, Okinawa Children's Medical Center, 118-1 Arakawa, Haebaru-chou, Okinawa, 901-1193, Japan
| | - Mami Nakayashiro
- Department of Pediatric Cardiology, Okinawa Children's Medical Center, 118-1 Arakawa, Haebaru-chou, Okinawa, 901-1193, Japan
| | - Hitoshi Ganaha
- Department of Pediatric Cardiology, Okinawa Children's Medical Center, 118-1 Arakawa, Haebaru-chou, Okinawa, 901-1193, Japan
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29
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Havakuk O, Viskin S. A Tale of 2 Diseases: The History of Long-QT Syndrome and Brugada Syndrome. J Am Coll Cardiol 2016; 67:100-8. [PMID: 26764071 DOI: 10.1016/j.jacc.2015.10.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 09/18/2015] [Accepted: 10/06/2015] [Indexed: 12/21/2022]
Abstract
The Brugada syndrome (BrS) and long-QT syndrome (LQTS) present as congenital or acquired disorders with diagnostic electrocardiograms (ST-segment elevation and prolonged QT interval, respectively) and increased risk for malignant arrhythmias. Our understanding of the 2 disease forms (congenital vs. acquired) differs. A female patient on quinidine for atrial fibrillation who develops ventricular fibrillation is diagnosed with "acquired LQTS" and is discharged with no therapy other than instructions to avoid QT-prolonging medications. In contrast, an asymptomatic male patient who develops a Brugada electrocardiogram on flecainide is diagnosed with "asymptomatic BrS" and could be referred for an electrophysiological evaluation that could result in defibrillator implantation. The typical patient undergoing defibrillator implantation for BrS is asymptomatic but has a Brugada electrocardiogram provoked by a drug. The authors describe how the histories of LQTS and BrS went through the same stages, but in different sequences, leading to different conclusions.
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Affiliation(s)
- Ofer Havakuk
- Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Sami Viskin
- Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
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30
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Herman ARM, Cheung C, Gerull B, Simpson CS, Birnie DH, Klein GJ, Champagne J, Healey JS, Gibbs K, Talajic M, Gardner M, Bennett MT, Steinberg C, Janzen M, Gollob MH, Angaran P, Yee R, Leather R, Chakrabarti S, Sanatani S, Chauhan VS, Krahn AD. Outcome of Apparently Unexplained Cardiac Arrest: Results From Investigation and Follow-Up of the Prospective Cardiac Arrest Survivors With Preserved Ejection Fraction Registry. Circ Arrhythm Electrophysiol 2016; 9:e003619. [PMID: 26783233 DOI: 10.1161/circep.115.003619] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The Cardiac Arrest Survivors with Preserved Ejection Fraction Registry (CASPER) enrolls patients with apparently unexplained cardiac arrest and no evident cardiac disease to identify the pathogenesis of cardiac arrest through systematic clinical testing. Exercise testing, drug provocation, advanced cardiac imaging, and genetic testing may be useful when a cause is not apparent. METHODS AND RESULTS The first 200 survivors of unexplained cardiac arrest from 14 centers across Canada were evaluated to determine the results of investigation and follow-up (age, 48.6±14.7 years, 41% female). Patients were free of evidence of coronary artery disease, left ventricular dysfunction, or evident repolarization syndromes. Advanced testing determined a diagnosis in 34% of patients at baseline, with a diagnosis emerging during follow-up in 7% of patients. Of those who were diagnosed, 28 (35%) had an underlying structural condition and 53 (65%) had a primary electric disease. During a mean follow-up of 3.15±2.34 years, 23% of patients had either a shock or an appropriate antitachycardia pacing from their implantable cardioverter defibrillator, or both. The implantable cardioverter defibrillator appropriate intervention rate was 8.4% at 1 year and 18.1% at 3 years, with no clear difference between diagnosed and undiagnosed subjects, or between those diagnosed with a primary electric versus structural pathogenesis. CONCLUSIONS Obtaining a diagnosis in previously unexplained cardiac arrest patients requires systematic clinical testing and regular follow-up to unmask the cause. Nearly half of apparently unexplained cardiac arrest patients ultimately received a diagnosis, allowing for improved treatment and family screening. A substantial proportion of patients received appropriate implantable cardioverter defibrillator therapy during medium-term follow-up. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00292032.
