Gender effects on novel indexes of heterogeneity of repolarization in patients with stable coronary artery disease.

INTRODUCTION There appear to be important gender differences with respect to the incidence and clinical course of arrhythmias. It has been shown that women with coronary artery disease (CAD) have a lower rate of ventricular arrhythmias and sudden cardiac death (SCD) than men. The T peak-to-end (Tpe) interval and the Tpe/QT ratio represent novel markers of arrhythmic risk that possibly correspond to the spatial dispersion of ventricular repolarization. We sought to examine the effect of gender on these indexes in patients with stable CAD. METHODS We studied 119 patients (age 62 ± 9 years, 85 men) with stable CAD. We recorded the demographic and clinical characteristics as well as electrocardiographic indexes of repolarization, such as corrected QT interval (QTc), Tpe interval, and Tpe/QT ratio. The QT interval was measured in each of the 12 leads while Tpe interval was measured in the precordial leads. RESULTS There were no significant differences in the demographic and clinical characteristics between men and women. The QTc intervals were comparable between the 2 groups (389 [368-419] ms in men, 374 [348-421] ms in women; p=0.39). A significant difference was observed with respect to Tpe (80 [58-86] ms in men vs. 48 [39-65] ms in women, p=0.008) and Tpe/QT ratio (0.20 [0.17-0.23] in men vs. 0.14 [0.12-0.22] in women, p=0.034). CONCLUSIONS Women with CAD have a lower Tpe interval and a lower Tpe/QT ratio compared to men. The decreased dispersion of ventricular repolarization may contribute to the lower incidence of ventricular arrhythmias and SCD in women with CAD.