al. showed in electrocardiographic experiments of stimulated mice hearts, which are homozygous for the CPVT-associated variant RYR2-P2328S (RYR2S/S), that the atria have reduced epicardial conduction velocities and lower maximum rates of action potential depolarization compared to wild-type mice [22]. The gene discussed is RYR2; the disease is catecholaminergic polymorphic ventricular tachycardia.