Fig. 2. Continuous left ventricular (LV) pressure, LV dP/dt, aortic pressure, left atrial (LA) pressure, LA short and long axis dimensions, and LA volume wave forms (left ) and corresponding LA pressure–volume diagrams (right ) resulting from intravenous administration of phenylephrine (200 μg) observed in a typical experiment. The LA maximum elastance (solid dots) and end-reservoir pressure and volume (solid squares) for each pressure–volume diagram were used to obtain the slopes (E^esand E^er) and extrapolated volume intercepts of the LA end-systolic and end-reservoir pressure–volume relations to quantify myocardial contractility and dynamic chamber stiffness, respectively.