The Journal of Thoracic and Cardiovascular Surgery, Vol 69, 117-125, Copyright © 1975 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Coronary collateral blood flow in acute myocardial infarction
JL Cox, HI Pass, AS Wechsler, HN Oldham Jr and DC Sabiston Jr
The evolution and transmural distribution of coronary collateral blood flow
in acute myocardial infarction was determined in 24 trained, unanesthetized
dogs by injection of radioactive microspheres into the coronary
circulation. Acute coronary artery occlusion resulted in a greater decrease
in subendocardial flow than subepicardial flow in both the central and
marginal zones of the infarct. Coronary collateral blood flow was
distributed primarily to the marginal zone and to the subepicardium of the
central zone of the infarct. The greatest increase in collateral flow
occured between 12 and 18 hours after coronary artery occlusion. By 24
hours after coronary occlusion, blood flow to all areas of the infarct
except the subendocardium of the central zone had returned to near control
levels. This dispropotionate distribution of coronary collateral blood flow
during the early stages of myocardial ischemic injury helps to explain the
apparent lack of protection of the subendocardium by collateral flow.