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Oliveira C, Pinho A, Santos L, Pinto RA, Oliveira S, Moreira H, Rocha M, Palma P, Pestana G, Madeira M, Lebreiro A, Adão L. Long-term prognosis of idiopathic ventricular fibrillation: An eighteen-year experience from a tertiary center. Rev Port Cardiol 2024; 43:331-336. [PMID: 38615880 DOI: 10.1016/j.repc.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/22/2024] [Accepted: 04/02/2024] [Indexed: 04/16/2024] Open
Abstract
INTRODUCTION AND OBJECTIVES Idiopathic ventricular fibrillation (IVF) is diagnosed in patients who survive sudden cardiac arrest (SCA), preferably with documented ventricular fibrillation (VF), without any identifiable structural or electrical abnormality. Current evidence provides limited guidance on the diagnosis and follow-up of these patients. Our aim was to assess the clinical outcomes of survivors of an aborted SCA attributed to IVF. METHODS We retrospectively collected clinical data from all patients who survived SCA and implanted a cardiac defibrillator (ICD) between 2005 and 2023. RESULTS A total of 38 patients, 36.8% female, with a mean age of 44±14 years old were included. Median follow-up time was 8.7 years (interquartile range (IQR) 4.7-14.7 years). All patients underwent a comprehensive diagnostic evaluation that excluded structural and coronary disease. During follow-up, underlying diagnoses were established in 34.2% of the whole cohort. Genetic testing, performed in 37.2%, revealed underlying diagnoses in 57.1% of those tested, compared to only 26.3% of patients who did not undergo genetic testing [p=0.035, OR=5.1 (95% confidence interval (CI) 1.2-21.5)]. Mortality was 10.5% (due to non-arrhythmic causes) and 36.8% patients received appropriate therapies with a median time to first ICD therapy of 39 [5.4-47.3] months. CONCLUSION(S) Etiological diagnosis and recurrence prediction in patients with IVF remains challenging, even with extensive diagnostic evaluation and long-term follow-up. In our study, genetic testing enhanced diagnostic yield. Consistent with previous findings, our cohort experienced a notable arrhythmic recurrence, with no cardiac deaths, underlining the pivotal role of ICD implantation in these patients.
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Affiliation(s)
- Cátia Oliveira
- Department of Cardiology, Local Health Unit of São João, E.P.E., Porto, Portugal.
| | - Ana Pinho
- Department of Cardiology, Local Health Unit of São João, E.P.E., Porto, Portugal
| | - Luís Santos
- Department of Cardiology, Local Health Unit of São João, E.P.E., Porto, Portugal
| | - Ricardo Alves Pinto
- Department of Cardiology, Local Health Unit of São João, E.P.E., Porto, Portugal
| | - Sílvia Oliveira
- Faculty of Medicine of University of Oporto, Porto, Portugal
| | - Helena Moreira
- Department of Cardiology, Local Health Unit of São João, E.P.E., Porto, Portugal
| | - Miguel Rocha
- Department of Cardiology, Local Health Unit of São João, E.P.E., Porto, Portugal
| | - Pedro Palma
- Department of Cardiology, Local Health Unit of São João, E.P.E., Porto, Portugal
| | - Gonçalo Pestana
- Department of Cardiology, Local Health Unit of São João, E.P.E., Porto, Portugal
| | - Marta Madeira
- Department of Cardiology, Local Health Unit of São João, E.P.E., Porto, Portugal
| | - Ana Lebreiro
- Department of Cardiology, Local Health Unit of São João, E.P.E., Porto, Portugal
| | - Luís Adão
- Department of Cardiology, Local Health Unit of São João, E.P.E., Porto, Portugal
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Verheul LM, Groeneveld SA, Stoks J, Hoeksema WF, Cluitmans MJM, Postema PG, Wilde AAM, Volders PGA, Hassink RJ. The Dutch Idiopathic Ventricular Fibrillation Registry: progress report on the quest to identify the unidentifiable. Neth Heart J 2024; 32:238-244. [PMID: 38653923 PMCID: PMC11143118 DOI: 10.1007/s12471-024-01870-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2024] [Indexed: 04/25/2024] Open
Abstract
BACKGROUND Idiopathic ventricular fibrillation (iVF) is a rare cause of sudden cardiac arrest and, by definition, a diagnosis of exclusion. Due to the rarity of the disease, previous and current studies are limited by their retrospective design and small patient numbers. Even though the incidence of iVF has declined owing to the identification of new disease entities, an important subgroup of patients remains. AIM To expand the existing Dutch iVF Registry into a large nationwide cohort of patients initially diagnosed with iVF, to reveal the underlying cause of iVF in these patients, and to improve arrhythmia management. METHODS The Dutch iVF Registry includes sudden cardiac arrest survivors with an initial diagnosis of iVF. Clinical data and outcomes are collected. Outcomes include subsequent detection of a diagnosis other than 'idiopathic', arrhythmia recurrence and death. Non-invasive electrocardiographic imaging is used to investigate electropathological substrates and triggers of VF. RESULTS To date, 432 patients have been included in the registry (median age at event 40 years (interquartile range 28-52)), 61% male. During a median follow-up of 6 (2-12) years, 38 patients (9%) received a diagnosis other than 'idiopathic'. Eleven iVF patients were characterised with electrocardiographic imaging. CONCLUSION The Dutch iVF Registry is currently the largest of its kind worldwide. In this heterogeneous population of index patients, we aim to identify common functional denominators associated with iVF. With the implementation of non-invasive electrocardiographic imaging and other diagnostic modalities (e.g. echocardiographic deformation, cardiac magnetic resonance), we advance the possibilities to reveal pro-fibrillatory substrates.
