Acute effects of captopril on the coronary circulation of patients with hypertension and angina.

Patients with hypertension have a high incidence of coronary artery disease. Captopril, the angiotensin-converting enzyme inhibitor, was given to eight patients with hypertension and coronary artery disease; it decreased mean arterial pressure from 121 to 103 mm Hg (p less than 0.01) but had no effect on heart rate. The rate-pressure product decreased from 12.5 to 11.4 X 10(3) (p less than 0.01). The change in coronary blood flow (90 to 80 ml per minute) and myocardial oxygen consumption (965 to 852 ml per minute) tended to parallel the decrease in the rate-pressure product. Captopril did not change global myocardial lactate (20 to 34 percent) or oxygen (9.6 to 10.0 volume percent) extraction. Hence, captopril decreases the rate-pressure product and tends to decrease myocardial oxygen consumption without causing global myocardial metabolic deterioration.