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Cruces PD, Toscano A, Rodríguez FJA, Romo-Vázquez R, Arini PD. Drug-induced symmetry effects on ventricular repolarization dynamics. Biomed Signal Process Control 2023. [DOI: 10.1016/j.bspc.2022.104493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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2
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Funck-Brentano C, Salem JE. Influence of baseline QTc on sotalol-induced prolongation of ventricular repolarization in men and women. Br J Clin Pharmacol 2021; 88:3510-3515. [PMID: 34921433 DOI: 10.1111/bcp.15188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/23/2021] [Accepted: 12/01/2021] [Indexed: 11/28/2022] Open
Abstract
The extent of sotalol-induced QTc prolongation on the electrocardiogram, is variable among subjects and influenced by sex. However, the influence of baseline QTc on the extent of drug-induced QTc prolongation remains unclear. This was studied around peak plasma concentration in a large cohort of 376 healthy male and 614 healthy female subjects who received 80 mg of sotalol orally. Baseline QTc was 379±16ms in men and 393±15ms in women (p<0.0001). The change in QTc from baseline was highly variable among both sexes and was greater in women than in men (26.5±13.2 vs.13.0±10.8ms; <0.0001). The slope of the regression line between QTc on sotalol and baseline QTc did not significantly differ from unity in men and in women indicating that the extent of QTc prolongation with sotalol was not influenced by baseline QTc. Assessing QTc after administration of an IKr blocker may be more important than measuring a baseline QTc.
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Affiliation(s)
- Christian Funck-Brentano
- Sorbonne Université, Institut national de la santé et de la recherche médicale (INSERM), Assistance Publique - Hôpitaux de Paris (AP-HP), Clinical Investigation Center (CIC-1901), Department of Pharmacology, Pitié-Salpêtrière Hospital, Paris, France
| | - Joe-Elie Salem
- Sorbonne Université, Institut national de la santé et de la recherche médicale (INSERM), Assistance Publique - Hôpitaux de Paris (AP-HP), Clinical Investigation Center (CIC-1901), Department of Pharmacology, Pitié-Salpêtrière Hospital, Paris, France.,Departments of Medicine and Pharmacology, Cardio-Oncology Program, Vanderbilt University Medical Center, Nashville, TN, USA.,AP-HP Sorbonne Université, UNICO-GRECO, Cardio-Oncology Program, Sorbonne Université, Paris, France
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Isaksen JL, Ghouse J, Graff C, Olesen MS, Holst AG, Pietersen A, Nielsen JB, Skov MW, Kanters JK. Electrocardiographic T-wave morphology and risk of mortality. Int J Cardiol 2020; 328:199-205. [PMID: 33321127 DOI: 10.1016/j.ijcard.2020.12.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/10/2020] [Accepted: 12/02/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND Electrocardiographic T-wave morphology is used in drug safety studies as an adjunct to the QTc interval, but few measurements of T-wave morphology can be interpreted in clinical practice. Morphology combination score (MCS) is a combination of T-wave flatness/peakedness, asymmetry, and notching, enabling easy visual assessment of T-wave morphology. We aimed to test the association between T-wave morphology, quantified by MCS, and mortality. METHODS We included electrocardiograms recorded in 2001-2011 from 342,294 primary care patients. Using Cox regression, we evaluated the association between MCS, cardiovascular death, and all-cause mortality, adjusting for heart rate, QTc, QT-prolonging drugs, diabetes, ischemic heart disease, hypertension, and congestive heart failure. RESULTS 270,039 individuals (44% men, median age 55 [inter-quartile range: 42-67 years]) were included and followed for a median of 9.3 years, during which time 13,489 (5.0%) died from cardiovascular causes and 50,481 (18.7%) from any cause. High values of MCS (i.e. asymmetric, flattened, and/or notched T waves) were associated with an adjusted mortality Hazard Ratio of 1.75 (95% CI 1.62-1.89) and 1.61 (1.43-1.92) for women and men, respectively. Low values of MCS (i.e. peaked and symmetric T waves) were associated with a Hazard Ratio of 1.18 (1.08-1.28) and 1.71 (1.48-1.98) for women and men, respectively. CONCLUSIONS In a large primary care population, we found that T-wave asymmetry, flatness, and notching provided prognostic information on mortality independent of heart rate, QTc, and baseline comorbidities.
