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Harvey A, Curnier D, Dodin P, Jacquemet V, Caru M. The Effects of Cycle Ergometer Versus Treadmill Exercise Stress Testing on QTc Interval Prolongation in Patients With Long QT Syndrome: A Systematic Review and Meta-analysis. Clin J Sport Med 2024; 34:474-502. [PMID: 39012267 DOI: 10.1097/jsm.0000000000001256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 01/16/2024] [Indexed: 07/17/2024]
Abstract
OBJECTIVE The safest and most effective exercise stress tests (EST) modalities for long QT syndrome (LQTS) are currently unknown. The main objective was to explore the effects of EST on the corrected QT interval (QTc) in patients with LQTS, and to compare the effects of different EST modalities (cycle ergometer vs treadmill). DATA SOURCES Systematic searches were performed in September 2022 in accordance with the PRISMA statement through PubMed, Medline, EBM Reviews, Embase, and Web of Science. MAIN RESULTS A total of 1728 patients with LQTS, whether congenital or acquired, without any age restrictions (pediatric age ≤18 years and adult age >19 years), and 2437 control subjects were included in the 49 studies. The QT interval data were available for 15 studies. Our analyses showed that the QT interval prolonged in a similar manner using either a cycle ergometer or a treadmill (standardized mean difference [SMD] = 1.89 [95% CI, 1.07-2.71] vs SMD = 1.46 [95% CI, 0.78-2.14], respectively). Therefore, it seems that either modality may be used to evaluate patients with LQTS. CONCLUSIONS The methodology for the measurement of the QT interval was very heterogeneous between studies, which inevitably influenced the quality of the analyses. Hence, researchers should proceed with caution when exploring and interpreting data in the field of exercise and LQTS.
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Affiliation(s)
- Audrey Harvey
- Laboratory of Pathophysiology of EXercise (LPEX), School of Kinesiology and Physical Activity Sciences, Faculty of Medicine, University of Montreal, Montreal, Canada
- Sainte-Justine University Health Center, Research Center, Montreal, Canada
| | - Daniel Curnier
- Laboratory of Pathophysiology of EXercise (LPEX), School of Kinesiology and Physical Activity Sciences, Faculty of Medicine, University of Montreal, Montreal, Canada
- Sainte-Justine University Health Center, Research Center, Montreal, Canada
| | - Philippe Dodin
- Sainte-Justine University Health Center, Research Center, Montreal, Canada
| | - Vincent Jacquemet
- Department of Pharmacology and Physiology, Faculty of Medicine, University of Montreal, Montreal, Canada ; and
| | - Maxime Caru
- Department of Pediatrics and Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
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Yang Y, Lv T, Li S, Liu P, Gao Q, Zhang P. Utility of Provocative Testing in the Diagnosis and Genotyping of Congenital Long QT Syndrome: A Systematic Review and Meta-Analysis. J Am Heart Assoc 2022; 11:e025246. [PMID: 35861842 PMCID: PMC9707831 DOI: 10.1161/jaha.122.025246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 04/27/2022] [Indexed: 11/16/2022]
Abstract
Background Diagnosis is particularly challenging in concealed or asymptomatic long QT syndrome (LQTS). Provocative testing, unmasking the characterization of LQTS, is a promising alternative method for the diagnosis of LQTS, but without uniform standards. Methods and Results A comprehensive search was conducted in PubMed, Embase, and the Cochrane Library through October 14, 2021. The fixed effects model was used to assess the effect of the provocative testing on QTc interval. A total of 22 studies with 1137 patients with LQTS were included. At baseline, QTc interval was 40 ms longer in patients with LQTS than in controls (mean difference [MD], 40.54 [95% CI, 37.43-43.65]; P<0.001). Compared with the control group, patients with LQTS had 28 ms longer ΔQTc upon standing (MD, 28.82 [95% CI, 23.05-34.58]; P<0.001), nearly 30 ms longer both at peak exercise (MD, 27.31 [95% CI, 21.51-33.11]; P<0.001) and recovery 4 to 5 minutes (MD, 29.85 [95% CI, 24.36-35.35]; P<0.001). With epinephrine infusion, QTc interval was prolonged both in controls and patients with QTS, most obviously in LQT1 (MD, 68.26 [95% CI, 58.91-77.60]; P<0.001) and LQT2 (MD, 60.17 [95% CI, 50.18-70.16]; P<0.001). Subgroup analysis showed QTc interval response to abrupt stand testing and exercise testing varied between LQT1, LQT2, and LQT3, named Type Ⅰ, Type Ⅱ, and Type Ⅲ. Conclusions QTc trend Type Ⅰ and Type Ⅲ during abrupt stand testing and exercise testing can be used to propose a prospective evaluation of LQT1 and LQT3, respectively. Type Ⅱ QTc trend combined epinephrine infusion testing could distinguish LQT2 from control. A preliminary diagnostic workflow was proposed but deserves further evaluation.
