1
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Rabkin SW. Relationship between Alzheimer dementia and QT interval: A meta-analysis. Aging Med (Milton) 2024; 7:214-223. [PMID: 38725696 PMCID: PMC11077339 DOI: 10.1002/agm2.12291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 01/20/2024] [Accepted: 01/28/2024] [Indexed: 05/12/2024] Open
Abstract
While the link between aging and mortality from dementia is widely appreciated, the mechanism is not clear. The objective of this study was to determine whether there is a direct relationship between Alzheimer dementia (AD) and the QT interval, because the latter has been related to cardiac mortality. A systematic review and meta-analysis were conducted after a Medline and EMBASE search using terms "Alzheimer disease or Dementia AND QT interval, QT dispersion or cardiac repolarization." Four studies with control groups were identified. There were significant differences in QT interval between individuals with AD vs individuals without dementia (controls) (odds ratio (OR)1.665 [random effects model] and 1.879 [fixed effect model]) (p < 0.001). There were significant differences in QT interval between individuals with AD vs individuals with mild cognitive impairment (MCI) (OR 1.760 [random effects] and 1.810 [fixed effect]) (p < 0.001). A significant (p <0.001) correlation exists between the QTc and the Mini-Mental State Exam (MMSE), a test of cognitive function. Two studies examined QT variability (the difference between the longest and shortest QT interval on a 12 lead ECG); the OR for QT variability AD vs MCI was 3.858 [random effects model] and 3.712 [fixed effects model] (p < 0.001). When compared to the control group, the OR for QT dispersion in AD was 6.358 [random effects model] or 5.143 ( P< 0.001) [fixed effects model]. A qualitative analysis of the data raised questions about paucity of data defining the nature of the control groups, the pathophysiologic mechanism, and the uniform use of a poor QT heart rate correction factor. The longer QT in AD, greater QT variability in AD, and the direct relationship between QT interval and AD severity supports a brain-heart connection in AD that might be fundamental to aging-induced AD and mortality. Issues with defining the control group, limited number of studies, conflicting data in population studies, and the lack of a strong electrophysiological basis underscore the need for additional research in this field.
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Affiliation(s)
- Simon W. Rabkin
- Division of CardiologyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
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2
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KUŞ G, ÇAĞIRCI G. FRONTAL QRS-T AÇISI İLE AMBULATUAR 24 SAAT HOLTERDE PREMATÜR VENTRİKÜLER KONTRAKSİYON YÜKÜ ARASINDAKİ İLİŞKİ. ACTA MEDICA ALANYA 2022. [DOI: 10.30565/medalanya.1131541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
AMAÇ
Sık prematür ventriküler kontraksiyonlar (PVK), ventriküler fonksiyonun bozulmasına veya ventriküler kavitelerin genişlemesine neden olabilir. Frontal düzlem QRS-T [f(QRS-T)] açısı, miyokardın elektrofizyolojik özelliklerindeki kararsızlığın bir göstergesidir ve aritmilerle ilişkilidir. Bu çalışma, ventriküler repolarizasyon heterojenitesinin bir belirteci olarak f(QRS-T) açısının, ambulatuar 24 saatlik holterde prematüre ventriküler kontraksiyon yükünü tahmin edip etmediğini araştırmayı amaçlamıştır.
METHOD
Çalışmada 100 hasta mevcuttu. Hastalar 24 saatlik Holter izleminde PVK yüklerine göre “sık PVK” ve “nadir PVK” olarak iki gruba ayrıldı. Laboratuar ve frontal plan QRS-T açısı dahil olmak üzere bazı ambulatuar elektrokardiyografi parametreleri iki grup arasında karşılaştırıldı.
BULGULAR
Frontal QRS-T açısı (63.34±37.86°'ye karşı 23.46±14.29° p
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3
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Verrier RL, Nearing BD, D'Avila A. Spectrum of clinical applications of interlead ECG heterogeneity assessment: From myocardial ischemia detection to sudden cardiac death risk stratification. Ann Noninvasive Electrocardiol 2021; 26:e12894. [PMID: 34592018 PMCID: PMC8588374 DOI: 10.1111/anec.12894] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/23/2021] [Accepted: 09/03/2021] [Indexed: 12/11/2022] Open
Abstract
Heterogeneity in depolarization and repolarization among regions of cardiac cells has long been recognized as a major factor in cardiac arrhythmogenesis. This fundamental principle has motivated development of noninvasive techniques for quantification of heterogeneity using the surface electrocardiogram (ECG). The initial approaches focused on interval analysis such as interlead QT dispersion and Tpeak -Tend difference. However, because of inherent difficulties in measuring the termination point of the T wave and commonly encountered irregularities in the apex of the T wave, additional techniques have been pursued. The newer methods incorporate assessment of the entire morphology of the T wave and in some cases of the R wave as well. This goal has been accomplished using a number of promising vectorial approaches with the resting 12-lead ECG. An important limitation of vectorcardiographic analyses is that they require exquisite stability of the recordings and are not inherently suitable for use in exercise tolerance testing (ETT) and/or ambulatory ECG monitoring for provocative stress testing or evaluation of the influence of daily activities on cardiac electrical instability. The objectives of the present review are to describe a technique that has been under clinical evaluation for nearly a decade, termed "interlead ECG heterogeneity." Preclinical testing data will be briefly reviewed. We will discuss the main clinical findings with regard to sudden cardiac death risk stratification, heart failure evaluation, and myocardial ischemia detection using standard recording platforms including resting 12-lead ECG, ambulatory ECG monitoring, ETT, and pharmacologic stress testing in conjunction with single-photon emission computed tomography myocardial perfusion imaging.
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Affiliation(s)
- Richard L Verrier
- Division of Cardiovascular Medicine, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Bruce D Nearing
- Division of Cardiovascular Medicine, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Andre D'Avila
- Division of Cardiovascular Medicine, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
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4
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Abstract
The normal physiologic range of QRS complex duration spans between 80 and 125 ms with known differences between females and males which cannot be explained by the anatomical variations of heart sizes. To investigate the reasons for the sex differences as well as for the wide range of normal values, a technology is proposed based on the singular value decomposition and on the separation of different orthogonal components of the QRS complex. This allows classification of the proportions of different components representing the 3-dimensional representation of the electrocardiographic signal as well as classification of components that go beyond the 3-dimensional representation and that correspond to the degree of intricate convolutions of the depolarisation sequence. The technology was applied to 382,019 individual 10-s ECG samples recorded in 639 healthy subjects (311 females and 328 males) aged 33.8 ± 9.4 years. The analyses showed that QRS duration was mainly influenced by the proportions of the first two orthogonal components of the QRS complex. The first component demonstrated statistically significantly larger proportion of the total QRS power (expressed by the absolute area of the complex in all independent ECG leads) in females than in males (64.2 ± 11.6% vs 59.7 ± 11.9%, p < 0.00001—measured at resting heart rate of 60 beats per minute) while the second component demonstrated larger proportion of the QRS power in males compared to females (33.1 ± 11.9% vs 29.6 ± 11.4%, p < 0.001). The analysis also showed that the components attributable to localised depolarisation sequence abnormalities were significantly larger in males compared to females (2.85 ± 1.08% vs 2.42 ± 0.87%, p < 0.00001). In addition to the demonstration of the technology, the study concludes that the detailed convolution of the depolarisation waveform is individual, and that smoother and less intricate depolarisation propagation is the mechanism likely responsible for shorter QRS duration in females.
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5
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Andršová I, Hnatkova K, Šišáková M, Toman O, Smetana P, Huster KM, Barthel P, Novotný T, Schmidt G, Malik M. Heart Rate Dependency and Inter-Lead Variability of the T Peak - T End Intervals. Front Physiol 2021; 11:595815. [PMID: 33384609 PMCID: PMC7769826 DOI: 10.3389/fphys.2020.595815] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 10/14/2020] [Indexed: 11/24/2022] Open
Abstract
The electrocardiographic (ECG) assessment of the T peak–T end (Tpe) intervals has been used in many clinical studies, but several related physiological aspects have not been reported. Specifically, the sources of the Tpe differences between different ECG leads have not been systematically researched, the relationship of Tpe duration to underlying heart rate has not been firmly established, and little is known about the mutual correspondence of Tpe intervals measured in different ECG leads. This study evaluated 796,620 10-s 12-lead ECGs obtained from long-term Holters recorded in 639 healthy subjects (311 female) aged 33.8 ± 9.4 years. For each ECG, transformation to orthogonal XYZ lead was used to measure Tpe in the orthogonal vector magnitude (used as a reference for lead-to-lead comparisons) and to construct a three-dimensional T wave loop. The loop roundness was expressed by a ratio between its circumference and length. These ratios were significantly related to the standard deviation of Tpe durations in different ECG leads. At the underlying heart rate of 60 beats per minute, Tpe intervals were shorter in female than in male individuals (82.5 ± 5.6 vs 90.0 ± 6.5 ms, p < 0.0001). When studying linear slopes between Tpe intervals measured in different leads and the underlying heart rate, we found only minimal heart rate dependency, which was not systematic across the ECG leads and/or across the population. For any ECG lead, positive Tpe/RR slope was found in some subjects (e.g., 79 and 25% of subjects for V2 and V4 measurements, respectively) and a negative Tpe/RR slope in other subjects (e.g., 40 and 65% for V6 and V5, respectively). The steepest positive and negative Tpe/RR slopes were found for measurements in lead V2 and V4, respectively. In all leads, the Tpe/RR slope values were close to zero, indicating, on average, Tpe changes well below 2 ms for RR interval changes of 100 ms. On average, longest Tpe intervals were measured in lead V2, the shortest in lead III. The study concludes that the Tpe intervals measured in different leads cannot be combined. Irrespective of the measured ECG lead, the Tpe interval is not systematically heart rate dependent, and no heart rate correction should be used in clinical Tpe investigations.
