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Bene Watts S, Gauthier B, Erickson AC, Morrison J, Sebastian M, Gillman L, McIntosh S, Ens C, Sherwin E, McCormick R, Sanatani S, Arbour L. A mild phenotype associated with KCNQ1 p.V205M mediated long QT syndrome in First Nations children of Northern British Columbia: effect of additional variants and considerations for management. Front Pediatr 2024; 12:1394105. [PMID: 38884101 PMCID: PMC11176454 DOI: 10.3389/fped.2024.1394105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 05/16/2024] [Indexed: 06/18/2024] Open
Abstract
Introduction Congenital Long QT Syndrome (LQTS) is common in a First Nations community in Northern British Columbia due to the founder variant KCNQ1 p.V205M. Although well characterized molecularly and clinically in adults, no data have been previously reported on the pediatric population. The phenotype in adults has been shown to be modified by a splice site variant in KCNQ1 (p.L353L). The CPT1A p.P479L metabolic variant, also common in Northern Indigenous populations, is associated with hypoglycemia and infant death. Since hypoglycemia can affect the corrected QT interval (QTc) and may confer risk for seizures (also associated with LQTS), we sought to determine the effect of all three variants on the LQTS phenotype in children within our First Nations cohort. Methods As part of a larger study assessing those with LQTS and their relatives in a Northern BC First Nation, we assessed those entering the study from birth to age 18 years. We compared the corrected peak QTc and potential cardiac events (syncope/seizures) of 186 children from birth to 18 years, with and without the KCNQ1 (p.V205M and p.L353L) and CPT1A variants, alone and in combination. Linear and logistic regression and student t-tests were applied as appropriate. Results Only the KCNQ1 p.V205M variant conferred a significant increase in peak QTc 23.8 ms (p < 0.001) above baseline, with females increased by 30.1 ms (p < 0.001) and males by 18.9 ms (p < 0.01). There was no evidence of interaction effects with the other two variants studied. Although the p.V205M variant was not significantly associated with syncope/seizures, the odds of having a seizure/syncope were significantly increased for those homozygous for CPT1A p.P479L compared to homozygous wild type (Odds Ratio [OR]3.0 [95% confidence interval (CI) 1.2-7.7]; p = 0.019). Conclusion While the KCNQ1 p.V205M variant prolongs the peak QTc, especially in females, the CPT1A p.P479L variant is more strongly associated with loss of consciousness events. These findings suggest that effect of the KCNQ1 p.V205M variant is mild in this cohort, which may have implications for standard management. Our findings also suggest the CPT1A p.P479L variant is a risk factor for seizures and possibly syncope, which may mimic a long QT phenotype.
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Affiliation(s)
- Simona Bene Watts
- Island Medical Program, University of British Columbia, Victoria, BC, Canada
| | - Barbara Gauthier
- Epidemiology and Surveillance Unit, Interior Health Authority, Kelowna, BC, Canada
| | | | | | | | - Lawrence Gillman
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Sarah McIntosh
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Connie Ens
- Department of Pediatrics, Division of Cardiology, British Columbia Children's Hospital, Vancouver, BC, Canada
| | - Elizabeth Sherwin
- Department of Pediatrics, Children's National Hospital, Washington, DC, United States
| | - Rod McCormick
- Department of Education and Social Work, Thompson Rivers University, Kamloops, BC, Canada
| | - Shubhayan Sanatani
- Department of Pediatrics, Division of Cardiology, British Columbia Children's Hospital, Vancouver, BC, Canada
| | - Laura Arbour
- Island Medical Program, University of British Columbia, Victoria, BC, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
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Balestra E, Bobbo M, Cittar M, Chicco D, D’Agata Mottolese B, Barbi E, Caiffa T. Congenital Long QT Syndrome in Children and Adolescents: A General Overview. CHILDREN (BASEL, SWITZERLAND) 2024; 11:582. [PMID: 38790576 PMCID: PMC11119491 DOI: 10.3390/children11050582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 04/24/2024] [Accepted: 05/06/2024] [Indexed: 05/26/2024]
Abstract
Congenital long QT syndrome (LQTS) represents a disorder of myocardial repolarization characterized by a prolongation of QTc interval on ECG, which can degenerate into fast polymorphic ventricular arrhythmias. The typical symptoms of LQTS are syncope and palpitations, mainly triggered by adrenergic stimuli, but it can also manifest with cardiac arrest. At least 17 genotypes have been associated with LQTS, with a specific genotype-phenotype relationship described for the three most common subtypes (LQTS1, -2, and -3). β-Blockers are the first-line therapy for LQTS, even if the choice of the appropriate patients needing to be treated may be challenging. In specific cases, interventional measures, such as an implantable cardioverter-defibrillator (ICD) or left cardiac sympathetic denervation (LCSD), are useful. The aim of this review is to highlight the current state-of-the-art knowledge on LQTS, providing an updated picture of possible diagnostic algorithms and therapeutic management.
