Fig. 2

Averaged end-systolic pressure–volume relationship at baseline, during dobutamine and verapamil. Single-loop derived by the LV end-systolic pressure–volume relationship (ESPVR) is plotted under various inotropic states. The green line corresponds to the averaged ESPVR during dobutamine infusion, the blue line represents the averaged ESPVR at baseline, while the red one represented the averaged ESPVR at verapamil. A steeper increase in ESPVR during dobutamine and a relevant decrease during verapamil are observed. The equation for each ESPVR is displayed in the graph. Data points are plotted for each animal during different inotropic states. The dashed lines represent the 95% confidence intervals