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Affiliation(s)
- Lisa M Verheul
- Department of Cardiology, University Medical Centre Utrecht, Utrecht, The Netherlands.
| | - Sanne A Groeneveld
- Department of Cardiology, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Job Stoks
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Wiert F Hoeksema
- Department of Cardiology, Amsterdam UMC, location University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands
| | - Matthijs J M Cluitmans
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Pieter G Postema
- Department of Cardiology, Amsterdam UMC, location University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands
| | - Arthur A M Wilde
- Department of Cardiology, Amsterdam UMC, location University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands
| | - Paul G A Volders
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Rutger J Hassink
- Department of Cardiology, University Medical Centre Utrecht, Utrecht, The Netherlands
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3
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Verheul LM, Hoeksema WF, Groeneveld SA, Mulder BA, Bootsma M, Alings M, Evertz R, Blank AC, Kammeraad JAE, Clur SAB, Yap SC, Postema PG, Wilde AAM, Volders PGA, Hassink RJ. Comparing adolescent- and adult-onset unexplained cardiac arrest: Results from the Dutch Idiopathic VF Registry. Heart Rhythm 2024:S1547-5271(24)00276-5. [PMID: 38493994 DOI: 10.1016/j.hrthm.2024.03.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 02/22/2024] [Accepted: 03/11/2024] [Indexed: 03/19/2024]
Abstract
BACKGROUND Current cohorts of patients with idiopathic ventricular fibrillation (IVF) primarily include adult-onset patients. Underlying causes of sudden cardiac arrest vary with age; therefore, underlying causes and disease course may differ for adolescent-onset vs adult-onset patients. OBJECTIVE The purpose of this study was to compare adolescent-onset with adult-onset patients having an initially unexplained cause of VF. METHODS The study included 39 patients with an index event aged ≤19 years (adolescent-onset) and 417 adult-onset patients from the Dutch Idiopathic VF Registry. Data on event circumstances, clinical characteristics, change in diagnosis, and arrhythmia recurrences were collected and compared between the 2 groups. RESULTS In total, 42 patients received an underlying diagnosis during follow-up (median 7 [2-12] years), with similar yields (15% adolescent-onset vs 9% adult-onset; P = .16). Among the remaining unexplained patients, adolescent-onset patients (n = 33) had their index event at a median age of 17 [16-18] years, and 72% were male. The youngest patient was aged 13 years. In comparison with adults (n = 381), adolescent-onset patients more often had their index event during exercise (P <.01). Adolescent-onset patients experienced more appropriate implantable cardioverter-defibrillator (ICD) therapy during follow-up compared with adults (44% vs 26%; P = .03). Inappropriate ICD therapy (26% vs 17%; P = .19), ICD complications (19% vs 14%; P = .41), and deaths (3% vs 4%; P = 1) did not significantly differ between adolescent-onset and adult-onset patients. CONCLUSION IVF may occur during adolescence. Adolescent-onset patients more often present during exercise compared with adults. Furthermore, they are more vulnerable to ventricular arrhythmias as reflected by a higher incidence of appropriate ICD therapy.
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Affiliation(s)
- Lisa M Verheul
- University Medical Center Utrecht, Utrecht, The Netherlands.
| | - Wiert F Hoeksema
- Amsterdam UMC location University of Amsterdam, Department of Cardiology, Heart Failure and Arrhythmias, Amsterdam, The Netherlands, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands
| | | | - Bart A Mulder
- University Medical Center Groningen, Groningen, The Netherlands
| | | | | | - Reinder Evertz
- Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Janneke A E Kammeraad
- Erasmus MC-Sophia Children's Hospital, Cardiovascular Institute, Department of Pediatric Cardiology, Rotterdam, The Netherlands
| | - Sally-Ann B Clur
- Amsterdam UMC location University of Amsterdam, Department of Cardiology, Heart Failure and Arrhythmias, Amsterdam, The Netherlands, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands; Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart: ERN GUARD-Heart,"
| | - Sing-Chien Yap
- Cardiovascular Institute, Thorax Center, Erasmus MC, Rotterdam, The Netherlands
| | - Pieter G Postema
- Amsterdam UMC location University of Amsterdam, Department of Cardiology, Heart Failure and Arrhythmias, Amsterdam, The Netherlands, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands; Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart: ERN GUARD-Heart,"
| | - Arthur A M Wilde
- Amsterdam UMC location University of Amsterdam, Department of Cardiology, Heart Failure and Arrhythmias, Amsterdam, The Netherlands, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands; Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart: ERN GUARD-Heart,"
| | - Paul G A Volders
- Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart: ERN GUARD-Heart,"; Maastricht University Medical Center, Maastricht, The Netherlands
| | - Rutger J Hassink
- University Medical Center Utrecht, Utrecht, The Netherlands; Member of the European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart: ERN GUARD-Heart,"
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4
