Postextrasystolic Repolarization Changes of Ventricular Premature Beats Correlate with Structural Heart Disease and Suggest Prognostic Implications

Ventricular premature beats (VPBs) can potentially lead to life-threatening arrhythmias, especially in patients with structural heart disease (SHD). However, identifying dangerous VPBs has always been a topic and challenge in clinical research. This study aimed to evaluate the relationship of postextrasystolic repolarization changes of VPBs with SHD and its possible additional prognostic value. 125 cases of frequent VPBs with SHD and 156 cases without SHD were included. VPBs were stratified selected from 24 h Holter recording according to the scale of heart rate. Average QT(DV) (difference value of QT interval between the first beat follow VPB with beats preceding VPB) and max QT(DV) were significantly longer in SHD group than that in the non-SHD group. For identifying patients with SHD, the best cutoff value were 19 ms for average QT(DV) (AUC = 0.931) and 29 ms for max QT(DV) (AUC = 0.910) respectively. For Tu morphology analysis, PT2 (postextrasystolic T wave amplitude change >= 2 mV), reversed T wave, and Pu (postextrasystolic u wave) change were all highly specific, but low sensitive as identification of SHD. Compared with average QT(DV) < 19 ms patients, average QT(DV) >= 19 ms patients had significantly larger left heart size and wores left cardiac function. The presence of non-persistent ventricular tachycardia runs was higher in average QT(DV) >= 19 ms group and positive Pu change group than that in control groups. The findings indicated that postextrasystolic repolarization changes of VPBs correlated with SHD and suggested potential value in prognosis asssessment.