Effects of angiotensin converting enzyme inhibitor, perindopril, on autonomic reflexes

The effect of the angiotensin converting enzyme inhibitor, perindopril, on autonomic function was assessed in a double blind, placebo controlled, crossover study in 10 normotensive males. Eight milligram of perindopril given orally lowered blood pressure without a change in heart rate. Perindopril enhanced the vagally mediated heart rate variation with deep breathing. There was no impairment of the responses to either bicycle exercise at 175 W for 5 min or isometric handgrip. The pressor response to cold was not changed and the response to the Valsalva manoeuvre was unaltered. These results suggest that the absence of tachycardia after perindopril may be in part related, as has been reported with other converting enzyme inhibitors, to enhanced cardiac parasympathetic tone. Vagomimetic action may be a property of converting enzyme inhibitors in general.