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van der Crabben SN, Wilde AAM. Idiopathic ventricular fibrillation: is it a case for genetic testing? Herzschrittmacherther Elektrophysiol 2024; 35:19-24. [PMID: 38334831 PMCID: PMC10879354 DOI: 10.1007/s00399-024-00994-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 01/15/2024] [Indexed: 02/10/2024]
Abstract
Idiopathic ventricular fibrillation (IVF) is a diagnosis of exclusion in sudden cardiac arrest (SCA) survivors. Although there are clear guidelines on the clinical work-up of SCA survivors, less than one in five patients receives a complete work-up. This increases the chances of erroneously labelling these patients as having IVF, while 10-20% of them have an inherited cardiac condition (ICC). Diagnoses of ICC increase over time due to (additional) deep phenotyping or as a result of spontaneous expression of ICC over time. As SCA survivors can also harbor (likely) pathogenic variants in cardiomyopathy-associated genes in the absence of a phenotype, or can have another ICC without a clear cardiac phenotype, the question arises as to whether genetic testing in this group should be routinely performed. Family history (mainly in the case of sudden death) can increase suspicion of an ICC in an SCA victim, but does not add great value when adults underwent a complete cardiological work-up. The diagnosis of ICC has treatment consequences not only for the patient but also for their family. Genetic diagnostic yield does not appear to increase with larger gene panels, but variants of unknown significance (VUS) do. Although VUS can be confusing, careful and critical segregation analysis in the family can be performed when discussed in a multidisciplinary team at a center of expertise with at least a cardiologist as well as a clinical and laboratory geneticist, thereby degrading or promoting VUS. When to introduce genetic testing in SCA survivors remains a matter of debate, but the combination of quick, deep phenotyping with additional genetic testing for the unidentifiable phenotypes, especially in the young, seems preferable.
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Affiliation(s)
- S N van der Crabben
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
- European Reference Network for rare, low prevalence, and/or complex diseases of the heart: ERN GUARD-Heart, Amsterdam, The Netherlands.
| | - A A M Wilde
- European Reference Network for rare, low prevalence, and/or complex diseases of the heart: ERN GUARD-Heart, Amsterdam, The Netherlands
- Amsterdam UMC, Department of Cardiology, University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure and arrhythmias, Amsterdam, The Netherlands
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Badura K, Buławska D, Dąbek B, Witkowska A, Lisińska W, Radzioch E, Skwira S, Młynarska E, Rysz J, Franczyk B. Primary Electrical Heart Disease-Principles of Pathophysiology and Genetics. Int J Mol Sci 2024; 25:1826. [PMID: 38339103 PMCID: PMC10855675 DOI: 10.3390/ijms25031826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 01/27/2024] [Accepted: 01/28/2024] [Indexed: 02/12/2024] Open
Abstract
Primary electrical heart diseases, often considered channelopathies, are inherited genetic abnormalities of cardiomyocyte electrical behavior carrying the risk of malignant arrhythmias leading to sudden cardiac death (SCD). Approximately 54% of sudden, unexpected deaths in individuals under the age of 35 do not exhibit signs of structural heart disease during autopsy, suggesting the potential significance of channelopathies in this group of age. Channelopathies constitute a highly heterogenous group comprising various diseases such as long QT syndrome (LQTS), short QT syndrome (SQTS), idiopathic ventricular fibrillation (IVF), Brugada syndrome (BrS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and early repolarization syndromes (ERS). Although new advances in the diagnostic process of channelopathies have been made, the link between a disease and sudden cardiac death remains not fully explained. Evolving data in electrophysiology and genetic testing suggest previously described diseases as complex with multiple underlying genes and a high variety of factors associated with SCD in channelopathies. This review summarizes available, well-established information about channelopathy pathogenesis, genetic basics, and molecular aspects relative to principles of the pathophysiology of arrhythmia. In addition, general information about diagnostic approaches and management is presented. Analyzing principles of channelopathies and their underlying causes improves the understanding of genetic and molecular basics that may assist general research and improve SCD prevention.
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Affiliation(s)
- Krzysztof Badura
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Dominika Buławska
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Bartłomiej Dąbek
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Alicja Witkowska
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Wiktoria Lisińska
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Ewa Radzioch
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Sylwia Skwira
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Ewelina Młynarska
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
| | - Jacek Rysz
- Department of Nephrology, Hypertension and Family Medicine, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland
| | - Beata Franczyk
- Department of Nephrocardiology, Medical University of Lodz, Ul. Zeromskiego 113, 90-549 Lodz, Poland (S.S.)