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Affiliation(s)
- Irena Andršová
- Department of Internal Medicine and Cardiology, University Hospital Brno, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Katerina Hnatkova
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Martina Šišáková
- Department of Internal Medicine and Cardiology, University Hospital Brno, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Ondřej Toman
- Department of Internal Medicine and Cardiology, University Hospital Brno, Faculty of Medicine, Masaryk University, Brno, Czechia
| | | | - Katharina M Huster
- Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Petra Barthel
- Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Tomáš Novotný
- Department of Internal Medicine and Cardiology, University Hospital Brno, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Georg Schmidt
- Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Marek Malik
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
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6
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Meo M, Denis A, Sacher F, Duchâteau J, Cheniti G, Puyo S, Bear L, Jaïs P, Hocini M, Haïssaguerre M, Bernus O, Dubois R. Insights Into the Spatiotemporal Patterns of Complexity of Ventricular Fibrillation by Multilead Analysis of Body Surface Potential Maps. Front Physiol 2020; 11:554838. [PMID: 33071814 PMCID: PMC7538856 DOI: 10.3389/fphys.2020.554838] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 08/12/2020] [Indexed: 12/12/2022] Open
Abstract
Background Ventricular fibrillation (VF) is the main cause of sudden cardiac death, but its mechanisms are still unclear. We propose a noninvasive approach to describe the progression of VF complexity from body surface potential maps (BSPMs). Methods We mapped 252 VF episodes (16 ± 10 s) with a 252-electrode vest in 110 patients (89 male, 47 ± 18 years): 50 terminated spontaneously, otherwise by electrical cardioversion (DCC). Changes in complexity were assessed between the onset (“VF start”) and the end (“VF end”) of VF by the nondipolar component index (NDIBSPM), measuring the fraction of energy nonpreserved by an equivalent 3D dipole from BSPMs. Higher NDI reflected lower VF organization. We also examined other standard body surface markers of VF dynamics, including fibrillatory wave amplitude (ABSPM), surface cycle length (BsCLBSPM) and Shannon entropy (ShEnBSPM). Differences between patients with and without structural heart diseases (SHD, 32 vs. NSHD, 78) were also tested at those stages. Electrocardiographic features were validated with simultaneous endocardium cycle length (CL) in a subset of 30 patients. Results All BSPM markers measure an increase in electrical complexity during VF (p < 0.0001), and more significantly in NSHD patients. Complexity is significantly higher at the end of sustained VF episodes requiring DCC. Intraepisode intracardiac CL shortening (VF start 197 ± 24 vs. VF end 169 ± 20 ms; p < 0.0001) correlates with an increase in NDI, and decline in surface CL, f-wave amplitude, and entropy (p < 0.0001). In SHD patients VF is initially more complex than in NSHD patients (NDIBSPM, p = 0.0007; ShEnBSPM, p < 0.0001), with moderately slower (BsCLBSPM, p = 0.06), low-amplitude f-waves (ABSPM, p < 0.0001). In this population, lower NDI (p = 0.004) and slower surface CL (p = 0.008) at early stage of VF predict self-termination. In the NSHD group, a more abrupt increase in VF complexity is quantified by all BSPM parameters during sustained VF (p < 0.0001), whereas arrhythmia evolution is stable during self-terminating episodes, hinting at additional mechanisms driving VF dynamics. Conclusion Multilead BSPM analysis underlines distinct degrees of VF complexity based on substrate characteristics.
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Affiliation(s)
- Marianna Meo
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France
| | - Arnaud Denis
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France.,Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Frédéric Sacher
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France.,Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Josselin Duchâteau
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France.,Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Ghassen Cheniti
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France.,Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Stéphane Puyo
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France.,Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Laura Bear
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France
| | - Pierre Jaïs
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France.,Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Mélèze Hocini
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France.,Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Michel Haïssaguerre
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France.,Electrophysiology and Ablation Unit, Bordeaux University Hospital, Bordeaux, France
| | - Olivier Bernus
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France
| | - Rémi Dubois
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, University of Bordeaux, Bordeaux, France.,Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, Institut National de la Santé et de la Recherche Médicale, Bordeaux, France
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7
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Vrinceanu T, Lagacé-Lavoie G, Kaushal N, Esmail A, Vu TTM, Berryman N, Nigam A, Bherer L. Mind the Rhythm: ECG QT Dispersion and Cognition in Healthy Older Adults. Front Psychol 2020; 11:566341. [PMID: 33117235 PMCID: PMC7561416 DOI: 10.3389/fpsyg.2020.566341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 09/14/2020] [Indexed: 12/19/2022] Open
Abstract
Background Autonomic function has been linked to cognitive abilities in aging. Even in non-clinical states, a certain variability in heart rhythm regulation can be measured with QT dispersion (QTcD), an ECG marker of ventricular repolarization which has been linked to autonomic function and cardiovascular health. QTcD has been shown to be higher in individuals with mild cognitive impairment, and the highest in individuals with Alzheimer’s disease. The goal of this study was to see if QTcD is associated with cognitive performance in healthy individuals. Methods Sixty-three healthy inactive older adults (> 60 years) completed an extensive cognitive assessment (including inhibition, divided attention, updating, working memory, and processing speed), a physical fitness assessment, and underwent a resting ECG. Results After controlling for age, sex, and education, QTcD significantly predicted global cognition (MoCA) scores (R2 = 0.17, F(4.58) = 3.00, p < 0.03, β = −0.36). Exploratory analysis on the MoCA subcomponents revealed a significant association between the visual/executive subcomponent and QTcD (R2 = 0.12, F(1.61) = 7.99, p < 0.01, β = −0.34). In individuals with high QTcD, QTcD values were linked to executive functions (R2 = 0.37), processing speed (R2 = 0.34), and dual-task performances (R2 = 0.47). No significant associations were found within the low QTcD group. Conclusion This study shows an association between ventricular repolarization (QTcD) and cognitive performance, in particular speed and executive functions, in healthy older adults. The results provide further support for linking autonomic heart regulation and age-related cognitive changes, and suggest that deviations on ECG, even within-normal range, could help detect early cognitive deficits.
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Affiliation(s)
- Tudor Vrinceanu
- Department of Medicine, Université de Montréal, Montreal, QC, Canada.,Research Centre, Montreal Heart Institute, Montreal, QC, Canada.,Research Centre, Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada
| | | | - Navin Kaushal
- Department of Health Sciences, School of Health & Human Sciences, Indiana University, Indianapolis, IN, United States
| | - Alida Esmail
- École de Réadaptation, Faculté de Médecine, Université de Montréal, Montreal, QC, Canada
| | - T T Minh Vu
- Department of Medicine, Université de Montréal, Montreal, QC, Canada.,Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada.,Centre de Recherché du CHUM, Montreal, QC, Canada
| | - Nicolas Berryman
- Research Centre, Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada.,Département des Sciences de l'Activité Physique, Université du Québec à Montréal, Montreal, QC, Canada
| | - Anil Nigam
- Department of Medicine, Université de Montréal, Montreal, QC, Canada.,Research Centre, Montreal Heart Institute, Montreal, QC, Canada
| | - Louis Bherer
- Department of Medicine, Université de Montréal, Montreal, QC, Canada.,Research Centre, Montreal Heart Institute, Montreal, QC, Canada.,Research Centre, Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada
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8
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Meo M, Bonizzi P, Bear LR, Cluitmans M, Abell E, Haïssaguerre M, Bernus O, Dubois R. Body Surface Mapping of Ventricular Repolarization Heterogeneity: An Ex-vivo Multiparameter Study. Front Physiol 2020; 11:933. [PMID: 32903614 PMCID: PMC7438571 DOI: 10.3389/fphys.2020.00933] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 07/10/2020] [Indexed: 12/15/2022] Open
Abstract
Background Increased heterogeneity of ventricular repolarization is associated with life-threatening arrhythmia and sudden cardiac death (SCD). T-wave analysis through body surface potential mapping (BSPM) is a promising tool for risk stratification, but the clinical effectiveness of current electrocardiographic indices is still unclear, with limited experimental validation. This study aims to investigate performance of non-invasive state-of-the-art and novel T-wave markers for repolarization dispersion in an ex vivo model. Methods Langendorff-perfused pig hearts (N = 7) were suspended in a human-shaped 256-electrode torso tank. Tank potentials were recorded during sinus rhythm before and after introducing repolarization inhomogeneities through local perfusion with dofetilide and/or pinacidil. Drug-induced repolarization gradients were investigated from BSPMs at different experiment phases. Dispersion of electrical recovery was quantified by duration parameters, i.e., the time interval between the peak and the offset of T-wave (TPEAK-TEND) and QT interval, and variability over time and electrodes was also assessed. The degree of T-wave symmetry to the peak was quantified by the ratio between the terminal and initial portions of T-wave area (Asy). Morphological variability between left and right BSPM electrodes was measured by dynamic time warping (DTW). Finally, T-wave organization was assessed by the complexity of repolarization index (CR), i.e., the amount of energy non-preserved by the dominant eigenvector computed by principal component analysis (PCA), and the error between each multilead T-wave and its 3D PCA approximation (NMSE). Body surface indices were compared with global measures of epicardial dispersion of repolarization, and with local gradients between adjacent ventricular sites. Results After drug intervention, both regional and global repolarization heterogeneity were significantly enhanced. On the body surface, TPEAK-TEND was significantly prolonged and less stable in time in all experiments, while QT interval showed higher variability across the interventions in terms of duration and spatial dispersion. The rising slope of the repolarization profile was steeper, and T-waves were more asymmetric than at baseline. Interventricular shape dissimilarity was enhanced by repolarization gradients according to DTW. Organized T-wave patterns were associated with abnormal repolarization, and they were properly described by the first principal components. Conclusion Repolarization heterogeneity significantly affects T-wave properties, and can be non-invasively captured by BSPM-based metrics.
