Fig. 2. Representative data showing left ventricular pressure (LVP) and aortic pressure (AoP), time derivative of LVP (dP/dt), and elastance curve from top to bottom. (A ) Bilinear approximation of elastance curve, its slope ratio (k), pre-ejection period (PEP), ejection time (ET), pressure at the onset of ejection (P^ad), and that at end-systole (P^es) are also indicated. (B ) The method to estimate E^esfrom multiple pressure–volume loops during vena cava occlusion.