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6
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Alqarawi W, Tadros R, Roberts JD, Cheung CC, Green MS, Burwash IG, Steinberg C, Healey JS, Khan H, McIntyre C, Cadrin-Touringy J, Laksman ZWM, Simpson CS, Sanatani S, Gardner M, Angaran P, Ilhan E, Talajic M, Arbour L, Leather R, Seifer C, Joza J, Lee F, Lau L, Nair G, Wells G, Krahn AD. The Prevalence and Characteristics of Arrhythmic Mitral Valve Prolapse in Patients With Unexplained Cardiac Arrest. JACC Clin Electrophysiol 2023; 9:2494-2503. [PMID: 37804262 DOI: 10.1016/j.jacep.2023.08.017] [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: 04/10/2023] [Revised: 07/25/2023] [Accepted: 08/02/2023] [Indexed: 10/09/2023]
Abstract
BACKGROUND There is growing evidence that mitral valve prolapse (MVP) is associated with otherwise unexplained cardiac arrest (UCA). However, reports are hindered by the absence of a systematic ascertainment of alternative diagnoses. OBJECTIVES This study reports the prevalence and characteristics of MVP in a large cohort of patients with UCA. METHODS Patients were enrolled following an UCA, defined as cardiac arrest with no coronary artery disease, preserved left ventricular ejection fraction, and no apparent explanation on electrocardiogram. A comprehensive evaluation was performed, and patients were diagnosed with idiopathic ventricular fibrillation (IVF) if no cause was found. Echocardiography reports were reviewed for MVP. Patients with MVP were divided into 2 groups: those with IVF (AMVP) and those with an alternative diagnosis (nonarrhythmic MVP). Patient characteristics were then compared. The long-term outcomes of AMVP were reported. RESULTS Among 571 with an initially UCA, 34 patients had MVP (6%). The prevalence of definite MVP was significantly higher in patients with IVF than those with an alternative diagnosis (24 of 366 [6.6%] vs 5 of 205 [2.4%]; P = 0.03). Bileaflet prolapse was significantly associated with AMVP (18 of 23 [78%] vs 1 of 8 [12.5%]; P = 0.001; OR: 25.2). The proportion of patients with AMVP who received appropriate implantable cardioverter-defibrillator therapies over a median follow-up of 42 months was 21.1% (4 of 19). CONCLUSIONS MVP is associated with otherwise UCA (IVF), with a prevalence of 6.6%. Bileaflet prolapse appears to be a feature of AMVP, although future studies need to ascertain its independent association. A significant proportion of patients with AMVP received appropriate implantable cardioverter-defibrillator therapies during follow-up.
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Affiliation(s)
- Wael Alqarawi
- Department of Cardiac Sciences, College of Medicine, King Saud University, Riyadh, Saudi Arabia; Division of Cardiology, University of Ottawa Heart Institute, University of Ottawa, Ottawa, Ontario, Canada.
| | - Rafik Tadros
- Cardiovascular Genetics Center, Montreal Heart Institute, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Jason D Roberts
- Population Health Research Institute, McMaster University, and Hamilton Health Sciences, Hamilton, Ontario, Canada
| | - Christopher C Cheung
- Center for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Martin S Green
- Division of Cardiology, University of Ottawa Heart Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Ian G Burwash
- Division of Cardiology, University of Ottawa Heart Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Christian Steinberg
- Institut Universitaire de Cardiologie et Pneumologie de Québec, Laval University, Quebec City, Quebec, Canada
| | - Jeffrey S Healey
- Population Health Research Institute, McMaster University, and Hamilton Health Sciences, Hamilton, Ontario, Canada
| | - Habib Khan
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, Ontario, Canada
| | | | - Julia Cadrin-Touringy
- Cardiovascular Genetics Center, Montreal Heart Institute, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Zachary W M Laksman
- Center for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Shubhayan Sanatani
- Division of Cardiology, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - Martin Gardner
- Dalhousie University and Queen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia, Canada
| | - Paul Angaran
- Cardiac Arrhythmia Service, St-Michael's Hospital, Toronto, Ontario, Canada
| | - Erkan Ilhan
- Division of Cardiology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada
| | - Mario Talajic
- Cardiovascular Genetics Center, Montreal Heart Institute, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Laura Arbour
- Center for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Richard Leather
- Center for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Colette Seifer
- St-Boniface Hospital, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jacqueline Joza
- Division of Cardiology, McGill University Health Center, Montreal, Quebec, Canada
| | - Felicity Lee
- Division of Cardiology, University of Ottawa Heart Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Lawrence Lau
- Division of Cardiology, University of Ottawa Heart Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Girish Nair
- Division of Cardiology, University of Ottawa Heart Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - George Wells
- Division of Cardiology, University of Ottawa Heart Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Andrew D Krahn
- Center for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
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7
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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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8
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Alqarawi W, Burwash IG, Krahn AD, Healey JS. Arrhythmic Mitral Valve Prolapse: Risk Assessment and Management. Can J Cardiol 2023; 39:1397-1409. [PMID: 37217162 DOI: 10.1016/j.cjca.2023.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/26/2023] [Accepted: 05/16/2023] [Indexed: 05/24/2023] Open
Abstract
Arrhythmic mitral valve prolapse (MVP) has gained great interest recently because of the increasing recognition of its potential role in unexplained cardiac arrest. Although evidence has accumulated to show the association of arrhythmic MVP (AMVP) with sudden cardiac death (SCD), risk stratification and management remain unclear. Physicians are faced with the challenges of screening for AMVP among MVP patients and the dilemma of when and how to intervene to prevent SCD in these patients. In addition, there is little guidance to help approach MVP patients who present with an otherwise unexplained cardiac arrest to know whether MVP was the primary cause of cardiac arrest or just an innocent bystander. Herein we review the epidemiology and definition of AMVP, the risk and mechanisms of SCD, and summarize the clinical evidence behind risk markers of SCD and therapeutic interventions that could potentially prevent it. We also propose an algorithm that provides guidance as to how to screen for AMVP and what therapeutic interventions to use. Last, we propose a diagnostic algorithm for approaching patients with otherwise unexplained cardiac arrest who are shown to have MVP.
