EFFECT OF SOTALOL ON ARRHYTHMIAS AND EXERCISE TOLERANCE IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY

The effect of sotalol on exercise tolerance and incidence of arrhythmi as was studied in 30 patients with hypertrophic cardiomyopathy (HCM). In this short-term, double-blind, crossover study, exercise time on so talol (320 mg/day) was significantly longer than on placebo (10.6 +/- 4. 0 vs. 9.4 +/- 3.6 min; p < 0.01). Sotalol eliminated supraventricul ar arrhythmias in 6 of 7 patients (p < 0.03) and suppressed ventricula r arrhythmias in 7 of 13 patients in whom they were present on placebo (p < 0.05). Ventricular tachycardia was abolished in 4 of 8 patients, but appeared during sotalol treatment in 1 patient who was free of re petitive arrhythmias on placebo. Twenty-five patients who had better e xercise tolerance on sotalol than on placebo and did not experience ag gravation of arrhythmia entered a 6-month prospective, open-label trea tment with sotalol (160-480 mg/day, mean +/- SD 377 +/- 94). One patie nt was withdrawn after 1 month because of bronchospasm. Mean exercise time improved from 9.8 +/- 3.6 min on placebo to 12.7 +/- 3.2 min (p < 0.01) after 6 months of treatment with sotalol. During the prospectiv e follow-up, sotalol abolished ventricular tachycardia in all 6 patien ts after 1 month (p = 0.022), and in 4 of 6 patients (p > 0.2) after 6 months of treatment. It is concluded that sotalol significantly impro ves exercise tolerance and is effective in suppressing both supraventr icular and ventricular arrhythmias in patients with HCM.