RYR2 and catecholaminergic polymorphic ventricular tachycardia: Chen et al. used in situ confocal Vm and [Ca2+]i imaging to investigate cardiac electrical signaling in a murine catecholaminergic polymorphic ventricular tachycardia model of type 2 ryanodine receptor[RyR]R4496C+/− mutation (Chen et al., 2012).