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Solhjoo S, Haigney MC, Siddharthan T, Koch A, Punjabi NM. Sleep-Disordered Breathing Destabilizes Ventricular Repolarization. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2023.02.10.23285789. [PMID: 36824787 PMCID: PMC9949208 DOI: 10.1101/2023.02.10.23285789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Rationale Sleep-disordered breathing (SDB) increases the risk of cardiac arrhythmias and sudden cardiac death. Objectives To characterize the associations between SDB, intermittent hypoxemia, and the beat-to-beat QT variability index (QTVI), a measure of ventricular repolarization lability associated with a higher risk for cardiac arrhythmias, sudden cardiac death, and mortality. Methods Three distinct cohorts were used for the current study. The first cohort, used for cross-sectional analysis, was a matched sample of 122 participants with and without severe SDB. The second cohort, used for longitudinal analysis, consisted of a matched sample of 52 participants with and without incident SDB. The cross-sectional and longitudinal cohorts were selected from the Sleep Heart Health Study participants. The third cohort comprised 19 healthy adults exposed to acute intermittent hypoxia and ambient air on two separate days. Electrocardiographic measures were calculated from one-lead electrocardiograms. Results Compared to those without SDB, participants with severe SDB had greater QTVI (-1.19 in participants with severe SDB vs. -1.43 in participants without SDB, P = 0.027), heart rate (68.34 vs. 64.92 beats/minute; P = 0.028), and hypoxemia burden during sleep as assessed by the total sleep time with oxygen saturation less than 90% (TST90; 11.39% vs. 1.32%, P < 0.001). TST90, but not the frequency of arousals, was a predictor of QTVI. QTVI during sleep was predictive of all-cause mortality. With incident SDB, mean QTVI increased from -1.23 to -0.86 over 5 years (P = 0.017). Finally, exposing healthy adults to acute intermittent hypoxia for four hours progressively increased QTVI (from -1.85 at baseline to -1.64 after four hours of intermittent hypoxia; P = 0.016). Conclusions Prevalent and incident SDB are associated with ventricular repolarization instability, which predisposes to ventricular arrhythmias and sudden cardiac death. Intermittent hypoxemia destabilizes ventricular repolarization and may contribute to increased mortality in SDB.
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Affiliation(s)
- Soroosh Solhjoo
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- F. Edward Hébert School of Medicine, Bethesda, Maryland, USA
| | - Mark C. Haigney
- F. Edward Hébert School of Medicine, Bethesda, Maryland, USA
- Military Cardiovascular Outcomes Research (MiCOR), Bethesda, Maryland, USA
| | | | - Abigail Koch
- University of Miami Miller School of Medicine, Miami, Florida, USA
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Couceiro SM, Sant’Anna LB, Sant’Anna MB, Menezes RSM, Mesquita ET, Sant’Anna FM. Auricular Vagal Neuromodulation and its Application in Patients with Heart Failure and Reduced Ejection Fraction. Arq Bras Cardiol 2023; 120:e20220581. [PMID: 37194830 PMCID: PMC10263391 DOI: 10.36660/abc.20220581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 12/29/2022] [Accepted: 02/15/2023] [Indexed: 05/18/2023] Open
Abstract
BACKGROUND The autonomic nervous system (ANS) imbalance in heart failure (HF) creates a vicious cycle, excess sympathetic activity, and decreased vagal activity contributing to the worsening of HF. Low-intensity transcutaneous electrical stimulation of the auricular branch of the vagus nerve (taVNS) is well tolerated and opens new therapeutic possibilities. OBJECTIVES To hypothesize the applicability and benefit of taVNS in HF through intergroup comparison of echocardiography parameters, 6-minute walk test, Holter heart rate variability (SDNN and rMSSD), Minnesota quality of life questionnaire, and functional class by the New York Heart Association. In comparisons, p values <0.05 were considered significant. METHODS Prospective, double-blind, randomized clinical study with sham methodology, unicentric. Forty-three patients were evaluated and divided into 2 groups: Group 1 received taVNS (frequencies 2/15 Hz), and Group 2 received sham. In comparisons, p values <0.05 were considered significant. RESULTS In the post-intervention phase, it was observed that Group 1 had better rMSSD (31 x 21; p = 0.046) and achieved better SDNN (110 vs. 84, p = 0.033). When comparing intragroup parameters before and after the intervention, it was observed that all of them improved significantly in group 1, and there were no differences in group 2. CONCLUSION taVNS is a safe to perform and easy intervention and suggests a probable benefit in HF by improving heart rate variability, which indicates better autonomic balance. New studies with more patients are needed to answer the questions raised by this study.
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Affiliation(s)
- Sergio Menezes Couceiro
- Universidade Federal FluminenseCabo FrioRJBrasilUniversidade Federal Fluminense, Cabo Frio, RJ – Brasil
- Clínica Santa Helena – CardiologiaCabo FrioRJBrasilClínica Santa Helena – Cardiologia, Cabo Frio, RJ – Brasil
| | - Lucas Bonacossa Sant’Anna
- Fundação Técnico-Educacional Souza MarquesEscola de Medicina Souza MarquesCabo FrioRJBrasilFundação Técnico-Educacional Souza Marques Escola de Medicina Souza Marques – Ensino e Graduação, Cabo Frio, RJ – Brasil
| | - Mariana Bonacossa Sant’Anna
- Fundação Técnico-Educacional Souza MarquesEscola de Medicina Souza MarquesCabo FrioRJBrasilFundação Técnico-Educacional Souza Marques Escola de Medicina Souza Marques – Ensino e Graduação, Cabo Frio, RJ – Brasil
| | | | - Evandro Tinoco Mesquita
- Complexo Hospitalar de NiteróiNiteróiRJBrasilComplexo Hospitalar de Niterói, Niterói, RJ – Brasil
- Universidade Federal FluminenseRio de JaneiroRJBrasilUniversidade Federal Fluminense, Rio de Janeiro, RJ – Brasil
| | - Fernando Mendes Sant’Anna
- Clínica Santa Helena – CardiologiaCabo FrioRJBrasilClínica Santa Helena – Cardiologia, Cabo Frio, RJ – Brasil
- Universidade Federal do Rio de JaneiroCampus Macaé – Ensino e GraduaçãoMacaéRJBrasilUniversidade Federal do Rio de Janeiro, Campus Macaé – Ensino e Graduação, Macaé, RJ – Brasil
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Amoni M, Ingelaere S, Moeyersons J, Vandenberk B, Claus P, Lemmens R, Van Huffel S, Sipido K, Varon C, Willems R. Temporal Changes in Beat-to-Beat Variability of Repolarization Predict Imminent Nonsustained Ventricular Tachycardia in Patients With Ischemic and Nonischemic Dilated Cardiomyopathy. J Am Heart Assoc 2022; 11:e024294. [PMID: 35730633 PMCID: PMC9333369 DOI: 10.1161/jaha.121.024294] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background An increase in beat‐to‐beat variability of repolarization (BVR) predicts arrhythmia onset in experimental models, but its clinical translation is not well established. We investigated the temporal changes in BVR before nonsustained ventricular tachycardia (nsVT) in patients with implantable cardioverter defibrillator (ICD). Methods and Results Patients with nsVT on 24‐hour Holter before ICD implantation for ischemic cardiomyopathy (ischemic cardiomyopathy+nsVT, n=43) or dilated cardiomyopathy (dilated cardiomyopathy+nsVT, n=37), matched ICD candidates without nsVT (ischemic cardiomyopathy‐nsVT, n=29 and dilated cardiomyopathy‐nsVT, n=26), and patients without ICD without structural heart disease (n=50) were studied. Digital Holter recordings from these patients were analyzed using a modified fiducial segment averaging technique to detect the QT interval. The nsVT episodes were semi‐automatically identified and QT‐BVR was assessed 1‐, 5‐, and 30‐minutes before nsVT, and at rest (at 3:00 am). Resting BVR was higher in ICD patients compared with controls without structural heart disease. In ICD patients with nsVT, BVR increased significantly 1‐minute pre‐nsVT in ischemic cardiomyopathy (2.21±0.59 ms, versus 5 minutes pre‐nsVT: 1.78±0.50 ms, P<0.001) and dilated cardiomyopathy (2.09±0.57 ms, versus 5‐minutes pre‐nsVT: 1.58±0.51 ms, P<0.001), but not in patients without nsVT. In multivariable Cox regression analysis, pre‐nsVT BVR was a significant predictor for appropriate therapy during follow‐up. Conclusions Baseline BVR is elevated and temporal changes in BVR predict imminent nsVT events in patients with ICD independent of underlying cause. Real‐time BVR monitoring could be used to predict impending ventricular arrhythmia and allow preventive therapy to be incorporated into ICDs.
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Affiliation(s)
- Matthew Amoni
- Cardiology University Hospitals Leuven Leuven Belgium.,Experimental Cardiology, Department of Cardiovascular Sciences University of Leuven Belgium
| | - Sebastian Ingelaere
- Cardiology University Hospitals Leuven Leuven Belgium.,Experimental Cardiology, Department of Cardiovascular Sciences University of Leuven Belgium
| | - Jonathan Moeyersons
- STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics, Department of Electrical Engineering University of Leuven Belgium
| | | | - Piet Claus
- Imaging and Cardiovascular Dynamics, Department of Cardiovascular Sciences KU Leuven Leuven Belgium
| | - Robin Lemmens
- Neurology University Hospitals Leuven Leuven Belgium.,Laboratory of Neurobiology, Department of Neurosciences University of Leuven Belgium
| | - Sabine Van Huffel
- STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics, Department of Electrical Engineering University of Leuven Belgium
| | - Karin Sipido
- Experimental Cardiology, Department of Cardiovascular Sciences University of Leuven Belgium
| | - Carolina Varon
- STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics, Department of Electrical Engineering University of Leuven Belgium
| | - Rik Willems
- Cardiology University Hospitals Leuven Leuven Belgium.,Experimental Cardiology, Department of Cardiovascular Sciences University of Leuven Belgium
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Toman O, Hnatkova K, Šišáková M, Smetana P, Huster KM, Barthel P, Novotný T, Andršová I, Schmidt G, Malik M. Short-Term Beat-to-Beat QT Variability Appears Influenced More Strongly by Recording Quality Than by Beat-to-Beat RR Variability. Front Physiol 2022; 13:863873. [PMID: 35431991 PMCID: PMC9011003 DOI: 10.3389/fphys.2022.863873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 02/28/2022] [Indexed: 12/14/2022] Open
Abstract
Increases in beat-to-beat variability of electrocardiographic QT interval duration have repeatedly been associated with increased risk of cardiovascular events and complications. The measurements of QT variability are frequently normalized for the underlying RR interval variability. Such normalization supports the concept of the so-called immediate RR effect which relates each QT interval to the preceding RR interval. The validity of this concept was investigated in the present study together with the analysis of the influence of electrocardiographic morphological stability on QT variability measurements. The analyses involved QT and RR measurements in 6,114,562 individual beats of 642,708 separate 10-s ECG samples recorded in 523 healthy volunteers (259 females). Only beats with high morphology correlation (r > 0.99) with representative waveforms of the 10-s ECG samples were analyzed, assuring that only good quality recordings were included. In addition to these high correlations, SDs of the ECG signal difference between representative waveforms and individual beats expressed morphological instability and ECG noise. In the intra-subject analyses of both individual beats and of 10-s averages, QT interval variability was substantially more strongly related to the ECG noise than to the underlying RR variability. In approximately one-third of the analyzed ECG beats, the prolongation or shortening of the preceding RR interval was followed by the opposite change of the QT interval. In linear regression analyses, underlying RR variability within each 10-s ECG sample explained only 5.7 and 11.1% of QT interval variability in females and males, respectively. On the contrary, the underlying ECG noise contents of the 10-s samples explained 56.5 and 60.1% of the QT interval variability in females and males, respectively. The study concludes that the concept of stable and uniform immediate RR interval effect on the duration of subsequent QT interval duration is highly questionable. Even if only stable beat-to-beat measurements of QT interval are used, the QT interval variability is still substantially influenced by morphological variability and noise pollution of the source ECG recordings. Even when good quality recordings are used, noise contents of the electrocardiograms should be objectively examined in future studies of QT interval variability.