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Affiliation(s)
- Marianna Meo
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Pessac-Bordeaux, France.,University of Bordeaux, CRCTB, Bordeaux, France.,INSERM, CRCTB, U1045, Bordeaux, France
| | - Pietro Bonizzi
- Department of Data Science and Knowledge Engineering, Maastricht University, Maastricht, Netherlands
| | - Laura R Bear
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Pessac-Bordeaux, France.,University of Bordeaux, CRCTB, Bordeaux, France.,INSERM, CRCTB, U1045, Bordeaux, France
| | - Matthijs Cluitmans
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, Netherlands
| | - Emma Abell
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Pessac-Bordeaux, France.,University of Bordeaux, CRCTB, Bordeaux, France.,INSERM, CRCTB, U1045, Bordeaux, France
| | - Michel Haïssaguerre
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Pessac-Bordeaux, France.,University of Bordeaux, CRCTB, Bordeaux, France.,INSERM, CRCTB, U1045, Bordeaux, France.,Bordeaux University Hospital (CHU), Electrophysiology and Ablation Unit, Pessac, France
| | - Olivier Bernus
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Pessac-Bordeaux, France.,University of Bordeaux, CRCTB, Bordeaux, France.,INSERM, CRCTB, U1045, Bordeaux, France
| | - Rémi Dubois
- Institute of Electrophysiology and Heart Modeling (IHU Liryc), Foundation Bordeaux University, Pessac-Bordeaux, France.,University of Bordeaux, CRCTB, Bordeaux, France.,INSERM, CRCTB, U1045, Bordeaux, France
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9
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Nussinovitch U. Normal ranges and potential modifiers of T-wave morphology parameters among healthy individuals: A meta-analysis. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2020; 43:655-663. [PMID: 32285458 DOI: 10.1111/pace.13918] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/18/2020] [Accepted: 04/07/2020] [Indexed: 01/09/2023]
Abstract
BACKGROUND T-wave morphology parameters, such as total cosine R-to-T (TCRT), T-wave loop dispersion (TWLD), T-wave morphology dispersion (TMD), and T-wave residuum (TWR), were suggested to be robust markers for adverse cardiovascular outcomes. Yet, the normal range of these parameters is unknown. This study aimed to evaluate the weighted normal values of T-wave morphology parameters of healthy individuals and study the effect of potential modifiers. METHODS A systematic search of studies published in PubMed was conducted. Only those reporting on control groups of healthy individuals were included. Weighted means were calculated for TCRT, TWLD, TMD, and TWR. Linear regression analysis was conducted for age, percentage of males, heart rate, and QTc. RESULTS The weighted TCRT was 0.40 ± 0.05, significantly higher than the various cutoffs previously suggested to identify high risk. There was some overlap between the results of weighted normal TMD (19.42 ± 6.77°), TWLD (38.51 ± 0.31), and relative TWR (0.118 ± 0.056%) and reports on the same parameters from patients with cardiovascular disease. Women were also characterized by higher TWLD, TMD, and relative TWR. TCRT was negatively correlated with age and heart rate, and positively correlated with QTc duration, although all associations were weak (R2 < 0.9). CONCLUSIONS T-wave morphology parameters reported in the medical literature span a broad range of values in healthy individuals. Seemingly abnormal values of TWLD, TMD, and relative TWR were often reported in healthy adults. The variability between studies may stem from methodological issues. Therefore, standardizing the methodology for measuring T-wave morphology is imperative.
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Affiliation(s)
- Udi Nussinovitch
- Department of Cardiology and Applicative Cardiovascular Research Center (ACRC), Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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10
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Sánez Tähtisalo H, Hiltunen TP, Kenttä T, Junttila J, Oikarinen L, Virolainen J, Kontula KK, Porthan K. Effect of four classes of antihypertensive drugs on cardiac repolarization heterogeneity: A double-blind rotational study. PLoS One 2020; 15:e0230655. [PMID: 32208439 PMCID: PMC7092984 DOI: 10.1371/journal.pone.0230655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 03/04/2020] [Indexed: 11/21/2022] Open
Abstract
Background T-wave area dispersion (TW-Ad) is a novel electrocardiographic (ECG) repolarization marker associated with sudden cardiac death. However, limited data is available on the clinical correlates of TW-Ad. In addition, there are no previous studies on cardiovascular drug effects on TW-Ad. In this study, we examined the relation between TW-Ad and left ventricular mass. We also studied the effects of four commonly used antihypertensive drugs on TW-Ad. Methods A total of 242 moderately hypertensive males (age, 51±6 years; office systolic/diastolic blood pressure during placebo, 153±14/100±8 mmHg), participating in the GENRES study, were included. Left ventricular mass index was determined by transthoracic echocardiography. Antihypertensive four-week monotherapies (a diuretic, a beta-blocker, a calcium channel blocker, and an angiotensin receptor antagonist) were administered in a randomized rotational fashion. Four-week placebo periods preceded all monotherapies. The average value of measurements (over 1700 ECGs in total) from all available placebo periods served as a reference to which measurements during each drug period were compared. Results Lower, i.e. risk-associated TW-Ad values correlated with a higher left ventricular mass index (r = −0.14, p = 0.03). Bisoprolol, a beta-blocker, elicited a positive change in TW-Ad (p = 1.9×10−5), but the three other drugs had no significant effect on TW-Ad. Conclusions Our results show that TW-Ad is correlated with left ventricular mass and can be modified favorably by the use of bisoprolol, although demonstration of any effects on clinical endpoints requires long-term prospective studies. Altogether, our results suggest that TW-Ad is an ECG repolarization measure of left ventricular arrhythmogenic substrate.
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Affiliation(s)
- Heini Sánez Tähtisalo
- Department of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Timo P. Hiltunen
- Department of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- * E-mail:
| | - Tuomas Kenttä
- Research Unit of Internal Medicine, Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Juhani Junttila
- Research Unit of Internal Medicine, Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Lasse Oikarinen
- Division of Cardiology, Heart and Lung Center, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - Juha Virolainen
- Division of Cardiology, Heart and Lung Center, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - Kimmo K. Kontula
- Department of Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Kimmo Porthan
- Division of Cardiology, Heart and Lung Center, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
- Department of Medicine, University of Helsinki and Minerva Foundation Institute for Medical Research, Helsinki, Finland
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11
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Skampardoni S, Poulikakos D, Malik M, Green D, Kalra PA. The potential of electrocardiography for cardiac risk prediction in chronic and end-stage kidney disease. Nephrol Dial Transplant 2020; 34:1089-1098. [PMID: 30085289 DOI: 10.1093/ndt/gfy255] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Indexed: 11/14/2022] Open
Abstract
Cardiovascular mortality is very high in chronic and end-stage kidney disease (ESKD). However, risk stratification data are lacking. Sudden cardiac deaths are among the most common cardiovascular causes of death in these populations. As a result, many studies have assessed the prognostic potential of various electrocardiographic parameters in the renal population. Recent data from studies of implantable loop recordings in haemodialysis patients from five different countries have shed light on a pre-eminent bradyarrhythmic risk of mortality. Importantly, heart block addressed by permanent pacing system was detected in a proportion of patients during the prolonged recording periods. Standard electrocardiogram is inexpensive, non-invasive and easily accessible. Hence, risk prediction models using this simple investigation tool could easily translate into clinical practice. We believe that electrocardiographic assessment is currently under-valued in renal populations. For this review, we identified studies from the preceding 10 years that assessed the use of conventional and novel electrocardiographic biomarkers as risk predictors in chronic and ESKD. The review indicates that conventional electrocardiographic markers are not reliable for risk stratification in the renal populations. Novel parameters have shown promising results in smaller studies, but further validation in larger populations is required.
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Affiliation(s)
- Sofia Skampardoni
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.,Renal Department, Salford Royal NHS Trust, Salford, UK
| | - Dimitrios Poulikakos
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.,Renal Department, Salford Royal NHS Trust, Salford, UK
| | - Marek Malik
- National Heart and Lung Institute, Imperial College, London, UK
| | - Darren Green
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.,Renal Department, Salford Royal NHS Trust, Salford, UK
| | - Philip A Kalra
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.,Renal Department, Salford Royal NHS Trust, Salford, UK
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12
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Lombardi F, Vicenzi M, Hnatkova K, Schmidt G, Malik M. The search for non-invasive markers of cardiac diseases comes back to the 12-lead electrocardiogram. Int J Cardiol 2020; 298:55-56. [DOI: 10.1016/j.ijcard.2019.10.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 10/07/2019] [Indexed: 11/26/2022]
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13
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Silva AC, de Antonio VZ, Sroubek J, Gervino E, Ho K, Medeiros SA, Silva FT, Pedreira GC, Stocco FG, Nearing BD, Verrier RL. Exercise and pharmacologic stress-induced interlead T-wave heterogeneity analysis to detect clinically significant coronary artery stenosis. Int J Cardiol 2020; 298:32-38. [PMID: 31412992 DOI: 10.1016/j.ijcard.2019.07.066] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/08/2019] [Accepted: 07/22/2019] [Indexed: 11/17/2022]
Abstract
BACKGROUND Despite widespread use of ETT and vasodilator-stress with myocardial perfusion imaging (MPI) for noninvasive detection of flow-limiting coronary artery disease, there is continued need to improve diagnostic accuracy. We examined whether measurement of interlead T-wave heterogeneity (TWH) during exercise tolerance testing (ETT) or pharmacologic stress testing improves detection of stenoses in large epicardial coronary arteries. METHODS All 137 patients at our institution who underwent diagnostic coronary angiography within 0 to 5 days after ETT (N = 81) or dipyridamole IV infusion (N = 58) in 2016 were studied, including 2 patients with both tests. Cases (N = 93) had angiographically significant stenosis (≥50% of left main or ≥ 70% of an epicardial coronary artery ≥2 mm in diameter); controls (N = 44) did not. TWH, i.e., interlead splay of T waves, was determined by second central moment analysis from precordial leads by an investigator blinded to angiographic results. RESULTS At rest, TWH levels were similar for cases and controls. ETT and dipyridamole stress testing increased TWH by 69% (p < 0.0001) and 27% (p < 0.0001), respectively, in cases. In controls, TWH did not change. Areas under the ROC curves for TWH increase for any flow-limiting coronary artery stenosis were 0.737 (p < 0.0001) for ETT and 0.818 (p < 0.0001) for dipyridamole stress testing. By contrast, neither ST-segment changes during ETT (p = 0.12) nor MPI during dipyridamole stress testing (p = 0.60) discriminated cases from controls. CONCLUSIONS TWH measurement is a novel method that improves detection of angiographically confirmed flow-limiting stenoses in large epicardial coronary arteries during both ETT and MPI during pharmacologic stress testing with dipyridamole.