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Affiliation(s)
- Jonas L Isaksen
- Laboratory of Experimental Cardiology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jonas Ghouse
- Laboratory of Molecular Cardiology, Department of Cardiology, The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Denmark
| | - Claus Graff
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Morten S Olesen
- Laboratory of Molecular Cardiology, Department of Cardiology, The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Denmark
| | - Anders G Holst
- Laboratory of Molecular Cardiology, Department of Cardiology, The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Denmark
| | - Adrian Pietersen
- Copenhagen General Practitioners' Laboratory, Copenhagen, Denmark
| | - Jonas B Nielsen
- Laboratory of Molecular Cardiology, Department of Cardiology, The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Denmark; Division of Cardiovascular Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, United States of America
| | - Morten W Skov
- Laboratory of Molecular Cardiology, Department of Cardiology, The Heart Centre, University Hospital of Copenhagen, Rigshospitalet, Denmark
| | - Jørgen K Kanters
- Laboratory of Experimental Cardiology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
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Stabenau HF, Shen C, Zimetbaum P, Buxton AE, Tereshchenko LG, Waks JW. Global electrical heterogeneity associated with drug-induced torsades de pointes. Heart Rhythm 2020; 18:57-62. [PMID: 32781158 DOI: 10.1016/j.hrthm.2020.07.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 07/27/2020] [Accepted: 07/29/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Drugs belonging to diverse therapeutic classes can prolong myocardial refractoriness or slow conduction. These drugs may be effective and well-tolerated, but the risk of sudden cardiac death from torsades de pointes (TdP) remains a major concern. The corrected QT interval has significant limitations when used for risk stratification. Measurement of global electrical heterogeneity (GEH) could help identify the substrate vulnerable to drug-induced ventricular arrhythmias. OBJECTIVE The purpose of this study was to improve risk stratification for drug-induced TdP by measuring GEH on the electrocardiogram (ECG). METHODS We analyzed ECG data from a case-control study of patients with a history of drug-induced TdP as well as age- and sex-matched controls. Vectorcardiograms were constructed from ECGs. GEH was measured via the spatial ventricular gradient (SVG) vector (magnitude, azimuth, and elevation). Log odds coefficients for TdP were estimated using multivariable logistic regression. RESULTS Among 17 cases (47% male; age 58.9 ± 12.5 years) and 17 controls (29% male; age 61.0 ± 12.2 years), 34 ECGs were analyzed. SVG azimuth was significantly different between cases and controls (3.4 vs 22.0 degrees, respectively; P = 0.02). After adjusting for sex and QTc interval, odds of TdP increased by a factor of 3.2 for each 1 SD change in SVG azimuth from the control group mean (95% confidence interval 1.07-9.14; P = .04). QTc was not significant in the multivariable analysis (P = .20). CONCLUSION SVG azimuth is correlated with a history of drug-induced TdP independent of QTc. GEH measurement may help identify patients at high risk for drug-induced arrhythmias.
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Affiliation(s)
- Hans F Stabenau
- Harvard-Thorndike Electrophysiology Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Changyu Shen
- Smith Center for Outcomes Research in Cardiology, Harvard Medical School, Boston, Massachusetts
| | - Peter Zimetbaum
- Harvard-Thorndike Electrophysiology Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Alfred E Buxton
- Harvard-Thorndike Electrophysiology Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Larisa G Tereshchenko
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon
| | - Jonathan W Waks
- Harvard-Thorndike Electrophysiology Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
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5
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Cruces PD, Torkar D, Arini PD. Biomarkers of pre-existing risk of Torsade de Pointes under Sotalol treatment. J Electrocardiol 2020; 60:177-183. [PMID: 32464371 DOI: 10.1016/j.jelectrocard.2020.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/09/2020] [Accepted: 04/15/2020] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Antiarrhythmic drugs therapies are currently going through a turning point. The high risk that exists during the treatments has led to an ongoing search for new non-invasive toxicity risk biomarkers. METHODS We propose the use of spatial biomarkers obtained through the quaternion algebra, evaluating the dynamics of the cardiac electrical vector in a non-invasive way in order to detect abnormal changes in ventricular heterogeneity. In groups of patients with and without history of Torsade de Pointes undergoing a Sotalol challenge, we compute the radius and the linear and angular velocities of QRS complex and T-wave loops. From these signals we extract significant features in order to compute a risk patient classifier. RESULTS Using machine learning techniques and statistical analysis, the combinations of few indices reach a pair of sensitivity/specificity of 100%/100% when separating patients with arrhythmogenic substrate. Several biomarkers not only measure drug-induced changes significantly but also observe differences in at-risk patients outperforming current standards. DISCUSSION Alternative biomarkers were able to describe pre-existing risk of patients. Given the high levels of significance and performance, these results could contribute to a better understanding of the torsadogenic substrate and to the safe development of drug therapies.
