RYR2 and catecholaminergic polymorphic ventricular tachycardia 1: The proposed therapeutic mechanism of flecainide for CPVT1 involves a direct effect on RyR2 (Kryshtal et al., 2021), an increase in the threshold for triggered activity (TA) (Liu et al., 2011a), and a decrease in INa, followed by activation of the Na+/Ca2+ exchanger, thereby reducing the probability of RyR2 opening (Bannister et al., 2015).