Dantrolene is thought to act by reinforcing the action of calmodulin (CaM) in stabilizing the interaction between the N-terminus and central domains of both RyR1 and RyR2, as suggested by the unzipping model of arrhythmogenesis in CPVT (Figure 2B). This evidence concerns the gene RYR2 and catecholaminergic polymorphic ventricular tachycardia.