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Affiliation(s)
- Ondřej Toman
- Department of Internal Medicine and Cardiology, University Hospital Brno, Brno, Czechia
- Department of Internal Medicine and Cardiology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Katerina Hnatkova
- National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Martina Šišáková
- Department of Internal Medicine and Cardiology, University Hospital Brno, Brno, Czechia
- Department of Internal Medicine and Cardiology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | | | | | - Petra Barthel
- Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Tomáš Novotný
- Department of Internal Medicine and Cardiology, University Hospital Brno, Brno, Czechia
- Department of Internal Medicine and Cardiology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Irena Andršová
- Department of Internal Medicine and Cardiology, University Hospital Brno, Brno, Czechia
- Department of Internal Medicine and Cardiology, Faculty of Medicine, Masaryk University, Brno, Czechia
- *Correspondence: Irena Andršová
| | - Georg Schmidt
- Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Marek Malik
- Department of Internal Medicine and Cardiology, Faculty of Medicine, Masaryk University, Brno, Czechia
- National Heart and Lung Institute, Imperial College, London, United Kingdom
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ter Woort F, Dubois G, Didier M, Van Erck-Westergren E. Validation of an equine fitness tracker: heart rate and heart rate variability. COMPARATIVE EXERCISE PHYSIOLOGY 2021. [DOI: 10.3920/cep200028] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The adoption of fitness tracker devices to monitor training in the equine market is in full expansion. However, the validity of most of these devices has not been assessed. The aim of this study was to examine the validity of heart rate (HR) and heart rate variability (HRV) measurements during high-intensity exercise by an integrated equine fitness tracker with an electrocardiogram (ECG) (Equimetre) in comparison to an ECG device (Televet). Twenty Thoroughbred racehorses were equipped with the two devices and completed a training session at the track. Data from 18 horses was readable to be analysed. Equimetre HR was compared to Televet HR derived from the corrected Televet ECG. HRV parameters were computed in a dedicated software (Kubios) on uncorrected and manually corrected ECG from both devices, and compared to the Televet corrected data. The HR was recorded on the entire training session and HRV parameters were calculated during the exercise and recovery periods. A strong correlation between the Equimetre HR and Televet HR on corrected data was found (Pearson correlation: r=0.992, P<0.001; root mean square error = 4.06 bpm). For HRV, the correlation was good for all parameters when comparing corrected Equimetre to corrected Televet data (Lin’s coefficient = 0.998). When comparing data obtained from uncorrected Equimetre data to the corrected Televet data, the correlation for HR was still good (Lin’s coefficient = 0.995) but the correlation for all HRV parameters was poor, except for the triangular index (Lin’s coefficient = 0.995). However, correlation between the uncorrected Televet HRV data and the corrected Televet data was equally poor (Lin’s coefficient <0.9). In conclusion, the integrated equine fitness tracker Equimetre satisfies validity criteria for HR monitoring in horses during high intensity exercise. When using corrected ECG data, it provides accurate HRV parameters as well.
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Affiliation(s)
- F. ter Woort
- Equine Sports Medicine Practice, 83 avenue Beau Sejour, 1410 Waterloo, Belgium
| | - G. Dubois
- Arioneo, 6 rue Claude Farrère, 75016 Paris, France
| | - M. Didier
- Arioneo, 6 rue Claude Farrère, 75016 Paris, France
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6
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Piccirillo G, Moscucci F, Bertani G, Lospinuso I, Sabatino T, Zaccagnini G, Crapanzano D, Diego ID, Corrao A, Rossi P, Magrì D. Short-period temporal repolarization dispersion in subjects with atrial fibrillation and decompensated heart failure. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2021; 44:327-333. [PMID: 33382121 DOI: 10.1111/pace.14158] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/13/2020] [Accepted: 12/27/2020] [Indexed: 12/23/2022]
Abstract
BACKGROUND/OBJECTIVES The association between chronic heart failure (CHF) and permanent atrial fibrillation is very frequent. The repolarization duration was already found predictive for atrial fibrillation. Aim of this study was to evaluate the influence of atrial fibrillation on short period repolarization variables in decompensated CHF patients. METHOD We used 5 min ECG recordings to assess the mean, standard deviation (SD), and normalized variance (NV) of the following variables: QT end (QTe), QT peak (QTp), and T peak to T end (Te) in 121 decompensated CHF, of whom 40 had permanent atrial fibrillation, too. We reported also the 30-day mortality. RESULTS QTpSD (p < .01), TeSD (p < .01), QTpVN (p < .01), and TeVN (p < .01) were higher in the atrial fibrillation than among sinus rhythm CHF subjects. Multivariable logistic analysis selected only TeSD (odd ratio, o.r.: 1.32, 95% confidence interval, c.i.: 1.06-1.65, p: .015) associated with atrial fibrillation. A total of 27 patients died during the 30-days follow-up (overall mortality rate 22%), 7 (18%), and 20 (25%) respectively in the atrial fibrillation and sinus rhythm patients. Furthermore, the following variables were associated to the morality risk: NT-pro Brain Natriuretic Peptide (o.r.: 1.00, 95% c.i.: 1.00-1.00, p: .041), left ventricular end diastolic diameter (o.r.: 0.81, 95% c.i.: 0.67-0.96, p: .010), and Te mean (o.r.: 1.04, 95% c.i.: 1.02-1.09, p: .012). CONCLUSION In decompensated CHF subjects, Te mean seems be associated to mortality and TeSD to the permanent atrial fibrillation. We could hypothesize that, during severe CHF, the multi-level ionic CHF channel derangement could be critical in influencing these non-invasive markers. (ClinicalTrials.gov number, NCT04127162).
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Affiliation(s)
- Gianfranco Piccirillo
- Dipartimento di Scienze Cliniche, Internistiche, Anestesiologiche e Cardiovascolari, Policlinico Umberto I, "Sapienza", University of Rome, Rome, Italy
| | - Federica Moscucci
- Dipartimento di Scienze Cliniche, Internistiche, Anestesiologiche e Cardiovascolari, Policlinico Umberto I, "Sapienza", University of Rome, Rome, Italy
| | - Gaetano Bertani
- Dipartimento di Scienze Cliniche, Internistiche, Anestesiologiche e Cardiovascolari, Policlinico Umberto I, "Sapienza", University of Rome, Rome, Italy
| | - Ilaria Lospinuso
- Dipartimento di Scienze Cliniche, Internistiche, Anestesiologiche e Cardiovascolari, Policlinico Umberto I, "Sapienza", University of Rome, Rome, Italy
| | - Teresa Sabatino
- Dipartimento di Scienze Cliniche, Internistiche, Anestesiologiche e Cardiovascolari, Policlinico Umberto I, "Sapienza", University of Rome, Rome, Italy
| | - Giulia Zaccagnini
- Dipartimento di Scienze Cliniche, Internistiche, Anestesiologiche e Cardiovascolari, Policlinico Umberto I, "Sapienza", University of Rome, Rome, Italy
| | - Davide Crapanzano
- Dipartimento di Scienze Cliniche, Internistiche, Anestesiologiche e Cardiovascolari, Policlinico Umberto I, "Sapienza", University of Rome, Rome, Italy
| | - Ilaria Di Diego
- Dipartimento di Scienze Cliniche, Internistiche, Anestesiologiche e Cardiovascolari, Policlinico Umberto I, "Sapienza", University of Rome, Rome, Italy
| | - Andrea Corrao
- Dipartimento di Scienze Cliniche, Internistiche, Anestesiologiche e Cardiovascolari, Policlinico Umberto I, "Sapienza", University of Rome, Rome, Italy
| | - Pietro Rossi
- Cardiology Division, Arrhytmology Unit, S. Giovanni Calibita, Isola Tiberina, Rome, Italy
| | - Damiano Magrì
- Dipartimento di Medicina Clinica e Molecolare, S. Andrea Hospital, "Sapienza" University of Rome, Rome, Italy
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DeMaria N, Selmi A, Kashtan S, Xia X, Wang M, Zareba W, Couderc JP, Auerbach DS. Autonomic and Cardiac Repolarization Lability in Long QT Syndrome Patients. Auton Neurosci 2020; 229:102723. [PMID: 32942226 DOI: 10.1016/j.autneu.2020.102723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 08/24/2020] [Accepted: 08/31/2020] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Long QT-Syndrome (LQTS) patients are at risk of arrhythmias and seizures. We investigated whether autonomic and cardiac repolarization measures differed based on LQTS genotypes, and in LQTS patients with vs. without arrhythmias and seizures. METHODS We used 24-h ECGs from LQTS1 (n = 87), LQTS2 (n = 50), and LQTS genotype negative patients (LQTS(-), n = 16). Patients were stratified by LQTS genotype, and arrhythmias/seizures. Heart rate variability (HRV) and QT variability index (QTVI) measures were compared between groups during specific physiological states (minimum, middle, & maximum sympathovagal balance, LF/HF). Results were further tested using logistic regression for each ECG measure, and all HRV measures in a single multivariate model. RESULTS Across multiple physiological states, total autonomic (SDNN) and vagal (RMSSD, pNN50) function were lower and repolarization dynamics (QTVI) were elevated in LQTS(+), LQTS1, and LQTS2, compared to LQTS(-). Many measures remained significant in the regression models. Multivariate modeling demonstrated that SDNN, RMSSD, and pNN50 were independent markers of LQTS(+) vs. LQTS(-), and SDNN and pNN50 were markers for LQTS1 vs. LQTS(-). During sympathovagal balance (middle LF/HF), RMSSD and pNN50 distinguished LQTS1 vs. LQTS2. LQTS1 patients with arrhythmias had lower total (SDNN) and vagal (RMSSD and pNN50) autonomic function, and SDNN remained significant in the models. In contrast, ECG measures did not differ in LQTS2 patients with vs. without arrhythmias, and LQTS1 and LQTS2 with vs. without seizures. CONCLUSION Autonomic (HRV) and cardiac repolarization (QTVI) ECG measures differ based on LQTS genotype and history of arrhythmias in LQTS1. SDNN, RMSSD, and pNN50 were each independent markers for LQTS genotype.
