Figure 10.

Pressure–volume loop. (a) Grade I heart failure (${\mathrm{E}}_{\max }$ = 1.05), (b) Grade II heart failure (${\mathrm{E}}_{\max }$= 0.83), (c) Grade III heart failure (${\mathrm{E}}_{\max }$= 0.713), (d) Grade IV heart failure (${\mathrm{E}}_{\max }$ = 0.63).