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Affiliation(s)
- Wael Alqarawi
- Department of Cardiac Sciences, College of Medicine, King Saud University, Riyadh, Saudi Arabia; Division of Cardiology, University of Ottawa Heart Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Ian G Burwash
- Division of Cardiology, University of Ottawa Heart Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Andrew D Krahn
- Center for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jeffrey S Healey
- Population Health Research Institute, McMaster University, and Hamilton Health Sciences, Hamilton, Ontario, Canada.
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9
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Steinberg C. Short-Coupled Ventricular Fibrillation. Card Electrophysiol Clin 2023; 15:331-341. [PMID: 37558303 DOI: 10.1016/j.ccep.2023.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Short-coupled ventricular fibrillation (SCVF) is a distinct phenotype among individuals with unexplained cardiac arrest accounting for 7% to 14% of cases of idiopathic ventricular fibrillation (IVF). VF is typically initiated by a trigger premature ventricular contraction with a short-coupling interval of less than 350 milliseconds. In the absence of specific electrocardiographic features or provocative tests, the diagnosis remains challenging and requires documentation of VF onset. Most cases are diagnosed during follow-up at the time of VF recurrence. SCVF is characterized by a high risk of VF recurrence. Insertion of an implantable cardioverter-defibrillator and quinidine are the keystones of SCVF management.
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Affiliation(s)
- Christian Steinberg
- Institut universitaire de cardiologie et pneumologie de Québec (IUCPQ-UL), Laval University, 2725 Chemin Ste-Foy, Quebec, QC, G1V 4G5, Canada.
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10
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Alsaeed AH, Alqarawi W. Investigation of Unexplained Cardiac Arrest: Phenotyping and Genetic Testing. Card Electrophysiol Clin 2023; 15:307-318. [PMID: 37558301 DOI: 10.1016/j.ccep.2023.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Unexplained cardiac arrest (UCA) is a working diagnosis that should be replaced by a final diagnosis once evaluation is completed. Complete evaluation of UCA should include high-yield tests like cardiac magnetic resonance imaging, exercise treadmill test, and sodium-channel blocker challenge to identify latent causes of UCA. If no clear etiology is revealed after complete evaluation, idiopathic ventricular fibrillation may be diagnosed, and the strength of its diagnosis can be divided into definitive, probable, and possible based on the number of high-yield tests performed. Care should be provided by a multidisciplinary team with expertise in this area.
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Affiliation(s)
- Abdulelah H Alsaeed
- Department of Cardiac Sciences, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Wael Alqarawi
- Department of Cardiac Sciences, College of Medicine, King Saud University, Riyadh, Saudi Arabia; University of Ottawa Heart Institute, University of Ottawa, Ottawa, Canada.
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11
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Steinberg C, Krahn AD. Seeking Certainty About the Uncertain. JACC Clin Electrophysiol 2023; 9:356-358. [PMID: 36990597 DOI: 10.1016/j.jacep.2022.11.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 03/29/2023]
Affiliation(s)
- Christian Steinberg
- Institut Universitaire de Cardiologie, et Pneumologie, de Québec, Laval University, Quebec City, Quebec, Canada
| | - Andrew D Krahn
- Center for Cardiovascular Innovation, Heart Rhythm Services, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
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12
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The Importance of Systematic Diagnostic Testing in Idiopathic Ventricular Fibrillation: Results From the Dutch iVF-Registry. JACC Clin Electrophysiol 2022; 9:345-355. [PMID: 36752476 DOI: 10.1016/j.jacep.2022.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 09/27/2022] [Accepted: 10/03/2022] [Indexed: 12/03/2022]
Abstract
BACKGROUND Idiopathic ventricular fibrillation (iVF) is a diagnosis of exclusion. Systematic diagnostic testing is important to exclude alternative causes for VF. The early use of "high yield" testing, including cardiac magnetic resonance (CMR), exercise testing, and sodium channel blocker provocation, has been increasingly recognized. OBJECTIVES The purpose of this study was to investigate the importance and consistency of systematic diagnostic testing in iVF. METHODS This study included 423 iVF patients from 11 large secondary and tertiary hospitals in the Netherlands. Clinical characteristics and diagnostic testing data were ascertained. RESULTS IVF patients experienced the index event at a median age of 40 years (IQR: 28-52 years), and 61% were men. The median follow-up time was 6 years (IQR: 2-12 years). Over the years, "high yield" diagnostic tests were increasingly performed (mean 68% in 2000-2010 vs 75% in 2011-2021; P < 0.001). During follow-up, 38 patients (9%) originally labeled as iVF received an alternative diagnosis. Patients in whom "high-yield" diagnostic tests were consistently performed during the initial work-up received an alternative diagnosis less frequently during follow-up (HR: 0.439; 95% CI: 0.219-0.878; P = 0.020). Patients who received an alternative diagnosis during follow-up had a worse prognosis in terms of cardiac death (P = 0.012) with a trend toward more implantable cardioverter-defibrillator therapy (P = 0.055). CONCLUSIONS Although adherence to (near) complete diagnostic testing in this population of iVF patients increased over the years, patients with iVF still undergo varying levels of diagnostic evaluation. The latter leads to initial underdiagnosis of alternative conditions and is associated with a worse prognosis. Our results underscore the importance of early systematic diagnostic assessment in patients with apparent iVF.
