Figure 5. Effect of 1 minimum alveolar concentration (MAC) isoflurane (n = 8) and 1 MAC sevoflurane (n = 8) on the positive lusitropic effects of beta-adrenoceptor stimulation, assessed by the relations between lusitropic parameters under (A) low (R1) or (B) high (R2) load and active isometric force (AF). Each point corresponds to a concentration of isoproterenol. Data are means +/- SEM. The probability value refers to between-group comparison using multivariate analysis of variance. NS = not significant.