QT dispersion as a marker of left ventricular mass in essential hypertension.

Increased left ventricular mass is an important risk factor in hypertension for various cardiovascular complications. We studied 49 patients of essential hypertension and the relationship between QT dispersion (defined as the difference between the maximum and the minimum QT interval in a 12-lead electrocardiogram) and M-mode echocardiographic left ventricular mass was analysed. Criterion of left ventricular hypertrophy was left ventricular mass index above 134 gm/m2 in men and above 110 gm/m2 in women. There were a total of 22 patients with left ventricular hypertrophy (15 men and 7 women). The mean QT dispersion was 82.66 +/- 35.34 milliseconds (ms) in men with left ventricular hypertrophy and 36.66 +/- 15.71 ms in men without left ventricular hypertrophy. The mean QT dispersion was 77.14 +/- 29.27 ms in women with left ventricular hypertrophy and 26.66 +/- 9.99 ms in women without left ventricular hypertrophy. The correlation co-efficient was 0.59 (p < 0.001) and 0.69 (p < 0.01) in men and women, respectively. Hence, we conclude that there is a direct, linear and positive correlation between left ventricular mass and QT dispersion in essential hypertension.