RYR2 and catecholaminergic polymorphic ventricular tachycardia: Therefore, flecainide can also be used to treat catecholaminergic polymorphic ventricular tachycardia (CPVT) (Figure 1), a genetic arrhythmogenic disorder associated with mutations in RyR2 (CPVT1) or in the SR Ca2+-binding protein calsequestrin (CPVT2), which both lead to dysregulated SR Ca2+ release through RyR2 in response to β-adrenergic stimulation [23,32,33].