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Affiliation(s)
- Natalia DeMaria
- Department of Pharmacology, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY, United States
| | - Ahmed Selmi
- Biomedical Engineering, ,University of Rochester, P.O. Box 270076, Rochester, NY, United States
| | - Samuel Kashtan
- Biomedical Engineering, ,University of Rochester, P.O. Box 270076, Rochester, NY, United States
| | - Xiaojuan Xia
- Medicine-Clinical Cardiology Research Center, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, United States
| | - Matthew Wang
- Department of Pharmacology, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY, United States
| | - Wojciech Zareba
- Medicine-Clinical Cardiology Research Center, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, United States
| | - Jean-Philippe Couderc
- Medicine-Clinical Cardiology Research Center, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, United States
| | - David S Auerbach
- Department of Pharmacology, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY, United States; Medicine-Aab Cardiovascular Research Institute, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, United States; Pharmacology/Physiology, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, United States.
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8
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Abstract
Current cardiopulmonary activity monitoring is based on contact devices which cannot be used in extreme cases such as premature infants, burnt victims or rescue operations. In order to overcome these limitations, the use of radar technologies emerges as an alternative. This paper aims to enhance the comprehension that non-contact technologies, in particular radar techniques, offer as a monitoring tool. For this purpose, a modified low cost commercial 122 GHz frequency-modulated continuous-wave (FMCW) radar is used to better fit the current application domain. The radar signals obtained are processed using a classic linear filtering algorithm aiming to separate the breathing from the heartbeat component while preserving signals integrity. In a standoff configuration and with different subject orientations, results show that the signal obtained with the radar can be used to extract not only the respiratory and heartbeat rates, but also the heart rate variability (HRV) sequence. Moreover, results evidence the coupling between breathing and heartbeat, also showing that the HRV sequence obtained can identify the respiratory sinus arrhythmia (RSA) effect. Finally, the radar is tested in a simultaneous multi-target scenario, demonstrating its monitoring capabilities in more complex situations. Nevertheless, there are some challenges left to use the system in a real-life monitoring environments, such as the removal of random body movements.
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Piccirillo G, Moscucci F, Bertani G, Lospinuso I, Mastropietri F, Fabietti M, Sabatino T, Zaccagnini G, Crapanzano D, Di Diego I, Corrao A, Rossi P, Magrì D. Short-Period Temporal Dispersion Repolarization Markers Predict 30-Days Mortality in Decompensated Heart Failure. J Clin Med 2020; 9:jcm9061879. [PMID: 32560151 PMCID: PMC7356287 DOI: 10.3390/jcm9061879] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 06/11/2020] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Electrocardiographic (ECG) markers of the temporal dispersion of the myocardial repolarization phase have been shown able to identify chronic heart failure (CHF) patients at high mortality risk. The present prospective single-center study sought to investigate in a well-characterized cohort of decompensated heart failure (HF) patients the ability of short-term myocardial temporal dispersion ECG variables in predicting the 30-day mortality, as well as their relationship with N-terminal Pro Brain Natriuretic Peptide (NT-proBNP) plasmatic values. METHOD One hundred and thirteen subjects (male: 59, 67.8%) with decompensated CHF underwent 5 min of ECG recording, via a mobile phone. We obtained QT end (QTe), QT peak (QTp) and T peak to T end (Te) and calculated the mean, standard deviation (SD), and normalized index (VN). RESULTS Death occurred for 27 subjects (24%) within 30 days after admission. Most of the repolarization indexes (QTe mean (p < 0.05), QTeSD (p < 0.01), QTpSD (p < 0.05), mean Te (p < 0.05), TeSD (p < 0.001) QTeVN (p < 0.05) and TeVN (p < 0.01)) were significantly higher in those CHF patients with the highest NT-proBNP (>75th percentile). In all the ECG data, only TeSD was significantly and positively related to the NT-proBNP levels (r: 0.471; p < 0.001). In the receiver operating characteristic (ROC) analysis, the highest accuracy for 30-day mortality was found for QTeSD (area under curve, AUC: 0.705, p < 0.01) and mean Te (AUC: 0.680, p < 0.01), whereas for the NT-proBNP values higher than the 75th percentile, the highest accuracy was found for TeSD (AUC: 0.736, p < 0.001) and QTeSD (AUC: 0.696, p < 0.01). CONCLUSION Both mean Te and TeSD could be considered as reliable markers of worsening HF and of 30-day mortality. Although larger and possibly interventional studies are needed to confirm our preliminary finding, these non-invasive and transmissible ECG parameters could be helpful in the remote monitoring of advanced HF patients and, possibly, in their clinical management. (ClinicalTrials.gov number, NCT04127162).
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Affiliation(s)
- Gianfranco Piccirillo
- Anestesiologiche e Cardiovascolari, Dipartimento di Scienze Cliniche Internistiche, Policlinico Umberto I, La Sapienza University of Rome, 00185 Rome, Italy; (G.P.); (G.B.); (I.L.); (F.M.); (M.F.); (T.S.); (G.Z.); (D.C.); (I.D.D.); (A.C.)
| | - Federica Moscucci
- Anestesiologiche e Cardiovascolari, Dipartimento di Scienze Cliniche Internistiche, Policlinico Umberto I, La Sapienza University of Rome, 00185 Rome, Italy; (G.P.); (G.B.); (I.L.); (F.M.); (M.F.); (T.S.); (G.Z.); (D.C.); (I.D.D.); (A.C.)
- Correspondence: ; Tel.: +39-06-4997-0118
| | - Gaetano Bertani
- Anestesiologiche e Cardiovascolari, Dipartimento di Scienze Cliniche Internistiche, Policlinico Umberto I, La Sapienza University of Rome, 00185 Rome, Italy; (G.P.); (G.B.); (I.L.); (F.M.); (M.F.); (T.S.); (G.Z.); (D.C.); (I.D.D.); (A.C.)
| | - Ilaria Lospinuso
- Anestesiologiche e Cardiovascolari, Dipartimento di Scienze Cliniche Internistiche, Policlinico Umberto I, La Sapienza University of Rome, 00185 Rome, Italy; (G.P.); (G.B.); (I.L.); (F.M.); (M.F.); (T.S.); (G.Z.); (D.C.); (I.D.D.); (A.C.)
| | - Fabiola Mastropietri
- Anestesiologiche e Cardiovascolari, Dipartimento di Scienze Cliniche Internistiche, Policlinico Umberto I, La Sapienza University of Rome, 00185 Rome, Italy; (G.P.); (G.B.); (I.L.); (F.M.); (M.F.); (T.S.); (G.Z.); (D.C.); (I.D.D.); (A.C.)
| | - Marcella Fabietti
- Anestesiologiche e Cardiovascolari, Dipartimento di Scienze Cliniche Internistiche, Policlinico Umberto I, La Sapienza University of Rome, 00185 Rome, Italy; (G.P.); (G.B.); (I.L.); (F.M.); (M.F.); (T.S.); (G.Z.); (D.C.); (I.D.D.); (A.C.)
| | - Teresa Sabatino
- Anestesiologiche e Cardiovascolari, Dipartimento di Scienze Cliniche Internistiche, Policlinico Umberto I, La Sapienza University of Rome, 00185 Rome, Italy; (G.P.); (G.B.); (I.L.); (F.M.); (M.F.); (T.S.); (G.Z.); (D.C.); (I.D.D.); (A.C.)
| | - Giulia Zaccagnini
- Anestesiologiche e Cardiovascolari, Dipartimento di Scienze Cliniche Internistiche, Policlinico Umberto I, La Sapienza University of Rome, 00185 Rome, Italy; (G.P.); (G.B.); (I.L.); (F.M.); (M.F.); (T.S.); (G.Z.); (D.C.); (I.D.D.); (A.C.)
| | - Davide Crapanzano
- Anestesiologiche e Cardiovascolari, Dipartimento di Scienze Cliniche Internistiche, Policlinico Umberto I, La Sapienza University of Rome, 00185 Rome, Italy; (G.P.); (G.B.); (I.L.); (F.M.); (M.F.); (T.S.); (G.Z.); (D.C.); (I.D.D.); (A.C.)
| | - Ilaria Di Diego
- Anestesiologiche e Cardiovascolari, Dipartimento di Scienze Cliniche Internistiche, Policlinico Umberto I, La Sapienza University of Rome, 00185 Rome, Italy; (G.P.); (G.B.); (I.L.); (F.M.); (M.F.); (T.S.); (G.Z.); (D.C.); (I.D.D.); (A.C.)
| | - Andrea Corrao
- Anestesiologiche e Cardiovascolari, Dipartimento di Scienze Cliniche Internistiche, Policlinico Umberto I, La Sapienza University of Rome, 00185 Rome, Italy; (G.P.); (G.B.); (I.L.); (F.M.); (M.F.); (T.S.); (G.Z.); (D.C.); (I.D.D.); (A.C.)
| | - Pietro Rossi
- Cardiology Division, Arrhythmology Unit, S. Giovanni Calibita, Isola Tiberina, 00186 Rome, Italy;
| | - Damiano Magrì
- Dipartimento di Medicina Clinica e Molecolare, S. Andrea Hospital, Sapienza University of Rome, 00185 Rome, Italy;
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La Rovere MT, Porta A, Schwartz PJ. Autonomic Control of the Heart and Its Clinical Impact. A Personal Perspective. Front Physiol 2020; 11:582. [PMID: 32670079 PMCID: PMC7328903 DOI: 10.3389/fphys.2020.00582] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 05/11/2020] [Indexed: 12/21/2022] Open
Abstract
This essay covers several aspects of the autonomic control of the heart, all relevant to cardiovascular pathophysiology with a direct impact on clinical outcomes. Ischemic heart disease, heart failure, channelopathies, and life-threatening arrhythmias are in the picture. Beginning with an overview on some of the events that marked the oscillations in the medical interest for the autonomic nervous system, our text explores specific areas, including experimental and clinical work focused on understanding the different roles of tonic and reflex sympathetic and vagal activity. The role of the baroreceptors, not just for the direct control of circulation but also because of the clinical value of interpreting alterations (spontaneous or induced) in their function, is discussed. The importance of the autonomic nervous system for gaining insights on risk stratification and for providing specific antiarrhythmic protection is also considered. Examples are the interventions to decrease sympathetic activity and/or to increase vagal activity. The non-invasive analysis of the RR and QT intervals provides additional information. The three of us have collaborated in several studies and each of us contributes with very specific and independent areas of expertise. Here, we have focused on those areas to which we have directly contributed and hence speak with personal experience. This is not an attempt to provide a neutral and general overview on the autonomic nervous system; rather, it represents our effort to share and provide the readers with our own personal views matured after many years of research in this field.
