RYR2 and catecholaminergic polymorphic ventricular tachycardia: The importance of mitochondria in this vicious cycle is exemplified in a recent study conducted by Hamilton et al. (2020), who demonstrated that mitochondrial ROS targeting ameliorates RyR2 leakiness in a mouse model of catecholaminergic polymorphic ventricular tachycardia (CPVT).