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Leung HT, Kwok SY, Kwong KY, Shih FY, Tsao S, Chung BHY. Prioritize Variant Reclassification in Pediatric Long QT Syndrome-Time to Revisit. Pediatr Cardiol 2024; 45:1023-1035. [PMID: 38565666 DOI: 10.1007/s00246-024-03461-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 02/26/2024] [Indexed: 04/04/2024]
Abstract
Congenital long QT syndrome (LQTS) is an inherited arrhythmia syndrome associated with sudden cardiac death. Accurate interpretation and classification of genetic variants in LQTS patients are crucial for effective management. All patients with LQTS with a positive genetic test over the past 18 years (2002-2020) in our single tertiary pediatric cardiac center were identified. Reevaluation of the reported variants in LQTS genes was conducted using the American College of Genetics and Genomics (ACMG) guideline after refinement by the US ClinGen SVI working group and guideline by Walsh et al. on genetic variant reclassification, under multidisciplinary input. Among the 59 variants identified. 18 variants (30.5%) were reclassified. A significant larger portion of variants of unknown significance (VUS) were reclassified compared to likely pathogenic (LP)/pathogenic (P) variants (57.7% vs 9.1%, p < 0.001). The rate of reclassification was significantly higher in the limited/disputed evidence group compared to the definite/moderate evidence group (p = 0.0006). All LP/P variants were downgraded in the limited/disputed evidence group (p = 0.0057). VUS upgrades are associated with VUS located in genes within the definite/moderate evidence group (p = 0.0403) and with VUS present in patients exhibiting higher corrected QT intervals (QTc) (p = 0.0445). A significant number of pediatric LQTS variants were reclassified, particularly for VUS. The strength of the gene-disease association of the genes influences the reclassification performance. The study provides important insights and guidance for pediatricians to seek for reclassification of "outdated variants" in order to facilitate contemporary precision medicine.
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Affiliation(s)
- Hei-To Leung
- Department of Paediatrics & Adolescent Medicine, Hong Kong Children's Hospital, 1 Shing Cheong Rd, Ngau Tau Kok, Hong Kong SAR, China
| | - Sit-Yee Kwok
- Department of Paediatrics & Adolescent Medicine, Hong Kong Children's Hospital, 1 Shing Cheong Rd, Ngau Tau Kok, Hong Kong SAR, China.
| | - Ka-Yee Kwong
- Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
| | - Fong-Ying Shih
- Clinical Genetics Service Unit, Hong Kong Children's Hospital, Kowloon Bay, Hong Kong SAR, China
| | - Sabrina Tsao
- Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
| | - Brian Hon-Yin Chung
- Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
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Abrahams T, Davies B, Laksman Z, Sy RW, Postema PG, Wilde AAM, Krahn AD, Han HC. Provocation testing in congenital long QT syndrome: A practical guide. Heart Rhythm 2023; 20:1570-1582. [PMID: 37481219 DOI: 10.1016/j.hrthm.2023.07.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/01/2023] [Accepted: 07/14/2023] [Indexed: 07/24/2023]
Abstract
Congenital long QT syndrome (LQTS) is a hereditary cardiac channelopathy with an estimated prevalence of 1 in 2500. A prolonged resting QT interval corrected for heart rate (QTc interval) remains a key diagnostic component; however, the QTc value may be normal in up to 40% of patients with genotype-positive LQTS and borderline in a further 30%. Provocation of QTc prolongation and T-wave changes may be pivotal to unmasking the diagnosis and useful in predicting genotype. LQTS provocation testing involves assessment of repolarization during and after exercise, in response to changes in heart rate or autonomic tone, with patients with LQTS exhibiting a maladaptive repolarization response. We review the utility and strengths and limitations of 4 forms of provocation testing-stand-up test, exercise stress test, epinephrine challenge, and mental stress test-in diagnosing LQTS and provide some practical guidance for performing provocation testing. Ultimately, exercise testing, when feasible, is the most useful form of provocation testing when considering diagnostic sensitivity and specificity.
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Affiliation(s)
- Timothy Abrahams
- Victorian Heart Institute & Monash Health Heart, Victorian Heart Hospital, Monash University, Melbourne, Victoria, Australia
| | - Brianna Davies
- Center for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Zachary Laksman
- Center for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Raymond W Sy
- Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Pieter G Postema
- Department of Cardiology, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands; Heart Failure & Arrhythmias, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands; European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart (ERN GUARD-Heart), Academic Medical Center, Amsterdam, The Netherlands
| | - Arthur A M Wilde
- Department of Cardiology, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands; Heart Failure & Arrhythmias, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands; European Reference Network for Rare, Low Prevalence and Complex Diseases of the Heart (ERN GUARD-Heart), Academic Medical Center, Amsterdam, The Netherlands
| | - Andrew D Krahn
- Center for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hui-Chen Han
- Victorian Heart Institute & Monash Health Heart, Victorian Heart Hospital, Monash University, Melbourne, Victoria, Australia.
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Asatryan B, Bleijendaal H, Wilde AAM. Toward advanced diagnosis and management of inherited arrhythmia syndromes: Harnessing the capabilities of artificial intelligence and machine learning. Heart Rhythm 2023; 20:1399-1407. [PMID: 37442407 DOI: 10.1016/j.hrthm.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/20/2023] [Accepted: 07/02/2023] [Indexed: 07/15/2023]
Abstract
The use of advanced computational technologies, such as artificial intelligence (AI), is now exerting a significant influence on various aspects of life, including health care and science. AI has garnered remarkable public notice with the release of deep learning models that can model anything from artwork to academic papers with minimal human intervention. Machine learning, a method that uses algorithms to extract information from raw data and represent it in a model, and deep learning, a method that uses multiple layers to progressively extract higher-level features from the raw input with minimal human intervention, are increasingly leveraged to tackle problems in the health sector, including utilization for clinical decision support in cardiovascular medicine. Inherited arrhythmia syndromes are a clinical domain where multiple unanswered questions remain despite unprecedented progress over the past 2 decades with the introduction of large panel genetic testing and the first steps in precision medicine. In particular, AI tools can help address gaps in clinical diagnosis by identifying individuals with concealed or transient phenotypes; enhance risk stratification by elevating recognition of underlying risk burden beyond widely recognized risk factors; improve prediction of response to therapy, and further prognostication. In this contemporary review, we provide a summary of the AI models developed to solve challenges in inherited arrhythmia syndromes and also outline gaps that can be filled with the development of intelligent AI models.
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Affiliation(s)
- Babken Asatryan
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland.
| | - Hidde Bleijendaal
- University of Amsterdam, Heart Center; Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands; Department of Clinical Epidemiology, Biostatistics and Bioinformatics, University of Amsterdam, Amsterdam, The Netherlands
| | - Arthur A M Wilde
- University of Amsterdam, Heart Center; Department of Clinical and Experimental Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands; Department of Clinical Epidemiology, Biostatistics and Bioinformatics, University of Amsterdam, Amsterdam, The Netherlands; European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (ERN GUARD-Heart)
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4
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Yee-ming Li J, Kwok SY, Tsao S, Hoi-yan Chung C, Hing-sang Wong W, Cheung YF. Detection of QT interval prolongation using Apple Watch electrocardiogram in children and adolescents with congenital long QT syndrome. Int J Cardiol Heart Vasc 2023; 47:101232. [PMID: 37346232 PMCID: PMC10279543 DOI: 10.1016/j.ijcha.2023.101232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/22/2023] [Accepted: 06/05/2023] [Indexed: 06/23/2023]
Abstract
Background Apple watch-derived electrocardiogram (awECG) may help identify prolongation of corrected QT (QTc) interval. This study aimed to determine its usefulness for assessment of prolongation of QTc interval in children and adolescents with long QT syndrome (LQTS). Methods Children and adolescents with and without LQTS were recruited for measurement of QTc intervals based on standard 12-lead (sECG) and awECG lead I, II and V5 tracings. Bland-Altman analysis of reproducibility, concordance assessment of T wave morphologies, and receiver operating characteristic (ROC) analysis of sensitivity and specificity of awECG-derived QTc interval for detecting QTc prolongation were performed. Results Forty-nine patients, 19 with and 30 without LQTS, aged 3-22 years were studied. The intraclass correlation coefficient was 1.00 for both intra- and inter-observer variability in the measurement of QTc interval. The awECG- and sECG-derived QTc intervals correlated strongly in all three leads (r = 0.90-0.93, all p < 0.001). Concordance between awECG and sECG in assessing T wave morphologies was 84% (16/19). For detection of QTc prolongation, awECG lead V5 had the best specificity (94.4% and 87.5%, respectively) and positive predictive value (87.5% and 80.0%, respectively), and for identification of patients with LQTS, awECG leads II and V5 had the greatest specificity (92.3%-94.1%) and positive predictive value (85.7% to 91.7%) in both males and females. Conclusions Apple Watch leads II and V5 tracings can be used for reproducible and accurate measurement of QTc interval, ascertainment of abnormal T wave morphologies, and detection of prolonged QTc interval in children and adolescents with LQTS.