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Affiliation(s)
- Maria Teresa La Rovere
- Department of Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Montescano (Pavia), Italy
| | - Alberto Porta
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.,Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Milan, Italy
| | - Peter J Schwartz
- Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, Istituto Auxologico Italiano, IRCCS, Milan, Italy
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11
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Heravi AS, Etzkorn LH, Urbanek JK, Crainiceanu CM, Punjabi NM, Ashikaga H, Brown TT, Budoff MJ, D'Souza G, Magnani JW, Palella FJ, Berger RD, Wu KC, Post WS. HIV Infection Is Associated With Variability in Ventricular Repolarization: The Multicenter AIDS Cohort Study (MACS). Circulation 2019; 141:176-187. [PMID: 31707799 DOI: 10.1161/circulationaha.119.043042] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND People living with human immunodeficiency virus (HIV+) have greater risk for sudden arrhythmic death than HIV-uninfected (HIV-) individuals. HIV-associated abnormal cardiac repolarization may contribute to this risk. We investigated whether HIV serostatus is associated with ventricular repolarization lability by using the QT variability index (QTVI), defined as a log measure of QT-interval variance indexed to heart rate variance. METHODS We studied 1123 men (589 HIV+ and 534 HIV-) from MACS (Multicenter AIDS Cohort Study), using the ZioXT ambulatory electrocardiography patch. Beat-to-beat analysis of up to 4 full days of electrocardiographic data per participant was performed using an automated algorithm (median analyzed duration [quartile 1-quartile 3]: 78.3 [66.3-83.0] hours/person). QTVI was modeled using linear mixed-effects models adjusted for demographics, cardiac risk factors, and HIV-related and inflammatory biomarkers. RESULTS Mean (SD) age was 60.1 (11.9) years among HIV- and 54.2 (11.2) years among HIV+ participants (P<0.001), 83% of whom had undetectable (<20 copies/mL) HIV-1 viral load (VL). In comparison with HIV- men, HIV+ men had higher QTVI (adjusted difference of +0.077 [95% CI, +0.032 to +0.123]). The magnitude of this association depended on the degree of viremia, such that in HIV+ men with undetectable VL, adjusted QTVI was +0.064 (95% CI, +0.017 to +0.111) higher than in HIV- men, whereas, in HIV+ men with detectable VL, adjusted QTVI was higher by +0.150 (95% CI, 0.072-0.228) than in HIV- referents. Analysis of QTVI subcomponents showed that HIV+ men had: (1) lower heart rate variability irrespective of VL status, and (2) higher QT variability if they had detectable, but not with undetectable, VL, in comparison with HIV- men. Higher levels of C-reactive protein, interleukin-6, intercellular adhesion molecule-1, soluble tumor necrosis factor receptor 2, and soluble cluster of differentiation-163 (borderline), were associated with higher QTVI and partially attenuated the association with HIV serostatus. CONCLUSIONS HIV+ men have greater beat-to-beat variability in QT interval (QTVI) than HIV- men, especially in the setting of HIV viremia and heightened inflammation. Among HIV+ men, higher QTVI suggests ventricular repolarization lability, which can increase susceptibility to arrhythmias, whereas lower heart rate variability signals a component of autonomic dysfunction.
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Affiliation(s)
- Amir S Heravi
- School of Medicine (A.S.H.), Johns Hopkins University, Baltimore, MD
| | - Lacey H Etzkorn
- Department of Biostatistics (L.H.E., J.K.U., C.M.C.), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Jacek K Urbanek
- Department of Biostatistics (L.H.E., J.K.U., C.M.C.), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Ciprian M Crainiceanu
- Department of Biostatistics (L.H.E., J.K.U., C.M.C.), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Naresh M Punjabi
- Division of Pulmonary and Critical Care Medicine (N.M.P.), Johns Hopkins University, Baltimore, MD
| | - Hiroshi Ashikaga
- Division of Cardiology, Department of Medicine (H.A., R.D.B., K.C.W., W.S.P.), Johns Hopkins University, Baltimore, MD
| | - Todd T Brown
- Division of Endocrinology, Diabetes, and Metabolism (T.T.B.), Johns Hopkins University, Baltimore, MD
| | - Matthew J Budoff
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, CA (M.J.B.)
| | - Gypsyamber D'Souza
- Department of Epidemiology (G.D.. W.S.P.), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Jared W Magnani
- Heart and Vascular Institute, Department of Medicine, University of Pittsburgh, PA (J.W.M.)
| | - Frank J Palella
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL (F.J.P.)
| | - Ronald D Berger
- Division of Cardiology, Department of Medicine (H.A., R.D.B., K.C.W., W.S.P.), Johns Hopkins University, Baltimore, MD
| | - Katherine C Wu
- Division of Cardiology, Department of Medicine (H.A., R.D.B., K.C.W., W.S.P.), Johns Hopkins University, Baltimore, MD
| | - Wendy S Post
- Division of Cardiology, Department of Medicine (H.A., R.D.B., K.C.W., W.S.P.), Johns Hopkins University, Baltimore, MD.,Department of Epidemiology (G.D.. W.S.P.), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
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12
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Detection of Congestive Heart Failure Based on LSTM-Based Deep Network via Short-Term RR Intervals. SENSORS 2019; 19:s19071502. [PMID: 30925693 PMCID: PMC6480269 DOI: 10.3390/s19071502] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 03/22/2019] [Accepted: 03/22/2019] [Indexed: 12/14/2022]
Abstract
Congestive heart failure (CHF) refers to the inadequate blood filling function of the ventricular pump and it may cause an insufficient heart discharge volume that fails to meet the needs of body metabolism. Heart rate variability (HRV) based on the RR interval is a proven effective predictor of CHF. Short-term HRV has been used widely in many healthcare applications to monitor patients’ health, especially in combination with mobile phones and smart watches. Inspired by the inception module from GoogLeNet, we combined long short-term memory (LSTM) and an Inception module for CHF detection. Five open-source databases were used for training and testing, and three RR segment length types (N = 500, 1000 and 2000) were used for the comparison with other studies. With blindfold validation, the proposed method achieved 99.22%, 98.85% and 98.92% accuracy using the Beth Israel Deaconess Medical Center (BIDMC) CHF, normal sinus rhythm (NSR) and the Fantasia database (FD) databases and 82.51%, 86.68% and 87.55% accuracy using the NSR-RR and CHF-RR databases, with N = 500, 1000 and 2000 length RR interval segments, respectively. Our end-to-end system can help clinicians to detect CHF using short-term assessment of the heartbeat. It can be installed in healthcare applications to monitor the status of human heart.
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13
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Su S. A CHF detection method based on deep learning with RR intervals. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2017:3369-3372. [PMID: 29060619 DOI: 10.1109/embc.2017.8037578] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
There are extensive studies investigating congestive heart failure (CHF) detection based on heart rate variability. Although a high level of accuracy has been achieved, its robustness under different conditions is not guaranteed. To improve the robustness, we applied sparse auto-encoder-based deep learning algorithm in CHF detection with RR intervals. A total data size of 30,592 (5-min RR interval) was obtained from 72 healthy persons and 44 CHF patients. The deep learning algorithm first extracts unsupervised features using a sparse auto-encoder from raw RR intervals, then constructs a deep neural network model with various hidden nodes combinations. Results showed that the model achieved 72.41% accuracy. This demonstrated that RR intervals have potential in CHF detection but cannot fully reflect dynamic change in 24-h.
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14
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Ayesta A, Martínez-Sellés H, Bayés de Luna A, Martínez-Sellés M. Prediction of sudden death in elderly patients with heart failure. J Geriatr Cardiol 2018; 15:185-192. [PMID: 29662512 PMCID: PMC5895958 DOI: 10.11909/j.issn.1671-5411.2018.02.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 02/25/2018] [Accepted: 02/27/2018] [Indexed: 02/06/2023] Open
Abstract
Most heart failure (HF) related mortality is due to sudden cardiac death (SCD) and worsening HF, particularly in the case of reduced ejection fraction. Predicting and preventing SCD is an important goal but most works include no or few patients with advanced age, and the prevention of SCD in elderly patients with HF is still controversial. A recent reduction in the annual rate of SCD has been recently described but it is not clear if this is also true in advanced age patients. Age is associated with SCD, although physicians frequently have the perception that elderly patients with HF die mainly of pump failure, underestimating the importance of SCD. Other clinical variables that have been associated to SCD are symptoms, New York Heart Association functional class, ischemic cause, and comorbidities (chronic obstructive pulmonary disease, renal dysfunction and diabetes). Some test results that should also be considered are left ventricular ejection fraction and diameters, natriuretic peptides, non-sustained ventricular tachycardias and autonomic abnormalities. The combination of all these markers is probably the best option to predict SCD. Different risk scores have been described and, although there are no specific ones for elderly populations, most include age as a risk predictor and some were developed in populations with mean age > 65 years. Finally, it is important to stress that these scores should be able to predict any type of SCD as, although most are due to tachyarrhythmias, bradyarrhythmias also play a role, particularly in the case of the elderly.
