Angiotensin-converting enzyme and coronary haemodynamics in coronary artery disease.

Abstract Coronary sinus pacing was performed in 12 patients with and 12 patients without significant coronary artery disease as verified by angiography in order to elucidate a possible link between cardiac exchange of angiotensin-converting enzyme and the coronary circulation. The coronary sinus and arterial blood enzyme activity remained unchanged and were similar in the two groups, both at rest and during pacing, and the activity was not related to pacing-induced changes in oxygen consumption or coronary vascular resistance. Therefore it does not seem that global cardiac formation or depletion of angiotensin-converting enzyme is of regulatory importance in the coronary vascular bed in patients with and without coronary artery disease under these circumstances.