MG53 is required to maintain E-C coupling function following pressure overload-induced cardiac stress. A, Representative cytosolic Ca2+ images (upper) and traces (lower) under autonomous beating in LV of intact hearts from WT mice and MG53-KO mice 5 weeks after sham or TAB surgery. B, Average data of the amplitude, time to peak, and decay (T50, T75, T90) of Ca2+ transients. n = 5, 5, 5, 7 mice per genotype for sham and TAB, respectively. **p <0.01 vs sham group; ##p< 0.01 vs WT TAB group (One-way ANOVA). Data shown are mean±SE.