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Affiliation(s)
- Ying Yang
- School of Clinical MedicineTsinghua UniversityBeijingChina
| | - Ting‐ting Lv
- Department of CardiologySchool of Clinical MedicineBeijing Tsinghua Changgung HospitalTsinghua UniversityBeijingChina
| | - Si‐yuan Li
- Department of CardiologySchool of Clinical MedicineBeijing Tsinghua Changgung HospitalTsinghua UniversityBeijingChina
| | - Peng Liu
- School of Clinical MedicineTsinghua UniversityBeijingChina
| | - Qing‐gele Gao
- School of Clinical MedicineTsinghua UniversityBeijingChina
| | - Ping Zhang
- School of Clinical MedicineTsinghua UniversityBeijingChina
- Department of CardiologySchool of Clinical MedicineBeijing Tsinghua Changgung HospitalTsinghua UniversityBeijingChina
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Harvey A, Curnier D, Dodin P, Abadir S, Jacquemet V, Caru M. OUP accepted manuscript. Eur J Prev Cardiol 2022; 29:1633-1677. [PMID: 35537006 DOI: 10.1093/eurjpc/zwac081] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 04/15/2022] [Accepted: 04/18/2022] [Indexed: 11/13/2022]
Abstract
Current exercise recommendations make it difficult for long QT syndrome (LQTS) patients to adopt a physically active and/or athletic lifestyle. The purpose of this review is to summarize the current evidence, identify knowledge gaps, and discuss research perspectives in the field of exercise and LQTS. The first aim is to document the influence of exercise training, exercise stress, and postural change interventions on ventricular repolarization in LQTS patients, while the second aim is to describe electrophysiological measurements used to study the above. Studies examining the effects of exercise on congenital or acquired LQTS in human subjects of all ages were included. Systematic searches were performed on 1 October 2021, through PubMed (NLM), Ovid Medline, Ovid All EBM Reviews, Ovid Embase, and ISI Web of Science, and limited to articles written in English or French. A total of 1986 LQTS patients and 2560 controls were included in the 49 studies. Studies were mainly case-control studies (n = 41) and examined exercise stress and/or postural change interventions (n = 48). One study used a 3-month exercise training program. Results suggest that LQTS patients have subtype-specific repolarization responses to sympathetic stress. Measurement methods and quality were found to be very heterogeneous, which makes inter-study comparisons difficult. In the absence of randomized controlled trials, the current recommendations may have long-term risks for LQTS patients who are discouraged from performing physical activity, rendering its associated health benefits out of range. Future research should focus on discovering the most appropriate levels of exercise training that promote ventricular repolarization normalization in LQTS.
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Affiliation(s)
- Audrey Harvey
- Laboratory of Pathophysiology of EXercise (LPEX), School of Kinesiology and Physical Activity Sciences, Faculty of Medicine, University of Montreal, Montreal, Canada
- Sainte-Justine University Health Center, Research Center, Montreal, Canada
| | - Daniel Curnier
- Laboratory of Pathophysiology of EXercise (LPEX), School of Kinesiology and Physical Activity Sciences, Faculty of Medicine, University of Montreal, Montreal, Canada
- Sainte-Justine University Health Center, Research Center, Montreal, Canada
| | - Philippe Dodin
- Sainte-Justine University Health Center, Research Center, Montreal, Canada
| | - Sylvia Abadir
- Department of Pediatric Cardiology, Sainte-Justine University Health Center, Montreal, Canada
| | - Vincent Jacquemet
- Department of Pharmacology and Physiology, Faculty of Medicine, University of Montreal, Montreal, Canada
| | - Maxime Caru
- Sainte-Justine University Health Center, Research Center, Montreal, Canada
- Department of Pediatrics, Pennsylvania State University College of Medicine, Hershey, PA, USA
- Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, PA, USA
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2017 AHA/ACC/HRS guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death. Heart Rhythm 2018; 15:e73-e189. [DOI: 10.1016/j.hrthm.2017.10.036] [Citation(s) in RCA: 177] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Indexed: 02/07/2023]
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Al-Khatib SM, Stevenson WG, Ackerman MJ, Bryant WJ, Callans DJ, Curtis AB, Deal BJ, Dickfeld T, Field ME, Fonarow GC, Gillis AM, Granger CB, Hammill SC, Hlatky MA, Joglar JA, Kay GN, Matlock DD, Myerburg RJ, Page RL. 2017 AHA/ACC/HRS Guideline for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation 2018; 138:e272-e391. [PMID: 29084731 DOI: 10.1161/cir.0000000000000549] [Citation(s) in RCA: 249] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
| | - William G Stevenson