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Affiliation(s)
- Anderson C Silva
- Beth Israel Deaconess Medical Center, Department of Medicine, Division of Cardiovascular Medicine, Boston, MA, United States of America; Harvard School of Public Health, Department of Environmental Sciences, Boston, MA, United States of America; Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Victor Z de Antonio
- Beth Israel Deaconess Medical Center, Department of Medicine, Division of Cardiovascular Medicine, Boston, MA, United States of America; Harvard School of Public Health, Department of Environmental Sciences, Boston, MA, United States of America; Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Jakub Sroubek
- Beth Israel Deaconess Medical Center, Department of Medicine, Division of Cardiovascular Medicine, Boston, MA, United States of America; Harvard Medical School, Department of Medicine, Boston, MA, United States of America
| | - Ernest Gervino
- Beth Israel Deaconess Medical Center, Department of Medicine, Division of Cardiovascular Medicine, Boston, MA, United States of America; Harvard Medical School, Department of Medicine, Boston, MA, United States of America
| | - Kalon Ho
- Beth Israel Deaconess Medical Center, Department of Medicine, Division of Cardiovascular Medicine, Boston, MA, United States of America; Harvard Medical School, Department of Medicine, Boston, MA, United States of America
| | - Sofia A Medeiros
- Beth Israel Deaconess Medical Center, Department of Medicine, Division of Cardiovascular Medicine, Boston, MA, United States of America; Harvard School of Public Health, Department of Environmental Sciences, Boston, MA, United States of America; Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Fernanda Tessarolo Silva
- Beth Israel Deaconess Medical Center, Department of Medicine, Division of Cardiovascular Medicine, Boston, MA, United States of America; Harvard School of Public Health, Department of Environmental Sciences, Boston, MA, United States of America; Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Giovanna C Pedreira
- Beth Israel Deaconess Medical Center, Department of Medicine, Division of Cardiovascular Medicine, Boston, MA, United States of America; Harvard School of Public Health, Department of Environmental Sciences, Boston, MA, United States of America; Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Fernando G Stocco
- Beth Israel Deaconess Medical Center, Department of Medicine, Division of Cardiovascular Medicine, Boston, MA, United States of America; Harvard School of Public Health, Department of Environmental Sciences, Boston, MA, United States of America; Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Bruce D Nearing
- Beth Israel Deaconess Medical Center, Department of Medicine, Division of Cardiovascular Medicine, Boston, MA, United States of America; Harvard Medical School, Department of Medicine, Boston, MA, United States of America
| | - Richard L Verrier
- Beth Israel Deaconess Medical Center, Department of Medicine, Division of Cardiovascular Medicine, Boston, MA, United States of America; Harvard School of Public Health, Department of Environmental Sciences, Boston, MA, United States of America; Harvard Medical School, Department of Medicine, Boston, MA, United States of America.
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14
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Próchnicki M, Rudzki G, Dzikowski M, Jaroszyński A, Karakula-Juchnowicz H. The impact of electroconvulsive therapy on the spatial QRS-T angle and cardiac troponin T concentration in psychiatric patients. PLoS One 2019; 14:e0224020. [PMID: 31644576 PMCID: PMC6808446 DOI: 10.1371/journal.pone.0224020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 10/04/2019] [Indexed: 01/10/2023] Open
Abstract
Background Electroconvulsive therapy (ECT) is an effective treatment method used in psychiatry; however, its cardiac safety has not been clearly demonstrated. The aim of the study was evaluation of the ECT effects on the myocardium based on troponin T concentrations and the following ECG parameters: the spatial QRS-T angle (QRS-TA), QRS duration (QRSd) and the corrected QT interval (QTc). Methods In the study 44 patients (12 female and 32 male) were enrolled diagnosed with schizophrenia (n = 21) and major depressive disorders (n = 23), according to the DSM-IVR criteria. All cases were undergoing ECT procedures. The mean age of the patients was 36.9±16 years (range: 18–74). Resting ECG was recorded before performing ECG and 1 hour after. The spatial QRS-TA was reconstructed from 12-lead ECG using the inverse Dower method. Troponin T concentration was assessed before the procedure and 6 hours after ECT. Results No significant changes to troponin T concentrations were observed during the ECT series. The pre-ECT value of the spatial QRS-TA was 41.1±18.9°. The follow-up examinations did not reveal any significant increase of this parameter (p = 0.09) in any of the consecutive measurements. There were no significant changes in the QTc interval duration or the QRS complex duration demonstrated before the third, fifth and last procedure in the cycle (p>0.05). No significant changes to troponin T concentrations were observed during the ECT series. Conclusions Our findings indicate a lack of negative ECT effects on the risk of adverse cardiovascular events measured by the spatial QRS-T angle and cardiac troponin T concentration.
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Affiliation(s)
- Michał Próchnicki
- I Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, Lublin, Poland
- * E-mail:
| | - Grzegorz Rudzki
- Department of Endocrinology, Medical University of Lublin, Lublin, Poland
| | - Michał Dzikowski
- I Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, Lublin, Poland
| | - Andrzej Jaroszyński
- Department of Family Medicine and Geriatrics, Jan Kochanowski University, Kielce, Poland
| | - Hanna Karakula-Juchnowicz
- I Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, Lublin, Poland
- Department of Clinical Neuropsychiatry, Medical University of Lublin, Lublin, Poland
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15
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Bonomini MP, Ortega DF, Barja LD, Mangani N, Arini PD. Depolarization spatial variance as a cardiac dyssynchrony descriptor. Biomed Signal Process Control 2019. [DOI: 10.1016/j.bspc.2018.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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16
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Malik M, Huikuri H, Lombardi F, Schmidt G, Zabel M. Conundrum of the Tpeak-Tend interval. J Cardiovasc Electrophysiol 2018; 29:767-770. [DOI: 10.1111/jce.13474] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 02/26/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Marek Malik
- National Heart and Lung Institute; Imperial College; London England
| | - Heikki Huikuri
- Research Unit of Internal Medicine; University of Oulu and University Hospital; Oulu Finland
| | | | - Georg Schmidt
- Klinik für Innere Medizin I; Technical University of Munich; Munich Germany
- DZHK; Partner site Munich Heart Alliance; Germany
| | - Markus Zabel
- Department of Cardiology and Pneumology - Heart Center; University of Göttingen Medical Center; Göttingen Germany
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17
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Verrier RL, Huikuri H. Tracking interlead heterogeneity of R- and T-wave morphology to disclose latent risk for sudden cardiac death. Heart Rhythm 2017; 14:1466-1475. [PMID: 28610987 DOI: 10.1016/j.hrthm.2017.06.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Indexed: 01/10/2023]
Abstract
Sudden cardiac death (SCD) due primarily to ventricular fibrillation claims 1.5 million lives worldwide each year. In 45%-50% of cases, it is the first manifestation of underlying heart disease. Traditional risk factors including smoking, hypertension, age, sex, as well as depressed left ventricular ejection fraction lack sufficient sensitivity and specificity to forewarn of impending life-threatening arrhythmias. There has been a decades-long search for electrocardiographic (ECG) markers of SCD risk. Several interval-based indices such as QT dispersion and Tpeak-Tend interval held initial promise but ultimately yielded mixed results. Recently, the focus has been on interlead heterogeneity of R- and T-wave morphology. The new approaches have involved advanced analytical tools including vectorcardiographic techniques and second central moment analysis of QRS-aligned templates to quantify heterogeneity of depolarization and repolarization waveforms. The results of current studies appear to be robust and worthy of further exploration. This review examines the electrophysiological underpinnings of heterogeneity-based risk assessment and provides an update of clinical techniques. We also discuss future directions whereby tracking heterogeneity may help to disclose latent risk for SCD not only in ECG recordings made at rest but also during ambulatory ECG monitoring and exercise tolerance testing.
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Affiliation(s)
- Richard L Verrier
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
| | - Heikki Huikuri
- Research Unit of Internal Medicine, Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
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18
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Electrocardiographic findings in hepatic cirrhosis and their association with the severity of disease. COR ET VASA 2017. [DOI: 10.1016/j.crvasa.2016.01.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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19
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T-wave loop area from a pre-implant 12-lead ECG is associated with appropriate ICD shocks. PLoS One 2017; 12:e0173868. [PMID: 28291831 PMCID: PMC5349693 DOI: 10.1371/journal.pone.0173868] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 02/28/2017] [Indexed: 11/19/2022] Open
Abstract
Aims In implantable cardioverter-defibrillator (ICD) patients, predictors of ICD shocks and mortality are needed to improve patient selection. Electrocardiographic (ECG) markers are simple to obtain and have been demonstrated to predict mortality. We aimed to assess the association of T-wave loop area and circularity with ICD shocks. Methods The study investigated patients with ICDs implanted between 1998 and 2010 for whom digital 12-lead ECGs (Schiller CS200 ECG-Network) of sufficient quality were obtained within 1 month prior to the implantation. T-wave loop area and circularity were calculated. Follow-up data of appropriate shocks were obtained during ICD clinic visits that included reviews of device stored electrograms. Results A total of 605 patients (82% males) were included; 68% had ischemic cardiomyopathy and 72% were treated for primary prevention. Over 3.8±1.4 years of follow-up, 114 patients (19%) experienced appropriate shock(s). Those with smaller T-wave loop area received fewer shocks (TLA, hazard ratio, HR, per increase of 1 technical unit, 0.71; [95% confidence interval, 0.53–0.94]; P = 0.02) and those with larger T-wave loop circularity (TLC) representing rounder T wave loop received more shocks (HR per 1% TLC increase 2.96; [0.85–10.36]; P = 0.09). When the quartile containing the largest TLA and TLC values, respectively, were compared to the remaining cases, TLA remained significantly associated with fewer and TLC with more frequent shocks also after multivariate adjustment for clinical variables (HR, 0.59 [0.35–0.99], P = 0.044; and 1.64 [1.08–2.49], P = 0.021, respectively). Conclusions The size and shape of the T-wave loop calculated from pre-implantation 12-lead ECGs are associated with appropriate ICD shocks.
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20
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Dilaveris P, Antoniou CK, Gatzoulis K, Tousoulis D. T wave axis deviation and QRS-T angle - Controversial indicators of incident coronary heart events. J Electrocardiol 2017; 50:466-475. [PMID: 28262257 DOI: 10.1016/j.jelectrocard.2017.02.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Indexed: 11/29/2022]
Abstract
Abnormal orientation of the T-wave axis and increased angle between the QRS complex (depolarization) and the T-wave (repolarization) have long been assumed to provide a global measure of repolarization abnormality, and have been used to assess ventricular repolarization. The ability of the T wave axis deviation and the QRS-T angle to predict incident coronary heart events was examined in several studies. However, conflicting results have led to significant controversy in the literature concerning their purported ability. Potential explanations involve true variation between study populations, non-standardized cut-off values, different baseline cardiovascular risk levels or different patterns of confounding by other concomitant cardiovascular risk factors. In the present article we will attempt to briefly present the rationale and pathophysiology behind these indices, summarize existing knowledge regarding their prognostic significance and their correlation with established cardiovascular disease risk factors. Further prospective studies are necessary to confirm or refute whether T-wave axis deviation, QRS-T angle and ventricular gradient may in the future serve as indicators of incident coronary heart events and mortality, both in populations with higher prevalence of subclinical advanced atherosclerotic heart disease and in apparently healthy subjects.
