We studied the early changes in collateral blood flow (CBF) after acute coronary artery occlusion and the relation of these changes to subsequent necrosis. We measured CBF with 7-9 μm radioactive microspheres before and at various times after circumflex artery occlusion in 42 conscious dogs that were killed 48 h later. CBF increased from 20 s postocclusion to later measurements (5 min, 15 min, 1 h, or 6 h) and did so in both necrotic and nonnecrotic areas of the occluded bed. However, the increase in CBF over time was not gradual, but appeared to occur between 20 s and 5 min, with no further changes for up to 6 h. There was a gradation of CBF in the occluded bed, from periphery to center and subepicardium to subendocardium. Central and subendocardial regions with CBF < 0.40 ml.min-1.g-1 at 5-15 min postocclusion subsequently showed necrosis whereas epicardial and lateral regions with CBF > 0.50 ml/min did not. Thus CBF increases very early throughout the occluded coronary bed, and the level of CBF by 5 min appears to determine whether necrosis ultimately occurs.
|Original language||English (US)|
|Journal||American Journal of Physiology - Heart and Circulatory Physiology|
|State||Published - Jan 1 1979|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Physiology (medical)