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Affiliation(s)
- Ana Ayesta
- Cardiology Department, Hospital Universitario del Sureste, Arganda del Rey, Madrid, Spain
| | | | | | - Manuel Martínez-Sellés
- Universidad Complutense, Madrid, Spain
- Cardiology Department, Hospital General Universitario Gregorio Marañón, CIVERCV, Universidad Europea, Madrid, Spain
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15
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Viigimae M, Karai D, Pilt K, Pirn P, Huhtala H, Polo O, Meigas K, Kaik J. QT interval variability index and QT interval duration during different sleep stages in patients with obstructive sleep apnea. Sleep Med 2017; 37:160-167. [DOI: 10.1016/j.sleep.2017.06.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 05/26/2017] [Accepted: 06/13/2017] [Indexed: 10/19/2022]
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16
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Imam MH, Karmakar CK, Khandoker AH, Jelinek HF, Palaniswami M. Heart rate independent QT variability component can detect subclinical cardiac autonomic neuropathy in diabetes. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2016:928-931. [PMID: 28268476 DOI: 10.1109/embc.2016.7590853] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Cardiac autonomic neuropathy (CAN) may lead to life threatening arrhythmia due to denervation of both the parasympathetic and sympathetic branches of autonomic nervous system innervating the heart. CAN is a frequently under diagnosed complication of diabetes, because a patient can have asymptomatic CAN for several years before it is clinically apparent. However, detection of CAN at the early or subclinical stage leads to more effective treatment outcomes. Cardiac autonomic reflex tests (CART) (i.e. Ewing test battery) are normally used for the detection and staging of CAN. These tests have limitations with the necessity of active participation of the patients for test maneuvers, as a majority of patients will not be able to complete all five tests required due to comorbidities such as frailty, obesity or cardiorespiratory disease. CAN affects both heart rate (measured by RR interval dynamics) and ventricular repolarization function (i.e. QT interval dynamics) of the heart, which can be efficiently analyzed from surface ECG. Therefore, ECG based diagnosis techniques of CAN analysis are becoming popular as they can reduce the limitations of CARTs used traditionally for CAN detection and it complements CART results. In this study, the performance of an ECG based QTV feature derived using a model free approach, which can quantify the QTV component not affected directly by the heart rate (HR) variation, is compared with some other measures of QTV and HRV in subclinical CAN detection in diabetes. Short-term ECGs (i.e. 5 min long) of 60 diabetic subjects without CAN and 50 diabetic subjects detected with early level of CAN determined by CART were analyzed. The proposed measure for quantifying the QTV component independent of HR denoted as QTV~RR stands out to be more discriminatory than other existing variability measures of QTV and HRV in subclinical detection of CAN.
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Piccirillo G, Ottaviani C, Fiorucci C, Petrocchi N, Moscucci F, Di Iorio C, Mastropietri F, Parrotta I, Pascucci M, Magrì D. Transcranial direct current stimulation improves the QT variability index and autonomic cardiac control in healthy subjects older than 60 years. Clin Interv Aging 2016; 11:1687-1695. [PMID: 27895475 PMCID: PMC5117948 DOI: 10.2147/cia.s116194] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Background Noninvasive brain stimulation technique is an interesting tool to investigate the causal relation between cortical functioning and autonomic nervous system (ANS) responses. Objective The objective of this report is to evaluate whether anodal transcranial direct current stimulation (tDCS) over the temporal cortex influences short-period temporal ventricular repolarization dispersion and cardiovascular ANS control in elderly subjects. Subjects and methods In 50 healthy subjects (29 subjects younger than 60 years and 21 subjects older than 60 years) matched for gender, short-period RR and systolic blood pressure spectral variability, QT variability index (QTVI), and noninvasive hemodynamic data were obtained during anodal tDCS or sham stimulation. Results In the older group, the QTVI, low-frequency (LF) power expressed in normalized units, the ratio between LF and high-frequency (HF) power, and systemic peripheral resistances decreased, whereas HF power expressed in normalized units and α HF power increased during the active compared to the sham condition (P<0.05). Conclusion In healthy subjects older than 60 years, tDCS elicits cardiovascular and autonomic changes. Particularly, it improves temporal ventricular repolarization dispersion, reduces sinus sympathetic activity and systemic peripheral resistance, and increases vagal sinus activity and baroreflex sensitivity.
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Affiliation(s)
- Gianfranco Piccirillo
- Department of Cardiovascular, Respiratory, Nephrological, Anestesiological and Geriatric Sciences, "Sapienza" University
| | | | - Claudia Fiorucci
- Department of Cardiovascular, Respiratory, Nephrological, Anestesiological and Geriatric Sciences, "Sapienza" University
| | | | - Federica Moscucci
- Department of Cardiovascular, Respiratory, Nephrological, Anestesiological and Geriatric Sciences, "Sapienza" University
| | - Claudia Di Iorio
- Department of Cardiovascular, Respiratory, Nephrological, Anestesiological and Geriatric Sciences, "Sapienza" University
| | - Fabiola Mastropietri
- Department of Cardiovascular, Respiratory, Nephrological, Anestesiological and Geriatric Sciences, "Sapienza" University
| | - Ilaria Parrotta
- Department of Cardiovascular, Respiratory, Nephrological, Anestesiological and Geriatric Sciences, "Sapienza" University
| | - Matteo Pascucci
- Department of Cardiovascular, Respiratory, Nephrological, Anestesiological and Geriatric Sciences, "Sapienza" University
| | - Damiano Magrì
- Department of Clinical and Molecular Medicine, University of Rome "Sapienza", Rome, Italy
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18
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Comparison of QT-interval and variability index methodologies in individuals with spinal cord injury. Spinal Cord 2016; 55:274-278. [PMID: 27481091 DOI: 10.1038/sc.2016.118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 06/20/2016] [Accepted: 06/22/2016] [Indexed: 01/10/2023]
Abstract
STUDY DESIGN Within-group comparison. OBJECTIVES Individuals with spinal cord injury (SCI) demonstrate an elevated risk for cardiac arrhythmias as indicated by an elevated QT-variability index (QTVI). The methodology measuring the QTVI, however, is not standardized, and therefore the purpose of this investigation is to determine whether the threshold and tangent methods of QT-interval measurement, as well as the electrocardiographic (ECG) epoch duration, influence the QTVI in individuals with SCI. SETTING Ontario, Canada. METHODS Ten minutes of resting ECG data were collected and analyzed from 14 individuals with SCI (C2-L3; ASIA Impairment Scale (AIS) A-D; 11.5±9.4 years post injury). The QTVI was analyzed via the threshold and tangent methods of QT-interval measurement, as well as from 1-, 5- and 10-min ECG epochs. RESULTS The threshold method produced significantly higher QTVI values compared with the tangent method. The QTVI from a 1-min epoch was significantly higher compared with that from 5- and 10-min epochs. The QTVI values acquired from the threshold method were shown to have higher reproducibility compared with those from the tangent method. There were no differences in QTVI values between participants with lesions above and below T1, as shown by both methods of QT-interval measurement. CONCLUSION The method of QT-interval measurement and the length of ECG epoch influence QTVI values in individuals with SCI. The methodology of QTVI analysis must be standardized in studies involving SCI individuals to reduce the variability accounted by methodological inconsistency.
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Baumert M, Porta A, Vos MA, Malik M, Couderc JP, Laguna P, Piccirillo G, Smith GL, Tereshchenko LG, Volders PGA. QT interval variability in body surface ECG: measurement, physiological basis, and clinical value: position statement and consensus guidance endorsed by the European Heart Rhythm Association jointly with the ESC Working Group on Cardiac Cellular Electrophysiology. Europace 2016; 18:925-44. [PMID: 26823389 PMCID: PMC4905605 DOI: 10.1093/europace/euv405] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 11/05/2015] [Indexed: 12/20/2022] Open
Abstract
This consensus guideline discusses the electrocardiographic phenomenon of beat-to-beat QT interval variability (QTV) on surface electrocardiograms. The text covers measurement principles, physiological basis, and clinical value of QTV. Technical considerations include QT interval measurement and the relation between QTV and heart rate variability. Research frontiers of QTV include understanding of QTV physiology, systematic evaluation of the link between QTV and direct measures of neural activity, modelling of the QTV dependence on the variability of other physiological variables, distinction between QTV and general T wave shape variability, and assessing of the QTV utility for guiding therapy. Increased QTV appears to be a risk marker of arrhythmic and cardiovascular death. It remains to be established whether it can guide therapy alone or in combination with other risk factors. QT interval variability has a possible role in non-invasive assessment of tonic sympathetic activity.
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Affiliation(s)
- Mathias Baumert
- School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide, SA, Australia
| | - Alberto Porta
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Milan, Italy
| | - Marc A Vos
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marek Malik
- St Paul's Cardiac Electrophysiology, University of London, and National Heart and Lung Institute, Imperial College, Dovehouse Street, London SW3 6LY, UK
| | - Jean-Philippe Couderc
- Heart Research Follow-Up Program, University of Rochester Medical Center, Rochester, NY, USA
| | - Pablo Laguna
- Zaragoza University and CIBER-BBN, Zaragoza, Spain
| | - Gianfranco Piccirillo
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Nefrologiche, Anestesiologiche e Geriatriche, Università 'La Sapienza' Rome, Rome, Italy
| | - Godfrey L Smith
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - Larisa G Tereshchenko
- Oregon Health and Science University, Knight Cardiovascular Institute, Portland, OR, USA
| | - Paul G A Volders
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre, Maastricht, The Netherlands
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20
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Feeny A, Tereshchenko LG. Beat-to-beat determinants of the beat-to-beat temporal and spatial variability of repolarization. J Electrocardiol 2016; 49:417-22. [PMID: 26874566 PMCID: PMC4853270 DOI: 10.1016/j.jelectrocard.2016.01.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Indexed: 11/22/2022]
Abstract
BACKGROUND The goal of this study was to compare the time series predictors of beat-to-beat variability in repolarization in healthy individuals. METHODS Spatial QRS- and T-vector amplitudes, spatial QRS-T, RR' and TT' angles, RR' and QT intervals, and QRS- and T-loop roundness were measured on 453 consecutive sinus beats in 168 healthy subjects (mean age 39.8±15.6years; 50% men; 93% white). Panel time-series regression models were adjusted by age, sex, and race. Appropriate time series of ECG metrics served as predictors and outcomes. RESULTS Increase in T-loop roundness index by 0.1 was associated with 1.1° (95%CI 0.9-2.2; P=0.048) increase in corresponding TT' angle. One unit increase in a respiration index was associated with 4ms (95%CI 0.6-7.0; P=0.021) increase in QT interval. CONCLUSIONS Spatial TT' angle and beat-to-beat variability in T-loop roundness represent intrinsic measures of repolarization variability. QT interval variability characterizes the effect of respiration and heart rate variability.