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Affiliation(s)
- Polychronis Dilaveris
- First Department of Cardiology, University of Athens Medical School, Hippokration Hospital, Athens, Greece.
| | | | - Konstantinos Gatzoulis
- First Department of Cardiology, University of Athens Medical School, Hippokration Hospital, Athens, Greece
| | - Dimitrios Tousoulis
- First Department of Cardiology, University of Athens Medical School, Hippokration Hospital, Athens, Greece
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21
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Shi B, Harding S, Larsen P. Analysis of ECG Measures of Cardiac Repolarization in Relation to Arrhythmic Events in an Implantable Cardioverter Defibrillator Population. Ann Noninvasive Electrocardiol 2016; 22. [PMID: 27292910 DOI: 10.1111/anec.12390] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND ECG-derived measures of cardiac repolarization may have utility in risk prediction of future ventricular arrhythmia, and a range of different measures have been proposed. We compared time-based, vectorcardiographic, and singular value decomposition (SVD) derived measures of repolarization to determine which was most predictive of appropriate therapy in an ICD population. METHODS We examined the independent prognostic value of a range of repolarization measures derived from 60 second 12-lead ECG recordings in 150 patients receiving new ICD implants in relation to the occurrence of appropriate therapy during follow-up. RESULTS Over an average follow-up of 2.15 ± 0.87 years, male gender, presence of premature ventricular complex (PVC), relative T wave residuum (TWR-rel, measures regional repolarization heterogeneity), and TCRT (the total cosine R-to-T, describes the global angle between repolarization and depolarization wavefronts) were the only independent predictors of appropriate therapy. With every 0.01% increase in TWR-rel, there was 2% increased risk of appropriate therapy (HR = 1.02, 95% CI 1.006-1.034, P < 0.001). With every 1° decrease in TCRT, there was an increase in arrhythmic risk of 0.9% (HR 1.009, 95% CI 1.003-1.015, P = 0.003). CONCLUSIONS The use of advanced analytic ECG techniques to derive measures of repolarization abnormality might shave utility in risk stratification in an ICD population.
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Affiliation(s)
- Bijia Shi
- Wellington Cardiovascular Research Group, Wellington, New Zealand.,Department of Surgery and Anaesthesia, University of Otago, Wellington, New Zealand
| | - Scott Harding
- Wellington Cardiovascular Research Group, Wellington, New Zealand.,Department of Cardiology, Wellington Regional Hospital, Wellington, New Zealand
| | - Peter Larsen
- Wellington Cardiovascular Research Group, Wellington, New Zealand.,Department of Surgery and Anaesthesia, University of Otago, Wellington, New Zealand
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22
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Vandenberk B, Hnatkova K, Goovaerts G, Garweg C, Ector J, Van Huffel S, Malik M, Willems R. Inappropriate ICD shocks do not induce pro-arrhythmic electrocardiographic changes in men. SCAND CARDIOVASC J 2016; 51:47-52. [PMID: 27268510 DOI: 10.1080/14017431.2016.1197418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVES Longer-term electrocardiographic effects of multiple inappropriate ICD shocks were investigated to study their hypothesized pro-arrhythmic potential. DESIGN Thirteen male patients with ischemic cardiomyopathy who received ≥2 inappropriate shocks within 24 h and for whom 12-lead ECGs were available both before and within 72h after the inappropriate shocks were analyzed. Exclusion criteria included continuous ventricular pacing, underlying AF, events within 6 weeks after lead implantation and concomitant acute medical problems. RESULTS A total of 149 inappropriate shocks (mean 11 ± 19) were received. There were no significant differences in any of the measured intervals or morphological indices, nor was there a correlation between the "before-after" differences and the number of shocks received. Non-significant changes showed Percentage of Loop Area increase and relative T-wave Residuum decrease while the opposite changes have previously been associated with arrhythmic risk. CONCLUSIONS No potentially pro-arrhythmic electrocardiographic changes were found 19 h after multiple inappropriate shocks.
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Affiliation(s)
- Bert Vandenberk
- a Department of Cardiovascular Sciences , University of Leuven , Leuven , Belgium.,b Department of Clinical Cardiology , University Hospitals Leuven , Leuven , Belgium
| | - Katerina Hnatkova
- c National Heart and Lung Institute, Imperial College , London , England
| | - Griet Goovaerts
- d Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics , University of Leuven , Leuven , Belgium.,e iMinds, Medical IT , Leuven , Belgium
| | - Christophe Garweg
- a Department of Cardiovascular Sciences , University of Leuven , Leuven , Belgium.,b Department of Clinical Cardiology , University Hospitals Leuven , Leuven , Belgium
| | - Joris Ector
- a Department of Cardiovascular Sciences , University of Leuven , Leuven , Belgium.,b Department of Clinical Cardiology , University Hospitals Leuven , Leuven , Belgium
| | - Sabine Van Huffel
- d Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics , University of Leuven , Leuven , Belgium.,e iMinds, Medical IT , Leuven , Belgium
| | - Marek Malik
- c National Heart and Lung Institute, Imperial College , London , England
| | - Rik Willems
- a Department of Cardiovascular Sciences , University of Leuven , Leuven , Belgium.,b Department of Clinical Cardiology , University Hospitals Leuven , Leuven , Belgium
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Giuliani C, Agostinelli A, Di Nardo F, Fioretti S, Burattini L. Automatic Identification of the Repolarization Endpoint by Computing the Dominant T-wave on a Reduced Number of Leads. Open Biomed Eng J 2016; 10:43-50. [PMID: 27347218 PMCID: PMC4901195 DOI: 10.2174/1874120701610010043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 02/05/2016] [Accepted: 02/10/2016] [Indexed: 11/22/2022] Open
Abstract
Electrocardiographic (ECG) T-wave endpoint (Tend) identification suffers lack of reliability due to the presence of noise and variability among leads. Tend identification can be improved by using global repolarization waveforms obtained by combining several leads. The dominant T-wave (DTW) is a global repolarization waveform that proved to improve Tend identification when computed using the 15 (I to III, aVr, aVl, aVf, V1 to V6, X, Y, Z) leads usually available in clinics, of which only 8 (I, II, V1 to V6) are independent. The aim of the present study was to evaluate if the 8 independent leads are sufficient to obtain a DTW which allows a reliable Tend identification. To this aim Tend measures automatically identified from 15-dependent-lead DTWs of 46 control healthy subjects (CHS) and 103 acute myocardial infarction patients (AMIP) were compared with those obtained from 8-independent-lead DTWs. Results indicate that Tend distributions have not statistically different median values (CHS: 340 ms vs. 340 ms, respectively; AMIP: 325 ms vs. 320 ms, respectively), besides being strongly correlated (CHS: ρ=0.97, AMIP: 0.88; P<10-27). Thus, measuring Tend from the 15-dependent-lead DTWs is statistically equivalent to measuring Tend from the 8-independent-lead DTWs. In conclusion, for the clinical purpose of automatic Tend identification from DTW, the 8 independent leads can be used without a statistically significant loss of accuracy but with a significant decrement of computational effort. The lead dependence of 7 out of 15 leads does not introduce a significant bias in the Tend determination from 15 dependent lead DTWs.
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Affiliation(s)
- C Giuliani
- Department of Information Engineering, Polytechnic University of Marche, 60121 Ancona, Italy
| | - A Agostinelli
- Department of Information Engineering, Polytechnic University of Marche, 60121 Ancona, Italy; B.M.E.D. Biomedical Engineering Development SRL, Department of Information Engineering, Polytechnic University of Marche, 60121 Ancona, Italy
| | - F Di Nardo
- Department of Information Engineering, Polytechnic University of Marche, 60121 Ancona, Italy
| | - S Fioretti
- Department of Information Engineering, Polytechnic University of Marche, 60121 Ancona, Italy; B.M.E.D. Biomedical Engineering Development SRL, Department of Information Engineering, Polytechnic University of Marche, 60121 Ancona, Italy
| | - L Burattini
- Department of Information Engineering, Polytechnic University of Marche, 60121 Ancona, Italy; B.M.E.D. Biomedical Engineering Development SRL, Department of Information Engineering, Polytechnic University of Marche, 60121 Ancona, Italy
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24
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Affiliation(s)
- Stuart B Prenner
- Division of Cardiology, Bluhm Cardiovascular Institute, Northwestern Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Sanjiv J Shah
- Division of Cardiology, Bluhm Cardiovascular Institute, Northwestern Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL
| | | | - Andrew J Sauer
- Division of Cardiology, University of Kansas School of Medicine, Kansas City, KS
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Malik M. Drug-Induced QT/QTc Interval Shortening: Lessons from Drug-Induced QT/QTc Prolongation. Drug Saf 2016; 39:647-59. [DOI: 10.1007/s40264-016-0411-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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26
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Tikkanen JT, Kenttä T, Porthan K, Huikuri HV, Junttila MJ. Electrocardiographic T Wave Abnormalities and the Risk of Sudden Cardiac Death: The Finnish Perspective. Ann Noninvasive Electrocardiol 2015; 20:526-33. [PMID: 26391699 DOI: 10.1111/anec.12310] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 07/13/2015] [Indexed: 02/06/2023] Open
Abstract
The identification of patients at risk for sudden cardiac death (SCD) is still a significant challenge to clinicians and scientists. Noninvasive identification of high-risk patients has been of great interest, and several ventricular depolarization and repolarization abnormalities in the standard 12-lead electrocardiogram (ECG) have been associated with increased vulnerability to lethal ventricular arrhythmias. Several benign and pathological conditions can induce changes in repolarization detected as alteration of the ST segment or T wave. Changes in the ST segment and T waves can be early markers of an underlying cardiovascular disease, and even minor ST-T abnormalities have predicted reduced survival and increased risk of SCD in the adult population. In this review, we will discuss the current knowledge of the SCD risk with standard 12-lead ECG T wave abnormalities in the general population, and possible T wave changes in various cardiac conditions predisposing to SCD.
