Assessment of cardiac function. (A) The change in LVEF was measured as an indicator of cardiac (systolic) function. Significant decreases in LVEF were seen with doxorubicin-alone-administered animals, which was significant versus control from 2 weeks. Supplementation of doxorubicin-treated animals with ET prevented this decline in LVEF, which was significantly different to doxorubicin-alone-treated animals at the 3-week time point. (B) Similarly, myocardial performance index was significantly increased in doxorubicin-treated animals (indicating declining cardiac function). ET administration decreased MPI but not to baseline/saline control levels. A 2-way ANOVA using multiple column comparison was performed, with indicated significance levels; **** p < 0.0001, *** p < 0.001, ** p < 0.01, * p < 0.05 vs. saline control, and #### p < 0.0001, ### p < 0.001, ## p < 0.01 vs. doxorubicin alone.