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Affiliation(s)
- Pablo Daniel Cruces
- Instituto de Ingeniería Biomédica, UBA, Paseo Colón 850 (C1063ACV), Buenos Aires, Argentina; Instituto Argentino de Matemática 'Alberto P. Calderón', CONICET, Saavedra 15 (C1083ACA), Buenos Aires, Argentina.
| | - Drago Torkar
- Institut 'Jožef Stefan', Department of Computer Systems, Jamova cesta 39 (SI-1000), Ljubljana, Slovenia
| | - Pedro David Arini
- Instituto de Ingeniería Biomédica, UBA, Paseo Colón 850 (C1063ACV), Buenos Aires, Argentina; Instituto Argentino de Matemática 'Alberto P. Calderón', CONICET, Saavedra 15 (C1083ACA), Buenos Aires, Argentina
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6
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Tse G, Gong M, Meng L, Wong CW, Bazoukis G, Chan MTV, Wong MCS, Letsas KP, Baranchuk A, Yan GX, Liu T, Wu WKK. Predictive Value of T peak - T end Indices for Adverse Outcomes in Acquired QT Prolongation: A Meta-Analysis. Front Physiol 2018; 9:1226. [PMID: 30233403 PMCID: PMC6129769 DOI: 10.3389/fphys.2018.01226] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 08/14/2018] [Indexed: 01/13/2023] Open
Abstract
Background: Acquired QT interval prolongation has been linked with malignant ventricular arrhythmias, such as torsade de pointes, in turn predisposing to sudden cardiac death. Increased dispersion of repolarization has been identified as a pro-arrhythmic factor and can be observed as longer Tpeak - Tend interval and higher Tpeak - Tend/QT ratio on the electrocardiogram. However, the values of these repolarization indices for predicting adverse outcomes in this context have not been systematically evaluated. Method: PubMed, Embase and Cochrane Library databases were searched until 14th February 2018, identifying 232 studies. Results: Five studies on acquired QT prolongation met the inclusion criteria and 308 subjects with drug-induced LQTS patients (mean age: 66 ± 18 years old; 46% male) were included in this meta-analysis. Tpeak - Tend intervals were longer [mean difference [MD]: 76 ms, standard error [SE]: 26 ms, P = 0.003; I2 = 98%] and Tpeak - Tend/QT ratios were higher (MD: 0.14, SE: 0.03, P = 0.000; I2 = 29%) in patients with torsade de pointes compared to those without these events. Conclusion: Tpeak - Tend interval and Tpeak - Tend/QT ratio were higher in patients with acquired QT prolongation suffering from torsade de pointes compared to those who did not. These repolarization indices may provide additional predictive value for identifying high-risk individuals.
