Verapamil Therapy: A New Approach to the Pharmacologic Treatment of Hypertrophic Cardiomyopathy

Treadmill exercise capacity and symptomatic status were evaluated in 19 patients with hypertrophic cardiomyopathy while on placebo, low and high dosages of propranolol and low and high dosages of verapamil. Exercise duration on placebo was 6.1 ± 0.8 minutes. Verapamil administration improved exercise capacity by 26 ± 8% (1.6 ± 0.5 minutes; p < 0.005); propranolol improved exercise capacity by 21 ± 8% (1.3 ± 0.5 minutes; p < 0.025). Twelve patients on verapamil and 11 on propranolol improved their exercise duration by at least 15% compared with placebo. No patient on verapamil but three on propranolol had more than 15% deterioration in exercise capacity. Seven patients considered their symptomatic status "best" while