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Affiliation(s)
- Jennifer Yee-ming Li
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children’s Hospital, Hong Kong
| | - Sit-yee Kwok
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children’s Hospital, Hong Kong
| | - Sabrina Tsao
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children’s Hospital, Hong Kong
- Department of Paediatrics and Adolescent Medicine, School of Clinical Medicine, The University of Hong Kong, Hong Kong
| | - Charis Hoi-yan Chung
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children’s Hospital, Hong Kong
| | - Wilfred Hing-sang Wong
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children’s Hospital, Hong Kong
| | - Yiu-fai Cheung
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children’s Hospital, Hong Kong
- Department of Paediatrics and Adolescent Medicine, School of Clinical Medicine, The University of Hong Kong, Hong Kong
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Wu MJ, Wang WQ, Zhang W, Li JH, Zhang XW. The diagnostic value of electrocardiogram-based machine learning in long QT syndrome: a systematic review and meta-analysis. Front Cardiovasc Med 2023; 10:1172451. [PMID: 37351282 PMCID: PMC10282180 DOI: 10.3389/fcvm.2023.1172451] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/16/2023] [Indexed: 06/24/2023] Open
Abstract
Introduction To perform a meta-analysis to discover the performance of ML algorithms in identifying Congenital long QT syndrome (LQTS). Methods The searched databases included Cochrane, EMBASE, Web of Science, and PubMed. Our study considered all English-language studies that reported the detection of LQTS using ML algorithms. Quality was assessed using QUADAS-2 and QUADAS-AI tools. The bivariate mixed effects models were used in our study. Based on genotype data for LQTS, we performed a subgroup analysis. Results Out of 536 studies, 8 met all inclusion criteria. The pooled area under the receiving operating curve (SAUROC) for detecting LQTS was 0.95 (95% CI: 0.31-1.00); sensitivity was 0.87 (95% CI: 0.83-0.90), and specificity was 0.91 (95% CI: 0.88-0.93). Additionally, diagnostic odd ratio (DOR) was 65 (95% CI: 39-109). The positive likelihood ratio (PLR) was 9.3 (95% CI: 7.0-12.3) and the negative likelihood ratio (NLR) was 0.14 (95% CI: 0.11-0.20), with very low heterogeneity (I2 = 16%). Discussion We found that machine learning can be used to detect features of rare cardiovascular disease like LQTS, thus increasing our understanding of intelligent interpretation of ECG. To improve ML performance in the classification of LQTS subtypes, further research is required. Systematic Review Registration identifier PROSPERO CRD42022360122.
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Affiliation(s)
- Min-Juan Wu
- School of Nursing, Hangzhou Medical College, Hangzhou, China
- School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Wen-Qin Wang
- School of Nursing, Hangzhou Normal University, Hangzhou, China
| | - Wei Zhang
- School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Jun-Hua Li
- School of Nursing, Hangzhou Normal University, Hangzhou, China
| | - Xing-Wei Zhang
- School of Clinical Medicine, Hangzhou Normal University, Hangzhou, China
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Quiñones ME, Joseph JK, Dowell S, Moore HJ, Karasik PE, Fonarow GC, Fletcher RD, Cheng Y, Zeng-Treitler Q, Arundel C, Liappis AP, Sheriff HM, Zhang S, Taub DD, Heimall MS, Faselis C, Kerr GS, Ahmed A. Hydroxychloroquine and Risk of Long QT Syndrome in Rheumatoid Arthritis: A Veterans Cohort Study With Nineteen-Year Follow-up. Arthritis Care Res (Hoboken) 2022. [PMID: 36039941 DOI: 10.1002/acr.25005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 08/14/2022] [Accepted: 08/25/2022] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Recent evidence suggests that hydroxychloroquine use is not associated with higher 1-year risk of long QT syndrome (LQTS) in patients with rheumatoid arthritis (RA). Less is known about its long-term risk, the examination of which was the objective of this study. METHODS We conducted a propensity score-matched active-comparator safety study of hydroxychloroquine in 8,852 veterans (mean age 64 ± 12 years, 14% women, 28% Black) with newly diagnosed RA. A total of 4,426 patients started on hydroxychloroquine and 4,426 started on another nonbiologic disease-modifying antirheumatic drug (DMARD) and were balanced on 87 baseline characteristics. The primary outcome was LQTS during 19-year follow-up through December 31, 2019. RESULTS Incident LQTS occurred in 4 (0.09%) and 5 (0.11%) patients in the hydroxychloroquine and other DMARD groups, respectively, during the first 2 years. Respective 5-year incidences were 17 (0.38%) and 6 (0.14%), representing 11 additional LQTS events in the hydroxychloroquine group (number needed to harm 403; [95% confidence interval (95% CI)], 217-1,740) and a 181% greater relative risk (95% CI 11%-613%; P = 0.030). Although overall 10-year risk remained significant (hazard ratio 2.17; 95% CI 1.13-4.18), only 5 extra LQTS occurred in hydroxychloroquine group over the next 5 years (years 6-10) and 1 over the next 9 years (years 11-19). There was no association with arrhythmia-related hospitalization or all-cause mortality. CONCLUSIONS Hydroxychloroquine use had no association with LQTS during the first 2 years after initiation of therapy. There was a higher risk thereafter that became significant after 5 years of therapy. However, the 5-year absolute risk was very low, and the absolute risk difference was even lower. Both risks attenuated during longer follow-up. These findings provide evidence for long-term safety of hydroxychloroquine in patients with RA.
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Affiliation(s)
| | | | - Sharon Dowell
- Veterans Affairs Medical Center, and Howard University, Washington, DC
| | - Hans J Moore
- Veterans Affairs Medical Center, Georgetown University, George Washington University, Uniformed Services University, and US Department of Veterans Affairs, Washington, DC
| | - Pamela E Karasik
- Veterans Affairs Medical Center, Georgetown University, George Washington University, and Uniformed Services University, Washington, DC
| | | | | | - Yan Cheng
- Veterans Affairs Medical Center and George Washington University, Washington, DC
| | - Qing Zeng-Treitler
- Veterans Affairs Medical Center and George Washington University, Washington, DC
| | - Cherinne Arundel
- Veterans Affairs Medical Center, George Washington University, and Uniformed Services University, Washington, DC
| | - Angelike P Liappis
- Veterans Affairs Medical Center, George Washington University, and Uniformed Services University, Washington, DC
| | - Helen M Sheriff
- Veterans Affairs Medical Center and George Washington University, Washington, DC
| | | | - Daniel D Taub
- Veterans Affairs Medical Center and George Washington University, Washington, DC
| | | | - Charles Faselis
- Veterans Affairs Medical Center, George Washington University, and Uniformed Services University, Washington, DC
| | - Gail S Kerr
- Veterans Affairs Medical Center, Howard University, and Georgetown University, Washington, DC
| | - Ali Ahmed
- Veterans Affairs Medical Center, Georgetown University, and George Washington University, Washington, DC
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Aufiero S, Bleijendaal H, Robyns T, Vandenberk B, Krijger C, Bezzina C, Zwinderman AH, Wilde AAM, Pinto YM. A deep learning approach identifies new ECG features in congenital long QT syndrome. BMC Med 2022; 20:162. [PMID: 35501785 PMCID: PMC9063181 DOI: 10.1186/s12916-022-02350-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 03/24/2022] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Congenital long QT syndrome (LQTS) is a rare heart disease caused by various underlying mutations. Most general cardiologists do not routinely see patients with congenital LQTS and may not always recognize the accompanying ECG features. In addition, a proportion of disease carriers do not display obvious abnormalities on their ECG. Combined, this can cause underdiagnosing of this potentially life-threatening disease. METHODS This study presents 1D convolutional neural network models trained to identify genotype positive LQTS patients from electrocardiogram as input. The deep learning (DL) models were trained with a large 10-s 12-lead ECGs dataset provided by Amsterdam UMC and externally validated with a dataset provided by University Hospital Leuven. The Amsterdam dataset included ECGs from 10000 controls, 172 LQTS1, 214 LQTS2, and 72 LQTS3 patients. The Leuven dataset included ECGs from 2200 controls, 32 LQTS1, and 80 LQTS2 patients. The performance of the DL models was compared with conventional QTc measurement and with that of an international expert in congenital LQTS (A.A.M.W). Lastly, an explainable artificial intelligence (AI) technique was used to better understand the prediction models. RESULTS Overall, the best performing DL models, across 5-fold cross-validation, achieved on average a sensitivity of 84 ± 2%, 90 ± 2% and 87 ± 6%, specificity of 96 ± 2%, 95 ± 1%, and 92 ± 4%, and AUC of 0.90 ± 0.01, 0.92 ± 0.02, and 0.89 ± 0.03, for LQTS 1, 2, and 3 respectively. The DL models were also shown to perform better than conventional QTc measurements in detecting LQTS patients. Furthermore, the performances held up when the DL models were validated on a novel external cohort and outperformed the expert cardiologist in terms of specificity, while in terms of sensitivity, the DL models and the expert cardiologist in LQTS performed the same. Finally, the explainable AI technique identified the onset of the QRS complex as the most informative region to classify LQTS from non-LQTS patients, a feature previously not associated with this disease. CONCLUSIONS This study suggests that DL models can potentially be used to aid cardiologists in diagnosing LQTS. Furthermore, explainable DL models can be used to possibly identify new features for LQTS on the ECG, thus increasing our understanding of this syndrome.