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13
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Norton C, Cooper DH, Ewald G, Husaini M. Idiopathic Ventricular Fibrillation in a Previously Healthy Recreational Athlete. JACC Case Rep 2022; 4:1129-1133. [PMID: 36124154 PMCID: PMC9481893 DOI: 10.1016/j.jaccas.2022.07.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 07/06/2022] [Accepted: 07/13/2022] [Indexed: 11/29/2022]
Abstract
There are several clinical challenges in the survivor of sudden cardiac arrest (SCA), including ensuring that a comprehensive diagnostic evaluation has been performed and providing counseling on return to activity. We report a case of a highly conditioned athlete who presented following aborted SCA during exercise with a diagnosis of idiopathic ventricular fibrillation arrest. (Level of Difficulty: Intermediate.)
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Affiliation(s)
- Caleb Norton
- Address for correspondence: Dr Caleb Norton, Division of Cardiovascular Disease, Washington University in St Louis, 660 South Euclid Avenue, CB 8086, St Louis, Missouri 63110, USA. @cardscalebMD
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14
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State-of-the-Art Multimodality Imaging in Sudden Cardiac Arrest with Focus on Idiopathic Ventricular Fibrillation: A Review. J Clin Med 2022; 11:jcm11164680. [PMID: 36012918 PMCID: PMC9410297 DOI: 10.3390/jcm11164680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/01/2022] [Accepted: 08/05/2022] [Indexed: 11/16/2022] Open
Abstract
Idiopathic ventricular fibrillation is a rare cause of sudden cardiac arrest and a diagnosis by exclusion. Unraveling the mechanism of ventricular fibrillation is important for targeted management, and potentially for initiating family screening. Sudden cardiac arrest survivors undergo extensive clinical testing, with a growing role for multimodality imaging, before diagnosing “idiopathic” ventricular fibrillation. Multimodality imaging, considered as using multiple imaging modalities as diagnostics, is important for revealing structural myocardial abnormalities in patients with cardiac arrest. This review focuses on combining imaging modalities (echocardiography, cardiac magnetic resonance and computed tomography) and the electrocardiographic characterization of sudden cardiac arrest survivors and discusses the surplus value of multimodality imaging in the diagnostic routing of these patients. We focus on novel insights obtained through electrostructural and/or electromechanical imaging in apparently idiopathic ventricular fibrillation patients, with special attention to non-invasive electrocardiographic imaging.
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15
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Krahn AD, Tfelt-Hansen J, Tadros R, Steinberg C, Semsarian C, Han HC. Latent Causes of Sudden Cardiac Arrest. JACC Clin Electrophysiol 2022; 8:806-821. [PMID: 35738861 DOI: 10.1016/j.jacep.2021.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/09/2021] [Accepted: 12/29/2021] [Indexed: 11/30/2022]
Abstract
Inherited arrhythmia syndromes are a common cause of apparently unexplained cardiac arrest or sudden cardiac death. These include long QT syndrome and Brugada syndrome, with a well-recognized phenotype in most patients with sufficiently severe disease to lead to cardiac arrest. Less common and typically less apparent conditions that may not be readily evident include catecholaminergic polymorphic ventricular tachycardia, short QT syndrome and early repolarization syndrome. In cardiac arrest patients whose extensive testing does not reveal an underlying etiology, a diagnosis of idiopathic ventricular fibrillation or short-coupled ventricular fibrillation is assigned. This review summarizes our current understanding of the less common inherited arrhythmia syndromes 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, British Columbia, Canada.
| | - Jacob Tfelt-Hansen
- The Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; Department of Forensic Medicine, Faculty of Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rafik Tadros
- Cardiovascular Genetics Center, Montreal Heart Institute, Department of Medicine, Université de Montréal, Montreal, Québec, Canada
| | - Christian Steinberg
- Institut universitaire de cardiologie et pneumologie de Québec (IUCPQ-UL), Laval University, Inherited Arrhythmia Services, Départment of Cardiology and Cardiac Surgery, Québec, Canada
| | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Hui-Chen Han
- Center for Cardiovascular Innovation, Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada; Victorian Heart Institute, Monash University, Clayton, Victoria, Australia
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16
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Belhassen B, Tovia-Brodie O. Short-Coupled Idiopathic Ventricular Fibrillation: A Literature Review With Extended Follow-Up. JACC Clin Electrophysiol 2022; 8:918-936. [PMID: 35597766 DOI: 10.1016/j.jacep.2022.04.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/25/2022] [Accepted: 04/18/2022] [Indexed: 01/07/2023]
Abstract
Idiopathic ventricular fibrillation is responsible for approximately 10% of cases of aborted cardiac arrest. Recent studies have shown that short-coupled ventricular premature complexes are present at the onset of idiopathic ventricular fibrillation in 6.6%-17% of patients. The present review provided information on 86 patients with short-coupled malignant ventricular arrhythmias that were reported as case reports or small patient series during the last 70 years. In 75% of the 81 cases published during the last 40 years, extended information and follow-up (from 2.63 ± 4.5 to 10.67 ± 7.8 years; P < 0.001, between the original publication to the latest update) could be obtained from the authors. The review shows that short-coupled malignant ventricular arrhythmias occurred almost equally in males and females, at the mean age of 40 years. A tendency for later occurrence of the arrhythmia by 4 years was observed in females. A prior history of syncope was noted in 45.3% of the patients, whereas arrhythmic storm occurred in 42% at presentation. The most common mode of revelation of short-coupled malignant ventricular arrhythmias was syncope (53.5%), followed by aborted cardiac arrest (26.7%) and recurrent arrhythmic event after prior implantable-cardioverter defibrillator implantation for idiopathic ventricular fibrillation (17.4%). For the first time, short-coupled malignant arrhythmias exhibiting "not-so-short" coupling intervals (≥350 ms) were found in a significant proportion of patients (17.4%). During long-term follow-up, quinidine yielded a slightly higher success rate in arrhythmia control than ablation. Larger studies are necessary to assess the best strategy for the management of this potentially lethal arrhythmia.