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Affiliation(s)
- Adam R M Herman
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Christopher Cheung
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Brenda Gerull
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Christopher S Simpson
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - David H Birnie
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - George J Klein
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Jean Champagne
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Jeffrey S Healey
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Karen Gibbs
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Mario Talajic
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Martin Gardner
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Matthew T Bennett
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Christian Steinberg
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Mikyla Janzen
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Michael H Gollob
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Paul Angaran
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Raymond Yee
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Richard Leather
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Santabhanu Chakrabarti
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Shubhayan Sanatani
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Vijay S Chauhan
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.)
| | - Andrew D Krahn
- From the Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada (A.R.M.H., C.C., K.G., M.T.B., C.S., M.J., S.C., A.D.K.); Department of Cardiovascular Sciences, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada (B.G.); Division of Cardiology, Department of Medicine, Queen's University, Kingston, ON, Canada (C.S.S.); University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B.); Division of Cardiology, Department of Medicine, Western University, London, ON, Canada (G.J.K., R.Y.); Department of Medicine, Quebec Heart and Lung Institute, Quebec City, QC, Canada (J.C.); Division of Cardiology, Department of Medicine, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada (M.T.); Division of Cardiology, Department of Medicine, QEII Health Sciences Center, Halifax, NS, Canada (M.G.); Division of Cardiology, Department of Medicine, University Health Network, Toronto, ON, Canada (M.H.G., V.S.C.); Division of Cardiology, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada (P.A.); Division of Cardiology, Department of Medicine, Royal Jubilee Hospital, Victoria, BC, Canada (R.L.); and Division of Cardiology, Department of Pediatrics, BC Children's Hospital, Vancouver, BC, Canada (S.S.).
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Jiménez-Jáimez J, Palomino Doza J, Ortega Á, Macías-Ruiz R, Perin F, Rodríguez-Vázquez del Rey MM, Ortiz-Genga M, Monserrat L, Barriales-Villa R, Blanca E, Álvarez M, Tercedor L. Calmodulin 2 Mutation N98S Is Associated with Unexplained Cardiac Arrest in Infants Due to Low Clinical Penetrance Electrical Disorders. PLoS One 2016; 11:e0153851. [PMID: 27100291 PMCID: PMC4839566 DOI: 10.1371/journal.pone.0153851] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 04/05/2016] [Indexed: 01/08/2023] Open
Abstract
Background Calmodulin 1, 2 and 3 (CALM) mutations have been found to cause cardiac arrest in children at a very early age. The underlying aetiology described is long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT) and idiopathic ventricular fibrillation (IVF). Little phenotypical data about CALM2 mutations is available. Objectives The aim of this paper is to describe the clinical manifestations of the Asn98Ser mutation in CALM2 in two unrelated children in southern Spain with apparently unexplained cardiac arrest/death. Methods Two unrelated children aged 4 and 7, who were born to healthy parents, were studied. Both presented with sudden cardiac arrest. The first was resuscitated after a VF episode, and the second died suddenly. In both cases the baseline QTc interval was within normal limits. Peripheral blood DNA was available to perform targeted gene sequencing. Results The surviving 4-year-old girl had a positive epinephrine test for LQTS, and polymorphic ventricular ectopic beats were seen on a previous 24-hour Holter recording from the deceased 7-year-old boy, suggestive of a possible underlying CPVT phenotype. A p.Asn98Ser mutation in CALM2 was detected in both cases. This affected a highly conserved across species residue, and the location in the protein was adjacent to critical calcium binding loops in the calmodulin carboxyl-terminal domain, predicting a high pathogenic effect. Conclusions Human calmodulin 2 mutation p.Asn98Ser is associated with sudden cardiac death in childhood with a variable clinical penetrance. Our results provide new phenotypical information about clinical behaviour of this mutation.