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Affiliation(s)
- Simona Aufiero
- Department of Experimental Cardiology, Amsterdam UMC, Amsterdam, The Netherlands. .,Department of Clinical Epidemiology Biostatistics and Bioinformatics, Amsterdam UMC, Amsterdam, The Netherlands.
| | - Hidde Bleijendaal
- Department of Experimental Cardiology, Amsterdam UMC, Amsterdam, The Netherlands.,Department of Clinical Epidemiology Biostatistics and Bioinformatics, Amsterdam UMC, Amsterdam, The Netherlands
| | - Tomas Robyns
- Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium
| | - Bert Vandenberk
- Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium
| | - Christian Krijger
- Department of Experimental Cardiology, Amsterdam UMC, Amsterdam, The Netherlands
| | - Connie Bezzina
- Department of Experimental Cardiology, Amsterdam UMC, Amsterdam, The Netherlands
| | - Aeilko H Zwinderman
- Department of Clinical Epidemiology Biostatistics and Bioinformatics, Amsterdam UMC, Amsterdam, The Netherlands
| | - Arthur A M Wilde
- Department of Experimental Cardiology, Amsterdam UMC, Amsterdam, The Netherlands
| | - Yigal M Pinto
- Department of Experimental Cardiology, Amsterdam UMC, Amsterdam, The Netherlands
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9
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Krahn AD, Laksman Z, Sy RW, Postema PG, Ackerman MJ, Wilde AAM, Han HC. Congenital Long QT Syndrome. JACC Clin Electrophysiol 2022; 8:687-706. [PMID: 35589186 DOI: 10.1016/j.jacep.2022.02.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 02/16/2022] [Accepted: 02/16/2022] [Indexed: 12/14/2022]
Abstract
Congenital long QT syndrome (LQTS) encompasses a group of heritable conditions that are associated with cardiac repolarization dysfunction. Since its initial description in 1957, our understanding of LQTS has increased dramatically. The prevalence of LQTS is estimated to be ∼1:2,000, with a slight female predominance. The diagnosis of LQTS is based on clinical, electrocardiogram, and genetic factors. Risk stratification of patients with LQTS aims to identify those who are at increased risk of cardiac arrest or sudden cardiac death. Factors including age, sex, QTc interval, and genetic background all contribute to current risk stratification paradigms. The management of LQTS involves conservative measures such as the avoidance of QT-prolonging drugs, pharmacologic measures with nonselective β-blockers, and interventional approaches such as device therapy or left cardiac sympathetic denervation. In general, most forms of exercise are considered safe in adequately treated patients, and implantable cardioverter-defibrillator therapy is reserved for those at the highest risk. This review summarizes our current understanding of LQTS and provides clinicians with a practical approach to diagnosis and management.
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Affiliation(s)
- Andrew D Krahn
- Center for Cardiovascular Innovation, Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, BC, Canada.
| | - Zachary Laksman
- Center for Cardiovascular Innovation, Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, BC, Canada
| | - Raymond W Sy
- Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Pieter G Postema
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Michael J Ackerman
- Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, Minnesota, USA; Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minnesota, USA; Departments of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota, USA
| | - Arthur A M Wilde
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam University Medical Centers, Amsterdam, the Netherlands; European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (ERN GUARD-Heart), Academic University Medical Center, Amsterdam, the Netherlands
| | - Hui-Chen Han
- Center for Cardiovascular Innovation, Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, BC, Canada; Victorian Heart Institute, Monash University, Clayton, VIC, Australia
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10
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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11
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Wilde AAM, Amin AS, Postema PG. Diagnosis, management and therapeutic strategies for congenital long QT syndrome. Heart 2021; 108:332-338. [PMID: 34039680 PMCID: PMC8862104 DOI: 10.1136/heartjnl-2020-318259] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/12/2021] [Accepted: 05/03/2021] [Indexed: 11/18/2022] Open
Abstract
Congenital long QT syndrome (LQTS) is characterised by heart rate corrected QT interval prolongation and life-threatening arrhythmias, leading to syncope and sudden death. Variations in genes encoding for cardiac ion channels, accessory ion channel subunits or proteins modulating the function of the ion channel have been identified as disease-causing mutations in up to 75% of all LQTS cases. Based on the underlying genetic defect, LQTS has been subdivided into different subtypes. Growing insights into the genetic background and pathophysiology of LQTS has led to the identification of genotype–phenotype relationships for the most common genetic subtypes, the recognition of genetic and non-genetic modifiers of phenotype, optimisation of risk stratification algorithms and the discovery of gene-specific therapies in LQTS. Nevertheless, despite these great advancements in the LQTS field, large gaps in knowledge still exist. For example, up to 25% of LQTS cases still remain genotype elusive, which hampers proper identification of family members at risk, and it is still largely unknown what determines the large variability in disease severity, where even within one family an identical mutation causes malignant arrhythmias in some carriers, while in other carriers, the disease is clinically silent. In this review, we summarise the current evidence available on the diagnosis, clinical management and therapeutic strategies in LQTS. We also discuss new scientific developments and areas of research, which are expected to increase our understanding of the complex genetic architecture in genotype-negative patients, lead to improved risk stratification in asymptomatic mutation carriers and more targeted (gene-specific and even mutation-specific) therapies.
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Affiliation(s)
- Arthur A M Wilde
- Heart Centre, Department of Cardiology, Amsterdam Universitair Medische Centra, Amsterdam, The Netherlands
| | - Ahmad S Amin
- Heart Centre, Department of Cardiology, Amsterdam Universitair Medische Centra, Amsterdam, The Netherlands
| | - Pieter G Postema
- Heart Centre, Department of Cardiology, Amsterdam Universitair Medische Centra, Amsterdam, The Netherlands
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12
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Beckmann BM, Scheiper-Welling S, Wilde AAM, Kääb S, Schulze-Bahr E, Kauferstein S. Clinical utility gene card for: Long-QT syndrome. Eur J Hum Genet 2021; 29:1825-1832. [PMID: 34031550 PMCID: PMC8633377 DOI: 10.1038/s41431-021-00904-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/25/2021] [Accepted: 04/23/2021] [Indexed: 11/09/2022] Open
Affiliation(s)
- Britt M Beckmann
- Department of Legal Medicine, University Hospital Frankfurt, Frankfurt am Main, Germany. .,Department of Medicine I, University Hospital, LMU Munich, Munich, Germany.
| | | | - Arthur A M Wilde
- Amsterdam UMC, University of Amsterdam, Heart Center, Amsterdam, The Netherlands.,European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (ERN GUARDHEART; http://guardheart.ern-net.eu), Amsterdam, The Netherlands.,Department of Clinical and Experimental Cardiology, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Stefan Kääb
- Department of Medicine I, University Hospital, LMU Munich, Munich, Germany.,German Center for Cardiovascular Research (DZHK), Partnersite Munich, Munich, Germany
| | - Eric Schulze-Bahr
- European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (ERN GUARDHEART; http://guardheart.ern-net.eu), Amsterdam, The Netherlands.,Institute for Genetics of Heart Diseases, University Hospital Münster, Münster, Germany
| | - Silke Kauferstein
- Department of Legal Medicine, University Hospital Frankfurt, Frankfurt am Main, Germany
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13
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Fadel S, Walker AE. The Postmortem Interpretation of Cardiac Genetic Variants of Unknown Significance in Sudden Death in the Young: A Case Report and Review of the Literature. Acad Forensic Pathol 2021; 10:166-175. [PMID: 33815637 DOI: 10.1177/1925362120984868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 10/04/2020] [Indexed: 11/16/2022]
Abstract
Sudden cardiac death (SCD) in adolescents and young adults is a major traumatic event for families and communities. In these cases, it is not uncommon to have a negative autopsy with structurally and histologically normal heart. Such SCD cases are generally attributed to channelopathies, which include long QT syndrome, short QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia. Our understanding of the causes for SCDs has changed significantly with the advancements in molecular and genetic studies, where many mutations are now known to be associated with certain channelopathies. Postmortem analysis provides great value in informing decision-making with regard to screening tests and prophylactic measures that should be taken to prevent sudden death in first degree relatives of the decedent. As this is a rapidly advancing field, our ability to identify genetic mutations has surpassed our ability to interpret them. This led to a unique challenge in genetic testing called variants of unknown significance (VUS). VUSs present a diagnostic dilemma and uncertainty for clinicians and patients with regard to next steps. Caution should be exercised when interpreting VUSs since misinterpretation can result in mismanagement of patients and their families. A case of a young adult man with drowning as his proximate cause of death is presented in circumstances where cardiac genetic testing was indicated and undertaken. Eight VUSs in genes implicated in inheritable cardiac dysfunction were identified and the interpretation of VUSs in this scenario is discussed.
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14
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van Dongen LH, Harms PP, Hoogendoorn M, Zimmerman DS, Lodder EM, 't Hart LM, Herings R, van Weert HCPM, Nijpels G, Swart KMA, van der Heijden AA, Blom MT, Elders PJ, Tan HL. Discovery of predictors of sudden cardiac arrest in diabetes: rationale and outline of the RESCUED (REcognition of Sudden Cardiac arrest vUlnErability in Diabetes) project. Open Heart 2021; 8:openhrt-2020-001554. [PMID: 33547224 PMCID: PMC7871346 DOI: 10.1136/openhrt-2020-001554] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 12/19/2022] Open
Abstract
Introduction Early recognition of individuals with increased risk of sudden cardiac arrest (SCA) remains challenging. SCA research so far has used data from cardiologist care, but missed most SCA victims, since they were only in general practitioner (GP) care prior to SCA. Studying individuals with type 2 diabetes (T2D) in GP care may help solve this problem, as they have increased risk for SCA, and rich clinical datasets, since they regularly visit their GP for check-up measurements. This information can be further enriched with extensive genetic and metabolic information. Aim To describe the study protocol of the REcognition of Sudden Cardiac arrest vUlnErability in Diabetes (RESCUED) project, which aims at identifying clinical, genetic and metabolic factors contributing to SCA risk in individuals with T2D, and to develop a prognostic model for the risk of SCA. Methods The RESCUED project combines data from dedicated SCA and T2D cohorts, and GP data, from the same region in the Netherlands. Clinical data, genetic data (common and rare variant analysis) and metabolic data (metabolomics) will be analysed (using classical analysis techniques and machine learning methods) and combined into a prognostic model for risk of SCA. Conclusion The RESCUED project is designed to increase our ability at early recognition of elevated SCA risk through an innovative strategy of focusing on GP data and a multidimensional methodology including clinical, genetic and metabolic analyses.
