Figure 4. Depolarization-induced Ca²⁺ transients in WT and heterozygous RyR2 Ex3-del mutant cardiomyocytes.

Ventricular myocytes isolated from RyR2 WT and Ex3-del^{+/ −} mutant hearts were loaded with Rhod-2-AM and perfused with 2 mM extracellular Ca²⁺ in KRH solution and paced at 3Hz. Ca²⁺ transients were monitored by line-scan confocal Ca²⁺ imaging. Representative images/traces of WT (A) and Ex3-del^{+/ −} mutant (B) cardiomyocytes, and average data of the amplitude (C), time to peak (D), and time to 50% decay (E) of Ca²⁺ transients in WT and Ex3-del^{+/ −} mutant cells are shown. Data shown are mean ± SEM from 35 WT and 58 mutant cells (**P<0.001; *P<0.05).