Separate contribution of ventricular · pumping and load impedance on ventricular power output

The heart is a rather special type of fluid pump in the sense that it is an $\text{organic}$ pump. In this paper, however, it is postulated that the heart behaves like any other mechanical pump whose power output may assume, for a primary change in load, values bounded by two limits which are power output values obtained had the pump been a pressure generator and a flow generator respectively. A power output value outside the limits would imply a definite alteration in ventricular pump function concomitant with the load change. A nomogram to illustrate the proposal is included. The hypothesis may be developed into a powerful tool for assessing the pumping capability of the left ventricle, and this has significant clinical and physiological implications.