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Affiliation(s)
- Laura H van Dongen
- Clinical and Experimental Cardiology, Amsterdam UMC - Locatie AMC, Heart Centre, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Peter P Harms
- General Practice Medicine, Amsterdam UMC - Locatie VUmc, Vrije Universiteit, Amsterdam Public Health Research Institute, Amsterdam, Netherlands
| | - Mark Hoogendoorn
- Computer Science, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Dominic S Zimmerman
- Clinical and Experimental Cardiology, Amsterdam UMC - Locatie AMC, Heart Centre, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Elisabeth M Lodder
- Clinical and Experimental Cardiology, Amsterdam UMC - Locatie AMC, Heart Centre, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Leen M 't Hart
- Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands.,Biomedical Data Sciences, section Molecular Epidemiology, Leiden University Medical Centre, Leiden, Netherlands.,Epidemiology and Data Science, Amsterdam UMC, Amsterdam Public Health Research Institute, Amsterdam, Netherlands
| | - Ron Herings
- PHARMO Institute, Utrecht, Utrecht, Netherlands
| | - Henk C P M van Weert
- Department of General Practice, Amsterdam Public Health, Amsterdam UMC Locatie AMC, Amsterdam, Netherlands
| | - Giel Nijpels
- General Practice Medicine, Amsterdam UMC - Locatie VUmc, Vrije Universiteit, Amsterdam Public Health Research Institute, Amsterdam, Netherlands
| | - Karin M A Swart
- General Practice Medicine, Amsterdam UMC - Locatie VUmc, Vrije Universiteit, Amsterdam Public Health Research Institute, Amsterdam, Netherlands.,PHARMO Institute, Utrecht, Utrecht, Netherlands
| | - Amber A van der Heijden
- General Practice Medicine, Amsterdam UMC - Locatie VUmc, Vrije Universiteit, Amsterdam Public Health Research Institute, Amsterdam, Netherlands
| | - Marieke T Blom
- Clinical and Experimental Cardiology, Amsterdam UMC - Locatie AMC, Heart Centre, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Petra J Elders
- General Practice Medicine, Amsterdam UMC - Locatie VUmc, Vrije Universiteit, Amsterdam Public Health Research Institute, Amsterdam, Netherlands
| | - Hanno L Tan
- Clinical and Experimental Cardiology, Amsterdam UMC - Locatie AMC, Heart Centre, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, Netherlands .,Netherlands Heart Institute, Utrecht, Netherlands
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15
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Roston TM, De Souza AM, Romans HV, Franciosi S, Armstrong KR, Sanatani S. Potential overdiagnosis of long QT syndrome using exercise stress and QT stand testing in children and adolescents with a low probability of disease. J Cardiovasc Electrophysiol 2021; 32:500-506. [PMID: 33382510 DOI: 10.1111/jce.14865] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 12/07/2020] [Accepted: 12/22/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Long QT syndrome (LQTS) is a dangerous arrhythmia disorder that often presents in childhood and adolescence. The exercise stress test (EST) and QT-stand test may unmask QT interval prolongation at key heart rate transition points in LQTS, but their utility in children is debated. OBJECTIVE To determine if the QT-stand test or EST can differentiate children with a low probability of LQTS from those with confirmed LQTS. METHODS This retrospective study compares the corrected QT intervals (QTc) of children (<19 years) during the QT-stand test and EST. Patients were divided into three groups for comparison: confirmed LQTS (n = 14), low probability of LQTS (n = 14), and a control population (n = 9). RESULTS Using the Bazett formula, confirmed LQTS patients had longer QTc intervals than controls when supine, standing, and at 3-4 min of recovery (p ≤ .01). Patients with a low probability of LQTS had longer QTc duration upon standing (p = .018) and at 1 min of recovery (p = .016) versus controls. There were no significant QTc differences at any transition point between low probability and confirmed LQTS. Using the Fridericia formula, differences in QTc between low probability and confirmed LQTS were also absent at the transition points examined, except at 1 min into exercise, where low probability patients had shorter QTc intervals (437 vs. 460 ms, p = .029). CONCLUSION The diagnostic utility of the QT stand test and EST remains unclear in pediatric LQTS. The formula used for heart rate correction may influence accuracy, and dynamic T-U wave morphology changes may confound interpretation in low probability situations.
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Affiliation(s)
- Thomas M Roston
- Department of Pediatrics, Division of Cardiology, British Columbia Children's Hospital and The University of British Columbia, Vancouver, Canada.,Department of Medicine, Division of Cardiology, The University of British Columbia, Vancouver, Canada
| | - Astrid M De Souza
- Department of Pediatrics, Division of Cardiology, British Columbia Children's Hospital and The University of British Columbia, Vancouver, Canada
| | - Hilary V Romans
- Department of Pediatrics, Division of Cardiology, British Columbia Children's Hospital and The University of British Columbia, Vancouver, Canada
| | - Sonia Franciosi
- Department of Pediatrics, Division of Cardiology, British Columbia Children's Hospital and The University of British Columbia, Vancouver, Canada
| | - Kathryn R Armstrong
- Department of Pediatrics, Division of Cardiology, British Columbia Children's Hospital and The University of British Columbia, Vancouver, Canada
| | - Shubhayan Sanatani
- Department of Pediatrics, Division of Cardiology, British Columbia Children's Hospital and The University of British Columbia, Vancouver, Canada
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16
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Hermans BJ, Bennis FC, Vink AS, Koopsen T, Lyon A, Wilde AA, Nuyens D, Robyns T, Pison L, Postema PG, Delhaas T. Improving long QT syndrome diagnosis by a polynomial-based T-wave morphology characterization. Heart Rhythm 2020; 17:752-8. [DOI: 10.1016/j.hrthm.2019.12.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 12/29/2019] [Indexed: 11/20/2022]
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17
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Suna G, Saguner AM, Brunckhorst CB. [CME ECG 63/Answers: Stress-Induced Ventricular Arrhythmias]. Praxis (Bern 1994) 2019; 108:567-572. [PMID: 31185841 DOI: 10.1024/1661-8157/a003244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Affiliation(s)
- Gonca Suna
- 1 Klinik für Kardiologie, Universitäres Herzzentrum, Universitätsspital Zürich
| | - Ardan M Saguner
- 1 Klinik für Kardiologie, Universitäres Herzzentrum, Universitätsspital Zürich
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18
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Filippini LHPM, Postema PG, Zoubin K, Hermans BJM, Blom NA, Delhaas T, Wilde AAM. The brisk-standing-test for long QT syndrome in prepubertal school children: defining normal. Europace 2019; 20:f108-f112. [PMID: 29036559 DOI: 10.1093/europace/eux259] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Accepted: 07/10/2017] [Indexed: 12/24/2022] Open
Abstract
Aims Long QT syndrome (LQTS) is associated with malignant arrhythmias and sudden death from birth to advanced age. Prolongation of the QT-interval, may however be concealed on standard electrocardiograms (ECG). The brisk-standing-test (BST) was developed to guide LQTS-diagnosis and treatment in adults. We hypothesized that the BST may be used in prepubertal children to identify LQTS subjects. Accordingly, reference values for the BST should be available to prevent incorrect diagnosis and treatment of LQTS. In this study, we aim to present reference values for prepubertal children. Methods and results Healthy, prepubertal children, aged 7-13 years underwent a standard supine resting ECG and during continuous ECG recording performed a BST. The QT-interval and heart rate corrected QTc were measured during the different BST stages. Fifty-seven children, 29 boys (10.2 ± 1.1 years) and 28 girls (9.9 ± 1.1 years) were included. Baseline characteristics and response to standing were not statistically different for boys and girls: mean supine pre-standing heart rate 74 ± 9 vs. 77 ± 9 bpm, supine pre-standing QTc 406 ± 27 vs. 407 ± 17 ms, maximal heart rate upon standing 109 ± 11 vs. 112 ± 11 bpm, and QTc at maximal heart rate 484 ± 29 vs. 487 ± 35 ms. The QT interval corrected for heart rate-prolongation at maximal tachycardia after standing was 79 ± 26 (19-144) ms, which is significantly longer than previously published values in adults (50± 30 ms). Conclusions The QT interval corrected for heart rate prolongation after brisk standing in healthy prepubertal children is more pronounced than in healthy adults. This finding advocates distinct prepubertal cut-off values because using adult values for prepubertal children would yield false positive results with the risk of incorrect LQTS-diagnosis and overtreatment.