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Affiliation(s)
- Elia Balestra
- Department of Medical, Surgical and Health Sciences, University of Trieste, 34127 Trieste, Italy;
| | - Marco Bobbo
- Institute for Maternal and Child Health, IRCCS “Burlo Garofolo”, 34127 Trieste, Italy; (M.B.); (D.C.); (B.D.M.); (T.C.)
| | - Marco Cittar
- Cardiovascular Department, Centre for Diagnosis and Management of Cardiomyopathies, Azienda Sanitaria Universitaria Integrata di Trieste, University of Trieste, 34127 Trieste, Italy;
| | - Daniela Chicco
- Institute for Maternal and Child Health, IRCCS “Burlo Garofolo”, 34127 Trieste, Italy; (M.B.); (D.C.); (B.D.M.); (T.C.)
| | - Biancamaria D’Agata Mottolese
- Institute for Maternal and Child Health, IRCCS “Burlo Garofolo”, 34127 Trieste, Italy; (M.B.); (D.C.); (B.D.M.); (T.C.)
| | - Egidio Barbi
- Department of Medical, Surgical and Health Sciences, University of Trieste, 34127 Trieste, Italy;
- Institute for Maternal and Child Health, IRCCS “Burlo Garofolo”, 34127 Trieste, Italy; (M.B.); (D.C.); (B.D.M.); (T.C.)
| | - Thomas Caiffa
- Institute for Maternal and Child Health, IRCCS “Burlo Garofolo”, 34127 Trieste, Italy; (M.B.); (D.C.); (B.D.M.); (T.C.)
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Cócera-Ortega L, Wilders R, Kamps SC, Fabrizi B, Huber I, van der Made I, van den Bout A, de Vries DK, Gepstein L, Verkerk AO, Pinto YM, Tijsen AJ. shRNAs Targeting a Common KCNQ1 Variant Could Alleviate Long-QT1 Disease Severity by Inhibiting a Mutant Allele. Int J Mol Sci 2022; 23:ijms23074053. [PMID: 35409410 PMCID: PMC9000197 DOI: 10.3390/ijms23074053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 12/02/2022] Open
Abstract
Long-QT syndrome type 1 (LQT1) is caused by mutations in KCNQ1. Patients heterozygous for such a mutation co-assemble both mutant and wild-type KCNQ1-encoded subunits into tetrameric Kv7.1 potassium channels. Here, we investigated whether allele-specific inhibition of mutant KCNQ1 by targeting a common variant can shift the balance towards increased incorporation of the wild-type allele to alleviate the disease in human-induced pluripotent stem-cell-derived cardiomyocytes (hiPSC-CMs). We identified the single nucleotide polymorphisms (SNP) rs1057128 (G/A) in KCNQ1, with a heterozygosity of 27% in the European population. Next, we determined allele-specificity of short-hairpin RNAs (shRNAs) targeting either allele of this SNP in hiPSC-CMs that carry an LQT1 mutation. Our shRNAs downregulated 60% of the A allele and 40% of the G allele without affecting the non-targeted allele. Suppression of the mutant KCNQ1 allele by 60% decreased the occurrence of arrhythmic events in hiPSC-CMs measured by a voltage-sensitive reporter, while suppression of the wild-type allele increased the occurrence of arrhythmic events. Furthermore, computer simulations based on another LQT1 mutation revealed that 60% suppression of the mutant KCNQ1 allele shortens the prolonged action potential in an adult cardiomyocyte model. We conclude that allele-specific inhibition of a mutant KCNQ1 allele by targeting a common variant may alleviate the disease. This novel approach avoids the need to design shRNAs to target every single mutation and opens up the exciting possibility of treating multiple LQT1-causing mutations with only two shRNAs.