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Affiliation(s)
- Jani T Tikkanen
- Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland.,Emergency Unit, Haartman Hospital, Helsinki, Finland
| | - Tuomas Kenttä
- Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Kimmo Porthan
- Division of Cardiology, Department of Medicine, Helsinki University Central Hospital, Finland
| | - Heikki V Huikuri
- Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - M Juhani Junttila
- Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
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Chang YC, Wu CC, Lin CH, Wu YW, Yang YC, Chang TJ, Jiang YD, Chuang LM. Early Myocardial Repolarization Heterogeneity Is Detected by Magnetocardiography in Diabetic Patients with Cardiovascular Risk Factors. PLoS One 2015; 10:e0133192. [PMID: 26185995 PMCID: PMC4505945 DOI: 10.1371/journal.pone.0133192] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 06/23/2015] [Indexed: 11/18/2022] Open
Abstract
Multi-channel magnetocardiography (MCG) is a sensitive technique to map spatial ventricular repolarization with high resolution and reproducibility. Spatial ventricular repolarization heterogeneity measured by MCG has been shown to accurately detect and localize myocardial ischemia. Here, we explored whether these measurements correlated with cardiovascular risk factors in patients with type 2 diabetes. Two hundreds and seventy-seven type 2 diabetic patients without known coronary artery disease (CAD) and arrhythmia were recruited consecutively from the outpatient clinic of National Taiwan University Hospital. The spatially distributed QTc contour maps were constructed with 64-channel MCG using the superconducting quantum interference device (SQUID) system. Indices of myocardial repolarization heterogeneity including the smoothness index of QTc (SI-QTc) and QTc dispersion were derived and analyzed for association with conventional cardiovascular risk factors. SI-QTc correlated strongly with the QTc dispersion (r = 0.70, p <0.0001). SI-QTc was significantly higher in patients with presence of metabolic syndrome in comparison to those without metabolic syndrome (8.56 vs. 7.96 ms, p = 0.02). In univariate correlation analyses, QTc dispersion was associated with smoking status (average 79.90, 83.83, 86.51, and 86.00 ms for never smokers, ex-smokers, current smokers reporting less than 10 cigarettes daily, and current smoker reporting more than 10 cigarettes daily, respectively, p = 0.03), body weight (r = 0.15, p = 0.01), and hemoglobin A1c (r = 0.12, p = 0.04). In stepwise multivariate regression analyses, QTc dispersion was associated with smoking (p = 0.02), body weight (p = 0.04), total cholesterol levels (p = 0.05), and possibly estimated glomerular filtration rate (p = 0.07). In summary, spatial heterogeneity of myocardial repolarization measured by MCG is positively associated cardiovascular risk factors including adiposity, smoking, and total cholesterol levels.
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Affiliation(s)
- Yi-Cheng Chang
- Graduate Institute of Medical Genomics and Proteomics, National Taiwan University, Taipei, Taiwan
- Department of Internal Medicine, National Taiwan University Hospital, HsinChu branch, HsinChu, Taiwan
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Department of Medicine, College of Medicine, National Taiwan University, Taipei; Taiwan
| | - Chau-Chung Wu
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Department of Primary Care Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chih-Hung Lin
- Department of Internal Medicine, Taipei Medical University Hospital, Taipei Taiwan
| | - Yen-Wen Wu
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Department of Nuclear Medicine and Cardiology Division of Cardiovascular Medical Center, Far Eastern Memorial Hospital, New Taipei City, Taiwan
- Departments of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
- National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Ying-Chieh Yang
- Department of Internal Medicine, National Taiwan University Hospital, HsinChu branch, HsinChu, Taiwan
| | - Tien-Jyun Chang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Department of Medicine, College of Medicine, National Taiwan University, Taipei; Taiwan
| | - Yi-Der Jiang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Department of Medicine, College of Medicine, National Taiwan University, Taipei; Taiwan
| | - Lee-Ming Chuang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Department of Medicine, College of Medicine, National Taiwan University, Taipei; Taiwan
- Institute of Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
- * E-mail:
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Bonomini MP, Corizzo SJ, Laguna P, Arini PD. 2D ECG differences in frontal vs preferential planes inpatients referred for percutaneous transluminal coronary angioplasty. Biomed Signal Process Control 2014. [DOI: 10.1016/j.bspc.2014.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Arini PD, Baglivo FH, Martínez JP, Laguna P. Evaluation of ventricular repolarization dispersion during acute myocardial ischemia: spatial and temporal ECG indices. Med Biol Eng Comput 2014; 52:375-91. [PMID: 24474594 DOI: 10.1007/s11517-014-1136-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 01/16/2014] [Indexed: 01/28/2023]
Abstract
In this work, we studied the evolution of different electrocardiogram (ECG) indices of ventricular repolarization dispersion (VRD) during acute transmural myocardial ischemia in 95 patients undergoing percutaneous coronary intervention (PCI). We studied both temporal indices of VRD (T-VRD), based on the time intervals of the ECG wave, and spatial indices of VRD (S-VRD), based on the eigenvalues of the spatial correlation matrix of the ECG. The T-wave peak-to-end interval I(TPE) index showed statistically significant differences during left anterior descending artery and right coronary artery (RCA) occlusion for almost the complete time course of the PCI procedure with respect to the control recording. Regarding S-VRD indices, we observed statistically significant increases in the ratio of second to the first eigenvalue I(T21), the ratio of the third to the first eigenvalue I(T31) and the T-wave residuum I(TWR) during RCA occlusions. We also found a statistically significant increase in the I(T31) during left circumflex artery occlusions. To evaluate the evolution of VRD indices during acute ischemia, we calculated the relative change parameter R(I) for each index I. Maximal relative changes (R(I)) during acute ischemia were found for the S-VRD indices I(T21), the first eigenvalue I(λ1) and the second eigenvalue I(λ2), with changes 64, 57 and 52 times their baseline range of variation during the control recording, respectively. Also, we found that relative changes with respect to the baseline were higher in patients with T-wave alternans (TWA) than in those without TWA. In conclusion, results suggest that I(TPE) as well as I(T21), I(T31) and I(TWR) are very responsive to dispersion changes induced by ischemia, but with a behavior which very much depends on the occluded artery.
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Affiliation(s)
- Pedro David Arini
- Argentine Institute of Mathematics, 'Alberto P. Calderón' (CONICET), Saavedra 15, C1083ACA, Buenos Aires, Argentina,
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Agostinelli A, Giuliani C, Burattini L. Use of the dominant T wave to enhance reliability of T-wave offset identification. J Electrocardiol 2013; 47:98-105. [PMID: 24268462 DOI: 10.1016/j.jelectrocard.2013.09.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Indexed: 10/26/2022]
Abstract
T-wave offset (Toff) identification may be jeopardized by the presence of a significant inter-method (IMV) and inter-lead (ILV) Toff variability. Thus, the aim of the present study was to investigate if the dominant T wave (DTW) may be used to enhance Toff-identification reliability. DTWs and 15-lead ECG T waves of 46 control healthy subjects (CHS) and 103 acute myocardial infarction patients (AMIP) were analyzed for Toff identification using Zhang et al.'s (M1) and Daskalov and Christov's (M2) methods. Results indicate that IMV is significantly reduced when identifying Toff from the DTW rather than from single ECG leads in both populations (CHS: 5ms vs. 5-15ms; AMIP: 10ms vs. 10-20ms). Moreover, when analyzing ILV, Toff was found to be equivalent (correlation=0.71-0.98; P<10(-14)) to the median Toff among leads, but required only one identification instead of 15. Thus, the DTW can be used to enhance Toff-identification reliability.
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Affiliation(s)
- Angela Agostinelli
- Department of Information Engineering, Polytechnic University of Marche, Ancona, Italy; National Inter-University Consortium for Telecommunications, Parma, Italy
| | - Corrado Giuliani
- Department of Information Engineering, Polytechnic University of Marche, Ancona, Italy
| | - Laura Burattini
- Department of Information Engineering, Polytechnic University of Marche, Ancona, Italy.
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Porthan K, Viitasalo M, Toivonen L, Havulinna AS, Jula A, Tikkanen JT, Väänänen H, Nieminen MS, Huikuri HV, Newton-Cheh C, Salomaa V, Oikarinen L. Predictive value of electrocardiographic T-wave morphology parameters and T-wave peak to T-wave end interval for sudden cardiac death in the general population. Circ Arrhythm Electrophysiol 2013; 6:690-6. [PMID: 23881778 DOI: 10.1161/circep.113.000356] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Previous population studies have found an association between electrocardiographic T-wave morphology parameters and cardiovascular mortality, but their relationship to sudden cardiac death (SCD) is not clear. To our knowledge, there are no follow-up studies assessing the association between electrocardiographic T-wave peak to T-wave end interval (TPE) and SCD. We assessed the predictive value of electrocardiographic T-wave morphology parameters and TPE for SCD in an adult general population sample. METHODS AND RESULTS A total of 4 T-wave morphology parameters (principal component analysis ratio, T-wave morphology dispersion, total cosine R-to-T, T-wave residuum) as well as TPE were measured from digital standard 12-lead ECGs in 5618 adults (46% men; mean age 50.9±12.5 years) participating in the Finnish population-based Health 2000 Study. After a mean follow-up time of 7.7±1.4 years, 72 SCDs had occurred. In univariable analyses, all T-wave morphology parameters were associated with an increased SCD risk. In multivariable Cox models, T-wave morphology dispersion and total cosine R-to-T remained as predictors of SCD, with T-wave morphology dispersion showing the highest SCD risk (hazard ratio of 1.4 [95% confidence interval 1.1-1.7, P=0.001] per 1 SD increase in the loge T-wave morphology dispersion). In contrast, TPE was not associated with SCD in univariable or multivariable analyses. CONCLUSIONS Electrocardiographic T-wave morphology parameters describing the 3-dimensional shape of the T-wave stratify SCD risk in the general population, but we did not find an association between TPE and SCD.
