 - Active cardiac disease coronary artery disease, congestive heart failure or cardiomyopathy requiring treatment with any of the following medications: antiarrhythmic agents including digitalis, anti-anginal drugs including topical or systemic nitrates, calcium channel blockers, and beta blockers, and afterload reducers including ACE inhibitors. Patients requiring any of these medications solely for the treatment of hypertension remain eligible for the study. 