Effects of acute and chronic angiotensin-converting enzyme inhibition on large arteries in human hypertension.

The effects of angiotensin-converting enzyme inhibition on large arteries have been examined in uncomplicated essential hypertensive patients (grade 1-2 WHO). These effects were determined from (a) changes in arterial compliance as measured from the slope of the decline in arterial pressure during diastole and (b) alterations in diameter of the brachial artery and blood flow velocity within its lumen, as assessed by pulsed Doppler velocimetry. Both acute and chronic ACE inhibition were accompanied by a significant increase in arterial compliance and a dilation of the brachial artery. This response might be related to changes in plasma and/or intraarterial angiotensin and/or to changes in plasma potassium. Whatever their mechanism, the arterial dilatation and increase in compliance would improve the buffering and the conducting functions of the large arteries, and these in turn may, if persistent, prove beneficial in possibly preventing arterial complications of hypertension.