Calcium Antagonists in Patients with Cardiovascular Disease

Since their introduction in the United States about 4 years ago, the calcium antagonists have achieved an important place in the medical therapy of several cardiovascular disease entities. These pharmacologic agents differ markedly in their clinical utility. Verapamil is extremely effective in patients with supraventricular tachyarrhythmias, hypertrophic cardiomyopathy, and the various anginal syndromes, but it appears to be ineffective or possibly even deleterious in those with pulmonary hypertension, congestive heart failure of any cause, and Raynaud's phenomenon or disease. Nifedipine exerts a powerful vasodilatory effect and, as a result, is efficacious in individuals with systemic or pulmonary hypertension, congestive heart failure, and Raynaud's phenomenon or disease. It is also beneficial in patients with various kinds of angina, especially when it is administered concomitantly with a beta-adrenergic blocker. It is totally ineffective as an antiarrhythmic agent. Diltiazem is an effective antianginal agent and may be beneficial as an antiarrhythmic agent, but it is largely untested in patients with systemic or pulmonary hypertension, Raynaud's disease, and hypertrophic cardiomyopathy. A thorough understanding of each drug's hemodynamic and electrophysiologic effects allows the practicing physician to prescribe them skillfully and safely.