RYR2 and catecholaminergic polymorphic ventricular tachycardia: Like the racemic carvedilol, the non-β-blocking R-carvedilol can also directly reduce the open duration of RyR2 and suppress stress-induced ventricular tachyarrhythmia (VT) in mice harboring a RyR2 mutation (RyR2-R4496C+/-) associated with catecholaminergic polymorphic ventricular tachycardia (CPVT).