Electrocardiographic changes after long-term treatment with sotalol in hypertensive patients.

The long-term electrocardiographic effects of sotalol, a beta blocker tha prolongs the cardiac repolarization time in animals, were investigated in ten hypertensive patients and compared to ten matched hypertensive patients treated with diuretics. An electrocardiogram was recorded before and during an exercise test on a bicycle. Heart rate was lower at rest and throughout exercise in the sotalol-treated patients. The PR and QT intervals of the ECG were significantly longer at rest and after exercise in the sotalol group, whereas QRS widths were similar in both groups. The QTC interval in the sotalol group was 0.41 +/- 0.02 s and 0.47 +/- 0.01 s, at rest and after exercise, respectively, which was not significantly different from 0.42 +/- 0.01 s and 0.43 +/- 0.02 s, respectively, in the diuretic group. These findings were discussed in relation to observations made with other beta blockers.