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Affiliation(s)
- Lucía Cócera-Ortega
- Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (L.C.-O.); (S.C.K.); (B.F.); (I.v.d.M.); (A.v.d.B.); (D.K.d.V.); (A.O.V.); (Y.M.P.)
| | - Ronald Wilders
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands;
| | - Selina C. Kamps
- Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (L.C.-O.); (S.C.K.); (B.F.); (I.v.d.M.); (A.v.d.B.); (D.K.d.V.); (A.O.V.); (Y.M.P.)
| | - Benedetta Fabrizi
- Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (L.C.-O.); (S.C.K.); (B.F.); (I.v.d.M.); (A.v.d.B.); (D.K.d.V.); (A.O.V.); (Y.M.P.)
| | - Irit Huber
- The Sohnis Family Laboratory for Cardiac Electrophysiology and Regenerative Medicine, Rappaport Faculty of Medicine and Research Institute, Technion—Israel Institute of Technology, Haifa 3109601, Israel; (I.H.); (L.G.)
| | - Ingeborg van der Made
- Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (L.C.-O.); (S.C.K.); (B.F.); (I.v.d.M.); (A.v.d.B.); (D.K.d.V.); (A.O.V.); (Y.M.P.)
| | - Anouk van den Bout
- Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (L.C.-O.); (S.C.K.); (B.F.); (I.v.d.M.); (A.v.d.B.); (D.K.d.V.); (A.O.V.); (Y.M.P.)
| | - Dylan K. de Vries
- Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (L.C.-O.); (S.C.K.); (B.F.); (I.v.d.M.); (A.v.d.B.); (D.K.d.V.); (A.O.V.); (Y.M.P.)
| | - Lior Gepstein
- The Sohnis Family Laboratory for Cardiac Electrophysiology and Regenerative Medicine, Rappaport Faculty of Medicine and Research Institute, Technion—Israel Institute of Technology, Haifa 3109601, Israel; (I.H.); (L.G.)
| | - Arie O. Verkerk
- Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (L.C.-O.); (S.C.K.); (B.F.); (I.v.d.M.); (A.v.d.B.); (D.K.d.V.); (A.O.V.); (Y.M.P.)
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands;
| | - Yigal M. Pinto
- Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (L.C.-O.); (S.C.K.); (B.F.); (I.v.d.M.); (A.v.d.B.); (D.K.d.V.); (A.O.V.); (Y.M.P.)
| | - Anke J. Tijsen
- Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (L.C.-O.); (S.C.K.); (B.F.); (I.v.d.M.); (A.v.d.B.); (D.K.d.V.); (A.O.V.); (Y.M.P.)
- Correspondence: ; Tel.: +31-205668544
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Martínez-Barrios E, Cesar S, Cruzalegui J, Hernandez C, Arbelo E, Fiol V, Brugada J, Brugada R, Campuzano O, Sarquella-Brugada G. Clinical Genetics of Inherited Arrhythmogenic Disease in the Pediatric Population. Biomedicines 2022; 10:106. [PMID: 35052786 PMCID: PMC8773373 DOI: 10.3390/biomedicines10010106] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/27/2021] [Accepted: 12/31/2021] [Indexed: 12/19/2022] Open
Abstract
Sudden death is a rare event in the pediatric population but with a social shock due to its presentation as the first symptom in previously healthy children. Comprehensive autopsy in pediatric cases identify an inconclusive cause in 40-50% of cases. In such cases, a diagnosis of sudden arrhythmic death syndrome is suggested as the main potential cause of death. Molecular autopsy identifies nearly 30% of cases under 16 years of age carrying a pathogenic/potentially pathogenic alteration in genes associated with any inherited arrhythmogenic disease. In the last few years, despite the increasing rate of post-mortem genetic diagnosis, many families still remain without a conclusive genetic cause of the unexpected death. Current challenges in genetic diagnosis are the establishment of a correct genotype-phenotype association between genes and inherited arrhythmogenic disease, as well as the classification of variants of uncertain significance. In this review, we provide an update on the state of the art in the genetic diagnosis of inherited arrhythmogenic disease in the pediatric population. We focus on emerging publications on gene curation for genotype-phenotype associations, cases of genetic overlap and advances in the classification of variants of uncertain significance. Our goal is to facilitate the translation of genetic diagnosis to the clinical area, helping risk stratification, treatment and the genetic counselling of families.