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - Michael J Ackerman
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - William J Bryant
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - David J Callans
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - Anne B Curtis
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - Barbara J Deal
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - Timm Dickfeld
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - Michael E Field
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - Gregg C Fonarow
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - Anne M Gillis
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - Christopher B Granger
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - Stephen C Hammill
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - Mark A Hlatky
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - José A Joglar
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - G Neal Kay
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - Daniel D Matlock
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - Robert J Myerburg
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
| | - Richard L Page
- Writing committee members are required to recuse themselves from voting on sections to which their specific relationships with industry may apply; see Appendix 1 for detailed information. †ACC/AHA Representative. ‡HRS Representative. §ACC/AHA Task Force on Performance Measures Liaison/HFSA Representative. ‖ACC/AHA Task Force on Clinical Practice Guidelines Liaison
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Al-Khatib SM, Stevenson WG, Ackerman MJ, Bryant WJ, Callans DJ, Curtis AB, Deal BJ, Dickfeld T, Field ME, Fonarow GC, Gillis AM, Granger CB, Hammill SC, Hlatky MA, Joglar JA, Kay GN, Matlock DD, Myerburg RJ, Page RL. 2017 AHA/ACC/HRS Guideline for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol 2018; 72:e91-e220. [PMID: 29097296 DOI: 10.1016/j.jacc.2017.10.054] [Citation(s) in RCA: 707] [Impact Index Per Article: 117.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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8
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Dawes D, Ho J. Commentary on: Gibbons J, Mojica A, Peele M. Human electrical muscular incapacitation and effects on QTc interval. J Forensic Sci https://doi.org/10.1111/1556-4029.13490. Epub 2017 April 17. J Forensic Sci 2017; 62:1418-1419. [DOI: 10.1111/1556-4029.13595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Donald Dawes
- Emergency Department; Lompoc Valley Medical Center; 1515 E Ocean Ave Lompoc CA 93436
| | - Jeffrey Ho
- Emergency Department; Hennepin County Medical Center; 701 Park Avenue South Minneapolis MN 55415
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Takahashi K, Nabeshima T, Nakayashiro M, Ganaha H. QT Dynamics During Exercise in Asymptomatic Children with Long QT Syndrome Type 3. Pediatr Cardiol 2016; 37:860-7. [PMID: 26921063 DOI: 10.1007/s00246-016-1360-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/13/2016] [Indexed: 01/08/2023]
Abstract
Sympathetic provocative testing is commonly used to detect the abnormal QT dynamics in long QT syndrome (LQTS) patients, particularly LQTS type 1 and type 2. However, little is known about LQTS type 3 (LQT3). We investigated QT dynamics during exercise testing in LQTS patients, particularly LQT3. This study included 37 subjects, comprising 16 genotyped LQTS patients and 21 unrelated healthy subjects without QT prolongation. LQTS patients were divided into LQT3 and non-LQT3 groups. During exercise tests using a modified Bruce protocol, 12-lead electrocardiogram monitoring was performed using a novel multifunctional electrocardiograph. QT intervals were automatically measured. The QT/heart rate (HR) relationship was visualized by plotting the beat-to-beat confluence of the recorded data. A linear regression analysis was performed to determine the QT/HR slope and intercept. Estimated QT intervals at HR 60 bpm (QT60) were calculated by the regression line formula. QT/HR slopes were steeper for each LQTS group than for the control group (P < 0.001). QT60 values demonstrated a moderate correlation with QT intervals at rest (P < 0.0001) for both groups. The corrected QT intervals (QTc) at 4 min of recovery after exercise were significantly longer in the non-LQT3 group than in the control group but were not different between the LQT3 and the control groups. Abnormal QT dynamics during exercise testing were observed in both LQT3 patients and other LQTS subtypes. This method may be useful for directing genetic testing in subjects with borderline prolonged QT intervals.
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Affiliation(s)
- Kazuhiro Takahashi
- Department of Pediatric Cardiology, Okinawa Children's Medical Center, 118-1 Arakawa, Haebaru-chou, Okinawa, 901-1193, Japan.