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Affiliation(s)
- Gary Tse
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, Hong Kong.,Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Mengqi Gong
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, Hong Kong
| | - Lei Meng
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, Hong Kong
| | - Cheuk W Wong
- Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong
| | - George Bazoukis
- Laboratory of Cardiac Electrophysiology, Second Department of Cardiology, Evangelismos General Hospital of Athens, Athens, Greece
| | - Matthew T V Chan
- Department of Anaesthesia and Intensive Care, Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Martin C S Wong
- JC School of Public Health and Primary Care, Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - Konstantinos P Letsas
- Laboratory of Cardiac Electrophysiology, Second Department of Cardiology, Evangelismos General Hospital of Athens, Athens, Greece
| | - Adrian Baranchuk
- Division of Cardiology, Kingston General Hospital, Queen's University, Kingston, ON, Canada
| | - Gan-Xin Yan
- Lankenau Institute for Medical Research and Lankenau Medical Center, Wynnewood, PA, United States.,Beijing Anzhen Hospital, Capital Medical University, Beijing, 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, Hong Kong
| | - William K K Wu
- Department of Anaesthesia and Intensive Care, Chinese University of Hong Kong, Hong Kong, Hong Kong
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Bhuiyan TA, Graff C, Kanters JK, Melgaard J, Toft E, Kääb S, Struijk JJ. A History of Drug‐Induced Torsades de Pointes Is Associated With T‐wave Morphological Abnormalities. Clin Pharmacol Ther 2017; 103:1100-1106. [DOI: 10.1002/cpt.886] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/07/2017] [Accepted: 09/14/2017] [Indexed: 12/17/2022]
Affiliation(s)
- Tanveer A. Bhuiyan
- Department of Health Science and TechnologyAalborg UniversityAalborg Denmark
| | - Claus Graff
- Department of Health Science and TechnologyAalborg UniversityAalborg Denmark
| | - Jørgen K. Kanters
- Laboratory of Experimental Cardiology, Department of Biomedical SciencesUniversity of CopenhagenCopenhagen Denmark
| | - Jacob Melgaard
- Department of Health Science and TechnologyAalborg UniversityAalborg Denmark
| | - Egon Toft
- College of Medicine, Qatar UniversityDoha Qatar
| | - Stefan Kääb
- Medizinische Klinik und Poliklinik I, University Hospital Munich, Ludvig Maximilians University, Munich, Germany; German Center for Cardiovascular Research (DZHK), partner site: Munich Heart AllianceMunich Germany
| | - Johannes J. Struijk
- Department of Health Science and TechnologyAalborg UniversityAalborg Denmark
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Shakibfar S, Graff C, Kanters JK, Nielsen J, Schmidt S, Struijk JJ. Minimal T-wave representation and its use in the assessment of drug arrhythmogenicity. Ann Noninvasive Electrocardiol 2017; 22. [DOI: 10.1111/anec.12413] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Saeed Shakibfar
- Center for Sensory Motor Interaction (SMI); Department of Health Science and Technology; Aalborg University; Aalborg Denmark
| | - Claus Graff
- Medical Informatics Group (MI); Department of Health Science and Technology; Aalborg University; Aalborg Denmark
| | - Jørgen K. Kanters
- Laboratory of Experimental Cardiology; Department of Biomedical Sciences; University of Copenhagen; Copenhagen Denmark
- Department of Cardiology; Herlev & Gentofte University Hospitals; Copenhagen Denmark
- Department of Cardiology; Aalborg University Hospital; Aalborg Denmark
| | - Jimmi Nielsen
- Center for Schizophrenia; Aalborg Psychiatric Hospital; Aalborg University Hospital; Aalborg Denmark
| | - Samuel Schmidt
- Medical Informatics Group (MI); Department of Health Science and Technology; Aalborg University; Aalborg Denmark
| | - Johannes J. Struijk
- Medical Informatics Group (MI); Department of Health Science and Technology; Aalborg University; Aalborg Denmark
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9