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Affiliation(s)
- L H P M Filippini
- Department of Paediatric Cardiology, Juliana Children's Hospital, Els Borst-Eilers plein 275, 2545 CH, The Hague, The Netherlands
| | - P G Postema
- Department of Cardiology, Academic Medical Centre, Amsterdam, The Netherlands
| | - K Zoubin
- Department of Paediatric Cardiology, Juliana Children's Hospital, Els Borst-Eilers plein 275, 2545 CH, The Hague, The Netherlands
| | - B J M Hermans
- Department of Biomedical Engineering, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - N A Blom
- Department of Cardiology, Academic Medical Centre, Amsterdam, The Netherlands.,Department of Paediatric Cardiology, Leiden University Medical Centre, Leiden University Hospital, Leiden, The Netherlands
| | - T Delhaas
- Department of Biomedical Engineering, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - A A M Wilde
- Department of Cardiology, Academic Medical Centre, Amsterdam, The Netherlands
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19
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Ozawa J, Ohno S, Fujii Y, Makiyama T, Suzuki H, Saitoh A, Horie M. Differential Diagnosis Between Catecholaminergic Polymorphic Ventricular Tachycardia and Long QT Syndrome Type 1 ― Modified Schwartz Score ―. Circ J 2018; 82:2269-2276. [DOI: 10.1253/circj.cj-17-1032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Junichi Ozawa
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science
- Department of Pediatrics, Niigata University Graduate School of Medical and Dental Sciences
| | - Seiko Ohno
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science
- Center for Epidemiologic Research in Asia, Shiga University of Medical Science
- Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center
| | - Yusuke Fujii
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science
| | - Takeru Makiyama
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine
| | - Hiroshi Suzuki
- Department of Pediatrics, Niigata University Graduate School of Medical and Dental Sciences
| | - Akihiko Saitoh
- Department of Pediatrics, Niigata University Graduate School of Medical and Dental Sciences
| | - Minoru Horie
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science
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20
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Yankelson L, Hochstadt A, Sadeh B, Pick B, Finkelstein A, Rosso R, Viskin S. New formula for defining "normal" and "prolonged" QT in patients with bundle branch block. J Electrocardiol 2018; 51:481-486. [PMID: 29395105 DOI: 10.1016/j.jelectrocard.2017.12.039] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 12/12/2017] [Indexed: 11/18/2022]
Abstract
OBJECTIVES To predict the QT interval in the presence of normal QRS for patients with left bundle branch block (LBBB). BACKGROUND There is no acceptable method for simple and reliable QT correction for patients with bundle branch block (BBB). METHODS We measured the QT interval in patients with new onset LBBB who had a recent electrocardiogram with narrow QRS for comparison. 48 patients who developed in-hospital LBBB were studied. Patients who had similar heart rate before and after LBBB were included. We used linear regression, the Bogossian method, and our new fixed QRS replacement method to evaluate the most reliable correction method. RESULTS JTc (QTc-QRS) interval was preserved before and after LBBB (328.9 ± 25.4 ms before LBBB vs. 327.3 ms post LBBB (p = 0.550). Mean predicted preLBBB QTc difference was 1.3 ms, -21.3 ms and 1.6 ms for the three methods respectively (p < 0.001 for Bogossian comparison with the other methods). Coefficients of correlation (R) between actual preLBBB QTc with predicted preLBBB QTc were 0.707, 0.683 and 0.665 respectively (p > 0.3 for R comparisons between all methods). The average absolute difference in preLBBB QTc was 15.5 ms and 16.7 ms for the regression and fixed-gender methods (p value between the two = 0.321) and 25.5 ms for the Bogossian method, which was found to be significantly underperforming. CONCLUSIONS In patients with LBBB, replacing of the QRS duration after deriving the QTc interval with a fixed value of 88 ms for female and 95 ms for male provides a simple and reliable method for predicting the QTc before the development of LBBB.
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Affiliation(s)
- Lior Yankelson
- Cardiac Electrophysiology, Division of Cardiology, NYU Langone Health, New York University School of Medicine, New York, USA.
| | - Aviram Hochstadt
- Department of Cardiology, Tel Aviv Sourasky Medical Center, Sackler School of Medicine, Tel Aviv University, Israel
| | - Ben Sadeh
- Department of Cardiology, Tel Aviv Sourasky Medical Center, Sackler School of Medicine, Tel Aviv University, Israel
| | - Benley Pick
- Department of Cardiology, Tel Aviv Sourasky Medical Center, Sackler School of Medicine, Tel Aviv University, Israel
| | - Ariel Finkelstein
- Department of Cardiology, Tel Aviv Sourasky Medical Center, Sackler School of Medicine, Tel Aviv University, Israel
| | - Raphael Rosso
- Department of Cardiology, Tel Aviv Sourasky Medical Center, Sackler School of Medicine, Tel Aviv University, Israel
| | - Sami Viskin
- Department of Cardiology, Tel Aviv Sourasky Medical Center, Sackler School of Medicine, Tel Aviv University, Israel
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21
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Affiliation(s)
| | - Robert M Gow
- Children's Hospital of Eastern Ontario, Ottawa, Canada
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22
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Vinet A, Dubé B, Nadeau R, Mahiddine O, Jacquemet V. Estimation of the QT-RR relation: trade-off between goodness-of-fit and extrapolation accuracy. Physiol Meas 2017; 38:397-419. [PMID: 28067212 DOI: 10.1088/1361-6579/aa57b4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Correction of the QT interval in the ECG for changes in heart rate (RR interval) is needed to compare groups of patients and assess the risk of sudden cardiac death. The QTc represents the QT interval at 60 bpm, although most patients typically have a faster heart rate, thus requiring extrapolation of the QT-RR relationship. OBJECTIVE This paper investigates the ability of QT-RR models with increasing number of parameters to fit beat-to-beat variations in the QT interval and provide a reliable estimate of the QTc. APPROACH One-, two- and three-parameter functions generalising the Bazett and Fridericia formulas were used in combination with hysteresis reduction (memory) obtained by time-averaging the history of RR intervals with exponentially-decaying weights. In normal men and women datasets of Holter recordings in normal subjects (24 h monitoring), two measures were computed for each model: the root mean square error (RMSE) of fitting and the difference between the estimated QTc and a reference QTc obtained by collecting data points around RR = 1000 ms. MAIN RESULTS The two- and three-parameter functions all gave similar low RMSE with uncorrelated residues. An optimal memory parameter was found that still minimized the RMSE and could be used for all functions and subjects. This reduction in RMSE resulted from changes in the parameters linked to the increased steepness of the QT-RR relation after hysteresis reduction. At optimal memory, the two and three-parameter models provided poorer prediction of the QTc as compared to the Fridericia's model in subjects with fast heart rates, since accurate representation of the steeper QT-RR relation worsened the extrapolation that was then needed to determine the QTc. SIGNIFICANCE As a result, among all models investigated, the Fridericia formulation offered the best trade-off for QTc prediction robust to memory and fast heart rates.
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Affiliation(s)
- Alain Vinet
- Faculty of Medicine, Department of pharmacology and physiology, Université de Montréal, Montréal, QC, Canada. Centre de Recherche, Hôpital du Sacré-Cœur, Montréal, QC, Canada. Institut de Génie Biomédical, Université de Montréal, Montréal, QC, Canada
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Chorin E, Hochstadt A, Viskin S, Rozovski U, Havakuk O, Baranchuk A, Enriquez A, Strasberg B, Guevara-Valdivia ME, Márquez MF, González-Pacheco H, Hasdemir C, Rosso R. Female gender as independent risk factor of torsades de pointes during acquired atrioventricular block. Heart Rhythm 2017; 14:90-95. [DOI: 10.1016/j.hrthm.2016.09.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Indexed: 11/29/2022]
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Abstract
Ventricular arrhythmias without structural heart disease are responsible for ∼35% of patients who have sudden cardiac death before the age of 40 years. Molecular autopsy and/or cardiological investigation of nearby family members often reveals the diagnosis and genetic testing can be helpful in family screening and risk stratification in disease carriers. Extended gene panels can be screened in a short period of time at low cost. A multidisciplinary team of (genetically) specialized clinicians is necessary to judge all the available details and to decide on the significance of the variant and further strategies.
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Affiliation(s)
- Nynke Hofman
- Department of Clinical Genetics, Academic Medical Center, M0-229, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands
| | - Arthur A M Wilde
- Department of Cardiology, Academic Medical Center, B2-239, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands.
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25
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Idris NS, Cheung MMH, Grobbee DE, Burgner D, Kurniati N, Djer MM, Uiterwaal CSPM. Effects of paediatric HIV infection on electrical conduction of the heart. Open Heart 2016; 3:e000340. [PMID: 27042320 PMCID: PMC4800758 DOI: 10.1136/openhrt-2015-000340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 12/15/2015] [Accepted: 12/20/2015] [Indexed: 01/08/2023] Open
Abstract
Objective To investigate the effects of HIV infection in children on heart electrical conduction, particularly to delineate the effects of HIV infection from treatment. Methods On a 12-lead ECG, available for 37 antiretroviral therapy (ART) naïve, 42 ART-exposed vertically-acquired HIV-infected and 50 healthy children in Jakarta, Indonesia, we measured cardiac conduction parameters: PR, QRS, and QTc (corrected using Bazett's formula) intervals. The associations between HIV infection/treatment status and ECG intervals were evaluated using general linear modelling with further adjustment for potential confounders or intermediary variables. Findings are presented as (adjusted) mean differences between each of the two HIV groups and healthy children. Results Although not exceeding the clinical threshold for long QT (QTc >460 ms for girls and >440 ms for boys) compared to healthy children, mean QTc intervals were longer in ART-naïve (difference 18.2 ms, 95% CI 7.0 to 29.3) and, to greater extent, in ART-exposed HIV-infected children (difference 28.9 ms, 19.3 to 38.5). Following adjustment for RR interval, age and height, prolongation of PR interval was seen only in ART-naïve HIV-infected children (difference 12.9 ms, 2.4 to 23.3). Cardiac mass/function, high-sensitive C reactive protein, cholesterol and glycated haemoglobin levels, systolic and diastolic blood pressures, or postnatal parental smoking exposure did not affect these associations. No difference in the QRS interval was observed between groups. Conclusions Prolongation of the QTc interval occurs in ART-naïve HIV-infected children and, to a greater extent, in the ART-exposed children, whereas a longer PR interval appears to be seen only among ART-naïve HIV-infected children.