| | - Taisuke Nabeshima
- Department of Pediatric Cardiology, Okinawa Children's Medical Center, 118-1 Arakawa, Haebaru-chou, Okinawa, 901-1193, Japan
| | - Mami Nakayashiro
- Department of Pediatric Cardiology, Okinawa Children's Medical Center, 118-1 Arakawa, Haebaru-chou, Okinawa, 901-1193, Japan
| | - Hitoshi Ganaha
- Department of Pediatric Cardiology, Okinawa Children's Medical Center, 118-1 Arakawa, Haebaru-chou, Okinawa, 901-1193, Japan
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Bennett MT, Gula LJ, Klein GJ, Skanes AC, Yee R, Leong-Sit P, Chattha I, Sy R, Jones DL, Krahn AD. Effect of beta-blockers on QT dynamics in the long QT syndrome: measuring the benefit. ACTA ACUST UNITED AC 2014; 16:1847-51. [DOI: 10.1093/europace/euu086] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abrahamsson C, Dota C, Skallefell B, Carlsson L, Frison L, Berggren A, Edvardsson N, Duker G. Assessment of ventricular repolarization variability with the DeltaT50 method improves identification of patients with congenital long QT syndromes. Ann Noninvasive Electrocardiol 2012; 18:240-50. [PMID: 23714082 DOI: 10.1111/anec.12016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
BACKGROUND We analyzed ventricular repolarization variability in genotyped long QT syndrome (LQTS) patients and in healthy volunteers (HV). METHOD The deltaT50, that is, the temporal variability of ventricular repolarization at 50% of the T-wave downslope, was analyzed every 15th minute on 175 and 390 Holter electrocardiogram (ECG) recordings from HV and genotyped LQTS patients, respectively. The average deltaT50 and QTcF were calculated in each subject. RESULTS DeltaT50 was 2.26 ± 0.71 ms (mean ± SD) in the HV and 5.74 ± 2.30 ms in the LQTS population (P < 0.0001). The sensitivity and specificity of QTcF (cutoff value 450 ms) to discriminate between the LQTS patients and the HV were 51.5% and 98.9%, and for deltaT50 (cutoff value 3 ms) 93.9% and 88.6%, respectively. The combination of both variables improved the diagnosis of the LQTS patients even further. Subgroups of LQTS patients at higher risk of cardiac events (with LQTS3, JLN, QTc > 500 ms or symptoms) had higher deltaT50 than subgroups at lower risk (with LQTS1, QTc < 450 ms or without symptoms). The variation in deltaT50 between day and night was concordant with the risk of symptoms; patients with LQTS1 had higher deltaT50 in the daytime and patients with LQTS3 had higher deltaT50 during the night. CONCLUSION DeltaT50 more accurately distinguished between LQTS patients and HV than QTcF and was higher in LQTS patients with a higher risk of cardiac events. DeltaT50 can be used together with QTcF to improve the diagnosis in patients with the LQTS phenotype and tentatively also be of value for risk assessment in such patients.
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Krahn AD, Healey JS, Chauhan VS, Birnie DH, Champagne J, Sanatani S, Ahmad K, Ballantyne E, Gerull B, Yee R, Skanes AC, Gula LJ, Leong-Sit P, Klein GJ, Gollob MH, Simpson CS, Talajic M, Gardner M. Epinephrine Infusion in the Evaluation of Unexplained Cardiac Arrest and Familial Sudden Death. Circ Arrhythm Electrophysiol 2012; 5:933-40. [DOI: 10.1161/circep.112.973230] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Epinephrine infusion may unmask latent genetic conditions associated with cardiac arrest, including long-QT syndrome and catecholaminergic polymorphic ventricular tachycardia (VT).
Methods and Results—
Patients with unexplained cardiac arrest (normal left ventricular function and QT interval) and selected family members from the Cardiac Arrest Survivors with Preserved Ejection Fraction Registry (CASPER) registry underwent epinephrine challenge at doses of 0.05, 0.10, and 0.20 μg/kg per minute. A test was considered positive for long-QT syndrome if the absolute QT interval prolonged by ≥30 ms at 0.10 μg/kg per minute and borderline if QT prolongation was 1 to 29 ms. Catecholaminergic polymorphic VT was diagnosed if epinephrine provoked ≥3 beats of polymorphic or bidirectional VT and borderline if polymorphic couplets, premature ventricular contractions, or nonsustained monomorphic VT was induced. Epinephrine infusion was performed in 170 patients (age, 42±16 years; 49% men), including 98 patients with unexplained cardiac arrest. Testing was positive for long-QT syndrome in 31 patients (18%) and borderline in 24 patients (14%). Exercise testing provoked an abnormal QT response in 42% of tested patients with a positive epinephrine response. Testing for catecholaminergic polymorphic VT was positive in 7% and borderline in 5%. Targeted genetic testing of abnormal patients was positive in 17% of long-QT syndrome patients and 13% of catecholaminergic polymorphic VT patients.
Conclusions—
Epinephrine challenge provoked abnormalities in a substantial proportion of patients, most commonly a prolonged QT interval. Exercise and genetic testing replicated the diagnosis suggested by the epinephrine response in a small proportion of patients. Epinephrine infusion combined with exercise testing and targeted genetic testing is recommended in the workup of suspected familial sudden death syndromes.
Clinical Trial Registration—
URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00292032.
