In previous reports1-3 we described a simple unoxygenated venoarterial bypass for the support of the circulation in the failing heart. Experiments in the dog uniformly showed a remarkable return of cardiac function with significant increases in the cardiac output when the bypass was instituted in the face of a fixed cardiac overload. The improvement in cardiac function was shown to be directly related to an increase in aortic root pressure, and we postulated that this elevated root pressure resulted in an increase in coronary blood flow, which in turn was responsible for the observed cardiac improvement.
We have now developed techniques for measuring coronary blood flow during our bypass experiments and have found that the coronary blood flow correlates directly with cardiac function. In this report we describe these studies in detail.
Coronary blood flow was measured by direct and indirect methods. In eight experiments an indirect measure