Normal and ACi hearts with or without MCU overexpression were retrogradely perfused and contractile and oxygen consumption parameters were measured at baseline and after 25nM ISO application. A) Representative recordings of LV pressure (upper panels) and oxygen consumption rate (OCR) (lower panels) of Normal, ACi, and ACi+MCU hearts at baseline and in the presence of ISO. B-G) Average LVDP (B), HR (C), rate pressure product (D), +dP/dtmax (E), -dP/dtmax (F), and OCR (G) at baseline and ISO in Normal (n=3), ACi (n=3), ACi+MCU (n=4) hearts. ISO effect was analyzed with paired t test in each group. Cross group comparisons were performed with 1-way ANOVA followed with post-hoc Tukey test at baseline or ISO.