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Affiliation(s)
- Andrew D. Krahn
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Jeffrey S. Healey
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Vijay S. Chauhan
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - David H. Birnie
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Jean Champagne
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Shubhayan Sanatani
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Kamran Ahmad
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Emily Ballantyne
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Brenda Gerull
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Raymond Yee
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Allan C. Skanes
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Lorne J. Gula
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Peter Leong-Sit
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - George J. Klein
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Michael H. Gollob
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Christopher S. Simpson
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Mario Talajic
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
| | - Martin Gardner
- From the University of British Columbia (A.D.K.), Vancouver, BC; Population Health Research Institute, McMaster University (J.S.H.), Hamilton, ON; University Health Network (V.S.C.), Toronto, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, ON; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, PQ; BC Children’s Hospital (S.S.), Vancouver, British Columbia, Vancouver, BC; St Michael’s Hospital (K.A.), Toronto, Canada; University of Western Ontario (E.B., R.Y., A.C.S.,
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Abstract
Acquired and hereditary long-QT syndromes are important causes of sudden cardiac death. Both categories are characterized by abnormally prolonged cardiac repolarization arising from a complex interaction between genetic and environmental factors. This produces a potentially dangerous substrate for polymorphic ventricular tachycardia and sudden cardiac death. In this review, the pathophysiologic, diagnostic, and prognostic features of long-QT syndromes, as well as recommendations regarding therapy, are reviewed.
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14
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Sy RW, van der Werf C, Chattha IS, Chockalingam P, Adler A, Healey JS, Perrin M, Gollob MH, Skanes AC, Yee R, Gula LJ, Leong-Sit P, Viskin S, Klein GJ, Wilde AA, Krahn AD. Derivation and Validation of a Simple Exercise-Based Algorithm for Prediction of Genetic Testing in Relatives of LQTS Probands. Circulation 2011; 124:2187-94. [DOI: 10.1161/circulationaha.111.028258] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Genetic testing can diagnose long-QT syndrome (LQTS) in asymptomatic relatives of patients with an identified mutation; however, it is costly and subject to availability. The accuracy of a simple algorithm that incorporates resting and exercise ECG parameters for screening LQTS in asymptomatic relatives was evaluated, with genetic testing as the gold standard.
Methods and Results—
Asymptomatic first-degree relatives of genetically characterized probands were recruited from 5 centers. QT intervals were measured at rest, during exercise, and during recovery. Receiver operating characteristics were used to establish optimal cutoffs. An algorithm for identifying LQTS carriers was developed in a derivation cohort and validated in an independent cohort. The derivation cohort consisted of 69 relatives (28 with LQT1, 20 with LQT2, and 21 noncarriers). Mean age was 35±18 years, and resting corrected QT interval (QTc) was 466±39 ms. Abnormal resting QTc (females ≥480 ms; males ≥470 ms) was 100% specific for gene carrier status, but was observed in only 48% of patients; however, mutations were observed in 68% and 42% of patients with a borderline or normal resting QTc, respectively. Among these patients, 4-minute recovery QTc ≥445 ms correctly restratified 22 of 25 patients as having LQTS and 19 of 21 patients as being noncarriers. The combination of resting and 4-minute recovery QTc in a screening algorithm yielded a sensitivity of 0.94 and specificity of 0.90 for detecting LQTS carriers. When applied to the validation cohort (n=152; 58 with LQT1, 61 with LQT2, and 33 noncarriers; QTc=443±47 ms), sensitivity was 0.92 and specificity was 0.82.
Conclusions—
A simple algorithm that incorporates resting and exercise-recovery QTc is useful in identifying LQTS in asymptomatic relatives.
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Affiliation(s)
- Raymond W. Sy
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Christian van der Werf
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Ishvinder S. Chattha
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Priya Chockalingam
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Arnon Adler
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Jeffrey S. Healey
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Mark Perrin
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Michael H. Gollob
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Allan C. Skanes
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Raymond Yee
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Lorne J. Gula
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Peter Leong-Sit
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Sami Viskin
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - George J. Klein
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Arthur A. Wilde
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
| | - Andrew D. Krahn
- From the University of Western Ontario, London, ON, Canada (R.W.S., I.S.C., A.C.S., R.Y., L.J.G., P.L.-S., G.J.K., A.D.K.); Academic Medical Center, Amsterdam, Netherlands (C.V.d.W., P.C., A.A.W.); Tel Aviv University, Tel Aviv, Israel (A.A., S.V.); McMaster University, Hamilton, ON, Canada (J.S.H.); and University of Ottawa, Ottawa, ON, Canada (M.P., M.H.G.)