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Graff C, Struijk JJ, Kanters JK, Andersen MP, Toft E, Tyl B. Effects of bilastine on T-wave morphology and the QTc interval: a randomized, double-blind, placebo-controlled, thorough QTc study. Clin Drug Investig 2012; 32:339-51. [PMID: 22393898 DOI: 10.2165/11599270-000000000-00000] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND OBJECTIVES The International Conference of Harmonisation (ICH) E14 guideline for thorough QT studies requires assessing the propensity of new non-antiarrhythmic drugs to affect cardiac repolarization. The present study investigates whether a composite ECG measure of T-wave morphology (Morphology Combination Score [MCS]) can be used together with the heart rate corrected QT interval (QTc) in a fully ICH E14-compliant thorough QT study to exclude clinically relevant repolarization effects of bilastine, a novel antihistamine. METHODS Thirty participants in this crossover study were randomly assigned to receive placebo, moxifloxacin 400 mg, bilastine at therapeutic and supratherapeutic doses (20 and 100 mg) and bilastine 20 mg co-administered with ketoconazole 400 mg. Resting ECGs recorded at 12 nominal time points before and after treatments were used to determine Fridericia corrected QTc (QTcF) and MCS from the T-wave characteristics: asymmetry, flatness and notching. RESULTS There were no effects of bilastine monotherapy (20 and 100 mg) on MCS or QTcF at those study times where the bilastine plasma concentrations were highest. MCS changes for bilastine monotherapy did not exceed the normal intrasubject variance of T-wave shapes for triplicate ECG recordings. Maximum QTcF prolongation for bilastine monotherapy was 5 ms or less: 3.8 ms (90% CI 0.3, 7.3 ms) for bilastine 20 mg and 5.0 ms (90% CI 2.0, 8.0 ms) for bilastine 100 mg. There were no indications of bilastine inducing larger repolarization effects on T-wave morphology as compared with the QTcF interval, as evidenced by the similarity of z-score equivalents for placebo-corrected changes in MCS and QTcF values. CONCLUSION This study shows that bilastine, at therapeutic and supratherapeutic dosages, does not induce any effects on T-wave morphology or QTcF. These results confirm the absence of an effect for bilastine on cardiac repolarization.
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Affiliation(s)
- Claus Graff
- Medical Informatics Group, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
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10
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Baumert M, Starc V, Porta A. Conventional QT variability measurement vs. template matching techniques: comparison of performance using simulated and real ECG. PLoS One 2012; 7:e41920. [PMID: 22860030 PMCID: PMC3408402 DOI: 10.1371/journal.pone.0041920] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Accepted: 06/29/2012] [Indexed: 12/14/2022] Open
Abstract
Increased beat-to-beat variability in the QT interval (QTV) of ECG has been associated with increased risk for sudden cardiac death, but its measurement is technically challenging and currently not standardized. The aim of this study was to investigate the performance of commonly used beat-to-beat QT interval measurement algorithms. Three different methods (conventional, template stretching and template time shifting) were subjected to simulated data featuring typical ECG recording issues (broadband noise, baseline wander, amplitude modulation) and real short-term ECG of patients before and after infusion of sotalol, a QT interval prolonging drug. Among the three algorithms, the conventional algorithm was most susceptible to noise whereas the template time shifting algorithm showed superior overall performance on simulated and real ECG. None of the algorithms was able to detect increased beat-to-beat QT interval variability after sotalol infusion despite marked prolongation of the average QT interval. The QTV estimates of all three algorithms were inversely correlated with the amplitude of the T wave. In conclusion, template matching algorithms, in particular the time shifting algorithm, are recommended for beat-to-beat variability measurement of QT interval in body surface ECG. Recording noise, T wave amplitude and the beat-rejection strategy are important factors of QTV measurement and require further investigation.
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Affiliation(s)
- Mathias Baumert
- School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide, Australia.
