Representative 0.5-second ECG excerpts for each genotype are shown in Figure 5A. Mean 24-hour RR, QRS, and QTC intervals gradually increased from Calm1+/+ to Calm1N98S/+ to Calm1N98S/N98S mice (Figure 5B and Supplemental Figure 5A), indicating that the extent of sinus bradycardia, intraventricular conduction deceleration, and ventricular repolarization delay seen in mutant mice aligned with the proportion of Calm1N98S alleles. Here, CALM1 is linked to Sinus bradycardia.