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Affiliation(s)
- Nikmah S Idris
- Faculty of Medicine University of Indonesia-Cipto Mangunkusumo Hospital, Department of Child Health, Jakarta, Indonesia; Julius Global Health, Julius Centre for Health Sciences and Primary Care, the University Medical Centre Utrecht, Utrecht, The Netherlands; Department of Paediatrics, University of Melbourne, Murdoch Childrens Research Institute; Royal Children's Hospital, Melbourne, Australia
| | - Michael M H Cheung
- Department of Paediatrics , University of Melbourne, Murdoch Childrens Research Institute; Royal Children's Hospital , Melbourne , Australia
| | - Diederick E Grobbee
- Julius Global Health , Julius Centre for Health Sciences and Primary Care, the University Medical Centre Utrecht , Utrecht , The Netherlands
| | - David Burgner
- Department of Paediatrics, University of Melbourne, Murdoch Childrens Research Institute; Royal Children's Hospital, Melbourne, Australia; Department of Paediatrics, Monash University, Victoria, Australia
| | - Nia Kurniati
- Faculty of Medicine University of Indonesia-Cipto Mangunkusumo Hospital, Department of Child Health, Jakarta , Indonesia
| | - Mulyadi M Djer
- Faculty of Medicine University of Indonesia-Cipto Mangunkusumo Hospital, Department of Child Health, Jakarta , Indonesia
| | - Cuno S P M Uiterwaal
- Julius Global Health , Julius Centre for Health Sciences and Primary Care, the University Medical Centre Utrecht , Utrecht , The Netherlands
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Padfield GJ, Escudero CA, DeSouza AM, Steinberg C, Gibbs K, Puyat JH, Lam PY, Sanatani S, Sherwin E, Potts JE, Sandor G, Krahn AD. Characterization of Myocardial Repolarization Reserve in Adolescent Females With Anorexia Nervosa. Circulation 2016; 133:557-65. [PMID: 26769740 DOI: 10.1161/circulationaha.115.016697] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 12/29/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Patients with anorexia nervosa exhibit abnormal myocardial repolarization and are susceptible to sudden cardiac death. Exercise testing is useful in unmasking QT prolongation in disorders associated with abnormal repolarization. We characterized QT adaptation during exercise in anorexia. METHODS AND RESULTS Sixty-one adolescent female patients with anorexia nervosa and 45 age- and sex-matched healthy volunteers performed symptom-limited cycle ergometry during 12-lead ECG monitoring. Changes in the QT interval during exercise were measured, and QT/RR-interval slopes were determined by using mixed-effects regression modeling. Patients had significantly lower body mass index than controls; however, resting heart rates and QT/QTc intervals were similar at baseline. Patients had shorter exercise times (13.7±4.5 versus 20.6±4.5 minutes; P<0.001) and lower peak heart rates (159±20 versus 184±9 beats/min; P<0.001). The mean QTc intervals were longer at peak exercise in patients (442±29 versus 422±19 ms; P<0.001). During submaximal exertion at comparable heart rates (114±6 versus 115±11 beats/min; P=0.54), the QTc interval had prolonged significantly more in patients than controls (37±28 versus 24±25 ms; P<0.016). The RR/QT slope, best described by a curvilinear relationship, was more gradual in patients than in controls (13.4; 95% confidence interval, 12.8-13.9 versus 15.8; 95% confidence interval, 15.3-16.4 ms QT change per 10% change in RR interval; P<0.001) and steepest in patients within the highest body mass index tertile versus the lowest (13.9; 95% confidence interval, 12.9-14.9 versus 12.3; 95% confidence interval, 11.3-13.3; P=0.026). CONCLUSIONS Despite the absence of manifest QT prolongation, adolescent anorexic females have impaired repolarization reserve in comparison with healthy controls. Further study may identify impaired QT dynamics as a risk factor for arrhythmias in anorexia nervosa.
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Affiliation(s)
- Gareth J Padfield
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Carolina A Escudero
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Astrid M DeSouza
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Christian Steinberg
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Karen Gibbs
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Joseph H Puyat
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Pei Yoong Lam
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Shubhayan Sanatani
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Elizabeth Sherwin
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - James E Potts
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - George Sandor
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Andrew D Krahn
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.).
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Affiliation(s)
- Ahmad S Amin
- Heart Centre AMC, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Arthur A M Wilde
- Heart Centre AMC, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, Jeddah, Kingdom of Saudi Arabia
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Arbour L, Asuri S, Whittome B, Polanco F, Hegele RA. The Genetics of Cardiovascular Disease in Canadian and International Aboriginal Populations. Can J Cardiol 2015; 31:1094-115. [DOI: 10.1016/j.cjca.2015.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 07/08/2015] [Accepted: 07/09/2015] [Indexed: 12/16/2022] Open
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Chorin E, Havakuk O, Adler A, Steinvil A, Rozovski U, van der Werf C, Postema PG, Topaz G, Wilde AAM, Viskin S, Rosso R. Diagnostic value of T-wave morphology changes during "QT stretching" in patients with long QT syndrome. Heart Rhythm 2015; 12:2263-71. [PMID: 26142298 DOI: 10.1016/j.hrthm.2015.06.040] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Indexed: 11/18/2022]
Abstract
BACKGROUND Specific T-wave patterns on the resting electrocardiogram (ECG) aid in diagnosing long QT syndrome (LQTS) and identifying the specific genotype. However, provocation tests often are required to establish a diagnosis when the QT interval is borderline at rest. OBJECTIVE The purpose of this study was to determine whether T-wave morphology changes provoked by standing aid in the diagnosis of LQTS and determination of the genotype. METHODS The quick-standing test was performed by 100 LQTS patients (40 type 1 [LQT1], 42 type 2 [LQT2], 18 type 3 [LQT3]) and 100 controls. Logistic regression was used to determine whether T-wave morphology changes provoked by standing added to the already established diagnostic value of QTc stretching in identifying LQTS. RESULTS During maximal QT stretching, the T-wave morphologies that best discriminated LQTS from controls included "notched," "late-onset," and "biphasic" T waves. These 3 categories were grouped into a category named "abnormal T-wave response to standing." During quick standing, a QTc stretched ≥490 ms increased the odds of correctly identifying LQTS. T-wave morphology changes provoked by standing were most helpful for identifying LQT2, less helpful for LQT1, and least helpful for LQT3. CONCLUSION The sudden heart rate acceleration produced by abrupt standing not only increases the QTc but also exposes abnormal T waves that are valuable for diagnosing LQTS.
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Affiliation(s)
- Ehud Chorin
- Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ofer Havakuk
- Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Arnon Adler
- Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Arie Steinvil
- Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Uri Rozovski
- Department of Internal Medicine, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Christian van der Werf
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Pieter G Postema
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Guy Topaz
- Department of Internal Medicine, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Arthur A M Wilde
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Sami Viskin
- Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Raphael Rosso
- Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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Abstract
Sudden cardiac death in the young is a relatively uncommon but marked event usually related to congenital diseases or anomalies. Despite the prevalence of each condition being variable, most common causes include primary myocardial diseases and arrhythmic disorder, frequently with inheritance pattern. Sudden cardiac death is usually preceded by symptoms, thus making personal and family history fundamental for its prevention. Nevertheless, in more than 50% of cases, sudden cardiac death is the first manifestation of the disease. In this review, we describe the different causes of sudden cardiac death, their incidence, and currently used preventive strategies.
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Rodríguez-balderrama I, Morales-rodríguez I, Rodríguez-martínez V, Rodríguez-bonito R. Long QT syndrome in a neonate. Medicina Universitaria 2015; 17:46-48. [DOI: 10.1016/j.rmu.2014.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Abstract
The evaluation of every electrocardiogram should also include an effort to interpret the QT interval to assess the risk of malignant arrhythmias and sudden death associated with an aberrant QT interval. The QT interval is measured from the beginning of the QRS complex to the end of the T-wave, and should be corrected for heart rate to enable comparison with reference values. However, the correct determination of the QT interval, and its value, appears to be a daunting task. Although computerized analysis and interpretation of the QT interval are widely available, these might well over- or underestimate the QT interval and may thus either result in unnecessary treatment or preclude appropriate measures to be taken. This is particularly evident with difficult T-wave morphologies and technically suboptimal ECGs. Similarly, also accurate manual assessment of the QT interval appears to be difficult for many physicians worldwide. In this review we delineate the history of the measurement of the QT interval, its underlying pathophysiological mechanisms and the current standards of the measurement of the QT interval, we provide a glimpse into the future and we discuss several issues troubling accurate measurement of the QT interval. These issues include the lead choice, U-waves, determination of the end of the T-wave, different heart rate correction formulas, arrhythmias and the definition of normal and aberrant QT intervals. Furthermore, we provide recommendations that may serve as guidance to address these complexities and which support accurate assessment of the QT interval and its interpretation.
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Affiliation(s)
| | - Arthur A M Wilde
- Department of Cardiology, Academic Medical Center, P.O. box 22660, 1100 DD Amsterdam, The Netherlands.
