TY - JOUR
T1 - Lability of R- and T-wave peaks in three-dimensional electrocardiograms in implantable cardioverter defibrillator patients with ventricular tachyarrhythmia during follow-up
AU - Han, Lichy
AU - Tereshchenko, Larisa G.
PY - 2010/11
Y1 - 2010/11
N2 - Introduction: From experiments, we know that the heterogeneity of action potential duration and morphology is an important mechanism of ventricular tachyarrhythmia. Electrocardiogram (ECG) markers of repolarization lability are known; however, lability of depolarization has not been systematically studied. We propose a novel method for the assessment of variability of both depolarization and repolarization phases of the cardiac cycle. Methods: Baseline orthogonal ECGs of 81 patients (mean ± SD age, 56 ± 13 years; 61 male [75%]) with structural heart disease and implanted single-chamber implantable cardioverter defibrillator (ICD) were analyzed. Clean 30-beat intervals with absence of premature beats were then selected. Baseline wandering was corrected before analysis. Peaks of R wave and peaks of T wave were detected for each beat, and the axis magnitude was calculated. The peaks were plotted to show clouds of peaks and then used to construct a convex hull, and the volumes of the R peaks cloud and T peaks cloud and ratio of volumes were calculated. Results: During a mean (SD) follow-up period of 13 (10) months, 9 of the 81 patients had sustained ventricular tachycardia or ventricular fibrillation (VT/VF) and received appropriate ICD therapies. All ICD events were adjudicated by three independent electrophysiologists. There was no statistically significant difference in the volume of T-wave peaks or R-wave peaks between patients with and without VT or VF during follow-up; however, R/T peaks cloud volume ratio was significantly lower in patients with subsequent VT/VF (22.4 ± 25.4 versus 13.1 ± 7.9, P = .024). Conclusions: Larger volume of T peaks cloud, measured during 30 beats of three-dimensional ECG, is associated with higher risk of sustained ventricular tachyarrhythmias and appropriate ICD therapies. New method to assess temporal variability of repolarization in three-dimensional ECGs by measuring volume of peak clouds shows potential for further exploration for VT/VF risk stratification.
AB - Introduction: From experiments, we know that the heterogeneity of action potential duration and morphology is an important mechanism of ventricular tachyarrhythmia. Electrocardiogram (ECG) markers of repolarization lability are known; however, lability of depolarization has not been systematically studied. We propose a novel method for the assessment of variability of both depolarization and repolarization phases of the cardiac cycle. Methods: Baseline orthogonal ECGs of 81 patients (mean ± SD age, 56 ± 13 years; 61 male [75%]) with structural heart disease and implanted single-chamber implantable cardioverter defibrillator (ICD) were analyzed. Clean 30-beat intervals with absence of premature beats were then selected. Baseline wandering was corrected before analysis. Peaks of R wave and peaks of T wave were detected for each beat, and the axis magnitude was calculated. The peaks were plotted to show clouds of peaks and then used to construct a convex hull, and the volumes of the R peaks cloud and T peaks cloud and ratio of volumes were calculated. Results: During a mean (SD) follow-up period of 13 (10) months, 9 of the 81 patients had sustained ventricular tachycardia or ventricular fibrillation (VT/VF) and received appropriate ICD therapies. All ICD events were adjudicated by three independent electrophysiologists. There was no statistically significant difference in the volume of T-wave peaks or R-wave peaks between patients with and without VT or VF during follow-up; however, R/T peaks cloud volume ratio was significantly lower in patients with subsequent VT/VF (22.4 ± 25.4 versus 13.1 ± 7.9, P = .024). Conclusions: Larger volume of T peaks cloud, measured during 30 beats of three-dimensional ECG, is associated with higher risk of sustained ventricular tachyarrhythmias and appropriate ICD therapies. New method to assess temporal variability of repolarization in three-dimensional ECGs by measuring volume of peak clouds shows potential for further exploration for VT/VF risk stratification.
KW - Temporal Variability
KW - Vectorcardiography
KW - Ventricular Arrhythmia
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U2 - 10.1016/j.jelectrocard.2010.05.011
DO - 10.1016/j.jelectrocard.2010.05.011
M3 - Article
C2 - 20655057
AN - SCOPUS:78049484484
SN - 0022-0736
VL - 43
SP - 577
EP - 582
JO - Journal of Electrocardiology
JF - Journal of Electrocardiology
IS - 6
ER -