The use of diltiazem hydrochloride in cardiovascular disorders.

Diltiazem, a calcium channel blocking agent, has potent cardiovascular effects that are directly related to its influence on vascular smooth muscle, ventricular myocardium, and specialized conducting tissue. It causes coronary and peripheral vasodilation, has a negative chronotropic and dromotropic effect, and little to no negative inotropic effect in patients with normal ventricular function. Diltiazem has potential use in a wide variety of cardiovascular disorders. It has been shown extremely effective in relieving the coronary artery spasm associated with variant angina. When compared with nitrates in patients with exertional angina, diltiazem has similar efficacy. Preliminary work indicates it will have a therapeutic role in the treatment of unstable angina. Because of its ability to improve the balance between myocardial oxygen supply and demand and reduce cellular injury secondary to ischemia, it is likely that diltiazem will be of benefit in the treatment of acutely ischemic myocardium during cardiopulmonary bypass and possibly acute myocardial infarction. It has proven efficacy in treating re-entrant supraventricular tachycardia. Adverse effects are seen in less than 5% of patients, indicating that it is well tolerated.