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15
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Aziz PF, Wieand TS, Ganley J, Henderson J, Patel AR, Iyer VR, Vogel RL, McBride M, Vetter VL, Shah MJ. Genotype- and mutation site-specific QT adaptation during exercise, recovery, and postural changes in children with long-QT syndrome. Circ Arrhythm Electrophysiol 2011; 4:867-73. [PMID: 21956039 DOI: 10.1161/circep.111.963330] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Exercise stress testing has shown diagnostic utility in adult patients with long-QT syndrome (LQTS); however, the QT interval adaptation in response to exercise in pediatric patients with LQTS has received little attention. METHODS AND RESULTS One-hundred fifty-eight patients were divided into 3 groups: Those with LQTS type 1 (LQT1) or LQTS type 2 (LQT2) and normal control subjects without cardiovascular disease. Each patient underwent a uniform exercise protocol with a cycle ergometer followed by a 9-minute recovery phase with continuous 12-lead ECG monitoring. Each patient underwent a baseline ECG while resting in the supine position and in a standstill position during continuous ECG recording to determine changes in the QT and RR intervals. Fifty patients were gene-positive for LQTS (n=29 for LQT1 and n=21 for LQT2), and the control group consisted of 108 patients. QT interval adaptation was abnormal in the LQT1 patients compared with LQT2 and control patients (P<0.001). A corrected QT interval (QTc) >460 ms in the late recovery phase at 7 minutes predicted LQT1 or LQT2 versus control subjects with 96% specificity, 86% sensitivity, and a 91% positive predictive value. A recovery ΔQTc((7 min-1 min)) >30 ms predicted LQT2 versus LQT1 with 75% sensitivity, 82% specificity, and a 75% positive predictive value. The postural ΔQT was significantly different between LQTS and control groups (P=0.005). CONCLUSIONS Genotype-specific changes in repolarization response to exercise and recovery exist in the pediatric population and are of diagnostic utility in LQTS. An extended recovery phase is preferable to assess the repolarization response after exercise in the pediatric population.
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Affiliation(s)
- Peter F Aziz
- The Children's Hospital of Philadelphia, Division of Cardiology, and University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
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16
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SY RAYMONDW, CHATTHA ISHVINDERS, KLEIN GEORGEJ, GULA LORNEJ, SKANES ALLANC, YEE RAYMOND, BENNETT MATTHEWT, KRAHN ANDREWD. Repolarization Dynamics During Exercise Discriminate Between LQT1 and LQT2 Genotypes. J Cardiovasc Electrophysiol 2010; 21:1242-6. [DOI: 10.1111/j.1540-8167.2010.01788.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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17
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Chattha IS, Sy RW, Yee R, Gula LJ, Skanes AC, Klein GJ, Bennett MT, Krahn AD. Utility of the recovery electrocardiogram after exercise: a novel indicator for the diagnosis and genotyping of long QT syndrome? Heart Rhythm 2010; 7:906-11. [DOI: 10.1016/j.hrthm.2010.03.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Accepted: 03/03/2010] [Indexed: 11/28/2022]
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Challenges of Diagnosing Long QT Syndrome in Patients With Nondiagnostic Resting QTc. J Am Coll Cardiol 2010; 55:1962-4. [DOI: 10.1016/j.jacc.2010.02.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 02/09/2010] [Indexed: 11/23/2022]
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Abstract
PURPOSE OF REVIEW Advances in understanding the biophysical underpinnings of long QT syndrome have provided growing insight into the risk of this syndrome in the pediatric population. This review focuses on developments in this area as reflected in the recent literature. RECENT FINDINGS QT interval prolongation on the surface ECG is the hallmark of long QT syndrome. This prolongation reflects protracted ventricular repolarization, primarily due to mutations in genes coding for cardiac ion channels. To date, 12 different genes have been implicated, and current genetic testing methods can provide a specific diagnosis in approximately 70% of patients. Clinical indicators, including age, sex, corrected QT duration, and prior syncope are the most powerful predictors of future life-threatening cardiac events. However, diagnosis, risk assessment, and therapeutic strategies are being guided by genetic analysis to an increasing degree. SUMMARY Impressive advancements have been made in understanding the genetic and clinical determinants of this heterogeneous syndrome. As genetic testing techniques become more robust, the ability to assess risk in affected individuals and tailor therapy will improve.
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20
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Abstract
PURPOSE To measure the corrected QT cardiac repolarization time before and during epileptic seizures. METHODS Thirty-nine video-EEG/ECG/SAO(2) (electroencephalography/electrocardiography/oxygen saturation) telemetry patients were included in this prospective study. Epileptic seizures were identified both clinically and electrographically. RR intervals and associated QT intervals were measured 5 min prior to the onset of the identified seizure. Consecutive RR and associated QT intervals were then measured from the seizure onset until the seizure had ended and the EEG had resumed its preseizure trace. Averaged RR and QT intervals over nine consecutive beats were applied to Bazett's, Hodge's, Fridericia's, and Framingham's formulas to compare the corrected QT values before and during the seizures. RESULTS A total of 156 seizures had corrected QT analysis performed. Nine generalized tonic-clonic seizures (5 patients), 34 absences (6 patients), 12 tonic seizures (6 patients), 27 temporal lobe seizures (14 patients), 58 frontal lobe seizures (4 patients), and 16 subclinical seizures (4 patients). All formulae reported a statistically significant difference in corrected QT (p < 0.001) during total seizure data compared to total preseizure values. According to Bazett's formula, 21 seizures (nine patients) transiently increased their corrected QT beyond normal limits, with a maximum corrected QT of 512 ms during a right temporal lobe seizure. CONCLUSION Significant lengthening of corrected QT cardiac repolarization time occurred during some epileptic seizures in this study. Prolonged corrected QT may have a role in sudden unexplained death in epilepsy (SUDEP).
