Relationship between coronary collateral growth in the dog and ischemic bed size

Two models of gradual coronary occlusion (Ameroid method) were compared in this study: 3 months circumflex and 3 months right coronary occlusion. Following coronary occlusion, the collaterals developed in intact, normally active dogs. The collateral flows were assessed in an isolated heat preparation. The results indicated a pattern for collateral development. Collateral flow was directed primarily toward the left heart with circumflex occlusion, and toward the right heart with right occlusion. Although dominant collateralization was via epicardial collaterals, intramyocardial septal collaterals strongly participated in growth development of both models. Collateral growth to the circumflex with circumflex occlusion was 6.54 fold greater than collateral growth to the right coronary artery with right occlusion. The data suggest a relationship between collateral growth and ischemic bed size.