The role of collateral circulation in the various coronary syndromes.

Coronary collaterals were evaluated at arteriography within 1 year of the onset of symptoms of coronary disease in 73 patients with transmural myocardial infarction (TMI), 63 patients with subendo- cardial myocardial infarction (SMI), and 164 patients with angina pectoris (AP) alone.An occluded artery was present in 79% of patients with TMI, 70% of patients with SMI and elevated serum enzymes, and 42% of patients with AP.Collateral vessels supplied the occluded artery in 91% of patients with AP, 93% of patients with SMI all had postinfarction AP -and 78% of patients with TMI and postinfarction AP, but in only 35% of patients with TMI and no postinfarction AP (p < 0.01).With the treadmill stress test in patients with AP alone and coronary lesions in the anterior wall coronary distribution, 97% had ischemia in leads V4 to V,.Only 25% of patients with coronary lesions in the inferior wall coronary distribution had ischemia in leads III and aVF (positive group) and 75% did not (false negative group).The affected artery was occluded and supplied by collaterals in only 9% of patients of the positive group, but in 57% of the false negative group (p < 0.01).These data and additional findings in the infarction syndromes suggest that in TMI and SMI the presence of collaterals maintains a peri-infarction ischemic zone with subsequent AP.In patients with AP alone, the tread- mill stress test is highly predictive of coronary disease in the anterior but not in the inferior wall coronary dis- tribution, in part because of the influence of collaterals.