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Affiliation(s)
- Bernard Belhassen
- Heart Institute, Hadassah Medical Center, Jerusalem, Israel; Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
| | - Oholi Tovia-Brodie
- Jesselson Integrated Heart Center, Shaare Zedek Medical Center, Jerusalem, Israel; Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
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17
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Franciosi S, Abrams DJ, Ingles J, Sanatani S. Sudden Cardiac Arrest in the Paediatric Population. CJC PEDIATRIC AND CONGENITAL HEART DISEASE 2022; 1:45-59. [PMID: 37969243 PMCID: PMC10642157 DOI: 10.1016/j.cjcpc.2022.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 02/03/2022] [Indexed: 11/17/2023]
Abstract
Sudden cardiac arrest in the young is a rare event with a range of potential causes including cardiomyopathies, ion channelopathies, and autonomic nervous system dysfunction. Investigations into the cause involve a multidisciplinary team, including cardiologists, geneticists, and psychologists. In addition to a detailed medical history, family history and circumstances surrounding the event are important in determining the cause. Clinical investigations including an electrocardiogram are fundamental in diagnosis and should be interpreted cautiously because some children may have atypical presentations and an evolving phenotype. The potential for misdiagnosis exists that could lead to incorrect long-term management strategies. If an inherited condition is suspected, genetic testing of the patient and cascade screening of family members is recommended with genetic counselling and psychological support. Medical management is left to the treating physician acknowledging that a clear diagnosis cannot be made in approximately half of cases. Secondary prevention implantable defibrillators are widely deployed but can be associated with complications in young patients. A plan for safe return to activity is recommended along with a proper transition of care into adulthood. Broad screening of the general population for arrhythmia syndromes is not recommended; preventative measures include screening paediatric patients for risk factors by their primary care physician. Several milestone events or activities that take place in youth could be used as opportunities to promote safety. Further work into risk stratification of this paediatric population through patient registries and greater awareness of cardiopulmonary resuscitation and automated external defibrillator use in saving lives is warranted.
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Affiliation(s)
- Sonia Franciosi
- BC Children’s Hospital Heart Centre, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dominic J. Abrams
- Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Jodie Ingles
- Centre for Population Genomics, Garvan Institute of Medical Research, and UNSW Sydney, Sydney, New South Wales, Australia
- Centre for Population Genomics, Murdoch Children’s Research Institute, Melbourne, Victoria, Australia
| | - Shubhayan Sanatani
- BC Children’s Hospital Heart Centre, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
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18
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Nine Reasons for Performing an Electrophysiologic Study in Patients with Apparently Idiopathic Ventricular Fibrillation. Heart Rhythm 2022; 19:1212-1213. [DOI: 10.1016/j.hrthm.2022.03.010] [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: 02/07/2022] [Revised: 03/04/2022] [Accepted: 03/07/2022] [Indexed: 11/19/2022]
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19
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Mellor GJ, Tadros R, Krahn AD. Cardiomyopathy Genes and Idiopathic VF: A Known Unknown? Circ Genom Precis Med 2022; 15:e003680. [DOI: 10.1161/circgen.122.003680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Greg J. Mellor
- Cardiology Department, Royal Papworth Hospital, Cambridge, United Kingdom (G.J.M.)
| | - Rafik Tadros
- Cardiovascular Genetics Center, Montreal Heart Institute and Faculty of Medicine, Université de Montréal, QC, Canada (R.T.)
| | - Andrew D. Krahn
- Division of Cardiology, Center for Cardiovascular Innovation, University of British Columbia, Vancouver, Canada (A.D.K.)