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Affiliation(s)
- Albert Feeny
- Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Larisa G Tereshchenko
- The Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA; The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA.
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Dong JG. The role of heart rate variability in sports physiology. Exp Ther Med 2016; 11:1531-1536. [PMID: 27168768 PMCID: PMC4840584 DOI: 10.3892/etm.2016.3104] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 02/23/2016] [Indexed: 11/16/2022] Open
Abstract
Heart rate variability (HRV) is a relevant marker reflecting cardiac modulation by sympathetic and vagal components of the autonomic nervous system (ANS). Although the clinical application of HRV is mainly associated with the prediction of sudden cardiac death and assessing cardiovascular and metabolic illness progression, recent observations have suggested its applicability to physical exercise training. HRV is becoming one of the most useful tools for tracking the time course of training adaptation/maladaptation of athletes and in setting the optimal training loads leading to improved performances. However, little is known regarding the role of HRV and the internal effects of physical exercise on an athlete, which may be useful in designing fitness programs ensuring sufficient training load that may correspond with the specific ability of the athlete. In this review, we offer a comprehensive assessment of investigations concerning the interrelation between HRV and ANS, and examine how the application of HRV to physical exercise may play a role in sports physiology.
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Affiliation(s)
- Jin-Guo Dong
- Institute of Physical Education, Chifeng University, Chifeng, Inner Mongolia 024000, P.R. China
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22
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Abstract
Ventricular repolarization is a complex electrical phenomenon which represents a crucial stage in electrical cardiac activity. It is expressed on the surface electrocardiogram by the interval between the start of the QRS complex and the end of the T wave or U wave (QT). Several physiological, pathological and iatrogenic factors can influence ventricular repolarization. It has been demonstrated that small perturbations in this process can be a potential trigger of malignant arrhythmias, therefore the analysis of ventricular repolarization represents an interesting tool to implement risk stratification of arrhythmic events in different clinical settings. The aim of this review is to critically revise the traditional methods of static analysis of ventricular repolarization as well as those for dynamic evaluation, their prognostic significance and the possible application in daily clinical practice.
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Sharif H, Allison D, O'Leary D, Ditor D. Reproducibility of the QT-variability index in individuals with spinal cord injury. Auton Neurosci 2016; 195:16-9. [DOI: 10.1016/j.autneu.2016.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 12/16/2015] [Accepted: 02/07/2016] [Indexed: 11/28/2022]
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Monitillo F, Leone M, Rizzo C, Passantino A, Iacoviello M. Ventricular repolarization measures for arrhythmic risk stratification. World J Cardiol 2016; 8:57-73. [PMID: 26839657 PMCID: PMC4728107 DOI: 10.4330/wjc.v8.i1.57] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 09/04/2015] [Accepted: 11/04/2015] [Indexed: 02/06/2023] Open
Abstract
Ventricular repolarization is a complex electrical phenomenon which represents a crucial stage in electrical cardiac activity. It is expressed on the surface electrocardiogram by the interval between the start of the QRS complex and the end of the T wave or U wave (QT). Several physiological, pathological and iatrogenic factors can influence ventricular repolarization. It has been demonstrated that small perturbations in this process can be a potential trigger of malignant arrhythmias, therefore the analysis of ventricular repolarization represents an interesting tool to implement risk stratification of arrhythmic events in different clinical settings. The aim of this review is to critically revise the traditional methods of static analysis of ventricular repolarization as well as those for dynamic evaluation, their prognostic significance and the possible application in daily clinical practice.
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QT Interval Variability Index and QT Interval Duration in Different Sleep Stages: Analysis of Polysomnographic Recordings in Nonapneic Male Patients. BIOMED RESEARCH INTERNATIONAL 2015; 2015:963028. [PMID: 26693490 PMCID: PMC4676997 DOI: 10.1155/2015/963028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 11/15/2015] [Indexed: 11/25/2022]
Abstract
The aim of the study was to determine whether different sleep stages, especially REM sleep, affect QT interval duration and variability in male patients without obstructive sleep apnea (OSA). Polysomnographic recordings of 30 patients were analyzed. Beat-to-beat QT interval variability was calculated using QTV index (QTVI) formula. For QTc interval calculation, in addition to Bazett's formula, linear and parabolic heart rate correction formulas with two separate α values were used. QTVI and QTc values were calculated as means of 2 awake, 3 NREM, and 3 REM sleep episodes; the duration of each episode was 300 sec. Mean QTVI values were not statistically different between sleep stages. Therefore, elevated QTVI values found in patients with OSA cannot be interpreted as physiological sympathetic impact during REM sleep and should be considered as a risk factor for potentially life-threatening ventricular arrhythmias. The absence of difference of the mean QTc interval values between NREM and REM stages seems to confirm our conclusion that sympathetic surges during REM stage do not induce repolarization variability. In patients without notable structural and electrical remodeling of myocardium, physiological elevation in sympathetic activity during REM sleep remains subthreshold concerning clinically significant increase of myocardial electrical instability.
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Sharif H, Millar PJ, Incognito AV, Ditor DS. Non-invasive electrocardiographic assessments of cardiac autonomic modulation in individuals with spinal cord injury. Spinal Cord 2015; 54:166-71. [DOI: 10.1038/sc.2015.207] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 10/09/2015] [Accepted: 10/16/2015] [Indexed: 12/11/2022]
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Analysis of speed, curvature, planarity and frequency characteristics of heart vector movement to evaluate the electrophysiological substrate associated with ventricular tachycardia. Comput Biol Med 2015; 65:150-60. [PMID: 25842361 DOI: 10.1016/j.compbiomed.2015.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 02/18/2015] [Accepted: 03/02/2015] [Indexed: 11/22/2022]
Abstract
BACKGROUND We developed a novel method of assessing ventricular conduction using the surface ECG. METHODS Orthogonal ECGs of 81 healthy controls (age 39.0±14.2 y; 51.8% males; 94% white), were compared with iDower-transformed 12-lead ECGs (both 1000Hz), recorded in 8 patients with infarct-cardiomyopathy and sustained monomorphic ventricular tachycardia (VT) (age 68.0±7.8y, 37.5% male, mean LVEF 29±12%). Normalized speed at 10 QRS segments was calculated as the distance traveled by the heart vector along the QRS loop in three-dimensional space, divided by 1/10th of the QRS duration. Curvature was calculated as the magnitude of the derivative of the QRS loop tangent vector divided by speed. Planarity was calculated as the mean of the dihedral angles between 2 consecutive planes for all planes generated for the median beat. Orbital frequency (a scalar measure of rotation rate of the QRS vector) was calculated as a product of speed and curvature. RESULTS Mixed regression analysis showed that speed was slower [6.6 (95%CI 4.4-8.9) vs. 24.6 (95%CI 11.5-37.7)µV/ms; P<0.0001]; orbital frequency was smaller [1.4 (95%CI 1.2-1.6) vs. 6.8 (95%CI 5.4-8.1)ms(-1); P<0.0001], and planarity was larger by 3.6° (95%CI 1.4°-5.8; P=0.002) in VT cases than in healthy controls. ROC AUC for orbital frequency was 0.940 (95%CI 0.935-0.944) across all frequencies and QRS segments. ROC AUC for planarity at 70-249Hz was 0.995 (95%CI 0.985-1.00). ROC AUC for speed at 70-79Hz was 0.979 (95%CI 0.969-0.989). CONCLUSION This novel method reveals characteristic features of an abnormal electrophysiological substrate associated with VT.
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Valenza G, Orini M, Citi L, Minchole A, Pueyo E, Laguna P, Barbieri R. Assessing real-time RR-QT frequency-domain measures of coupling and causality through inhomogeneous point-process bivariate models. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:6475-8. [PMID: 25571479 DOI: 10.1109/embc.2014.6945111] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Ventricular repolarization instability is known to be related to arrhythmogenesis and increased risk of sudden cardiac death. These repolarization dynamics are linked to the distance between T-wave and Q-wave occurrences (QT) on the ECG, and they are coupled with R-wave to R-wave interval variability (RRV). Several efforts have been dedicated to the analysis of QT-RR interactions in order to provide both a quantification of the coupling and estimates of intrinsic repolarization dynamics. However, a methodology able to quantify dynamic changes in repolarization variability unrelated to RRV dynamics is still needed. In this study, we propose a bivariate model embedded within a multiple inhomogeneous point-process framework to obtain time-varying tracking of (causal) interactions between QT variability (QTV), a marker of repolarization variability, and RRV. Data from 15 healthy subjects undergoing a tilt table test were analyzed. Our results demonstrate that the model effectively captures the time-varying mutual QTV-RRV interactions. The analysis of time-varying coherence confirms that head-up tilt is associated with a decrease in linear QTV-RRV coupling, while time-varying directed coherence shows that intrinsic QTV becomes more prominent during head-up tilt.
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Chan YH, Lau KK, Yiu KH, Li SW, Tam S, Lam TH, Lau CP, Siu CW, Cheung BM, Tse HF. Vascular protective effects of statin-related increase in serum 25-hydroxyvitamin D among high-risk cardiac patients. J Cardiovasc Med (Hagerstown) 2015; 16:51-8. [DOI: 10.2459/jcm.0000000000000026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Intra-QT spectral coherence as a possible noninvasive marker of sustained ventricular tachycardia. BIOMED RESEARCH INTERNATIONAL 2014; 2014:583035. [PMID: 25133170 PMCID: PMC4123476 DOI: 10.1155/2014/583035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 05/28/2014] [Indexed: 12/15/2022]
Abstract
Sudden cardiac death is the main cause of mortality in patients affected by chronic heart failure (CHF) and with history of myocardial infarction. No study yet investigated the intra-QT phase spectral coherence as a possible tool in stratifying the arrhythmic susceptibility in patients at risk of sudden cardiac death (SCD). We, therefore, assessed possible difference in spectral coherence between the ECG segment extending from the q wave to the T wave peak (QTp) and the one from T wave peak to the T wave end (Te) between patients with and without Holter ECG-documented sustained ventricular tachycardia (VT). None of the QT variability indexes as well as most of the coherences and RR power spectral variables significantly differed between the two groups except for the QTp-Te spectral coherence. The latter was significantly lower in patients with sustained VT than in those without (0.508 ± 0.150 versus 0.607 ± 0.150, P < 0.05). Although the responsible mechanism remains conjectural, the QTp-Te spectral coherence holds promise as a noninvasive marker predicting malignant ventricular arrhythmias.
