Controls of ventricular contractility assessed by pressure-volume ration, Emax.

The present study on canine left ventricles showed that Emax which we previously proposed as a good index of both ventricular contractility and its pumping capability, decreased from 2.06 to 1.38 kPa/ml (15.5 to 10.4 mmHg/ml) via the sino-aortic baroreceptor reflex. Cerebral ischaemic response increased Emax to 3.83 kPa/ml (28.8 mmHg/ml). Emax decreased to 1.17 kPa/ml (8.8 mmHg/ml) after cardiac denervation.