Influence of counterpulsation on collateral circulation after acute occlusion of the left anterior descending coronary artery in dogs

The effect of counterpulsation on collateral circulation was studied in dogs after acute occlusion of the left anterior descending coronary artery. The post mortem coronary angiograms showed clear anastomoses between the left anterior descending coronary artery and other coronary branches, but no significant changes in peripheral coronary pressure (PCP) and only minimal changes in 133Xe-clearance could be demonstrated after 3 hr of counterpulsation. Consequently, the pre-existent interarterial anastomoses apparently do not increase in diameter by counterpulsation. Possible useful effects of counterpulsation described by other authors probably cannot be explained on the basis of improved collateral blood flow.