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Affiliation(s)
- Kimmo Porthan
- Division of Cardiology, Department of Medicine, Helsinki University Central Hospital, Finland
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Osadchii OE. Quinidine elicits proarrhythmic changes in ventricular repolarization and refractoriness in guinea-pig. Can J Physiol Pharmacol 2013; 91:306-15. [DOI: 10.1139/cjpp-2012-0379] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Quinidine is a class Ia Na+ channel blocker that prolongs cardiac repolarization owing to the inhibition of IKr, the rapid component of the delayed rectifier current. Although quinidine may induce proarrhythmia, the contributing mechanisms remain incompletely understood. This study examined whether quinidine may set proarrhythmic substrate by inducing spatiotemporal abnormalities in repolarization and refractoriness. The monophasic action potential duration (APD), effective refractory periods (ERPs), and volume-conducted electrocardiograms (ECGs) were assessed in perfused guinea-pig hearts. Quinidine was found to produce the reverse rate-dependent prolongation of ventricular repolarization, which contributed to increased steepness of APD restitution. Throughout the epicardium, quinidine elicited a greater APD increase in the left ventricular chamber compared with the right ventricle, thereby enhancing spatial repolarization heterogeneities. Quinidine prolonged APD to a greater extent than ERP, thus extending the vulnerable window for ventricular re-excitation. This change was attributed to increased triangulation of epicardial action potential because of greater APD lengthening at 90% repolarization than at 30% repolarization. Over the transmural plane, quinidine evoked a greater ERP prolongation at endocardium than epicardium and increased dispersion of refractoriness. Premature ectopic beats and monomorphic ventricular tachycardia were observed in 50% of quinidine-treated heart preparations. In summary, abnormal changes in repolarization and refractoriness contribute greatly to proarrhythmic substrate upon quinidine infusion.
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Affiliation(s)
- Oleg E. Osadchii
- Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark
- Department of Health Science and Technology, University of Aalborg, Fredrik Bajers Vej 7E, 9220 Aalborg, Denmark
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Holzgrefe HH, Ferber G, Morrison R, Meyer O, Greiter-Wilke A, Singer T. Characterization of the Human QT Interval: Novel Distribution-Based Assessment of the Repolarization Effects of Moxifloxacin. J Clin Pharmacol 2013; 52:1222-39. [DOI: 10.1177/0091270011409234] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Sex differences in cardiac autonomic regulation and in repolarisation electrocardiography. Pflugers Arch 2013; 465:699-717. [PMID: 23404618 DOI: 10.1007/s00424-013-1228-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Accepted: 01/28/2013] [Indexed: 12/16/2022]
Abstract
The review summarises the present knowledge on the sex differences in cardiac autonomic regulations and in related aspects of electrocardiography with particular attention to myocardial repolarisation. Although some of the sex differences are far from fully established, multitude of observations show consistent differences between women and men. Despite more pronounced parasympathetic cardiac regulation, women have higher resting heart rate and lower baroreflex sensitivity. Of the electrocardiographic phenomena, women have longer QT interval duration, repolarisation sequence more synchronised with the inverse of the depolarisation sequence, and likely increased regional heterogeneity of myocardial repolarisation. Studies investigating the relationship of these sex disparities to hormonal differences led frequently to conflicting results. Although sex hormones seem to play a key role by influencing both autonomic tone and electrophysiological properties at the cellular level, neither the truly relevant hormones nor their detailed actions are known. Physiologic usefulness of the described sex differences is also unknown. The review suggests that new studies are needed to advance the understanding of the physiologic mechanisms responsible for these inequalities between women and men and provides key methodological suggestions that need to be followed in future research.
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Affiliation(s)
- David Pickham
- David Pickham, is Assistant Adjunct Professor, Department of Physiological Nursing, School of Nursing, University of California, 2 Koret Way, San Francisco, CA 94143 . Amer A. Hasanien, is Doctoral Student, Department of Physiological Nursing, School of Nursing, University of California, San Francisco
| | - Amer A. Hasanien
- David Pickham, is Assistant Adjunct Professor, Department of Physiological Nursing, School of Nursing, University of California, 2 Koret Way, San Francisco, CA 94143 . Amer A. Hasanien, is Doctoral Student, Department of Physiological Nursing, School of Nursing, University of California, San Francisco
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Brennan T, Tarassenko L. Review of T-wave morphology-based biomarkers of ventricular repolarisation using the surface electrocardiogram. Biomed Signal Process Control 2012. [DOI: 10.1016/j.bspc.2011.05.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Spiljak Pakkanen M, Domanjko Petrič A, Olsen LH, Stepančič A, Schlegel TT, Falk T, Rasmussen CE, Starc V. Advanced electrocardiographic parameters change with severity of mitral regurgitation in Cavalier King Charles Spaniels in sinus rhythm. J Vet Intern Med 2011; 26:93-100. [PMID: 22168834 DOI: 10.1111/j.1939-1676.2011.00845.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 08/24/2011] [Accepted: 10/26/2011] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Multiple advanced resting ECG (A-ECG) techniques have improved the diagnostic or prognostic value of ECG in detecting human cardiac diseases even before onset of clinical signs or changes in conventional ECG. OBJECTIVE To determine which A-ECG parameters, derived from 12-lead A-ECG recordings, change with severity of mitral regurgitation (MR) caused by myxomatous mitral valve disease (MMVD) in Cavalier King Charles Spaniels (CKCSs) in sinus rhythm. ANIMALS Seventy-six privately owned CKCSs. METHODS Dogs were prospectively divided into 5 groups according to the degree of MR (estimated by color Doppler mapping as the percentage of the left atrial area affected by the MR jet) and presence of clinical signs. High fidelity approximately 5-minute 12-lead ECG recordings were evaluated using custom software to calculate multiple conventional and A-ECG parameters. RESULTS Nineteen of 76 ECG parameters were significantly different (P < .05) across the 5 dog groups. A 4-parameter model that incorporated results from 1 parameter of heart rate variability, 2 parameters of QT variability, and 1 parameter of QRS amplitude was identified that explained 82.4% of the variance with a correlation coefficient (R) of 0.60 (P < .01). When age or murmur grade was included in the statistical model the prediction value further increased the R to 0.74 and 0.85 (P < .01), respectively. CONCLUSION In CKCSs with sinus rhythm, 4 selected A-ECG parameters further improve prediction of MR jet severity beyond age and murmur grade, although the predictive increment in this study probably is not sufficient to warrant utilization in clinical veterinary practice.
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Smetana P, Schmidt A, Zabel M, Hnatkova K, Franz M, Huber K, Malik M. Assessment of repolarization heterogeneity for prediction of mortality in cardiovascular disease: peak to the end of the T wave interval and nondipolar repolarization components. J Electrocardiol 2011; 44:301-8. [PMID: 21511064 DOI: 10.1016/j.jelectrocard.2011.03.004] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Indexed: 12/23/2022]
Abstract
BACKGROUND In the canine wedge preparation, the interval from the peak to the end of the T wave (TpTe) reflects transwedge heterogeneities. Increase of ventricular dispersion of action potential durations has been repeatedly shown to be arrhythmogenic; thus, prolonged TpTe intervals were assumed to reflect increased risk. However, despite attempted extrapolation to clinical electrocardiograms, the appropriateness of this assumption has not been investigated in a large population. In another animal model, nondipolar components of the descending T-wave limb (TWRd) have been shown to correlate with TpTe interval. Although total T-wave nondipolar components (TWRt), believed to reflect heterogeneities during total repolarization, were shown associated with worse outcome of cardiac patients, this has not been investigated for TWRd. METHODS AND RESULTS Male cardiovascular patients (n = 813) had digital 12-lead electrocardiograms recorded between 1984 and 1991 and were followed until 2000. Using commercial and previously validated technology, QT intervals, TpTe intervals, TWRd, and TWRt were calculated, heart rate corrected, and compared between survivors and nonsurvivors. Their predictive power was also compared with established markers of mortality risk. In contrast to former reports, TpTe(c) intervals were significantly shorter in nonsurvivors (98.76 ± 20.63 milliseconds vs 103.14 ± 20.87 milliseconds, P = .016) and not predictive of outcome. Although TWRd(c) was significantly higher in nonsurvivors (0.007% ± 0.02% vs 0.005% ± 0.08%, P = .03), it was also not predictive of outcome. Only increased TWRt(c), increased heart rate, and increased age were predictive of death. CONCLUSIONS The findings challenge the concept that prolongation of TpTe corresponds to higher risk of death from any cause in every population. Further investigations are needed to confirm that clinically measured TpTe reflects transmural repolarization heterogeneity in all clinical populations and indeed is a useful risk marker.
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Affiliation(s)
- Peter Smetana
- Division of Clinical Sciences, St. George's, University of London, England
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Rashba EJ, Estes Iii NAM. Is there a mechanistic link between atrial fibrillation and vulnerability to ventricular arrhythmias? J Cardiovasc Electrophysiol 2011; 22:1253-5. [PMID: 21806695 DOI: 10.1111/j.1540-8167.2011.02135.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Dilaveris P, Roussos D, Giannopoulos G, Katinakis S, Maragiannis D, Raftopoulos L, Arsenos P, Gatzoulis K, Stefanadis C. Clinical determinants of electrocardiographic and spatial vectorcardiographic descriptors of ventricular repolarization in healthy children. Ann Noninvasive Electrocardiol 2011; 16:49-55. [PMID: 21251134 DOI: 10.1111/j.1542-474x.2010.00408.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Although the association of repolarization alterations to the development of life-threatening ventricular arrhythmias has received considerable research attention, there is paucity of data regarding what may be considered as normal, especially in children. METHODS To define electrocardiographic (ECG) and vectorcardiographic (VCG) descriptors of ventricular repolarization in healthy school-age children, 12-lead digital ECGs were obtained from 646 children (348 males/298 females, mean age 8.54 ± 1.86 years). All QT intervals were measured manually using the digitally stored ECGs. Orthogonal X, Y, and Z leads were reconstructed from the standard 12-lead ECGs and the maximal amplitudes of the spatial QRS and T vectors were calculated, as well as the spatial QRS-T angle. RESULTS The mean heart rate was 95.3 ± 15.8 bpm and the QRS duration was 83.4 ± 9.3 ms. Mean QT interval was 334.1 ± 24.2 ms and the corrected QT interval was 436.5 ± 23.8 ms (Bazzet) and 404.3 ± 19.4 ms (Fridericia). Although the uncorrected maximum and mean QT intervals were significantly higher in boys (P values 0.011 and 0.009, respectively), there was no difference in the rate-corrected QT interval. The spatial QRS and T-vector amplitudes were 1512.0 ± 365.7 μV and 478.8 ± 149.3 μV, respectively. The spatial QRS-T angle was 14.1 ± 8.0 degrees. Although the mean QT interval showed significant increase with age (P = 0.014), all VCG parameters did not show significant variance with age. CONCLUSIONS A range of ECG and VCG descriptors of ventricular repolarization was determined in a large sample of healthy school-age children to provide a data basis of normal values for future reference.