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Affiliation(s)
- Estefanía Martínez-Barrios
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08007 Barcelona, Spain; (E.M.-B.); (S.C.); (J.C.); (C.H.); (V.F.); (J.B.)
| | - Sergi Cesar
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08007 Barcelona, Spain; (E.M.-B.); (S.C.); (J.C.); (C.H.); (V.F.); (J.B.)
| | - José Cruzalegui
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08007 Barcelona, Spain; (E.M.-B.); (S.C.); (J.C.); (C.H.); (V.F.); (J.B.)
| | - Clara Hernandez
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08007 Barcelona, Spain; (E.M.-B.); (S.C.); (J.C.); (C.H.); (V.F.); (J.B.)
| | - Elena Arbelo
- Centro de Investigación Biomédica en Red, Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain; (E.A.); (R.B.)
- Arrhythmias Unit, Hospital Clinic, University of Barcelona-IDIBAPS, 08036 Barcelona, Spain
| | - Victoria Fiol
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08007 Barcelona, Spain; (E.M.-B.); (S.C.); (J.C.); (C.H.); (V.F.); (J.B.)
| | - Josep Brugada
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08007 Barcelona, Spain; (E.M.-B.); (S.C.); (J.C.); (C.H.); (V.F.); (J.B.)
- Centro de Investigación Biomédica en Red, Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain; (E.A.); (R.B.)
- Arrhythmias Unit, Hospital Clinic, University of Barcelona-IDIBAPS, 08036 Barcelona, Spain
| | - Ramon Brugada
- Centro de Investigación Biomédica en Red, Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain; (E.A.); (R.B.)
- Medical Science Department, School of Medicine, University of Girona, 17004 Girona, Spain
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
- Cardiology Service, Hospital Josep Trueta, University of Girona, 17007 Girona, Spain
| | - Oscar Campuzano
- Centro de Investigación Biomédica en Red, Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain; (E.A.); (R.B.)
- Medical Science Department, School of Medicine, University of Girona, 17004 Girona, Spain
- Cardiovascular Genetics Center, University of Girona-IDIBGI, 17190 Girona, Spain
| | - Georgia Sarquella-Brugada
- Arrhythmias Unit, Hospital Sant Joan de Déu, University of Barcelona, 08007 Barcelona, Spain; (E.M.-B.); (S.C.); (J.C.); (C.H.); (V.F.); (J.B.)
- Medical Science Department, School of Medicine, University of Girona, 17004 Girona, Spain
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Lee S, Zhou J, Jeevaratnam K, Wong WT, Wong ICK, Mak C, Mok NS, Liu T, Zhang Q, Tse G. Paediatric/young versus adult patients with long QT syndrome. Open Heart 2021; 8:openhrt-2021-001671. [PMID: 34518285 PMCID: PMC8438947 DOI: 10.1136/openhrt-2021-001671] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 08/02/2021] [Indexed: 12/20/2022] Open
Abstract
Introduction Long QT syndrome (LQTS) is a less prevalent cardiac ion channelopathy than Brugada syndrome in Asia. The present study compared the outcomes between paediatric/young and adult LQTS patients. Methods This was a population-based retrospective cohort study of consecutive patients diagnosed with LQTS attending public hospitals in Hong Kong. The primary outcome was spontaneous ventricular tachycardia/ventricular fibrillation (VT/VF). Results A total of 142 LQTS (mean onset age=27±23 years old) were included. Arrhythmias other than VT/VF (HR 4.67, 95% CI (1.53 to 14.3), p=0.007), initial VT/VF (HR=3.25 (95% CI 1.29 to 8.16), p=0.012) and Schwartz score (HR=1.90 (95% CI 1.11 to 3.26), p=0.020) were predictive of the primary outcome for the overall cohort, while arrhythmias other than VT/VF (HR=5.41 (95% CI 1.36 to 21.4), p=0.016) and Schwartz score (HR=4.67 (95% CI 1.48 to 14.7), p=0.009) were predictive for the adult subgroup (>25 years old; n=58). A random survival forest model identified initial VT/VF, Schwartz score, initial QTc interval, family history of LQTS, initially asymptomatic and arrhythmias other than VT/VF as the most important variables for risk prediction. Conclusion Clinical and ECG presentation varies between the paediatric/young and adult LQTS population. Machine learning models achieved more accurate VT/VF prediction.
