Pressure-volume correlates of left ventricular oxygen consumption in the hypervolemic dog.

• Both ventricular size and pressure have been considered as possible determinants of myocardial oxygen consumption (Vo2) m studies of cardiac energetics in isolated dogheart preparations.' In other work, however, only pressure has been examined for its relationship to ventricular energy requirements. Sarnoff and co-workers advanced the tension-time index (area beneath the systolic pressure curve) as a correlate of myocardial Vo,,, and the cardiac effort index (product of mean aortic pressure and heart rate) was proposed by Katz et al. for the prediction of ^o.,-"' The importance of these indices has been confirmed for the intact dog heart. Despite the interest in ventricular size and its bearing on ventricular wall tension,* the role of ventricular volume as a specific variable influencing the magnitude of myocardial