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Affiliation(s)
- Juan Jiménez-Jáimez
- Cardiology Department, Complejo Hospitalario Universitario de Granada, Granada, Spain
- Instituto de Investigación Biosanitario de Granada, Granada, Spain
- * E-mail:
| | | | - Ángeles Ortega
- Paediatrics Department, Hospital de Torrecárdenas, Almería, Spain
| | - Rosa Macías-Ruiz
- Cardiology Department, Complejo Hospitalario Universitario de Granada, Granada, Spain
- Instituto de Investigación Biosanitario de Granada, Granada, Spain
| | - Francesca Perin
- Paediatrics Department, Complejo Hospitalario Universitario de Granada, Granada, Spain
| | | | | | | | | | - Enrique Blanca
- Paediatrics Department, Complejo Hospitalario Universitario de Granada, Granada, Spain
| | - Miguel Álvarez
- Cardiology Department, Complejo Hospitalario Universitario de Granada, Granada, Spain
- Instituto de Investigación Biosanitario de Granada, Granada, Spain
| | - Luis Tercedor
- Cardiology Department, Complejo Hospitalario Universitario de Granada, Granada, Spain
- Instituto de Investigación Biosanitario de Granada, Granada, Spain
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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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Effects of epinephrine over P wave duration and ventricular repolarization in subjects without structural heart disease. Int J Cardiol 2016; 204:142-6. [PMID: 26657609 DOI: 10.1016/j.ijcard.2015.11.182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 11/23/2015] [Accepted: 11/27/2015] [Indexed: 11/24/2022]
Abstract
BACKGROUND Little is known about the effects of epinephrine over atrial electrical function, AV conduction and ventricular repolarization in normal subjects. We intended to study the effects of intravenous epinephrine on the duration of P wave, inter-atrial conduction time, PR, QRS, QT, corrected QT (QTc), QTc dispersion (QTc max-min), the peak-to-end interval of T wave (Tp-e), the Tp-e/QT index, and the middle portion of ventricular repolarization length (QT-(QRS+Tp-e)) in healthy subjects. METHODS Forty-three, 37.20 ± 17.05 year-old, 25 (58%) female patients without structural heart disease took part in the study. They underwent an electrophysiological study. An epinephrine infusion (50 to 100 ng/kg/min) was administered for 5 min until an increase of at least 10% of the initial heart rate (HR) was achieved. RESULTS No complication arose from epinephrine infusion, and the drug facilitated arrhythmia induction. A significant increase in heart rate, systolic blood pressure, QRS, QTc, Tp-e, Tp-e/QT index, and QTc max-min interval duration was documented. No significant effect on diastolic blood pressure, P wave duration, inter-atrial conduction time, and PR, QT and QT-(Tp-e+QRS interval) was observed. CONCLUSIONS In this group of patients without structural heart disease, epinephrine infusion did not produce any complication and it facilitated arrhythmia induction. It did not modify P wave duration, PR interval or inter-atrial conduction time. Moreover, it significantly increased the duration of depolarization, the final portion of repolarization, transmural dispersion of repolarization, and regional dispersion of repolarization without inducing significant changes in the middle portion of repolarization.