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11
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Shakibfar S, Graff C, Ehlers LH, Toft E, Kanters JK, Struijk JJ. Assessing common classification methods for the identification of abnormal repolarization using indicators of T-wave morphology and QT interval. Comput Biol Med 2012; 42:485-91. [DOI: 10.1016/j.compbiomed.2012.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 01/03/2012] [Accepted: 01/06/2012] [Indexed: 10/14/2022]
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12
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Lahti AL, Kujala VJ, Chapman H, Koivisto AP, Pekkanen-Mattila M, Kerkelä E, Hyttinen J, Kontula K, Swan H, Conklin BR, Yamanaka S, Silvennoinen O, Aalto-Setälä K. Model for long QT syndrome type 2 using human iPS cells demonstrates arrhythmogenic characteristics in cell culture. Dis Model Mech 2011; 5:220-30. [PMID: 22052944 PMCID: PMC3291643 DOI: 10.1242/dmm.008409] [Citation(s) in RCA: 213] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Long QT syndrome (LQTS) is caused by functional alterations in cardiac ion channels and is associated with prolonged cardiac repolarization time and increased risk of ventricular arrhythmias. Inherited type 2 LQTS (LQT2) and drug-induced LQTS both result from altered function of the hERG channel. We investigated whether the electrophysiological characteristics of LQT2 can be recapitulated in vitro using induced pluripotent stem cell (iPSC) technology. Spontaneously beating cardiomyocytes were differentiated from two iPSC lines derived from an individual with LQT2 carrying the R176W mutation in the KCNH2 (HERG) gene. The individual had been asymptomatic except for occasional palpitations, but his sister and father had died suddenly at an early age. Electrophysiological properties of LQT2-specific cardiomyocytes were studied using microelectrode array and patch-clamp, and were compared with those of cardiomyocytes derived from control cells. The action potential duration of LQT2-specific cardiomyocytes was significantly longer than that of control cardiomyocytes, and the rapid delayed potassium channel (IKr) density of the LQT2 cardiomyocytes was significantly reduced. Additionally, LQT2-derived cardiac cells were more sensitive than controls to potentially arrhythmogenic drugs, including sotalol, and demonstrated arrhythmogenic electrical activity. Consistent with clinical observations, the LQT2 cardiomyocytes demonstrated a more pronounced inverse correlation between the beating rate and repolarization time compared with control cells. Prolonged action potential is present in LQT2-specific cardiomyocytes derived from a mutation carrier and arrhythmias can be triggered by a commonly used drug. Thus, the iPSC-derived, disease-specific cardiomyocytes could serve as an important platform to study pathophysiological mechanisms and drug sensitivity in LQT2.
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Affiliation(s)
- Anna L Lahti
- Institute of Biomedical Technology, University of Tampere, Tampere, Finland
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13
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Rashba EJ, Estes Iii NAM. Is there a mechanistic link between atrial fibrillation and vulnerability to ventricular arrhythmias? J Cardiovasc Electrophysiol 2011; 22:1253-5. [PMID: 21806695 DOI: 10.1111/j.1540-8167.2011.02135.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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14
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Couderc JP, Garnett C, Li M, Handzel R, McNitt S, Xia X, Polonsky S, Zareba W. Highly automated QT measurement techniques in 7 thorough QT studies implemented under ICH E14 guidelines. Ann Noninvasive Electrocardiol 2011; 16:13-24. [PMID: 21251129 DOI: 10.1111/j.1542-474x.2010.00402.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Thorough QT (TQT) studies are designed to evaluate potential effect of a novel drug on the ventricular repolarization process of the heart using QTc prolongation as a surrogate marker for torsades de pointes. The current process to measure the QT intervals from the thousands of electrocardiograms is lengthy and expensive. In this study, we propose a validation of a highly automatic-QT interval measurement (HA-QT) method. We applied a HA-QT method to the data from 7 TQT studies. We investigated both the placebo and baseline-adjusted QTc interval prolongation induced by moxifloxacin (positive control drug) at the time of expected peak concentration. The comparative analysis evaluated the time course of moxifloxacin-induced QTc prolongation in one study as well. The absolute HA-QT data were longer than the FDA-approved QTc data. This trend was not different between ECGs from the moxifloxacin and placebo arms: 9.6 ± 24 ms on drug and 9.8 ± 25 ms on placebo. The difference between methods vanished when comparing the placebo-baseline-adjusted QTc prolongation (1.4 ± 2.8 ms, P = 0.4). The differences in precision between the HA-QT and the FDA-approved measurements were not statistically different from zero: 0.1 ± 0.1 ms (P = 0.7). Also, the time course of the moxifloxacin-induced QTc prolongation adjusted for placebo was not statistically different between measurements methods.
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Affiliation(s)
- Jean-Philippe Couderc
- Heart Research Follow-up Program, Cardiology Department, University of Rochester Medical Center, Rochester, NY 14642, USA.
