Controlled Cardiac Output Studies in Dogs (Part I)

Abstract

A method lias been presented whereby a semiquantitative estiTiiation of the coronary flow in dogs can be made (within certain experimental limits) by means of a regression equation based on the relationship that coronary flow appears to bear to the product of mean arterial blood pressure times heart rate. The data, from which the regression equation was derived, were obtained by means of the utilization of the "complete right-heart bypass preparation" in seven dogs. The equation for the prediction of coronary return was tested in an additional six dogs, using the "complete right-heart bypass preparation" and the results showed that, if the value for the estimated coronary return were added to the value for caval return, the resultant sum would give a significantly better estimate of the cardiac output than if the value for caval flow only were used as the index.