Assessment of ventricular repolarization inhomogeneity in patients with mitral valve prolapse: value of T wave peak to end interval

Abstract

Mitral valve prolapse (MVP) has been long known for causing susceptibility for ventricular arrhythmogenesis, and this risk was evaluated by various methods, mostly by using QT interval related measurements on surface electrocardiogram. T wave peak to end (Tp-e) interval is a relatively new marker for ventricular arrhythmogenesis and repolarization heterogeneity. Prolongation of this interval represents a period of potential vulnerability to re-entrant ventricular arrhythmias. However, there is no information available assessing the Tp-e interval and related calculations in patients with MVP. The aim of this study was to assess ventricular repolarization in patients with MVP by using QT, corrected QT (QTc) and Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio. Electrocardiogram of consecutive 72 patients, who were followed by outpatient clinic because of mitral valve prolapse, were obtained and scanned. Electrocardiograms of age and sex matched 60 healthy control individuals were also gained for comparison. QT, QTc, Tp-e/QT and Tp-e/QTc were calculated. Baseline characteristics were similar in both groups. QT (405.1±64.3 vs. 362.1±39.1; p<0.001), QTc (457.6±44.4 vs. 428.3±44.7; p<0.001), Tp-e (100.2±22.1 vs. 74.6±10.2; p<0.001) and Tp-e/QT (0.24 vs. 0.20; p<0.001) and Tp-e/QTc (0.21 vs. 0.17; p<0.001) were significantly worse in MVP group. Our study revealed that Tp-e interval and Tp-e/QT ratio were increased in MVP patients. Tp-e interval and Tp-e/QT ratio might be a useful marker of cardiovascular morbidity and mortality due to ventricular arrhythmias in patients with MVP.

Keywords: Prolapse; T wave peak to end; arrhythmogenesis.

Figure 1

Demonstration of T wave peak to end and QT intervals.

Figure 2

The ROC Curve. Tp-e, T wave peak to end interval; msec, millisecond; QTc, corrected QT.