Fig. 1
Pressure-volume loops obtained during three seconds showing left ventricular (LV) hemodynamics during steady state (a) and vena cava occlusion (b). a LV function is described during 4 phases of the cardiac cycle: 1) diastolic filling, 2) isovolumetric contraction, 3) ejection and 4) isovolumetric relaxation. EDP = end-diastolic pressure, ESP = end-systolic pressure, Ea = effective arterial elastance which slope is calculated by end-systolic pressure divided by stroke volume, dP/dtmax = maximum rate of pressure development during isovolumetric contraction, dP/dtmin = maximum rate of pressure decline during isovolumetric relaxation. b By decreasing preload through vena cava occlusion, the pressure-volume loops move to the left and become smaller, enabling the measurement of end-systolic elastance (Ees) by the pressure-volume relationship at end-systole. Simultaneously, end-diastolic elastance (Eed) can be measured by the pressure-volume relationship at end-diastole. A representative sample trace as displayed and analyzed by PVAN 3.6 is shown