RYR2 and catecholaminergic polymorphic ventricular tachycardia: Depending on the CPVT mutation, a number of molecular mechanisms have been suggested by different groups: defective SR luminal Ca2+ sensing [13], defective inter-domain interaction [14], increased cytosolic Ca2+ sensitivity [15], reduced calmodulin binding [16], activation of RyR2 channels by mutant calmodulin [17], among other mechanisms.