Coronary sinus drainage and measurement of left coronary artery flow in the dog

Abstract

The indicator-dilution principle has been employed to study coronary blood flow and the venous drainage into the coronary sinus (CS) in the dog. Nine open-chest dogs were prepared to allow separate perfusion and flow measurement of the right and left coronary arteries (RCAand LCA) as well as simultaneous sampling at two sites in the CS. By injecting indicator at various sites in the arterial tree, it has been demonstrated that the posterior circumflex artery drains chiefly to the CS near the CS ostium; the left anterior descending drains chiefly to the area of the CS far upstream from the CS ostium, and the RCA does not drain to the CS. These drainage data have been used to help determine the adequacy of mixing of dye and blood, and to measure LCA flow. Adequate mixing of dye and blood was frequently achieved by the criteria established, but LCA flow was accurately measured with only a minority of injections. It is likely that pecularities of the anatomy of the coronary vascular bed account for the discrepancies.