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20
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Grondin S, Davies B, Cadrin-Tourigny J, Steinberg C, Cheung CC, Jorda P, Healey JS, Green MS, Sanatani S, Alqarawi W, Angaran P, Arbour L, Antiperovitch P, Khan H, Leather R, Guerra PG, Rivard L, Simpson CS, Gardner M, MacIntyre C, Seifer C, Fournier A, Joza J, Gollob MH, Lettre G, Talajic M, Laksman ZW, Roberts JD, Krahn AD, Tadros R. OUP accepted manuscript. Eur Heart J 2022; 43:3071-3081. [PMID: 35352813 PMCID: PMC9392649 DOI: 10.1093/eurheartj/ehac145] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 01/25/2022] [Accepted: 03/07/2022] [Indexed: 12/04/2022] Open
Abstract
Aims Genetic testing is recommended in specific inherited heart diseases but its role remains unclear and it is not currently recommended in unexplained cardiac arrest (UCA). We sought to assess the yield and clinical utility of genetic testing in UCA using whole-exome sequencing (WES). Methods and results Survivors of UCA requiring external defibrillation were included from the Cardiac Arrest Survivor with Preserved Ejection fraction Registry. Whole-exome sequencing was performed, followed by assessment of rare variants in previously reported cardiovascular disease genes. A total of 228 UCA survivors (mean age at arrest 39 ± 13 years) were included. The majority were males (66%) and of European ancestry (81%). Following advanced clinical testing at baseline, the likely aetiology of cardiac arrest was determined in 21/228 (9%) cases. Whole-exome sequencing identified a pathogenic or likely pathogenic (P/LP) variant in 23/228 (10%) of UCA survivors overall, increasing the proportion of ‘explained’ cases from 9% only following phenotyping to 18% when combining phenotyping with WES. Notably, 13 (57%) of the 23 P/LP variants identified were located in genes associated with cardiomyopathy, in the absence of a diagnosis of cardiomyopathy at the time of arrest. Conclusions Genetic testing identifies a disease-causing variant in 10% of apparent UCA survivors. The majority of disease-causing variants was located in cardiomyopathy-associated genes, highlighting the arrhythmogenic potential of such variants in the absence of an overt cardiomyopathy diagnosis. The present study supports the use of genetic testing including assessment of arrhythmia and cardiomyopathy genes in survivors of UCA.
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Affiliation(s)
- Steffany Grondin
- Cardiovascular Genetics Center, Montreal Heart Institute, Department of Medicine, Université de Montréal, 5000 Belanger, Montreal, QC, Canada H1T 1C8
| | - Brianna Davies
- Center for Cardiovascular Innovation, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Julia Cadrin-Tourigny
- Cardiovascular Genetics Center, Montreal Heart Institute, Department of Medicine, Université de Montréal, 5000 Belanger, Montreal, QC, Canada H1T 1C8
| | - Christian Steinberg
- Institut universitaire de cardiologie et pneumologie de Québec, Université Laval, Québec City, QC, Canada
| | - Christopher C Cheung
- Center for Cardiovascular Innovation, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Paloma Jorda
- Cardiovascular Genetics Center, Montreal Heart Institute, Department of Medicine, Université de Montréal, 5000 Belanger, Montreal, QC, Canada H1T 1C8
| | - Jeffrey S Healey
- Population Health Research Institute, McMaster University, and Hamilton Health Sciences, Hamilton, ON, Canada
| | - Martin S Green
- Division of Cardiology, University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Shubhayan Sanatani
- Division of Pediatric Cardiology, British Columbia Children’s Hospital, Vancouver, BC, Canada
| | - Wael Alqarawi
- Division of Cardiology, University of Ottawa Heart Institute, Ottawa, ON, Canada
- Department of Cardiac Sciences, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Paul Angaran
- Cardiac Arrhythmia Service, St Michael’s Hospital, Toronto, ON, Canada
| | - Laura Arbour
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Pavel Antiperovitch
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada
| | - Habib Khan
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada
| | - Richard Leather
- Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada
| | - Peter G Guerra
- Cardiovascular Genetics Center, Montreal Heart Institute, Department of Medicine, Université de Montréal, 5000 Belanger, Montreal, QC, Canada H1T 1C8
| | - Lena Rivard
- Cardiovascular Genetics Center, Montreal Heart Institute, Department of Medicine, Université de Montréal, 5000 Belanger, Montreal, QC, Canada H1T 1C8
| | | | - Martin Gardner
- Queen Elizabeth II Health Sciences Center, Halifax, NS, Canada
| | | | - Colette Seifer
- St Boniface Hospital, University of Manitoba, Winnipeg, MB, Canada
| | - Anne Fournier
- Ste-Justine Hospital, Université de Montréal, Montreal, QC, Canada
| | - Jacqueline Joza
- Department of Medicine, McGill University Health Center, Montreal, QC, Canada
| | - Michael H Gollob
- Division of Cardiology, University Health Network, Toronto General Hospital, Toronto, ON, Canada
| | - Guillaume Lettre
- Cardiovascular Genetics Center, Montreal Heart Institute, Department of Medicine, Université de Montréal, 5000 Belanger, Montreal, QC, Canada H1T 1C8
| | - Mario Talajic
- Cardiovascular Genetics Center, Montreal Heart Institute, Department of Medicine, Université de Montréal, 5000 Belanger, Montreal, QC, Canada H1T 1C8
| | - Zachary W Laksman
- Center for Cardiovascular Innovation, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Jason D Roberts
- Population Health Research Institute, McMaster University, and Hamilton Health Sciences, Hamilton, ON, Canada
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON, Canada
| | - Andrew D Krahn
- Center for Cardiovascular Innovation, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Rafik Tadros
- Corresponding author. Tel: +1 514 376 3330, Fax: +1 514 593 2158, , Twitter: @rafik_tadros
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