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Affiliation(s)
- Sharen Lee
- Cardiovascular Analytics Group, Hong Kong, China-UK Collaboration
| | - Jiandong Zhou
- School of Data Science, City University of Hong Kong, Hong Kong, People's Republic of China
| | - Kamalan Jeevaratnam
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | - Wing Tak Wong
- School of Life Sciences, Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Ian Chi Kei Wong
- Research Department of Practice and Policy, University College London School of Pharmacy, London, UK
| | - Chloe Mak
- Department of Pathology, Hong Kong Children's Hospital, Hong Kong, People's Republic of China
| | - Ngai Shing Mok
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Hong Kong, People's Republic of China
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, People's Republic of China
| | - Qingpeng Zhang
- School of Data Science, City University of Hong Kong, Hong Kong, People's Republic of China
| | - Gary Tse
- Cardiovascular Analytics Group, Hong Kong, China-UK Collaboration .,Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK.,Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, People's Republic of China
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Went TR, Sultan W, Sapkota A, Khurshid H, Qureshi IA, Jahan N, Tara A, Win M, Wiltshire DA, Kannan A, Ruo SW, Alfonso M. A Systematic Review on the Role of Βeta-Blockers in Reducing Cardiac Arrhythmias in Long QT Syndrome Subtypes 1-3. Cureus 2021; 13:e17632. [PMID: 34646680 PMCID: PMC8485362 DOI: 10.7759/cureus.17632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2021] [Indexed: 12/12/2022] Open
Abstract
Long QT syndrome (LQTS) is one of the most common inherited cardiac channelopathies with a prevalence of 1:2000. The condition can be congenital or acquired with 15 recognized genotypes; the most common subtypes are LQTS 1, 2, and 3 making up to 85%-90% of the cases. LQTS is characterized by delayed ventricular cardiomyocyte repolarization manifesting on the surface electrocardiogram (EKG) by a prolonged corrected QT (QTc) interval. The mainstay of treatment for this condition involves in part or combination medical therapy via β-blockers as first-line (or other anti-arrhythmic), left cardiac sympathectomy, or implantable cardiac defibrillator placement. Given the high rate of adverse cardiac events (ACE) or sudden cardiac death (SCD) in this population of patients with this disease, this review seeks to highlight the genotype-specific treatment consensus in β-blocker therapy of the most common subtypes. A database search of PubMed, PMC, and Medline was conducted to ascertain the most recent data in the last five years on the management of LQTS types 1-3 and the role of β-blockers in reducing ACE in these types. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were adhered to in the study selection, and selected studies focused on humans, written in the English Language, and within the last five years of LQTS subtypes 1, 2, and 3. Eleven relevant studies were selected after considering inclusion criteria, exclusion criteria, and quality appraisal within the last five years, focusing on β-blocker selection directed based on the subtypes of LQTS. Two meta-analyses, one cohort study, and eight reviews provided significant data that non-selective β-blockers unequivocally are of benefit in these LQTS types. Summary of findings suggested nadolol followed by propranolol yields the best results in LQTS 1, while nadolol would yield the best effect in LQTS 2 and 3.
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Affiliation(s)
- Terry R Went
- Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Waleed Sultan
- Medicine, Beni Suef University Faculty of Medicine, Beni Suef, EGY
- Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
- Surgery, Halifax Health Medical Center, Daytona Beach, USA
| | - Alisha Sapkota
- Psychiatry, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Hajra Khurshid
- Medicine and Psychiatry, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Israa A Qureshi
- Internal Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Nasrin Jahan
- Psychiatry, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Anjli Tara
- General Medicine, General Surgery, and Emergency Department, Jinnah Postgraduate Medical Centre, Karachi, PAK
- Neurosurgery and General Surgery, Liaquat University of Medical and Health Sciences, Karachi, PAK
- Neurosurgery and General Surgery, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Myat Win
- General Surgery, Nottingham University Hospitals NHS Trust, Nottingham, GBR
- General Surgery, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Dwayne A Wiltshire
- Internal Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Amudhan Kannan
- Neurological Surgery Research, Surgical Oncology Research, and General Surgery Research, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
- Surgical Pharmacology, General Surgery, and Surgery, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, IND
| | - Sheila W Ruo
- General Surgery Research, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Michael Alfonso
- Medicine, Universidad del Rosario, Bogota, COL
- Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
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Abstract
Congenital Long QT Syndrome (LQTS) is a dangerous arrhythmic disorder that can be diagnosed in children with bradycardia. It is characterised by a prolonged QT interval and torsades de pointes that may cause sudden death. Long QT syndrome is an ion channelopathy with complex molecular and physiological infrastructure. Unlike the acquired type, congenital LQTS has a genetic inheritance and it may be diagnosed by syncope, stress in activity, cardiac dysfunction, sudden death or sometimes incidentally. Permanent pacemaker implantation is required for LQTS with resistant bradycardia even in children to resolve symptoms and avoid sudden death.
