Relation of ventricular repolarization to electrocardiographic T wave-form and arrhythmia vulnerability

Burgess, M. J.

doi:10.1152/ajpheart.1979.236.3.h391

Cited by 49 publications

(38 citation statements)

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“…A gradient of ARIs from RV to LV and from LV apex to base was imaged. Similar gradients were measured in canine hearts (14,19). The normal canine heart (14) was found to have an average ARI of 200 ms (vs. 235 ms for human hearts in this study).…”

Section: Discussionsupporting

confidence: 78%

“…The much lower similarity to the activation-time isochrone map of the same subject (Fig. 3A) indicates a minor role for the activation sequence in determining the repolarization sequence, an observation also documented by direct mapping in normal canine hearts (19). This property of normal repolarization results from the fast spread of activation in the normal heart, where the Purkinje system plays a major role.…”

mentioning

confidence: 67%

“…The ability to image and determine cardiac repolarization is important, because repolarization abnormalities and large dispersions are underlying causes of many arrhythmias (14,19). Normal ventricular repolarization was characterized by T wave electrograms, potential maps, recovery-time isochrones, and ARI maps.…”

Section: Discussionmentioning

confidence: 99%

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Activation and repolarization of the normal human heart under complete physiological conditions

Ramanathan

Jia

Ghanem

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

227

166

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Knowledge of normal human cardiac excitation stems from isolated heart or intraoperative mapping studies under nonphysiological conditions. Here, we use a noninvasive imaging modality (electrocardiographic imaging) to study normal activation and repolarization in intact unanesthetized healthy adults under complete physiological conditions. Epicardial potentials, electrograms, and isochrones were noninvasively reconstructed. The normal electrophysiological sequence during activation and repolarization was imaged in seven healthy subjects (four males and three females). Electrocardiographic imaging depicted salient features of normal ventricular activation, including timing and location of the earliest right ventricular (RV) epicardial breakthrough in the anterior paraseptal region, subsequent RV and left ventricular (LV) breakthroughs, apex-to-base activation of posterior LV, and late activation of LV base or RV outflow tract. The repolarization sequence was unaffected by the activation sequence, supporting the hypothesis that in normal hearts, local action potential duration (APD) determines local repolarization time. Mean activation recovery interval (ARI), reflecting local APD, was in the typical human APD range (235 ms). Mean LV apex-to-base ARI dispersion was 42 ms. Average LV ARI exceeded RV ARI by 32 ms. Atrial images showed activation spreading from the sinus node to the rest of the atria, ending at the left atrial appendage. This study provides previously undescribed characterization of human cardiac activation and repolarization under normal physiological conditions. A common sequence of activation was identified, with interindividual differences in specific patterns. The repolarization sequence was determined by local repolarization properties rather than by the activation sequence, and significant dispersion of repolarization was observed between RV and LV and from apex to base.noninvasive electrocardiographic imaging ͉ normal cardiac activation and repolarization ͉ normal sinus rhythm U nderstanding normal cardiac excitation provides a necessary baseline for understanding abnormal cardiac electrical activity and rhythm disorders of the heart, a major cause of death and disability. So far, knowledge of normal human cardiac excitation has been obtained mostly through extrapolation from animal studies, including canine (1, 2) and chimpanzee (3). In addition, human data have been obtained from intraoperative epicardial mapping (4-7) and isolated human hearts (8). Extrapolation of animal studies to humans is limited by interspecies differences in anatomy and electrophysiology. Also, the animal and human studies were conducted under nonphysiological conditions (e.g., anesthesia effects and heart exposure during intraoperative mapping; effects of isolation and absence of neural inputs, mechanical loading, and normal perfusion in isolated heart studies). Until now, it has not been possible to study cardiac excitation in intact healthy subjects under normal physiological conditions because of the unavailabili...

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Section: Discussionsupporting

confidence: 78%

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confidence: 67%

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Activation and repolarization of the normal human heart under complete physiological conditions

Ramanathan

Jia

Ghanem

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

227

166

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“…5,21 However, because QT measures ventricular repolarization duration only, it may leave undetected even gross changes in T-wave morphology, which nonetheless increase arrhythmia vulnerability. 27 T-wave morphology parameters measure temporospatial changes throughout the ventricular repolarization phase. These parameters have shown prognostic value for cardiovascular morbidity and mortality in several population studies, [7][8][9][10][11][12]14 whereas the association between T-wave morphology parameters and SCD specifically has not been reported earlier.…”