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Affiliation(s)
- Ruth Brotherstone
- Department of Clinical Neurophysiology, Western General Hospital, Edinburgh, United Kingdom.
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21
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Krahn AD, Healey JS, Chauhan V, Birnie DH, Simpson CS, Champagne J, Gardner M, Sanatani S, Exner DV, Klein GJ, Yee R, Skanes AC, Gula LJ, Gollob MH. Systematic Assessment of Patients With Unexplained Cardiac Arrest. Circulation 2009; 120:278-85. [DOI: 10.1161/circulationaha.109.853143] [Citation(s) in RCA: 242] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Cardiac arrest without evident cardiac disease may be caused by subclinical genetic conditions. Provocative testing to unmask a phenotype is often necessary to detect primary electrical disease, direct genetic testing, and perform family screening.
Methods and Results—
Patients with apparently unexplained cardiac arrest and no evident cardiac disease (normal cardiac function on echocardiogram, no evidence of coronary artery disease, and a normal ECG) underwent systematic evaluation that included cardiac magnetic resonance imaging, signal-averaged ECG, exercise testing, drug challenge, and selective electrophysiological testing. Diagnostic criteria were based on accepted criteria or provocation of the characteristic clinical features for long-QT syndrome, catecholaminergic polymorphic ventricular tachycardia, Brugada syndrome, early repolarization, arrhythmogenic right ventricular cardiomyopathy, coronary spasm, and myocarditis. Sixty-three patients in 9 centers were enrolled (age 43.0±13.4 years, 29 women). A diagnosis was obtained in 35 patients (56%): Long-QT syndrome in 8, catecholaminergic polymorphic ventricular tachycardia in 8, arrhythmogenic right ventricular cardiomyopathy in 6, early repolarization in 5, coronary spasm in 4, Brugada syndrome in 3, and myocarditis in 1. Targeted genetic testing demonstrated evidence of causative mutations in 9 (47%) of 19 patients. Screening of 64 family members of these patients identified 15 affected individuals who were treated (24%). The remaining 28 patients (44%) were considered to have idiopathic ventricular fibrillation.
Conclusions—
Systematic clinical testing, including drug provocation and advanced imaging, results in unmasking of the cause of apparently unexplained cardiac arrest in >50% of patients. This approach assists in directing genetic testing to diagnose genetically mediated arrhythmia syndromes, which results in successful family screening.
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Affiliation(s)
- Andrew D. Krahn
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
| | - Jeffrey S. Healey
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
| | - Vijay Chauhan
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
| | - David H. Birnie
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
| | - Christopher S. Simpson
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
| | - Jean Champagne
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
| | - Martin Gardner
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
| | - Shubhayan Sanatani
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
| | - Derek V. Exner
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
| | - George J. Klein
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
| | - Raymond Yee
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
| | - Allan C. Skanes
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
| | - Lorne J. Gula
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
| | - Michael H. Gollob
- From University of Western Ontario (A.D.K., G.J.K., R.Y., A.C.S., L.J.G.), London, Ontario, Canada; Hamilton Health Sciences Center (J.S.H.), Hamilton, Ontario, Canada; University Health Network (V.C.), Toronto, Ontario, Canada; University of Ottawa Heart Institute (D.H.B., M.H.G.), Ottawa, Ontario, Canada; Queen’s University (C.S.S.), Kingston, Ontario, Canada; Quebec Heart Institute (J.C.), Laval Hospital, Quebec City, Quebec, Canada; QEII Health Sciences Center (M.G.), Halifax, Nova Scotia,
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Dalla Pozza R, Bechtold S, Urschel S, Netz H, Schwarz HP. QTc interval prolongation in children with Turner syndrome: the results of exercise testing and 24-h ECG. Eur J Pediatr 2009; 168:59-64. [PMID: 18392639 DOI: 10.1007/s00431-008-0709-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 02/21/2008] [Accepted: 02/26/2008] [Indexed: 01/08/2023]
Abstract
BACKGROUND Turner syndrome (TS) is the most common sex chromosome abnormality in females. Recently, a prolongation of the rate-corrected QT (QTc) interval in the electrocardiogram (ECG) of TS patients has been reported. A prolonged QTc interval has been correlated to an increased risk for sudden cardiac death, and medical treatment is warranted in patients with congenital long QT syndrome (LQTS). Additionally, several drugs of common use are contraindicated in LQTS because of their effects on myocardial repolarization. The importance of the QTc prolongation in TS patients is not known at present. MATERIALS AND METHODS Eighteen TS patients with a prolonged QTc interval (group 1) and 11 TS patients with a normal QTc interval (group 2) (mean age 12.6+/-3.1 vs. 11.8+/-2.1 years, respectively) were tested. The QTc interval was calculated during exercise testing and during 24-h ECG recordings. RESULTS None of the patients experienced adverse cardiac events during the tests. The mean QTc interval decreased from 0.467 to 0.432 s in group 1 and from 0.432 to 0.412 s in group 2. During the 24-h ECG, the maximum QTc interval was significantly prolonged in group 1 (0.51 vs. 0.465 s, p<0.05, respectively). We conclude that exercise testing and 24-h ECG recording provide valuable information about the cardiac risk in the single TS patient with a prolonged QTc interval. This helps in counseling these girls, as clear therapeutic guidelines are currently lacking.