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8
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Wallace E, Howard L, Liu M, O'Brien T, Ward D, Shen S, Prendiville T. Long QT Syndrome: Genetics and Future Perspective. Pediatr Cardiol 2019; 40:1419-1430. [PMID: 31440766 PMCID: PMC6785594 DOI: 10.1007/s00246-019-02151-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Accepted: 07/10/2019] [Indexed: 01/19/2023]
Abstract
Long QT syndrome (LQTS) is an inherited primary arrhythmia syndrome that may present with malignant arrhythmia and, rarely, risk of sudden death. The clinical symptoms include palpitations, syncope, and anoxic seizures secondary to ventricular arrhythmia, classically torsade de pointes. This predisposition to malignant arrhythmia is from a cardiac ion channelopathy that results in delayed repolarization of the cardiomyocyte action potential. The QT interval on the surface electrocardiogram is a summation of the individual cellular ventricular action potential durations, and hence is a surrogate marker of the abnormal cellular membrane repolarization. Severely affected phenotypes administered current standard of care therapies may not be fully protected from the occurrence of cardiac arrhythmias. There are 17 different subtypes of LQTS associated with monogenic mutations of 15 autosomal dominant genes. It is now possible to model the various LQTS phenotypes through the generation of patient-specific induced pluripotent stem cell-derived cardiomyocytes. RNA interference can silence or suppress the expression of mutant genes. Thus, RNA interference can be a potential therapeutic intervention that may be employed in LQTS to knock out mutant mRNAs which code for the defective proteins. CRISPR/Cas9 is a genome editing technology that offers great potential in elucidating gene function and a potential therapeutic strategy for monogenic disease. Further studies are required to determine whether CRISPR/Cas9 can be employed as an efficacious and safe rescue of the LQTS phenotype. Current progress has raised opportunities to generate in vitro human cardiomyocyte models for drug screening and to explore gene therapy through genome editing.
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Affiliation(s)
- Eimear Wallace
- Regenerative Medicine Institute, School of Medicine, National University of Ireland (NUI) Galway, Galway, Ireland
| | - Linda Howard
- Regenerative Medicine Institute, School of Medicine, National University of Ireland (NUI) Galway, Galway, Ireland
| | - Min Liu
- Regenerative Medicine Institute, School of Medicine, National University of Ireland (NUI) Galway, Galway, Ireland
| | - Timothy O'Brien
- Regenerative Medicine Institute, School of Medicine, National University of Ireland (NUI) Galway, Galway, Ireland
| | - Deirdre Ward
- Department of Cardiology, Tallaght University Hospital, Dublin, Ireland
| | - Sanbing Shen
- Regenerative Medicine Institute, School of Medicine, National University of Ireland (NUI) Galway, Galway, Ireland
| | - Terence Prendiville
- Department of Paediatric Cardiology, Our Lady's Children's Hospital Crumlin, Dublin, Ireland.
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9
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Skinner JR, Winbo A, Abrams D, Vohra J, Wilde AA. Channelopathies That Lead to Sudden Cardiac Death: Clinical and Genetic Aspects. Heart Lung Circ 2019; 28:22-30. [DOI: 10.1016/j.hlc.2018.09.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 09/20/2018] [Accepted: 09/23/2018] [Indexed: 12/19/2022]
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10
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Hylind RJ, Chandler SF, Skinner JR, Abrams DJ. Genetic Testing for Inherited Cardiac Arrhythmias: Current State-of-the-Art and Future Avenues. J Innov Card Rhythm Manag 2018; 9:3406-3416. [PMID: 32494476 PMCID: PMC7252877 DOI: 10.19102/icrm.2018.091102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 03/14/2018] [Indexed: 12/24/2022] Open
Abstract
The seminal discovery that sequence variation in genes encoding cardiac ion channels was behind the inherited cardiac arrhythmic syndromes has led to major advances in understanding the functional biological mechanisms of cardiomyocyte depolarization and repolarization. The cost and speed with which these genes can now be sequenced have allowed for genetic testing to become a major component of clinical care and have led to important ramifications, yet interpretation of specific variants needs to be performed within the context of the clinical findings in the proband and extended family. As technology continues to advance, the promise of therapeutic manipulation of certain genetic pathways grows ever more real.
