Figure 2. Histograms depicting (A) left ventricular-arterial coupling (Ees/Ea) and (B) left ventricular mechanical efficiency (SW/PVA) before (control; C) and during 5, 10, 20, and 40 mg [center dot] kg sup -1 [center dot] h sup -1 propofol infusions. Data are mean +/- SEM; n = 8.aSignificantly (P < 0.05) different from C.