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15
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T-wave morphology abnormalities in benign, potent, and arrhythmogenic I(kr) inhibition. Heart Rhythm 2011; 8:1036-43. [PMID: 21315844 DOI: 10.1016/j.hrthm.2011.02.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Accepted: 02/01/2011] [Indexed: 11/20/2022]
Abstract
BACKGROUND There is a consensus on the limited value of the QTc interval prolongation as a surrogate marker of drug cardiotoxicity and as a risk stratifier in inherited long QT syndrome (LQTS) patients. OBJECTIVE We investigated the interest of repolarization morphology in the acquired and the inherited LQTS. METHODS We analyzed 2 retrospective electrocardiographic (ECG) datasets from healthy on/off moxifloxacin and from genotyped KCNH2 patients. We measured QT, RR, and T-peak to T-end intervals, early repolarization duration (ERD) and late repolarization duration, T-roundness, T-amplitude, left (αL) and right slopes of T-waves. We designed multivariate logistic models to predict the presence of the KCNH2 mutation or moxifloxacin while adjusting for the level of QTc prolongation and the level of heart rate in LQT2 patients. Independent learning and validation sets were used. A list of 4,874 ECGs from 411 healthy individuals, 293 from 143 LQT2 carriers and 150 noncarrier family members were analyzed. RESULTS In the moxifloxacin model, ERD was associated with the presence of the drug (odds ratio = 1.15 per ms increase, confidence interval 1.04 to 1.26, P = .0001) after adjustment for QTc. The model for the LQT2 revealed that left slope was associated with the presence of the KCNH2 mutation (odds ratio = 0.38 per 1.5 μV/ms decrease, confidence interval 0.23 to 0.64, P = .0002). Only T-roundness complemented QTc in the model investigating cardiac events in LQT2. CONCLUSIONS These observations demonstrate that the phenotypic expression of KCNH2 mutations and the effect of IKr-inhibitory drug on the surface electrocardiogram are specific. Future research should investigate whether this phenomenon is linked to different level/form of loss functions of Ikr channels, and whether they could result in different arrhythmogenic mechanisms.
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A unique digital electrocardiographic repository for the development of quantitative electrocardiography and cardiac safety: the Telemetric and Holter ECG Warehouse (THEW). J Electrocardiol 2010; 43:595-600. [PMID: 20863512 DOI: 10.1016/j.jelectrocard.2010.07.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Indexed: 11/22/2022]
Abstract
The sharing of scientific data reinforces open scientific inquiry; it encourages diversity of analysis and opinion while promoting new research and facilitating the education of next generations of scientists. In this article, we present an initiative for the development of a repository containing continuous electrocardiographic information and their associated clinical information. This information is shared with the worldwide scientific community to improve quantitative electrocardiology and cardiac safety. First, we present the objectives of the initiative and its mission. Then, we describe the resources available in this initiative following 3 components: data, expertise, and tools. The data available in the Telemetric and Holter ECG Warehouse (THEW) includes continuous electrocardiogram signals and associated clinical information. The initiative attracted various academic and private partners whom expertise covers a large list of research arenas related to quantitative electrocardiography; their contribution to the THEW promotes cross-fertilization of scientific knowledge, resources, and ideas that will advance the field of quantitative electrocardiography. Finally, the tools of the THEW include software and servers to access and review the data available in the repository. To conclude, the THEW is an initiative developed to benefit the scientific community and to advance the field of quantitative electrocardiography and cardiac safety. It is a new repository designed to complement the existing ones such as Physionet, the American Heart Association - Beth Israel Hospital (AHA-BIH) arrhythmia database, and the Common Standard for Electrocardiography (CSE) database. The THEW hosts unique datasets from clinical trials and drug safety studies that, so far, were not available.
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Graff C, Struijk JJ, Matz J, Kanters JK, Andersen MP, Nielsen J, Toft E. Covariate analysis of QTc and T-wave morphology: new possibilities in the evaluation of drugs that affect cardiac repolarization. Clin Pharmacol Ther 2010; 88:88-94. [PMID: 20485337 DOI: 10.1038/clpt.2010.51] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This study adds the dimension of a T-wave morphology composite score (MCS) to the QTc interval-based evaluation of drugs that affect cardiac repolarization. Electrocardiographic recordings from 62 subjects on placebo and 400 mg moxifloxacin were compared with those from 21 subjects on 160 and 320 mg D,L-sotalol. T-wave morphology changes, as assessed by DeltaMCS, are larger after 320 mg D,L-sotalol than after 160 mg D,L-sotalol; and the changes associated with 160 mg D,L-sotalol are, in turn, larger than those associated with moxifloxacin and placebo. Covariate analyses of DeltaQTc and DeltaMCS showed that changes in T-wave morphology are a significant effect of D,L-sotalol. By contrast, moxifloxacin was found to have no significant effect on T-wave morphology (DeltaMCS) at any given change in QTc. This study offers new insights into the repolarization behavior of a drug associated with low cardiac risk vs. one associated with a high risk and describes the added benefits of a T-wave MCS as a covariate to the assessment of the QTc interval.