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Affiliation(s)
- Robyn J. Hylind
- Inherited Cardiac Arrhythmia Program, Department of Cardiology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Stephanie F. Chandler
- Inherited Cardiac Arrhythmia Program, Department of Cardiology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Jonathan R. Skinner
- Green Lane Paediatric and Congenital Cardiac Services, Starship Children’s Hospital, Auckland, New Zealand
- Department of Paediatrics, Child and Youth Health, The University of Auckland, Auckland, New Zealand
| | - Dominic J. Abrams
- Inherited Cardiac Arrhythmia Program, Department of Cardiology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
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11
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Waddell-Smith KE, Li J, Smith W, Crawford J, Skinner JR. β-Blocker Adherence in Familial Long QT Syndrome. Circ Arrhythm Electrophysiol 2016; 9:CIRCEP.115.003591. [DOI: 10.1161/circep.115.003591] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 07/07/2016] [Indexed: 11/16/2022]
Abstract
Background—
Long-term uninterrupted β-blockade significantly reduces cardiac events in long QT syndrome (LQTS). Despite this, data on nonadherence are scarce and quantified only on the day of cardiac arrest in LQTS literature. We aimed to describe β-blocker adherence, and predictors thereof, among patients with LQTS types 1 and 2.
Methods and Results—
Electronic health records and pharmacy dispensing data were reviewed for 90 patients with LQTS 1 and 2 who reside in Auckland, New Zealand, during a 34-month period. For each patient, the medication possession ratio (MPR: proportion of follow-up days patients were dispensed β-blocker) was calculated. Adequate adherence was characterized by an MPR ≥0.8 and ideal as MPR=1.0. Clinical and demographic features were assessed to determine whether they predicted adherence. Long-term β-blockers were prescribed to 74 patients (82%). Side effects were described as intolerable by 6 (8%) and their β-blockers were stopped. MPR was calculated in the remaining 68 patients >151.7 patient-years of follow-up. Median MPR was 0.79 (range, 0–1.3). Suboptimal adherence (MPR<0.8) was recorded in 35 (51%). Seven patients (10%) never took up a prescription (MPR=0). Adequate adherence was present in 33 (49%), including 9 (13%) who had ideal adherence. Age, sex, clinical presentation, family history of sudden death, ethnicity, and deprivation index did not predict adherence.
Conclusions—
Adherence to β-blockers in LQTS is suboptimal in half of those with LQTS 1 and 2. Risk factors for nonadherence could not be identified in our population. Further research into β-blocker adherence is imperative in this high-risk population.
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Affiliation(s)
- Kathryn E. Waddell-Smith
- From the Green Lane Paediatric and Congenital Cardiac Services, Starship Children’s Hospital, Auckland, New Zealand (K.E.W.-S., J.C., J.R.S.); Department of Child Health, The University of Auckland, New Zealand (K.E.W.-S., J.L., J.R.S.); and Green Lane Cardiovascular Services, Auckland City Hospital, New Zealand (W.S.)
| | - Jian Li
- From the Green Lane Paediatric and Congenital Cardiac Services, Starship Children’s Hospital, Auckland, New Zealand (K.E.W.-S., J.C., J.R.S.); Department of Child Health, The University of Auckland, New Zealand (K.E.W.-S., J.L., J.R.S.); and Green Lane Cardiovascular Services, Auckland City Hospital, New Zealand (W.S.)
| | - Warren Smith
- From the Green Lane Paediatric and Congenital Cardiac Services, Starship Children’s Hospital, Auckland, New Zealand (K.E.W.-S., J.C., J.R.S.); Department of Child Health, The University of Auckland, New Zealand (K.E.W.-S., J.L., J.R.S.); and Green Lane Cardiovascular Services, Auckland City Hospital, New Zealand (W.S.)