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Padfield GJ, Escudero CA, DeSouza AM, Steinberg C, Gibbs K, Puyat JH, Lam PY, Sanatani S, Sherwin E, Potts JE, Sandor G, Krahn AD. Characterization of Myocardial Repolarization Reserve in Adolescent Females With Anorexia Nervosa. Circulation 2016; 133:557-65. [PMID: 26769740 DOI: 10.1161/circulationaha.115.016697] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 12/29/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Patients with anorexia nervosa exhibit abnormal myocardial repolarization and are susceptible to sudden cardiac death. Exercise testing is useful in unmasking QT prolongation in disorders associated with abnormal repolarization. We characterized QT adaptation during exercise in anorexia. METHODS AND RESULTS Sixty-one adolescent female patients with anorexia nervosa and 45 age- and sex-matched healthy volunteers performed symptom-limited cycle ergometry during 12-lead ECG monitoring. Changes in the QT interval during exercise were measured, and QT/RR-interval slopes were determined by using mixed-effects regression modeling. Patients had significantly lower body mass index than controls; however, resting heart rates and QT/QTc intervals were similar at baseline. Patients had shorter exercise times (13.7±4.5 versus 20.6±4.5 minutes; P<0.001) and lower peak heart rates (159±20 versus 184±9 beats/min; P<0.001). The mean QTc intervals were longer at peak exercise in patients (442±29 versus 422±19 ms; P<0.001). During submaximal exertion at comparable heart rates (114±6 versus 115±11 beats/min; P=0.54), the QTc interval had prolonged significantly more in patients than controls (37±28 versus 24±25 ms; P<0.016). The RR/QT slope, best described by a curvilinear relationship, was more gradual in patients than in controls (13.4; 95% confidence interval, 12.8-13.9 versus 15.8; 95% confidence interval, 15.3-16.4 ms QT change per 10% change in RR interval; P<0.001) and steepest in patients within the highest body mass index tertile versus the lowest (13.9; 95% confidence interval, 12.9-14.9 versus 12.3; 95% confidence interval, 11.3-13.3; P=0.026). CONCLUSIONS Despite the absence of manifest QT prolongation, adolescent anorexic females have impaired repolarization reserve in comparison with healthy controls. Further study may identify impaired QT dynamics as a risk factor for arrhythmias in anorexia nervosa.
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Affiliation(s)
- Gareth J Padfield
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Carolina A Escudero
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Astrid M DeSouza
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Christian Steinberg
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Karen Gibbs
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Joseph H Puyat
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Pei Yoong Lam
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Shubhayan Sanatani
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Elizabeth Sherwin
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - James E Potts
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - George Sandor
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Andrew D Krahn
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.).
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Jiménez-Jáimez J, de la Torre I, Peinado Peinado R, Zorio Grima E, Segura F, Moriña P, Sánchez Muñoz JJ, Mazuelos F, Cózar R, Gimeno JR, Picón Heras R, Monserrat L, Macías Ruiz R, Álvarez M, Tercedor L. Penetrancia familiar en la parada cardíaca en ausencia de cardiopatía aparente: observaciones del estudio FIVI-Gen. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.carcor.2015.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Romero L, Trenor B, Yang PC, Saiz J, Clancy CE. In silico screening of the impact of hERG channel kinetic abnormalities on channel block and susceptibility to acquired long QT syndrome. J Mol Cell Cardiol 2015; 87:271-82. [DOI: 10.1016/j.yjmcc.2015.08.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Spears DA, Gollob MH. Genetics of inherited primary arrhythmia disorders. APPLICATION OF CLINICAL GENETICS 2015; 8:215-33. [PMID: 26425105 PMCID: PMC4583121 DOI: 10.2147/tacg.s55762] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A sudden unexplained death is felt to be due to a primary arrhythmic disorder when no structural heart disease is found on autopsy, and there is no preceding documentation of heart disease. In these cases, death is presumed to be secondary to a lethal and potentially heritable abnormality of cardiac ion channel function. These channelopathies include congenital long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, Brugada syndrome, and short QT syndrome. In certain cases, genetic testing may have an important role in supporting a diagnosis of a primary arrhythmia disorder, and can also provide prognostic information, but by far the greatest strength of genetic testing lies in the screening of family members, who may be at risk. The purpose of this review is to describe the basic genetic and molecular pathophysiology of the primary inherited arrhythmia disorders, and to outline a rational approach to genetic testing, management, and family screening.