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Affiliation(s)
- Robert Dalla Pozza
- Department of Pediatric Cardiology, Ludwig-Maximilians-University, Marchioninistr. 15, 81377, Munich, Germany,
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Tobin MD, Kähönen M, Braund P, Nieminen T, Hajat C, Tomaszewski M, Viik J, Lehtinen R, Ng GA, Macfarlane PW, Burton PR, Lehtimäki T, Samani NJ. Gender and effects of a common genetic variant in the NOS1 regulator NOS1AP on cardiac repolarization in 3761 individuals from two independent populations. Int J Epidemiol 2008; 37:1132-41. [PMID: 18511491 DOI: 10.1093/ije/dyn091] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND A longer heart-rate corrected QT interval (QTc) is associated with increased risk of ventricular arrhythmias. Women have longer resting QTc and are more likely than men to develop drug-induced QT prolongation. Recent studies have shown association between resting QTc and a common variant (rs10494366) of the NOS1 regulator, NOS1AP. We investigated the association between rs10494366 in NOS1AP and QTc, and assessed gender-specific NOS1AP associations with QTc during rest and after exercise. METHODS We investigated the SNP associations with resting QTc in 919 women and 918 men from 504 representative families in the UK GRAPHIC study, and with QTc at rest and at 3 min recovery after exercise in 699 women and 1225 men referred for exercise testing in the Finnish FINCAVAS study. RESULTS In the GRAPHIC study the minor allele (G) of the NOS1AP SNP rs10494366 prolonged QTc by 4.59 ms (95% CI 2.77-6.40; P = 7.63/10(7)) in women, but only by 1.62 ms (95% CI -0.15 to 3.38; P = 0.073) in men (gender-SNP interaction term P = 0.025). In the FINCAVAS study the G allele significantly prolonged QTc in both women (P = 0.0063) and men (P = 0.0043) at 3 min recovery after exercise, but at rest an association was only seen in women (P = 0.020 excluding outliers). CONCLUSIONS A common NOS1AP variant prolongs QTc with a difference between genders. Further studies should aim to confirm this finding and to assess whether NOS1AP genotype influences the risk of drug-induced QT prolongation and risk of consequent arrhythmias.
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Affiliation(s)
- Martin D Tobin
- Department of Health Sciences, University of Leicester, UK.
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Medeiros-Domingo A, Iturralde-Torres P, Ackerman MJ. Clínica y genética en el síndrome de QT largo. Rev Esp Cardiol 2007. [DOI: 10.1157/13108280] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Abstract
PURPOSE OF REVIEW Dramatic advances have been made in understanding of both the genetics and the phenotypic expression of congenital long QT syndrome. This paper reviews recent clinically relevant literature. RECENT FINDINGS Long QT syndrome is one of the leading causes of sudden cardiac death. This syndrome, once diagnosed by a clinical profile, has been more clearly defined by specific gene defects causing ion channel abnormalities in the beating heart. Genetic testing for long QT syndrome, once available only through research laboratories, is now commercially available. Diagnosis, risk assessment, and management are increasingly being guided by gene-specific diagnoses. In a family with suspected disease, the genetic test will determine the defect in as many as 75% of subjects. Once the diagnosis is made, the mainstay of therapy continues to be beta-blockers. Implantable cardioverter-defibrillators are indicated in patients at high risk for malignant arrhythmias. SUMMARY Long QT syndrome is one of the first cardiovascular diseases to see the dramatic changes that bench research can bring to the clinical arena. Future research is needed to determine the gene defect in the remaining 25% of patients with suspected long QT syndrome and in risk stratification.
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Affiliation(s)
- Kathryn K Collins
- University of California-San Francisco, 521 Parnassus, San Francisco, CA 94143, USA.
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