Haemodynamic effects of ACE inhibitors.

This paper reviews the haemodynamic effects of angiotensin-converting enzyme (ACE) inhibitors in hypertension, focusing on their ability to cause a fall in systemic vascular resistance, with no change in cardiac output and no reduction and even an increase in blood flow to vital organs such as the brain, the kidney and the heart. The haemodynamic effects of ACE inhibitors are qualitatively similar in congestive heart failure, except that, in the presence of impaired cardiac function, the fall in resistance is accompanied by a pronounced increase in cardiac output and tissue perfusion. In both conditions ACE inhibition opposes sympathetic influences and enhances vagal influences and, in hypertension, this intervention is followed by a regression of left ventricular hypertrophy providing a multifold background for a cardioprotective action. The new ACE inhibitor quinapril appears to share the haemodynamic effects of other ACE inhibitors with an improvement of cardiovascular function in congestive heart failure.