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Affiliation(s)
- Danna A Spears
- Division of Cardiology - Electrophysiology, University Health Network, Toronto General Hospital, Toronto, ON, Canada
| | - Michael H Gollob
- Division of Cardiology - Electrophysiology, University Health Network, Toronto General Hospital, Toronto, ON, Canada
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Diagnostic Approach to Unexplained Cardiac Arrest (from the FIVI-Gen Study). Am J Cardiol 2015; 116:894-9. [PMID: 26189708 DOI: 10.1016/j.amjcard.2015.06.030] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 06/14/2015] [Accepted: 06/14/2015] [Indexed: 01/12/2023]
Abstract
Unexplained cardiac arrest (UCA) can be caused by low-penetrance genetic disorders. The aim of this cross-sectional study is to assess the usefulness of a new diagnostic protocol: Thirty-five patients were recruited from 9 Spanish centers. Electrocardiogram, echocardiogram, and coronary catheterization were used to rule out electrical or structural heart disease in all subjects. Patients underwent pharmacologic tests with epinephrine and flecainide, followed by assessment of family members using electrocardiogram and echocardiogram, and next-generation genetic sequencing to analyze 126 genes if all the other test results were negative. A firm diagnosis of channelopathy required phenotypic proof of the condition in unmasking tests, the presence of a pathogenic variant consistent with the phenotype observed, and/or co-segregation of the mutation found in a family member's phenotype. A firm diagnosis was made in 18 cases. The diagnoses were 7 Brugada syndrome, 5 catecholaminergic polymorphic ventricular tachycardia, 3 long QT syndrome, 2 early repolarization syndrome, and 1 short QT syndrome. Pharmacologic testing was the most frequent method of diagnosis. In 5 cases, the diagnosis was made based on positive genetic testing without phenotypic alterations. In conclusion, this sequential diagnostic protocol allows diagnoses to be made in approximately half of the UCA cases. These diagnoses are low clinical penetrance channelopathies. If interpreted carefully, genetic tests can be a useful tool for diagnosing UCA without a phenotype.
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Page A, Aktas MK, Soyata T, Zareba W, Couderc JP. "QT clock" to improve detection of QT prolongation in long QT syndrome patients. Heart Rhythm 2015; 13:190-8. [PMID: 26334569 DOI: 10.1016/j.hrthm.2015.08.037] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND The QT interval is a risk marker for cardiac events such as torsades de pointes. However, QT measurements obtained from a 12-lead ECG during clinic hours may not capture the full extent of a patient's daily QT range. OBJECTIVE The purpose of this study was to evaluate the utility of 24-hour Holter ECG recording in patients with long QT syndrome (LQTS) to identify dynamic changes in the heart rate-corrected QT interval and to investigate methods of visualizing the resulting datasets. METHODS Beat-to-beat QTc (Bazett) intervals were automatically measured across 24-hour Holter recordings from 202 LQTS type 1, 89 type 2, and 14 type 3 genotyped patients and a reference group of 200 healthy individuals. We measured the percentage of beats with QTc greater than the gender-specific threshold (QTc ≥470 ms in women and QTc ≥450 ms in men). The percentage of beats with QTc prolongation was determined across the 24-hour recordings. RESULTS Based on the median percentage of heartbeats per patient with QTc prolongation, LQTS type 1 patients showed more frequent QTc prolongation during the day (~3 PM) than they did at night (~3 AM): 97% vs 48%, P ~10(-4) for men, and 68% vs 30%, P ~10(-5) for women. LQTS type 2 patients showed less frequent QTc prolongation during the day compared to nighttime: 87% vs 100%, P ~10(-4) for men, and 62% vs 100%, P ~10(-3) for women. CONCLUSION In patients with genotype-positive LQTS, significant differences exist in the degree of daytime and nocturnal QTc prolongation. Holter monitoring using the "QT clock" concept may provide an easy, fast, and accurate method for assessing the true personalized burden of QTc prolongation.
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Affiliation(s)
- Alex Page
- Electrical and Computer Engineering Department, University of Rochester, Rochester, New York
| | - Mehmet K Aktas
- Cardiology Department, University of Rochester Medical Center, Rochester, New York
| | - Tolga Soyata
- Electrical and Computer Engineering Department, University of Rochester, Rochester, New York
| | | | - Jean-Philippe Couderc
- Electrical and Computer Engineering Department, University of Rochester, Rochester, New York; Heart Research Follow Up Program, Rochester, New York.