Section: T-wave Morphology and Scd In The General Populationmentioning

confidence: 99%

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

Porthan

Viitasalo

Toivonen

et al. 2013

Circ: Arrhythmia and Electrophysiology

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Ventricular repolarization abnormalities increase the risk of ventricular arrhythmias, and prolongation and shortening of the electrocardiographic QT interval increase the risk of SCD. 4,5 However, the association between QT duration and SCD in the general population has been relatively weak. Recently, an association between prolongation of the T-wave peak to T-wave end interval (TPE) and SCD was found in a general population sample.6 Furthermore, computerized measures of the 3-dimensional T-wave loop, the T-wave morphology parameters, have contained prognostic value for cardiovascular morbidity and mortality in several population studies, 7−12 but their relation specifically to SCD is less clear. The aim of the present study was to test the hypothesis that TPE and T-wave morphology parameters predict SCD in the general population.© 2013 American Heart Association, Inc. Original ArticleBackground-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 log e 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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“…The morphology of the T-wave reflects the distribution of the repolarization sequence along the ventricle [2][3][4]. Therefore, the spatio-temporal inhomogeneity of the ventricular repolarization process as a response to changes in heart rate may be captured by an index measuring T-wave morphological changes.…”

Section: Introductionmentioning

confidence: 99%

T-wave Morphology Restitution Dependency with Heart Rate Range and Its Association with Sudden Cardiac Death in Chronic Heart Failure

Ramírez

Orini

Pueyo

et al. 2017

Computing in Cardiology Conference (CinC)

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The index of T-wave morphology restitution (TMR) has recently been presented as a sudden cardiac death (SCD) predictor in a population of chronic heart failure (CHF) patients. This index quantifies the level of variation in the T-wave morphology per RR interval (RRI) increment. The impact of using different definitions of ranges of RRI (∆RRI) and the study of the interaction between TMR and ∆RRI are relevant for both the optimization and the mechanistic interpretation of the index. This study aims to investigate the interaction between ∆RRI and TMR and to assess whether different definitions of ∆RRI (patientsindependent or patient-specific) may affect the predictive value of TMR. Holter ECG recordings from 651 patients with CHF, including SCD, victims of other causes and survivors, were analyzed. Mann-Whitney test was used to evaluate significant differences between SCD victims and the rest of patients. In the patient-independent analysis, TMR values only showed significant differences when 0.25s≤ ∆RR≤0.3s, while in the patient-specific analysis TMR values were significantly different when ∆RR≥0.6 of the maximum RR range, ∆RR max . In conclusion, the index TMR is a predictor of SCD robust to variations in ∆RR values evaluated in segments comprising at least 0.6 of ∆RR max . IntroductionThe action potential duration (APD) restitution (APDR) curve represents the interaction between local APD and local cycle length [1]. The morphology of the T-wave reflects the distribution of the repolarization sequence along the ventricle [2][3][4]. Therefore, the spatio-temporal inhomogeneity of the ventricular repolarization process as a response to changes in heart rate may be captured by an index measuring T-wave morphological changes.In a recent study, the index of T-wave morphology restitution (TMR) was proposed and proved to predict sudden cardiac death (SCD) in a population of 651 chronic heart failure (CHF) patients [5]. The TMR is calculated as the difference in the morphology of two T-waves measured at two RR intervals (RRI) defining the maximum intrasubject RRI range, ∆RRI, and normalized by ∆RRI. The impact of using different definitions of ∆RRI and the study of the interaction between TMR and ∆RRI are relevant for both the optimization and the mechanistic interpretation of the index. This study aims to investigate the interaction between ∆RRI and TMR and to assess whether different definitions of ∆RRI may affect the predictive value of TMR.In this study we calculated the evolution of the index TMR with an patient-independent and patient-specific change in ∆RR. Then, we calculated the SCD predictive value of TMR at each value of ∆RR and we compared the patient-independent and patient-specific results. 2.Materials and Methods MaterialsThe study population included 651 consecutive patients with symptomatic CHF corresponding to NYHA classes II and III enrolled in the MUSIC study, a prospective, multicenter study designed to assess risk predictors for cardiovascular mortality in ambulatory patients with CHF [6]. ...

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Relation of ventricular repolarization to electrocardiographic T wave-form and arrhythmia vulnerability

Cited by 49 publications

References 0 publications

Activation and repolarization of the normal human heart under complete physiological conditions

Activation and repolarization of the normal human heart under complete physiological conditions

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

T-wave Morphology Restitution Dependency with Heart Rate Range and Its Association with Sudden Cardiac Death in Chronic Heart Failure

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