Stroke w/in the last 6 mth, CV shock, valvular heart disease (higher-grade aortic or moral stenosis), hypertrophic obstructive cardiomyopathy, unstable angina pectoris, acute MI w/in the last 8 wk, 2nd- & 3rd-degree AV block, CHF, severe hepatic & renal impairment. Pregnancy. Childn.