Left Ventricular Geometric Patterns and QT Dispersion in Borderline and Mild Hypertension: Their Evolution and Regression

To investigate whether QT dispersion increases in borderline and mild hypertension during a longitudinal observation of > 3 years and whether it is improved with medications, left ventricular geometric patterns and QT dispersion were studied with special regard to their longitudinal changes in 85 male borderline and mild hypertensive subjects with left ventricular mass index < 125 g/m2. These subjects were followed for > 3 years without medication. Thirty-two patients with a left ventricular mass index > 125 g/m2 at the end of follow-up period were further observed using antihypertensive drugs for an additional 3 years. Echocardiograms and electrocardiograms were obtained at the beginning and end of the follow-up period. At the end of the follow-up period, subjects were classified into four groups based on ventricular geometric patterns determined by left ventricular mass index and relative wall thickness in diastole. The QT dispersion was greater in patients with concentric hypertrophy (56+/-18 msec) than in patients with normal geometry (41+/-17 msec) (P < .05) and increased significantly in the former group during the follow-up period. After medication, the left ventricular mass index regressed and the QT dispersion decreased (from 55+/-21 to 50+/-26 msec, P < .01) in these patients. Thus, these findings suggest that changes in the QT dispersion reflect both concentric evolution and regression of left ventricular hypertrophy.