Fig. 3. Maximal performance of in situ trout hearts measured before and after recovery from 20 min of anoxia. (A-D) Line plots of cardiovascular variables before (filled symbols) and after (open symbols) recovery from 20 min anoxia. (A) Cardiac output, (B) power output, (C) stroke volume, (D) heart rate. (E-H) Recovery of cardiac output, power output, stroke volume and heart rate after anoxia, expressed as the second maxtest relative to the first maxtest. Significant differences (P<0.05) between the initial and second maxtest are indicated with an asterisk, while dissimilar letters indicate significant differences between the relative recovery of cardiac performance. Control 10°C (1) and (2) indicate measurements taken at the onset and conclusion of the experiment, respectively.