The effect of captopril on heart rate in several types of hypertensive patients

Captopril, an orally active converting enzyme inhibitor, was administered in a dose of 50 mg to 88 untreated hypertensives (70 essential hypertensives, 8 patients with renal arterial disease, 10 patients with renal parenchymal disease). Captopril caused a decrease in heart rate in 18 patients but an increase in 2 patients. In the remaining 68, heart rate did not change. As a whole captopril caused a significant decrease in blood pressure without compensatory increase in heart rate. The change in heart rate caused by captopril in patients with renal arterial disease was significantly higher than that in essential hypertensives. A significant negative correlation was observed between the change in heart rate and plasma renin activity obtained immediately before captopril administration (n=79, r=0.425, p less than 0.001).