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Affiliation(s)
- C Graff
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
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Zhou Y, Sedransk N. Functional data analytic approach of modeling ECG T-wave shape to measure cardiovascular behavior. Ann Appl Stat 2009. [DOI: 10.1214/09-aoas273] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Haarmark C, Hansen PR, Vedel-Larsen E, Pedersen SH, Graff C, Andersen MP, Toft E, Wang F, Struijk JJ, Kanters JK. The prognostic value of the Tpeak-Tend interval in patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction. J Electrocardiol 2009; 42:555-60. [PMID: 19643432 DOI: 10.1016/j.jelectrocard.2009.06.009] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2009] [Indexed: 01/07/2023]
Abstract
INTRODUCTION The Tpeak-Tend interval (TpTe) has been linked to increased arrhythmic risk. TpTe was investigated before and after primary percutaneous coronary intervention (pPCI) in patients with ST-segment elevation myocardial infarction (STEMI). METHOD Patients with first-time STEMI treated with pPCI were included (n = 101; mean age 62 years; range 39-89 years; 74% men). Digital electrocardiograms were taken pre- and post-PCI, respectively. Tpeak-Tend interval was measured in leads with limited ST-segment deviation. The primary end point was all-cause mortality during 22 +/- 7 months (mean +/- SD) of follow-up. RESULTS Pre- and post-PCI TpTe were 104 milliseconds [98-109 milliseconds] and 106 milliseconds [99-112 milliseconds], respectively (mean [95% confidence interval], P = .59). A prolonged pre-PCI TpTe was associated with increased mortality (hazard ratio, 10.5 [1.7-20.4] for a cutoff value of 100 milliseconds). Uncorrected QT and heart rate-corrected QT intervals (Fridericia-corrected QT) were prolonged after PCI (QT: 401 vs 410 milliseconds, P = .022, and Fridericia-corrected QT: 430 vs 448 milliseconds, P < .0001). CONCLUSION In patients with STEMI undergoing pPCI, pre-PCI TpTe predicted subsequent all-cause mortality, and the QT interval was increased after the procedure.
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Affiliation(s)
- Christian Haarmark
- Laboratory of Experimental Cardiology, University of Copenhagen, Copenhagen, Denmark
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Couderc JP. Measurement and regulation of cardiac ventricular repolarization: from the QT interval to repolarization morphology. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2009; 367:1283-99. [PMID: 19324709 PMCID: PMC2635501 DOI: 10.1098/rsta.2008.0284] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Ventricular repolarization (VR) is a crucial step in cardiac electrical activity because it corresponds to a recovery period setting the stage for the next heart contraction. Small perturbations of the VR process can predispose an individual to lethal arrhythmias. In this review, I aim to provide an overview of the methods developed to analyse static and dynamic aspects of the VR process when recorded from a surface electrocardiogram (ECG). The first section describes the list of physiological and clinical factors that can affect the VR. Technical aspects important to consider when digitally processing ECGs are provided as well. Special attention is given to the analysis of the effect of heart rate on the VR and its regulation by the autonomic nervous system. The final section provides the rationale for extending the analysis of the VR from its duration to its morphology. Several modelling techniques and measurement methods will be presented and their role within the arena of cardiac safety will be discussed.
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Affiliation(s)
- Jean-Philippe Couderc
- Heart Research Follow-Up Program, Cardiology Department, Box 653, University of Rochester Medical Center, 601 Elmwood Avenue, University of Rochester, Rochester, NY 14642, USA.
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