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Lucas BP, Mendes de Leon CF, Prineas RJ, Bienias JL, Evans DA. Relation of cardiac ventricular repolarization and global cognitive performance in a community population. Am J Cardiol 2010; 106:1169-73. [PMID: 20920659 PMCID: PMC2955511 DOI: 10.1016/j.amjcard.2010.06.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 06/02/2010] [Accepted: 06/02/2010] [Indexed: 11/21/2022]
Abstract
Atherosclerosis is a risk factor for dementia. However, little is known about the association between cognitive performance and a widely used indicator of coronary heart disease, at rest electrocardiography. We identified 839 older residents (mean age 81 years, 58% black) from a geographically defined biracial community in Chicago, Illinois, who had undergone extensive cognitive performance testing and met the electrocardiographic eligibility criteria, including a QRS duration of < 120 ms. We then examined multivariate regression coefficients that described the associations between global cognitive performance and 4 novel descriptors of ventricular repolarization waveforms. All analyses were adjusted for age, gender, education, and race. The T wave nondipolar voltage had a significant association with global cognitive performance (p = 0.01), and this association largely remained after adjustment for cardiovascular disease risk factors (p = 0.03). In contrast, global cognitive performance was not significantly associated with the rate-adjusted QT interval, the voltage change from the beginning to end of the ST segment in lead V(5), or the spatial angle between the mean QRS and T wave vectors. In conclusion, the strengths of the associations varied between the novel electrocardiographic descriptors of ventricular repolarization and global cognitive performance. Nevertheless, the significant association observed with T wave nondipolar voltage suggests that the cardiac effects of heart disease are associated with cognitive declines.
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Affiliation(s)
- Brian P Lucas
- Department of Medicine, Cook County Hospital, Chicago, Illinois, USA.
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Sheridan PJ, Marques JL, Newman CM, Heller SR, Clayton RH. Rate-dependent measures of repolarization predict inducibility of ventricular arrhythmias. ACTA ACUST UNITED AC 2010; 12:553-60. [DOI: 10.1093/europace/euq024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Lin YH, Lin LY, Chen YS, Huang HC, Lee JK, Ho YL, Liao LC, Chen WJ. The association between T-wave morphology and life-threatening ventricular tachyarrhythmias in patients with congestive heart failure. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2009; 32:1173-7. [PMID: 19719495 DOI: 10.1111/j.1540-8159.2009.02461.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Whether T-wave morphology descriptors on the 12-lead electrocardiogram (ECG) can predict the occurrence of life-threatening ventricular arrhythmia in patients with advanced congestive heart failure is unclear. METHODS Standard 12-lead ECGs were photoscanned and digitized for analysis in 27 heart failure patients with ventricular tachycardia/ventricular fibrillation (VT/VF; study group), as well as in 54 age- and sex-matched heart failure patients without life-threatening ventricular arrhythmia as a control group. Novel T-wave morphology descriptors were compared. RESULTS The results showed that the temporal descriptor, the lead dispersion (LD; 426.5 +/- 279.8 vs 189.0 +/- 125.7, P < 0.001), was significantly higher in the study than in the control group. The other T-wave morphology parameters, such as the T-wave morphology dispersion (45.7 +/- 20.1 vs 44.9 +/- 18.6), the total cosine between QRS and T wave (TCRT; -0.4 +/- 0.4 vs -0.5 +/- 0.3), and the normalized T-loop area (NTLA; 0.5 +/- 0.1 vs 0.4 +/- 0.1), were not significantly different between the two groups (all P value > 0.05). After an adjustment for other clinical variables, increased LD (odds ratio: 9.9, 95% confidence interval [CI]: 2.9-33.4, P < 0.001) or decreased NTLA (odds ratio: 0.4, 95% CI: 0.1-1.0, P =0.05) was associated with VT/VF. CONCLUSION The novel T-wave morphology analysis may help in identifying heart failure patients at high risk for VT/VF.
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Affiliation(s)
- Yen-Hung Lin
- Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
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Voulgari C, Tentolouris N. Assessment of the Spatial QRS-T Angle by Vectorcardiography: Current Data and Perspectives. Curr Cardiol Rev 2009; 5:251-62. [PMID: 21037841 PMCID: PMC2842956 DOI: 10.2174/157340309789317850] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2008] [Revised: 03/26/2009] [Accepted: 03/31/2009] [Indexed: 01/19/2023] Open
Abstract
The concept of the ventricular gradient (VG) was conceived in the 1930s and its calculation yielded information that was not otherwise obtainable. The VG was not utilized by clinicians at large because it was not easy to understand and its computation time-consuming. Spatial vectorcardiography is based on the concept of the VG. Its current major clinical use is to identify primary [heterogeneity of ventricular action potential (VAP) morphology] in the presence of secondary [heterogeneity in ventricular depolarization instants] T-wave abnormalities in an ECG. Nowadays, the calculation of the spatial VG can be computed on the basis of a regular routine ECG and contributes to localization of arrhythmogenic areas in the heart by assessing overall and local VAP duration heterogeneity. Recent population-based studies suggest that the spatial VG is a dominant ECG predictor of future cardiovascular events and death and it is superior to more conventional ECG parameters. Its assessment warrants consideration for intensified primary and secondary prevention efforts and can be included in everyday clinical practice. This review addresses the nature and diagnostic potential of the spatial VG. The main focus is the role of the spatial VG in ECG assessment of dispersion of repolarization, a key factor in arrhythmogeneity.
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Affiliation(s)
| | - Nicholas Tentolouris
- 1st Department of Propaedeutic Medicine, Athens University Medical School, Laiko General Hospital Athens, Greece
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Huang HC, Lin LY, Yu HY, Ho YL. Risk stratification by T-wave morphology for cardiovascular mortality in patients with systolic heart failure. Europace 2009; 11:1522-8. [PMID: 19819880 DOI: 10.1093/europace/eup294] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS The objective was to investigate the prognostic value of T-wave morphology in systolic heart failure patients. T-wave morphology descriptors on standard 12-lead electrocardiograms (ECG) have been shown to have prognostic importance concerning the arrhythmic susceptibility of patients with previous myocardial infarction. However, these descriptors have not been considered with regard to further risk stratification in patients with systolic heart failure. METHODS AND RESULTS Patients with systolic heart failure [defined by a left ventricular ejection fraction (LVEF) <50%] were enrolled. Standard digitized 12-lead ECGs were used for analysis of T-wave morphology descriptors [lead dispersion, T-wave morphology dispersion, percentage of the loop area, percentage of the outer area, and the total cosine between QRS and T-wave (TCRT)]. A total of 650 patients with a mean age of 63 +/- 14 years were enrolled and followed-up for 2.7 +/- 1.8 years. The mean LVEF was 36 +/- 9%. During this study, the total mortality rate was 32.7% and cardiovascular mortality rate was 22.3%. A stepwise backward Cox regression analysis showed that cardiovascular mortality was significantly associated with age (P < 0.001), diabetes mellitus (P = 0.022), haemoglobin (P = 0.001), LVEF (P = 0.001), and TCRT (P = 0.003). On the basis of a median TCRT of -0.473 as a cut-off point, a significant difference in cardiovascular mortality was observed from a Kaplan-Meier survival curve (P = 0.01). Total cosine between QRS and T-wave further stratified the risk of LVEF (P = 0.007), age (P = 0.001), haemoglobin (P < 0.001), and diabetes mellitus (P < 0.001) in cardiovascular mortality for these patients. CONCLUSION Total cosine between QRS and T-wave may provide further risk stratification for and therefore impact on the prognosis of patients with systolic heart failure.
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Affiliation(s)
- Hui-Chun Huang
- Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei 100, Taiwan
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Kesek M, Gustavsson O, Wiklund U. Nondipolar content of T wave derived from a myocardial source simulation with increased repolarization inhomogeneity. Ann Noninvasive Electrocardiol 2009; 14:185-92. [PMID: 19419404 DOI: 10.1111/j.1542-474x.2009.00294.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Several conditions with repolarization disturbances are associated with increased level of nondipolar components of the T wave. The nondipolar content has been proposed as a measure of repolarization inhomogeneity. This computer simulation study examines the link between increased nondipolar components and increased repolarization inhomogeneity in an established model. METHODS The simulation was performed with Ecgsim software that uses the equivalent double-layer source model. In the model, the shape of transmembrane potential is derived from biological recordings. Increased repolarization inhomogeneity was simulated globally by increasing the variance in action potential duration and locally by introducing changes mimicking acute myocardial infarction. We synthesized surface ECG recordings with 12, 18, and 300 leads. The T-wave residue was calculated by singular value decomposition. The study examined the effects of the number of ECG leads, changes in definition of end of T wave and random noise added to the signal. RESULTS Normal myocardial source gave a low level of nondipolar content. Increased nondipolar content was observed in the two types of increased repolarization inhomogeneity. Noise gave a large increase in the nondipolar content. The sensitivity of the result to noise increased when a higher number of principal components were used in the computation. CONCLUSIONS The nondipolar content of the T wave was associated with repolarization inhomogeneity in the computer model. The measure was very sensitive to noise, especially when principal components of high order were included in the computations. Increased number of ECG leads resulted in an increased signal-to-noise ratio.
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Affiliation(s)
- Milos Kesek
- Department of Cardiology, Heart Center, University Hospital, Umeå, Sweden.
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Dilaveris P, Giannopoulos G, Synetos A, Aggeli C, Raftopoulos L, Arsenos P, Gatzoulis K, Stefanadis C. Effect of biventricular pacing on ventricular repolarization and functional indices in patients with heart failure: lack of association with arrhythmic events. Europace 2009; 11:741-50. [DOI: 10.1093/europace/eup094] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Rautaharju PM, Surawicz B, Gettes LS, Bailey JJ, Childers R, Deal BJ, Gorgels A, Hancock EW, Josephson M, Kligfield P, Kors JA, Macfarlane P, Mason JW, Mirvis DM, Okin P, Pahlm O, van Herpen G, Wagner GS, Wellens H. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part IV: the ST segment, T and U waves, and the QT interval: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society. Endorsed by the International Society for Computerized Electrocardiology. J Am Coll Cardiol 2009; 53:982-91. [PMID: 19281931 DOI: 10.1016/j.jacc.2008.12.014] [Citation(s) in RCA: 565] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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