T-wave morphology and arrhythmic events in patients with dilated cardiomyopathy

Atypical T wave morphology on scalar ECG may reflect abnormalities of the ventricular repolarization process but the link between these abnormalities and the occurrence of arrhythmic events is unclear. In this study, we investigated whether the occurrence of ventricular tachycardia (VT) in patients with dilated cardiomyopathy (DCM) have specific T wave morphology that may characterize their increased risk for cardiac death (CD). From 24-hour Holter ECG recordings, T-wave morphology and symmetry were quantified in the three orthogonal leads using T-wave area based measurements in addition to conventional QT interval measurements. We compared the T wave characteristics (duration and morphology) between patients according to their cardiac history (VT or CD). Our results did not evidence significant differences in QT durations between patients with and without a history of VT at any heart rate but revealed a prolongation of the terminal portion of the T-wave at high heart rate in patients with VT (91 ± 21 vs. 102 ± 20 ms, p = 0.03 for RR between 600-700 ms). Analysis of T wave morphology may play a role in the identification of patients with dilated cardiomyopathy at higher risk for arrhythmic events.