Optimal stroke volume in left-ventricular ejection

Optimal value of stroke volume ejected against a given arterial load is studied, i.e. left-ventricular function is described by an optimization model. In the model, end-diastolic volume (V/sub ed/), the linear end-systolic pressure-volume relation, heart rate, and ejection time are given, and arterial load is described by the three-element windkessel model. The cost function of the model takes into account two optimality criteria for ventricular function: energy economy and efficient response to an increase in V/sub ed/. The observed stroke volumes of isolated canine hearts could be predicted quite accurately by the model. It is concluded that the left-ventricular response to a change in arterial load and V/sub ed/ can be explained by an optimization model when contractility and heart rate are kept constant. The results also strongly suggest that energy economy and efficiency are essential features of left-ventricular function.<>