Abstract

The relation of angiographically recognized coronary occlusion to regional myocardial blood flow has not been studied adequately in spite of its clinical significance. This is particularly important, as revascularization procedures, based on angiographic studies, are being performed with increasing frequency. To compare the severity of reduction in flow to the severity of coronary occlusion, regional myocardial blood flow (85-Kr washout) was measured in 34 patients. Selective coronary anteriograms were obtained using the Sones technique, and occlusions were graded as a percentage of luminal diameter. Of 26 right coronary arteries for which satisfactory arteriograms and coronary blood flow measurements were obtained, 16 were normal and 10 had significant stenosis (greater than 50%). Dominant right coronary arteries appeared to have high flows (67 plus or minus 6 ml min-minus1 per 100 g muscle) and a greater incidence of occlusion (10 of 20) than nondominant arteries, which had less flow (41 plus or minus 2 ml min-minus1 per 100 g muscle) and a lower incidence of occlusion (1 of 8). Coronary blood flow in 16 normal left coronary arteries was 84 plus or minus 5 ml min-minus1 per 100 g muscle and in 15 with 50 per cent or greater occlusion, 68 plus or minus 3 ml min-minus1 per 100 g muscle. Though coronary blood flow appeared reduced when lesions of both the right and left coronary arteries were present, a critical reduction was seen only when occlusion was greater than 90 per cent.