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Dohadwala M, Link MS. Implantable Defibrillators in Long QT Syndrome, Brugada Syndrome, Hypertrophic Cardiomyopathy, and Arrhythmogenic Right Ventricular Cardiomyopathy. Cardiol Clin 2014; 32:305-18. [DOI: 10.1016/j.ccl.2013.11.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Vittoria Matassini M, Krahn AD, Gardner M, Champagne J, Sanatani S, Birnie DH, Gollob MH, Chauhan V, Simpson CS, Hamilton RM, Talajic M, Ahmad K, Gerull B, Chakrabarti S, Healey JS. Evolution of clinical diagnosis in patients presenting with unexplained cardiac arrest or syncope due to polymorphic ventricular tachycardia. Heart Rhythm 2013; 11:274-81. [PMID: 24239842 DOI: 10.1016/j.hrthm.2013.11.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Indexed: 11/16/2022]
Abstract
BACKGROUND A systematic evaluation of patients with unexplained cardiac arrest (UCA) yields a diagnosis in 50% of the cases. However, evolution of clinical phenotype, identification of new disease-causing mutations, and description of new syndromes may revise the diagnosis. OBJECTIVE To assess the evolution in diagnosis among patients with initially UCA. METHODS Diagnoses were reviewed for all patients with UCA recruited from the Cardiac Arrest Survivors with Preserved Ejection Fraction Registry with at least 1 year of follow-up. RESULTS After comprehensive investigation of 68 patients (age 45.2 ± 14.9 years; 63% men), the initial diagnosis was as follows: idiopathic ventricular fibrillation (n = 34 [50%]), a primary arrhythmic disorder (n = 21 [31%]), and an occult structural cause (n = 13 [19%]). Patients were followed for 30 ± 17 months, during which time the diagnosis changed in 12 (18%) patients. A specific diagnosis emerged for 7 patients (21%) with an initial diagnosis of idiopathic ventricular fibrillation. A structural cardiomyopathy evolved in 2 patients with an initial diagnosis of primary electrical disorder, while the specific structural cardiomyopathy was revised for 1 patient. Two patients with an initial diagnosis of a primary arrhythmic disorder were subsequently considered to have a different primary arrhythmic disorder. A follow-up resting electrocardiogram was the test that most frequently changed the diagnosis (67% of the cases), followed by genetic testing (17%). CONCLUSIONS The reevaluation of patients presenting with UCA may lead to a change in diagnosis in up to 20%. This emphasizes the need to actively monitor the phenotype and also has implications for the treatment of these patients and the screening of their relatives.
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Affiliation(s)
- Maria Vittoria Matassini
- Population Health Research Institute, McMaster University, Hamilton, Canada; Polytechnic University of Marche, Ancona, Italy
| | - Andrew D Krahn
- University of British Columbia, Vancouver, British Columbia, Canada
| | | | | | - Shubhayan Sanatani
- British Columbia Children's Hospital, Vancouver, British Columbia, Canada
| | | | | | - Vijay Chauhan
- University Health Network, University of Toronto, Toronto, Ontario, Canada
| | | | | | | | - Kam Ahmad
- St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
| | | | | | - Jeff S Healey
- Population Health Research Institute, McMaster University, Hamilton, Canada.
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Abstract
Proper generation and conduction of the cardiac electrical impulse is essential for the continuous coordinated contraction of the heart. Dysregulation of cardiac electrical function may lead to cardiac arrhythmias, which constitute a huge medical and social burden. Identifying the genetic factors underlying cardiac electrical activity serves the double purpose of allowing the early identification of individuals at risk for arrhythmia and discovering new potential therapeutic targets for prevention. The aim of this review is to provide an overview of the genes and genetic loci linked thus far to cardiac electrical function and arrhythmia. These genes and loci have been primarily uncovered through studies on the familial rhythm disorders and through genome-wide association studies on electrocardiographic parameters in large sets of the general population. An overview of all genes and loci with their respective effect is given.
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Affiliation(s)
- Elisabeth M Lodder
- Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Tel.: +31 20 5665962; Fax: +31 20 6976177;
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Müller M, Seufferlein T, Illing A, Homann J. Modelling human channelopathies using induced pluripotent stem cells: a comprehensive review. Stem Cells Int 2013; 2013:496501. [PMID: 23766769 DOI: 10.1155/2013/496501] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 04/16/2013] [Indexed: 12/13/2022] Open
Abstract
The generation of induced pluripotent stem cells (iPS cells) has pioneered the field of regenerative medicine and developmental biology. They can be generated by overexpression of a defined set of transcription factors in somatic cells derived from easily accessible tissues such as skin or plucked hair or even human urine. In case of applying this tool to patients who are classified into a disease group, it enables the generation of a disease- and patient-specific research platform. iPS cells have proven a significant tool to elucidate pathophysiological mechanisms in various diseases such as diabetes, blood disorders, defined neurological disorders, and genetic liver disease. One of the first successfully modelled human diseases was long QT syndrome, an inherited cardiac channelopathy which causes potentially fatal cardiac arrhythmia. This review summarizes the efforts of reprogramming various types of long QT syndrome and discusses the potential underlying mechanisms and their application.
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Vahedi F, Diamant UB, Lundahl G, Bergqvist G, Gransberg L, Jensen SM, Bergfeldt L. Instability of repolarization in LQTS mutation carriers compared to healthy control subjects assessed by vectorcardiography. Heart Rhythm 2013; 10:1169-75. [PMID: 23643511 DOI: 10.1016/j.hrthm.2013.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Indexed: 11/18/2022]
Abstract
BACKGROUND Potassium channel dysfunction in congenital and acquired forms of long QT syndrome types 1 and 2 (LQT1 and LQT2) increases the beat-to-beat variability of the QT interval. OBJECTIVE To study about the little known variability (instability) of other aspects of ventricular repolarization (VR) in humans by using vectorcardiography. METHODS Beat-to-beat analysis was performed regarding vectorcardiography derived RR, QRS, and QT intervals, as well as T vector- and T vector loop-based parameters during 1-minute recordings of uninterrupted sinus rhythm at rest in 41 adult LQT1 (n = 31) and LQT2 (n = 10) mutation carriers and 41 age- and sex-matched control subjects. The short-term variability for each parameter, describing the mean orthogonal distance to the line of identity on the Poincaré plot, was calculated. RESULTS Mutation carriers showed significantly larger (by a factor 2) instability in most VR parameters compared to controls despite higher instantaneous heart rate variability (STVRR) in the control group. The longer the QT interval, the greater was its instability, and the instability of VR dispersion measures. CONCLUSIONS A greater instability of most aspects of VR already at rest seems to be a salient feature in both LQT1 and LQT2, which might pave the way for early afterdepolarizations and torsades de pointes ventricular tachycardia. In contrast, no signs of increased VR dispersion per se were observed in mutation carriers.
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Affiliation(s)
- Farzad Vahedi
- Department of Molecular and Clinical Medicine/Cardiology, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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Linta L, Stockmann M, Lin Q, Lechel A, Proepper C, Boeckers TM, Kleger A, Liebau S. Microarray-Based Comparisons of Ion Channel Expression Patterns: Human Keratinocytes to Reprogrammed hiPSCs to Differentiated Neuronal and Cardiac Progeny. Stem Cells Int 2013; 2013:784629. [PMID: 23690787 PMCID: PMC3649712 DOI: 10.1155/2013/784629] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 03/06/2013] [Indexed: 11/17/2022] Open
Abstract
Ion channels are involved in a large variety of cellular processes including stem cell differentiation. Numerous families of ion channels are present in the organism which can be distinguished by means of, for example, ion selectivity, gating mechanism, composition, or cell biological function. To characterize the distinct expression of this group of ion channels we have compared the mRNA expression levels of ion channel genes between human keratinocyte-derived induced pluripotent stem cells (hiPSCs) and their somatic cell source, keratinocytes from plucked human hair. This comparison revealed that 26% of the analyzed probes showed an upregulation of ion channels in hiPSCs while just 6% were downregulated. Additionally, iPSCs express a much higher number of ion channels compared to keratinocytes. Further, to narrow down specificity of ion channel expression in iPS cells we compared their expression patterns with differentiated progeny, namely, neurons and cardiomyocytes derived from iPS cells. To conclude, hiPSCs exhibit a very considerable and diverse ion channel expression pattern. Their detailed analysis could give an insight into their contribution to many cellular processes and even disease mechanisms.
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Affiliation(s)
- Leonhard Linta
- Institute for Anatomy Cell Biology, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Marianne Stockmann
- Institute for Anatomy Cell Biology, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Qiong Lin
- Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen, Pauwelstrasse 30, 52074 Aachen, Germany
| | - André Lechel
- Department of Internal Medicine I, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Christian Proepper
- Institute for Anatomy Cell Biology, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Tobias M. Boeckers
- Institute for Anatomy Cell Biology, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Alexander Kleger
- Department of Internal Medicine I, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Stefan Liebau
- Institute for Anatomy Cell Biology, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
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Varkevisser R, Wijers SC, van der Heyden MA, Beekman JD, Meine M, Vos MA. Beat-to-beat variability of repolarization as a new biomarker for proarrhythmia in vivo. Heart Rhythm 2012; 9:1718-26. [DOI: 10.1016/j.hrthm.2012.05.016] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Indexed: 11/20/2022]
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Zumhagen S, Stallmeyer B, Friedrich C, Eckardt L, Seebohm G, Schulze-Bahr E. Inherited long QT syndrome: clinical manifestation, genetic diagnostics, and therapy. Herzschrittmacherther Elektrophysiol 2012; 23:211-219. [PMID: 22996910 DOI: 10.1007/s00399-012-0232-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 07/20/2012] [Indexed: 06/01/2023]
Abstract
Inherited long QT syndrome (LQTS) is characterized by a prolonged ventricular repolarization (QTc interval) and symptoms (syncope, sudden cardiac arrest) due to polymorphic ventricular arrhythmias. As of today, 13 different cardiac ion channel genes have been associated with congenital LQTS. The most common ones are due to KCNQ1 (LQT-1), KCNH2 (LQT-2), and SCN5A (LQT-3) gene mutations and account for up to 75 % of cases. Typical clinical findings are an increased QT interval on the surface electrocardiogram, specifically altered T wave morphologies, polymorphic ventricular arrhythmias, or an indicative family history. Recently, in the HRS/EHRA expert consensus statement, comprehensive genetic testing of major LQTS genes was recommended for index patients for whom there is a strong clinical suspicion of LQTS. Overall, antiadrenergic therapy, in particular β-receptor blockers, has been the mainstay of therapy and has significantly reduced cardiac events. For high-risk patients, an implantable cardioverter defibrillator (ICD) is recommended. Importantly, lifestyle modification and avoidance of arrhythmia triggers are additional important approaches.