| | - Jackie Crawford
- From the Green Lane Paediatric and Congenital Cardiac Services, Starship Children’s Hospital, Auckland, New Zealand (K.E.W.-S., J.C., J.R.S.); Department of Child Health, The University of Auckland, New Zealand (K.E.W.-S., J.L., J.R.S.); and Green Lane Cardiovascular Services, Auckland City Hospital, New Zealand (W.S.)
| | - Jonathan R. Skinner
- From the Green Lane Paediatric and Congenital Cardiac Services, Starship Children’s Hospital, Auckland, New Zealand (K.E.W.-S., J.C., J.R.S.); Department of Child Health, The University of Auckland, New Zealand (K.E.W.-S., J.L., J.R.S.); and Green Lane Cardiovascular Services, Auckland City Hospital, New Zealand (W.S.)
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12
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Waddell-Smith KE, Skinner JR. Update on the Diagnosis and Management of Familial Long QT Syndrome. Heart Lung Circ 2016; 25:769-76. [PMID: 27262388 DOI: 10.1016/j.hlc.2016.01.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 01/20/2016] [Indexed: 01/16/2023]
Abstract
This update was reviewed by the CSANZ Continuing Education and Recertification Committee and ratified by the CSANZ board in August 2015. Since the CSANZ 2011 guidelines, adjunctive clinical tests have proven useful in the diagnosis of LQTS and are discussed in this update. Understanding of the diagnostic and risk stratifying role of LQTS genetics is also discussed. At least 14 LQTS genes are now thought to be responsible for the disease. High-risk individuals may have multiple mutations, large gene rearrangements, C-loop mutations in KCNQ1, transmembrane mutations in KCNH2, or have certain gene modifiers present, particularly NOS1AP polymorphisms. In regards to treatment, nadolol is preferred, particularly for long QT type 2, and short acting metoprolol should not be used. Thoracoscopic left cardiac sympathectomy is valuable in those who cannot adhere to beta blocker therapy, particularly in long QT type 1. Indications for ICD therapies have been refined; and a primary indication for ICD in post-pubertal females with long QT type 2 and a very long QT interval is emerging.
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Affiliation(s)
- Kathryn E Waddell-Smith
- Green Lane Paediatric and Congenital Cardiac Services, Starship Children's Hospital, Auckland New Zealand; The University of Auckland, Department of Child Health, Auckland, New Zealand
| | - Jonathan R Skinner
- Green Lane Paediatric and Congenital Cardiac Services, Starship Children's Hospital, Auckland New Zealand; The University of Auckland, Department of Child Health, Auckland, New Zealand.
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13
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Ramakrishna H, O’Hare M, Mookadam F, Gutsche JT, Shah R, Augoustides JG. Sudden Cardiac Death and Disorders of the QT Interval: Anesthetic Implications and Focus on Perioperative Management. J Cardiothorac Vasc Anesth 2015; 29:1723-33. [DOI: 10.1053/j.jvca.2015.07.026] [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] [Received: 07/20/2015] [Indexed: 12/19/2022]
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14
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Abstract
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Whole human genome sequencing of
individuals is becoming rapid
and inexpensive, enabling new strategies for using personal genome
information to help diagnose, treat, and even prevent human disorders
for which genetic variations are causative or are known to be risk
factors. Many of the exploding number of newly discovered genetic
variations alter the structure, function, dynamics, stability, and/or
interactions of specific proteins and RNA molecules. Accordingly,
there are a host of opportunities for biochemists and biophysicists
to participate in (1) developing tools to allow accurate and sometimes
medically actionable assessment of the potential pathogenicity of
individual variations and (2) establishing the mechanistic linkage
between pathogenic variations and their physiological consequences,
providing a rational basis for treatment or preventive care. In this
review, we provide an overview of these opportunities and their associated
challenges in light of the current status of genomic science and personalized
medicine, the latter often termed precision medicine.
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Affiliation(s)
- Brett M Kroncke
- †Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States.,‡Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Carlos G Vanoye
- §Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, United States
| | - Jens Meiler
- ‡Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232, United States.,∥Departments of Chemistry, Pharmacology, and Bioinformatics, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Alfred L George
- §Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, United States
| | - Charles R Sanders
- †Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States.,‡Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
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