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Abstract
Sudden cardiac death (SCD) from cardiac arrest is a major international public health problem accounting for an estimated 15%-20% of all deaths. Although resuscitation rates are generally improving throughout the world, the majority of individuals who experience a sudden cardiac arrest will not survive. SCD most often develops in older adults with acquired structural heart disease, but it also rarely occurs in the young, where it is more commonly because of inherited disorders. Coronary heart disease is known to be the most common pathology underlying SCD, followed by cardiomyopathies, inherited arrhythmia syndromes, and valvular heart disease. During the past 3 decades, declines in SCD rates have not been as steep as for other causes of coronary heart disease deaths, and there is a growing fraction of SCDs not due to coronary heart disease and ventricular arrhythmias, particularly among certain subsets of the population. The growing heterogeneity of the pathologies and mechanisms underlying SCD present major challenges for SCD prevention, which are magnified further by a frequent lack of recognition of the underlying cardiac condition before death. Multifaceted preventative approaches, which address risk factors in seemingly low-risk and known high-risk populations, will be required to decrease the burden of SCD. In this Compendium, we review the wide-ranging spectrum of epidemiology underlying SCD within both the general population and in high-risk subsets with established cardiac disease placing an emphasis on recent global trends, remaining uncertainties, and potential targeted preventive strategies.
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Affiliation(s)
- Meiso Hayashi
- From the Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan (M.H., W.S.); and Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.M.A.)
| | - Wataru Shimizu
- From the Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan (M.H., W.S.); and Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.M.A.).
| | - Christine M Albert
- From the Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan (M.H., W.S.); and Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (C.M.A.).
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Chorin E, Havakuk O, Adler A, Steinvil A, Rozovski U, van der Werf C, Postema PG, Topaz G, Wilde AAM, Viskin S, Rosso R. Diagnostic value of T-wave morphology changes during "QT stretching" in patients with long QT syndrome. Heart Rhythm 2015; 12:2263-71. [PMID: 26142298 DOI: 10.1016/j.hrthm.2015.06.040] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Indexed: 11/18/2022]
Abstract
BACKGROUND Specific T-wave patterns on the resting electrocardiogram (ECG) aid in diagnosing long QT syndrome (LQTS) and identifying the specific genotype. However, provocation tests often are required to establish a diagnosis when the QT interval is borderline at rest. OBJECTIVE The purpose of this study was to determine whether T-wave morphology changes provoked by standing aid in the diagnosis of LQTS and determination of the genotype. METHODS The quick-standing test was performed by 100 LQTS patients (40 type 1 [LQT1], 42 type 2 [LQT2], 18 type 3 [LQT3]) and 100 controls. Logistic regression was used to determine whether T-wave morphology changes provoked by standing added to the already established diagnostic value of QTc stretching in identifying LQTS. RESULTS During maximal QT stretching, the T-wave morphologies that best discriminated LQTS from controls included "notched," "late-onset," and "biphasic" T waves. These 3 categories were grouped into a category named "abnormal T-wave response to standing." During quick standing, a QTc stretched ≥490 ms increased the odds of correctly identifying LQTS. T-wave morphology changes provoked by standing were most helpful for identifying LQT2, less helpful for LQT1, and least helpful for LQT3. CONCLUSION The sudden heart rate acceleration produced by abrupt standing not only increases the QTc but also exposes abnormal T waves that are valuable for diagnosing LQTS.
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Affiliation(s)
- Ehud Chorin
- Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ofer Havakuk
- Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Arnon Adler
- Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Arie Steinvil
- Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Uri Rozovski
- Department of Internal Medicine, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Christian van der Werf
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Pieter G Postema
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Guy Topaz
- Department of Internal Medicine, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Arthur A M Wilde
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Sami Viskin
- Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Raphael Rosso
- Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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Abstract
Molecular genetic studies in the last 2 decades have revealed a link between several inherited cardiac arrhythmias and genes encoding for ion channels or other membrane components. Two recent international expert consensus statements endorsed by 3 continental electrophysiology societies have updated the clinical and genetic diagnoses and management in patients with inherited arrhythmia syndromes, including congenital long QT syndrome (LQTS) and Brugada syndrome. Thirteen genotypes have been identified in 50% to 80% of clinically affected patients with congenital LQTS. Therefore, genotype-phenotype correlations have been investigated, especially, in the 3 major genotypes--LQT1, LQT2 and LQT3 syndromes--enabling genotype-specific management and therapy. On the other hand, less than half of patients with Brugada syndrome can be genotyped, and mainly for the sodium channel gene, SCN5A. However, recent advances in molecular genetic testing include genome-wide association studies using gene arrays and targeted, whole-exome and whole-genome next-generation sequencing techniques. In this article, I will review the clinical and genetic diagnoses in congenital LQTS and Brugada syndrome.
