Calcium transients in intact PMs from HCM-A57G, RCM-E143K, and Δ43 versus WT-ELC hearts. Data for HCM-A57G and Δ43 were taken, with permission, from Sitbon et al. (2020). (A) Normalized calcium transients for HCM-A57G (green), RCM-E143K (black), Δ43 (red), and WT (blue) mice. (B) Time points t₂₅, t₅₀, and t₇₅, depicting the time (in milliseconds) from peak [Ca²⁺] to 25%, 50%, and 75% baseline for all four genotypes. Open symbols depict female mice and closed symbols depict male mice. The hearts of n = 8 (5 M, 3 F) HCM-A57G, n = 6 (3 M, 3 F) Δ43, n = 8 (3 M, 5 F) RCM-E143K, and n = 15 (10 M, 5 F) WT-ELC mice were tested. Values are mean ± SD and were analyzed by one-way ANOVA with Tukey’s multiple comparisons test. Significance was depicted as *, P < 0.05 for mutant versus WT-ELC; and &, P < 0.05 for RCM-E143K versus Δ43. Note delayed relaxation times for HCM-A57G (t₅₀) and RCM-E143K (t₂₅, t₅₀, and t₇₅) compared with WT-ELC mice.