Long-Term Clinical Effects of Verapamil in Patients with Hypertrophic Cardiomyopathy

For many years beta adrenergic receptor blocking drugs have been the primary pharmacologic agents for treating symptomatic patients with hypertrophic cardiomyopathy [1–3]. Although effective, not all patients respond adequately to this type of therapy and many experience unpleasant side effects. Recent studies from our laboratory have demonstrated that verapamil administration to patients with hypertrophic cardiomyopathy reduces left ventricular outflow obstruction [4], increases exercise capacity [5], and reduces subjective symptomatology (see below [5]). Kaltenbach and associates have also reported chronic verapamil administration improves symptoms in patients with hypertrophic cardiomyopathy [6]. In addition, angiographic, electrocardiographic, and echocardiography data have been interpreted as suggesting that verapamil reduces left ventricular muscle mass or ventricular septal thickness in these patients [6, 7]. In the present study, we report the results of continued examination of the clinical effects of verapamil in patients with hypertrophic cardiomyopathy discharged from the hospital on chronic therapy.