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Affiliation(s)
- Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School
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43
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Jiménez-Jáimez J, Álvarez López M, Tercedor Sánchez L. Asymptomatic 43-year-old man with family history of sudden death. Heart 2015; 101:1232, 1239. [PMID: 25832545 DOI: 10.1136/heartjnl-2014-307362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 03/03/2015] [Indexed: 11/04/2022] Open
Affiliation(s)
- Juan Jiménez-Jáimez
- Arrhythmias Unit, Granada University Hospitals, Granada Institute of Biohealth Research, Granada, Spain
| | - Miguel Álvarez López
- Arrhythmias Unit, Granada University Hospitals, Granada Institute of Biohealth Research, Granada, Spain
| | - Luis Tercedor Sánchez
- Arrhythmias Unit, Granada University Hospitals, Granada Institute of Biohealth Research, Granada, Spain
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44
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The potassium current carried by TREK-1 channels in rat cardiac ventricular muscle. Pflugers Arch 2014; 467:1069-79. [PMID: 25539776 DOI: 10.1007/s00424-014-1678-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 12/15/2014] [Accepted: 12/16/2014] [Indexed: 01/13/2023]
Abstract
We studied the potassium current flowing through TREK-1 channels in rat cardiac ventricular myocytes. We separated the TREK-1 current from other current components by blocking most other channels with a blocker cocktail. We tried to inhibit the TREK-1 current by activating protein kinase A (PKA) with a mixture of forskolin and isobutyl-methylxanthine (IBMX). Activation of PKA blocked an outwardly rectifying current component at membrane potentials positive to -40 mV. At 37 °C, application of forskolin plus IBMX reduced the steady-state outward current measured at positive voltages by about 52 %. Application of the potassium channel blockers quinidine or tetrahexylammonium also reduced the steady-state outward current by about 50 %. Taken together, our results suggest that the increase in temperature from 22 to 37 °C increased the TREK-1 current by a factor of at least 5 and that the average density of the TREK-1 current in rat cardiomyocytes at 37 °C is about 1.5 pA/pF at +30 mV. The contribution of TREK-1 to the action potential was assessed by using a dynamic patch clamp technique. After subtraction of simulated TREK-1 currents, action potential duration at 50 or 90 % repolarisation was increased by about 12 %, indicating that TREK-1 may be functionally important in rat ventricular muscle. During sympathetic stimulation, inhibition of TREK-1 channels via PKA is expected to prolong the action potential primarily in subendocardial myocytes; this may decrease the transmural dispersion of repolarisation and thus may serve to prevent the occurrence of arrhythmias.
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45
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Mellor G, Behr ER. Sudden Unexplained Death - Treating the Family. Arrhythm Electrophysiol Rev 2014; 3:156-60. [PMID: 26835084 DOI: 10.15420/aer.2014.3.3.156] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 11/03/2014] [Indexed: 01/08/2023] Open
Abstract
Sudden unexplained death in the context of a normal heart at post-mortem and negative toxicological analysis is termed sudden arrhythmic death syndrome (SADS). SADS is often due to cardiac genetic disease, particularly channelopathies. Assessment of family members of SADS victims will reveal at least one affected individual in up to half of families. Specialist evaluation begins with an expert cardiac autopsy that improves diagnostic accuracy and minimises erroneous interpretation of minor pathological findings. Retention of appropriate material for post-mortem genetic testing, 'the molecular autopsy', is recommended as this may provide a genetic diagnosis in up to a third of cases. Clinical assessment of families initially comprises 12-lead ECG with high right ventricular leads, echocardiogram and exercise testing. Additional investigations include sodium channel blocker and epinephrine provocation tests. Families with a diagnosis should be managed as per guidelines. Those with negative investigations can generally be discharged unless they are young and/or symptomatic.