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Feeny A, Han L, Tereshchenko LG. Repolarization lability measured on 10-second ECG by spatial TT' angle: reproducibility and agreement with QT variability. J Electrocardiol 2014; 47:708-15. [PMID: 25012076 DOI: 10.1016/j.jelectrocard.2014.06.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Reproducibility of spatial TT' angle on the 10-second ECG and its agreement with QT variability has not been previously studied. METHODS We analyzed 2 randomly selected 10-second segments within 3-minute resting orthogonal ECG in 172 healthy IDEAL study participants (age 38.1±15.2years, 50% male, 94% white). Repolarization lability was measured by the QT variance (QTV), short-term QT variability (STV(QT)), and spatial TT' angle. Bland-Altman analysis was used to assess the agreement between different log-transformed metrics of repolarization lability, and to assess the reproducibility. RESULTS The heart rate showed a very high reproducibility (bias 0.14%, Lin's rho_c=0.99). As expected, noise suppression by averaging improves reproducibility. Agreement between two 10-second LogQTV was poor (bias -0.04; 95% limits of agreement [-1.89; 1.81]), while LogSTV(QT) (0.04 [-1.01; 1.10]), and especially LogTT' angle (-0.009 [-0.84; 0.82]) was better. CONCLUSION TT' angle is a satisfactory reproducible metric of repolarization lability on the 10-second ECG.
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Affiliation(s)
- Albert Feeny
- Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Lichy Han
- Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Larisa G Tereshchenko
- The Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA; The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA.
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Hoogstraaten E, Rijkenberg S, van der Voort PHJ. Corrected QT-interval prolongation and variability in intensive care patients. J Crit Care 2014; 29:835-9. [PMID: 24986247 DOI: 10.1016/j.jcrc.2014.05.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 04/25/2014] [Accepted: 05/06/2014] [Indexed: 01/08/2023]
Abstract
PURPOSE Critically ill patients are at risk for prolongation of the interval between the Q wave and the T wave in the electrocardiogram (corrected QT [QTc]). Corrected QT prolongation is probably a dynamic process. It is unknown how many patients have a QTc prolongation during their intensive care stay and how variable QTc prolongation is. MATERIALS AND METHODS In a prospective cohort study, continuous 5-minute QTc measurements of 50 consecutive patients were collected. A prolonged QTc interval was more than 500 milliseconds for at least 15 minutes. The QT variance and variability index was used to evaluate QTc variation. RESULTS Fifty-two percent of included patients had a prolonged QTc interval. In a single patient, 0.2% to 91.3% of the QTc intervals over time were prolonged. The use of erythromycin and amiodarone was associated with the mean QTc (P = .02 and P = .006, respectively). The Acute Physiology and Chronic Health Evaluation IV and Sequential Organ Failure Assessment scores were significantly higher in patients with a prolonged QTc interval (30.8 vs 8.6 and 7 vs 5.5, respectively). Eighty-four percent of all patients received at least 1 QTc-prolonging drug. The QT variance and QTc variance were significantly higher in patients with a prolonged QTc (P = .019 and P = .001, respectively). CONCLUSION Continuous QTc monitoring showed a prolonged QTc interval in 52% of intensive care patients. Severity of illness and QT and QTc variances are higher in these patients.
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Affiliation(s)
| | - Saskia Rijkenberg
- Dept of Intensive Care, Onze Lieve Vrouwe Gasthuis, Amsterdam, the Netherlands.
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Prediction of heart rate variability on cardiac sudden death in heart failure patients: a systematic review. Int J Cardiol 2014; 174:857-860. [PMID: 24804906 DOI: 10.1016/j.ijcard.2014.04.176] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 04/14/2014] [Accepted: 04/17/2014] [Indexed: 01/08/2023]
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Piccirillo G, Moscucci F, D'Alessandro G, Pascucci M, Rossi P, Han S, Chen LS, Lin SF, Chen PS, Magrì D. Myocardial repolarization dispersion and autonomic nerve activity in a canine experimental acute myocardial infarction model. Heart Rhythm 2014; 11:110-8. [PMID: 24120873 PMCID: PMC4078249 DOI: 10.1016/j.hrthm.2013.10.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Indexed: 11/22/2022]
Abstract
BACKGROUND Evidence from a canine experimental acute myocardial infarction (MI) model shows that until the seventh week after MI, the relationship between stellate ganglion nerve activity (SGNA) and vagal nerve activity (VNA) progressively increases. OBJECTIVE The purpose of this study was to evaluate how autonomic nervous system activity influences temporal myocardial repolarization dispersion at this period. METHODS We analyzed autonomic nerve activity as well as QT and RR variability from recordings previously obtained in nine dogs. From a total of 48 short-term ECG segments, 24 recorded before and 24 recorded 7 weeks after experimentally-induced MI, we obtained three indices of temporal myocardial repolarization dispersion: QTe (from Q-wave to T-wave end), QTp (from Q-wave to T-wave peak), and Te (from T-wave peak to T-wave end) variability index (QTeVI, QTpVI, TeVI). We also performed heart rate variability power spectral analysis on the same segments. RESULTS After MI, all the QT variables increased QTeVI (median [interquartile range]) (from -1.76[0.82] to -1.32[0.68]), QTeVI (from -1.90[1.01] to -1.45[0.78]), and TeVI (from -0.72[0.67] to -0.22[1.00]), whereas all RR spectral indices decreased (P <.001 for all). Distinct circadian rhythms in QTeVI (P <.05,) QTpVI (P <.001) and TeVI (P <.05) appeared after MI with circadian variations resembling that of SGNA/VNA. The morning QTpVI and TeVI acrophases approached the SGNA/VNA acrophase. Conversely, the evening QTeVI acrophase coincided with another SGNA/VNA peak. After MI, regression analysis detected a positive relationship between SGNA/VNA and TeVI (R(2): 0.077; β: 0.278; p< 0.001). CONCLUSION Temporal myocardial repolarization dispersion shows a circadian variation after MI reaching its peak at a time when sympathetic is highest and vagal activity lowest.
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Affiliation(s)
- Gianfranco Piccirillo
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Nefrologiche, Anestesiologiche e Geriatriche, Policlinico Umberto I, "Sapienza" University of Rome, Rome, Italy; Krannert Institute of Cardiology, Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana.
| | - Federica Moscucci
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Nefrologiche, Anestesiologiche e Geriatriche, Policlinico Umberto I, "Sapienza" University of Rome, Rome, Italy
| | - Gaetana D'Alessandro
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Nefrologiche, Anestesiologiche e Geriatriche, Policlinico Umberto I, "Sapienza" University of Rome, Rome, Italy
| | - Matteo Pascucci
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Nefrologiche, Anestesiologiche e Geriatriche, Policlinico Umberto I, "Sapienza" University of Rome, Rome, Italy
| | - Pietro Rossi
- Dipartimento di Medicina Interna e Specialità Mediche, Policlinico Umberto I, University of Rome, Rome, Italy
| | - Seongwook Han
- Krannert Institute of Cardiology, Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Lan S Chen
- Department of Neurology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Shien-Fong Lin
- Krannert Institute of Cardiology, Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Peng-Sheng Chen
- Krannert Institute of Cardiology, Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Damiano Magrì
- Dipartimento di Medicina Clinica e Molecolare, Azienda Ospedaliera Sant' Andrea, University of Rome, Rome, Italy
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Abstract
The QT Variability Index (QTVI) is a non-invasive measure of repolarization lability that has been applied to a wide variety of subjects with cardiovascular disease. It is a ratio of normalized QT variability to normalized heart rate variability, and therefore includes an assessment of autonomic nervous system tone. The approach assesses beat-to-beat variability in the duration of the QT and U wave in conventional surface electrocardiographic recordings, as well as determines the heart rate variability (HRV) from the same recording. As opposed to T wave alternans, QTVI assesses variance in repolarization at all frequencies. Nineteen studies have published data on QTVI in healthy individuals, while 20 have evaluated its performance in cohorts with cardiovascular disease. Six studies have assessed the utility of QTVI in predicting VT/VF, cardiac arrest, or cardiovascular death. A prospective study utilizing QTVI to determine therapy allocation has not been performed, and therefore the final determination of the value of the metric awaits definitive exploration.
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Affiliation(s)
- Craig P Dobson
- Department of Medicine, Division of Cardiology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA; Walter Reed National Military Medical Center, Bethesda, MD, USA
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Hasan MA, Abbott D, Baumert M. Beat-to-beat QT interval variability and T-wave amplitude in patients with myocardial infarction. Physiol Meas 2013; 34:1075-83. [PMID: 23956333 DOI: 10.1088/0967-3334/34/9/1075] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The purpose of this study was to investigate the effects of T-wave amplitude and ECG lead on beat-to-beat QT interval variability (QTV) in patients with myocardial infarction (MI) compared to healthy subjects. Standard resting 12-lead ECGs of 79 MI patients and 69 healthy subjects were investigated. Beat-to-beat QT intervals were measured separately for each lead using a template matching algorithm. In addition, we extracted the beat-to-beat T-wave amplitude in each lead. We computed the standard deviation of beat-to-beat QT intervals as a marker of QTV for both healthy subjects and MI patients. Significant QTV differences were observed between the 12 ECG leads as well as between the groups of healthy subjects and MI patients. Beat-to-beat QTV was significantly higher in MI patients than in healthy subjects for half of the leads. Furthermore, significant T-wave amplitude differences across leads and between groups were observed. A significant inverse relation between beat-to-beat QTV and T-wave amplitude was demonstrated. The group differences in QTV remained significant after co-varying for the T-wave amplitude. In conclusion, the increase in beat-to-beat QTV that has been repeatedly reported in patients with MI is partly due to the lower T-wave amplitudes. However, QTV remains significantly increased in MI patients after covarying for this effect.
