Collateral circulation after coronary artery constriction

Abstract

The extent and distribution of the collateral circulation to the ventricular myocardium which develops after partial constriction of the left circumflex coronary artery for 1 week were investigated by means of the Rb86-clearance technic. Interarterial communications were distinguished from anastomoses occurring at lower levels of the vascular tree by comparing the Rb86 clearances obtained while the retrograde-flow tubing was clamped with clearances obtained while the tubing was patent. In the central region of the ischemic myocardium, there was a two- to threefold increase in the total collateral flow after coronary artery narrowing. The collateral vessels to this region were predominantly interarterial communications. The data suggested, however, that non-interarterial anastomoses to the central zones must also have proliferated. In the marginal zones of the ischemic region, the predominant communications were non-interarterial.