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Affiliation(s)
- Greg Mellor
- Clinical Research Fellow & Specialist Registrar Cardiology
| | - Elijah R Behr
- Reader in Cardiovascular Medicine & Honorary Consultant Cardiologist & Electrophysiologist Cardiac Research Centre, Institute of Cardiovascular and Cell Sciences, St. George's University of London, London
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46
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Pedersen CT, Kay GN, Kalman J, Borggrefe M, Della-Bella P, Dickfeld T, Dorian P, Huikuri H, Kim YH, Knight B, Marchlinski F, Ross D, Sacher F, Sapp J, Shivkumar K, Soejima K, Tada H, Alexander ME, Triedman JK, Yamada T, Kirchhof P, Lip GY, Kuck KH, Mont L, Haines D, Indik J, Dimarco J, Exner D, Iesaka Y, Savelieva I. EHRA/HRS/APHRS expert consensus on ventricular arrhythmias. J Arrhythm 2014. [DOI: 10.1016/j.joa.2014.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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48
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Brygger L, Herrstedt J. 5-Hydroxytryptamine3receptor antagonists and cardiac side effects. Expert Opin Drug Saf 2014; 13:1407-22. [DOI: 10.1517/14740338.2014.954546] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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49
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Pedersen CT, Kay GN, Kalman J, Borggrefe M, Della-Bella P, Dickfeld T, Dorian P, Huikuri H, Kim YH, Knight B, Marchlinski F, Ross D, Sacher F, Sapp J, Shivkumar K, Soejima K, Tada H, Alexander ME, Triedman JK, Yamada T, Kirchhof P, Lip GYH, Kuck KH, Mont L, Haines D, Indik J, Dimarco J, Exner D, Iesaka Y, Savelieva I. EHRA/HRS/APHRS expert consensus on ventricular arrhythmias. Europace 2014; 16:1257-83. [PMID: 25172618 DOI: 10.1093/europace/euu194] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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50
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Arakawa J, Hamabe A, Aiba T, Nagai T, Yoshida M, Touya T, Ishigami N, Hisadome H, Katsushika S, Tabata H, Miyamoto Y, Shimizu W. A novel cardiac ryanodine receptor gene (RyR2) mutation in an athlete with aborted sudden cardiac death: a case of adult-onset catecholaminergic polymorphic ventricular tachycardia. Heart Vessels 2014; 30:835-40. [PMID: 25092222 DOI: 10.1007/s00380-014-0555-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 07/11/2014] [Indexed: 12/26/2022]
Abstract
Sudden cardiac death (SCD) in athletes <35 years of age are mostly due to congenital or acquired cardiac malformations or hypertrophic cardiomyopathy. However, ion channelopathies such as catecholaminergic polymorphic ventricular tachycardia (CPVT) or long-QT syndromes, which are less frequently observed, are also potential pathogenesis of SCD in young athletes. CPVT is an inherited arrhythmia that is induced by physical or emotional stress and may lead to ventricular fibrillation syncope or SCD. Here, we report a case of athlete woman with adult-onset CPVT and aborted SCD who has a novel missense mutation (K4392R) in the cardiac RyR2 gene.
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Affiliation(s)
- Junko Arakawa
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan.
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan.
| | - Akira Hamabe
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Takeshi Aiba
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Tomoo Nagai
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Mikoto Yoshida
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Takumi Touya
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Norio Ishigami
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Hideki Hisadome
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Shuichi Katsushika
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Hirotsugu Tabata
- Department of Cardiology, Japan Self-Defense Forces Central Hospital, Ikejiri 1-2-24, Setagaya-ku, Tokyo, 154-8532, Japan
- Department of Cardiology, KKR Mishuku Hospital, Tokyo, Japan
| | - Yoshihiro Miyamoto
- Laboratory of Molecular Genetics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan
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