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Affiliation(s)
- M A Hasan
- School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide, Australia
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Guduru A, Lansdown J, Chernichenko D, Berger RD, Tereshchenko LG. Longitudinal changes in intracardiac repolarization lability in patients with implantable cardioverter-defibrillator. Front Physiol 2013; 4:208. [PMID: 23964242 PMCID: PMC3740232 DOI: 10.3389/fphys.2013.00208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 07/22/2013] [Indexed: 11/13/2022] Open
Abstract
Background: While it is known that elevated baseline intracardiac repolarization lability is associated with the risk of fast ventricular tachycardia (FVT)/ventricular fibrillation (VF), the effect of its longitudinal changes on the risk of FVT/VF is unknown. Methods and Results: Near-field (NF) right ventricular (RV) intracardiac electrograms (EGMs) were recorded every 3–6 months at rest in 248 patients with structural heart disease [mean age 61.2 ± 13.3; 185(75%) male; 162(65.3%) ischemic cardiomyopathy] and implanted cardioverter-defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) [201 (81%) primary prevention]. Intracardiac beat-to-beat QT variability index (QTVINF) was measured on NF RV EGM. During the first study phase (median 18 months), participants made on average 2.4 visits. Then remote follow-up was continued for an additional median period of 3 years. Average QTVINF did not change during the first year after ICD implantation (−0.342 ± 0.603 at baseline vs. −0.262 ± 0.552 at 6 months vs. −0.334 ± 0.603 at 12 months); however, it decreased thereafter (−0.510 ± 0.603 at 18 months; P = 0.042). Adjusted population-averaged GEE model showed that the odds of developing FVT/VF increased by 75% for each 1 unit increase in QTVINF. (OR 1.75 [95%CI 1.05–2.92]; P = 0.031). However, individual patient–specific QTVINF trends (increasing, decreasing, flat) varied from patient to patient. For a given patient, the odds of developing FVT/VF were not associated with increasing or decreasing QTVINF over time [OR 1.27; (95%CI 0.05–30.10); P = 0.881]. Conclusion: While on average the odds of FVT/VF increased with an increase in QTVINF, patient-specific longitudinal trends in QTVINF did not affect the odds of FVT/VF.
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Affiliation(s)
- Abhilash Guduru
- Whiting School of Engineering, Department of Biomedical Engineering, The Johns Hopkins University Baltimore, MD, USA
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Tereshchenko LG. Electrocardiogram as a screening tool in the general population: a strategic review. J Electrocardiol 2013; 46:553-6. [PMID: 23938106 DOI: 10.1016/j.jelectrocard.2013.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Indexed: 01/06/2023]
Abstract
Sudden cardiac death (SCD) is a major public health concern, accounting for 400,000 deaths in the US each year. Clinical and autopsy studies have consistently demonstrated a predominant, common pathophysiology in Western populations, showing that the most common electrophysiological mechanism of SCD is ventricular fibrillation, and the most common pathologic substrate is coronary heart disease (CHD). In about half of SCD cases, death is the first clinical manifestation of CHD. Yet risk factors of SCD early in the natural history of conditions predisposing SCD have not been fully identified, and SCD risk stratification strategy in the general population has not been developed. ECG is an easily available, non-expensive and non-invasive tool, which carries valuable information on electrophysiological properties of the heart. However, traditional analysis of ECG includes very limited assessment of the arrhythmogenic substrate. In this review rationale for development of ECG SCD risk score for screening in the general population is discussed.
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Affiliation(s)
- Larisa G Tereshchenko
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Nayyar S, Roberts-Thomson KC, Hasan MA, Sullivan T, Harrington J, Sanders P, Baumert M. Autonomic modulation of repolarization instability in patients with heart failure prone to ventricular tachycardia. Am J Physiol Heart Circ Physiol 2013; 305:H1181-8. [PMID: 23934852 DOI: 10.1152/ajpheart.00448.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
QT variability (QTV) signifies repolarization lability, and increased QTV is a risk predictor for sudden cardiac death. The aim of the present study was to investigate the role of autonomic nervous system activity on QTV. This study was performed in 29 subjects: 10 heart failure (HF) patients with spontaneous ventricular tachycardia [HFVT(+)], 10 HF patients without spontaneous VT [HFVT(-)], and 9 subjects with structurally normal hearts (HNorm). The beat-to-beat QT interval was measured on 3-min records of surface ECGs at baseline and during interventions (atrial pacing and esmolol, isoprenaline, and atropine infusion). Variability in QT intervals was expressed as the SD of all QT intervals (SDQT). The ratio of the SDQT to SD of RR intervals (SDRR) was calculated as an index of QTV normalized to heart rate variability. There was a trend toward a higher baseline SDQT-to-SDRR ratio in the HFVT(+) group compared with the HFVT(-) and HNorm groups (P = 0.09). SDQT increased significantly in the HFVT(+) and HFVT(-) groups compared with the HNorm group during fixed-rate atrial pacing (P = 0.008). Compared with baseline, isoprenaline infusion increased SDQT in HNorm subjects (P = 0.02) but not in HF patients. SDQT remained elevated in the HFVT(+) group relative to the HNorm group despite acute β-adrenoceptor blockade with esmolol (P = 0.02). In conclusion, patients with HF and spontaneous VT have larger fluctuations in beat-to-beat QT intervals. This appears to be a genuine effect that is not solely a consequence of heart rate variation. The effect of acute autonomic nervous system modulation on QTV appears to be limited in HF patients.
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Affiliation(s)
- Sachin Nayyar
- Centre for Heart Rhythm Disorders, The University of Adelaide and Royal Adelaide Hospital, Adelaide, South Australia, Australia
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40
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Affiliation(s)
- Shlomo Stern
- Hebrew University of Jerusalem, Emeritus Professor of Medicine, Jerusalem 94631, Israel.
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Piccirillo G, Moscucci F, Pascucci M, Pappadà MA, D'Alessandro G, Rossi P, Quaglione R, Di Barba D, Barillà F, Magrì D. Influence of aging and chronic heart failure on temporal dispersion of myocardial repolarization. Clin Interv Aging 2013; 8:293-300. [PMID: 23662051 PMCID: PMC3646393 DOI: 10.2147/cia.s41879] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Indexed: 01/01/2023] Open
Abstract
Background and purpose: QT and Tpeak-Tend (Te) intervals are associated with sudden cardiac death
in patients with chronic heart failure (CHF). We studied age-dependent influence on short-term
temporal dispersion of these two variables in patients with postischemic CHF. Method: We grouped 75 CHF and 53 healthy control subjects into three age subsets: ≤50 years,
>50 years and ≤65 years, and >65 years. We then calculated the following
indices: QT and Te variability index (QTVI and TeVI), the ratio between the short-term variability
(STV) of QT or Te, and the STV of resting rate (RR) (QT/RR STV and Te/RR STV). Results: In all different age subgroups, patients with CHF showed a higher level of QTVI than age-matched
control subjects (≤50 years: P < 0.0001; >50 years and
≤65 years: P < 0.05; >65 years: P
< 0.05). Patients with CHF < 50 years old also had all repolarization variability
indices higher than normal age-matched controls (TeVI, P < 0.05; QT/RR STV,
P < 0.05; Te/RR STV, P < 0.05), whereas we did not
find any difference between the two older classes of subjects. Both QTVI
(r2: 0.178, P < 0.05) and TeVI
(r2: 0.433, P < 0.001) were positively related
to age in normal subjects, even if the first correlation was weaker than the second one. Conclusion: Our data showed that QTVI could be used in all ages to evaluate repolarization temporal
liability, whereas the other indices are deeply influenced by age. Probably, the age-dependent
increase in QTVI was more influenced by a reduction of RR variability reported in older normal
subjects.
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Affiliation(s)
- Gianfranco Piccirillo
- Department of Cardiovascular, Respiratory, Nephrological and Geriatric Sciences, Policlinico Umberto I, "Sapienza" University of Rome, Rome, Italy.
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Sur S, Han L, Tereshchenko LG. Comparison of sum absolute QRST integral, and temporal variability in depolarization and repolarization, measured by dynamic vectorcardiography approach, in healthy men and women. PLoS One 2013; 8:e57175. [PMID: 23451181 PMCID: PMC3579786 DOI: 10.1371/journal.pone.0057175] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 01/17/2013] [Indexed: 11/28/2022] Open
Abstract
Background Recently we showed the predictive value of sum absolute QRST integral (SAI QRST) and repolarization lability for risk stratification of sudden cardiac death (SCD) in heart failure patients. The goal of this study was to compare SAI QRST and metrics of depolarization and repolarization variability in healthy men and women. Methods Orthogonal ECGs were recorded at rest for 10 minutes in 160 healthy men and women (mean age 39.6±14.6, 80 men). Mean spatial TT′ angle, and normalized variances of T loop area, of spatial T vector amplitude, of QT interval and Tpeak-Tend area were measured for assessment of repolarization lability. Normalized variances of spatial QRS vector and QRS loop area characterized variability of depolarization. In addition, variability indices (VI) were calculated to adjust for normalized heart rate variance. SAI QRST was measured as the averaged arithmetic sum of areas under the QRST curve. Results Men were characterized by shorter QTc (430.3±21.7 vs. 444.7±22.2 ms; P<0.0001) and larger SAI QRST (282.1±66.7 vs.204.9±58.5 mV*ms; P<0.0001). Repolarization lability negatively correlated with spatial T vector amplitude. Adjusted by normalized heart rate variance, QT variability index was significantly higher in women than in men (−1.54±0.38 vs. −1.70±0.33; P = 0.017). However, in multivariate logistic regression after adjustment for body surface area, QTc, and spatial T vector amplitude, healthy men had 1.5–3 fold higher probability of having larger repolarization lability, as compared to healthy women (T vector amplitude variability index odds ratio 3.88(95%CI 1.4–11.1; P = 0.012). Conclusions Healthy men more likely than women have larger repolarization lability.
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Affiliation(s)
- Sanjoli Sur
- Whiting School of Engineering, The Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Lichy Han
- Whiting School of Engineering, The Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Larisa G. Tereshchenko
- The Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, Maryland, United States of America
- * E-mail:
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Hasan MA, Starc V, Porta A, Abbott D, Baumert M. Improved ECG pre-processing for beat-to-beat QT interval variability measurement. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2013:2563-2566. [PMID: 24110250 DOI: 10.1109/embc.2013.6610063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The aim of this study was to enhance the ECG pre-processing modalities for beat-to-beat QT interval variability measurement based on template matching. The R-peak detection algorithm has been substituted and an efficient baseline removal algorithm has been implemented in existing computer software. To test performance we used simulated ECG data with fixed QT intervals featuring Gaussian noise, baseline wander and amplitude modulation and two alternative algorithms. We computed the standard deviation of beat-to-beat QT intervals as a marker of QT interval variability (QTV). Significantly a lower beat-to-beat QTV was found in the updated approach compared the original algorithm. In addition, the updated template matching computer software outperformed the previous version in discarding fewer beats. In conclusion, the updated ECG preprocessing algorithm is recommended for more accurate quantification of beat-to-beat QT interval variability.
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ROSENHECK SHIMON. Sympathetic Dysinnervation, QT Variability and the Limitations of Statistical Work-Up. J Cardiovasc Electrophysiol 2012; 24:314-5. [DOI: 10.1111/jce.12055] [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: 11/27/2022]
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