Long-term effect of verapamil in hypertrophic cardiomyopathy

We studied the long-term effects of oral verapamil (240-720 mg) daily on 10 patients with hypertrophic cardiomyopathy. Symptomatic improvement of chest pain or shortness of breath occurred in all the patients although 4 deteriorated after 1 year. Side effects occurred in 3 patients. The electrocardiogram improved in 4 subjects. Quantitative echocardiography showed a significant (P<0.05) decrease in left ventricular contractility (% ΔS decreased from 44±9 to 38±9, mean±SD), septal hypertrophy (1.6±0.5 to 1.4±0.5 cm) and % thickening of the left ventricular free wall (79±29 to 57±22). There was also moderate evidence of improvement in left ventricular compliance; mitral valve EF slope increased from 38 to 55 mm/sec and left atrial diameter decreased.