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Affiliation(s)
- Sven Zumhagen
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Albert-Schweitzer-Campus 1, Gebäude D3, 48149, Münster, Germany.
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Roy AK, McCarthy C, Kiernan G, McGorrian C, Keenan E, Mahon NG, Sweeney B. Increased incidence of QT interval prolongation in a population receiving lower doses of methadone maintenance therapy. Addiction 2012; 107:1132-9. [PMID: 22168435 DOI: 10.1111/j.1360-0443.2011.03767.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS The aim of this study was to investigate the frequency of corrected QT interval (QTc) prolongation in a methadone maintenance therapy (MMT) population, and to examine potential associations between this QTc interval and methadone dose as well as concurrent use of opiates, cocaine and benzodiazepines. DESIGN Cross-sectional study of patients attending a specialist drug treatment clinic from July 2008 to January 2009. SETTING Single-centre inner-city specialist drug treatment clinic, Ireland. PARTICIPANTS A total of 180 patients on stable MMT attending for daily methadone doses, over a 6-month period, where a total of 376 patients were attending during the study period. MEASUREMENTS All patients agreeing to participate in the study underwent 12-lead electrocardiograms and QTc analysis, as well as analysis of urine toxicology screen results for opiates, benzodiazepines and cocaine. ECGs were carried out prior to methadone dose being received, regardless of time of day (trough ECG). FINDINGS The average age was 32.6 ± 7.1 years, with mean [standard deviation (SD)] methadone dose 80.4 ± 27.5 mg. The mean (SD) QTc was 420.9 ± 21.1 ms, range 368-495 ms. Patients who had a positive toxicology screen for opiates were receiving significantly lower doses of methadone (77.8 ± 23.5 mg versus 85.0 ± 21.4 mg, P = 0.04). No significant association was noted between QTc interval prolongation and presence of cocaine metabolites in the urine (P = 0.13) or methadone dose (P = 0.33). 8.8% of patients had evidence of prolonged QTc interval (8.3% male QTc ≥ 450 ms and 0.5% female QTc ≥ 470 ms), with 11.1% (n = 20) having QTc intervals > 450 ms. CONCLUSIONS Drug-induced corrected QT interval prolongation is evident (ranging from 8.8-11.1%, depending on definition applied) in patients receiving relatively low daily doses of methadone therapy, with no evidence of a dose-response relationship. The presence of cocaine metabolites in urine does not appear to be associated with increased corrected QT interval. Increased awareness of cardiac safety guidelines, including relevant clinical and family history, baseline and trough dose ECG monitoring, should be incorporated into methadone maintenance therapy protocols.
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Affiliation(s)
- Andrew K Roy
- Mater Misericordiae University Hospital, Dublin, Ireland.
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Obeyesekere MN, Leong-Sit P, Gula LJ, Yee R, Skanes AC, Klein GJ, Krahn AD. The Evaluation of a Borderline Long QT Interval in an Asymptomatic Patient. Card Electrophysiol Clin 2012; 4:227-238. [PMID: 26939820 DOI: 10.1016/j.ccep.2012.02.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
QT prolongation on resting electrocardiography (ECG) is common, and the clinician is often challenged by the dilemma of excluding acquired causes and recognizing potential congenital long QT syndrome (LQTS). The hallmark of LQTS is an abnormally long QT interval. However, a normal or borderline long QT interval may be observed in up to 50% of patients with LQTS because of the intermittent nature of QT prolongation. This review presents an approach to evaluating the asymptomatic patient with a borderline long QT interval, which incorporates a comprehensive clinical assessment, rest and provocative ECG testing, and genetic testing when appropriate.
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Affiliation(s)
- Manoj N Obeyesekere
- Division of Cardiology, The University of Western Ontario, 339 Windermere Road, London, Ontario N6A 5A5, Canada
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OBEYESEKERE MANOJN, SY RAYMONDW, KLEIN GEORGEJ, GULA LORNEJ, MODI SIMON, CONACHER SUSAN, LEONG-SIT PETER, SKANES ALLANC, YEE RAYMOND, KRAHN ANDREWD. End-Recovery QTc: A Useful Metric for Assessing Genetic Variants of Unknown Significance in Long-QT syndrome. J Cardiovasc Electrophysiol 2012; 23:637-42. [DOI: 10.1111/j.1540-8167.2011.02265.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Adler A, van der Werf C, Postema PG, Rosso R, Bhuiyan ZA, Kalman JM, Vohra JK, Guevara-Valdivia ME, Marquez MF, Halkin A, Benhorin J, Antzelevitch C, Wilde AAM, Viskin S. The phenomenon of "QT stunning": the abnormal QT prolongation provoked by standing persists even as the heart rate returns to normal in patients with long QT syndrome. Heart Rhythm 2012; 9:901-8. [PMID: 22300664 DOI: 10.1016/j.hrthm.2012.01.026] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Indexed: 01/08/2023]
Abstract
BACKGROUND Patients with long QT syndrome (LQTS) have inadequate shortening of the QT interval in response to the sudden heart rate accelerations provoked by standing-a phenomenon of diagnostic value. We now validate our original observations in a cohort twice as large. We also describe that this abnormal QT-interval response persists as the heart rate acceleration returns to baseline. OBJECTIVES To describe a novel observation, termed "QT stunning" and to validate previous observations regarding the "QT-stretching" phenomenon in patients with LQTS by using our recently described "standing test." METHODS The electrocardiograms of 108 patients with LQTS and 112 healthy subjects were recorded in the supine position. Subjects were then instructed to stand up quickly and remain standing for 5 minutes during continuous electrocardiographic recording. The corrected QT interval was measured at baseline (QTc(base)), when heart rate acceleration without appropriate QT-interval shortening leads to maximal QT stretching (QTc(stretch)) and upon return of heart rate to baseline (QTc(return)). RESULTS QTc(stretch) lengthened significantly more in patients with LQTS (103 ± 80 ms vs 66 ± 40 ms in controls; P <.001) and so did QTc(return) (28 ± 48 ms for patients with LQTS vs -3 ± 32 ms for controls; P <.001). Using a sensitivity cutoff of 90%, the specificity for diagnosing LQTS was 74% for QTc(base), 84% for QTc(return), and 87% for QTc(stretch). CONCLUSIONS The present study extends our previous findings on the abnormal response of the QT interval in response to standing in patients with LQTS. Our study also shows that this abnormal response persists even after the heart rate slows back to baseline.
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Affiliation(s)
- Arnon Adler
- Tel Aviv Sourasky Medical Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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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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Obeyesekere MN, Klein GJ, Modi S, Leong-Sit P, Gula LJ, Yee R, Skanes AC, Krahn AD. How to Perform and Interpret Provocative Testing for the Diagnosis of Brugada Syndrome, Long-QT Syndrome, and Catecholaminergic Polymorphic Ventricular Tachycardia. Circ Arrhythm Electrophysiol 2011; 4:958-64. [DOI: 10.1161/circep.111.965947] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Manoj N. Obeyesekere
- From the University of Western Ontario, Division of Cardiology, London, Ontario, Canada
| | - George J. Klein
- From the University of Western Ontario, Division of Cardiology, London, Ontario, Canada
| | - Simon Modi
- From the University of Western Ontario, Division of Cardiology, London, Ontario, Canada
| | - Peter Leong-Sit
- From the University of Western Ontario, Division of Cardiology, London, Ontario, Canada
| | - Lorne J. Gula
- From the University of Western Ontario, Division of Cardiology, London, Ontario, Canada
| | - Raymond Yee
- From the University of Western Ontario, Division of Cardiology, London, Ontario, Canada
| | - Allan C. Skanes
- From the University of Western Ontario, Division of Cardiology, London, Ontario, Canada
| | - Andrew D. Krahn
- From the University of Western Ontario, Division of Cardiology, London, Ontario, Canada
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Massey SL, Wise MS, Madan N, Carvalho K, Khurana D, Legido A, Valencia I. Comparison of corrected QT interval as measured on electroencephalography versus 12-lead electrocardiography in children with a history of syncope. J Child Neurol 2011; 26:1401-4. [PMID: 21633105 DOI: 10.1177/0883073811408421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Long QT syndrome can present with neurological manifestations, including syncope and seizure-like activity. These patients often receive an initial neurologic evaluation, including electroencephalography (EEG). Our previous retrospective study suggested an increased prevalence of prolonged corrected QT interval (QTc) measured during the EEG of patients with syncope. The aim of the current study is to assess the accuracy of the EEG QTc reading compared with the nonsimultaneous 12-lead electrocardiography (ECG) in children with syncope. Abnormal QTc was defined as ≥450 ms in boys, ≥460 ms in girls. Forty-two children were included. There was no significant correlation between QTc readings in the EEG and ECG. EEG failed to identify 2 children with prolonged QTc in the ECG and overestimated the QTc in 3 children with normal QTc in the ECG. This study suggests that interpretation of the QTc segment during an EEG is limited. Further studies with simultaneous EEG and 12-lead ECG are warranted.
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Affiliation(s)
- Shavonne L Massey
- Department of Pediatrics, St. Christopher's Hospital for Children, Drexel University College of Medicine, Philadelphia, Pennsylvania 19134, USA
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