However, its primary action in CPVT is considered (or has been suggested) to be on RyR2 channels, with the proposal that flecainide blocks the open channel and hence reduces, or prevents, inappropriate RyR2 channel‐mediated release of Ca2+ from the SR (Hilliard et al., 2010). Here, RYR2 is linked to catecholaminergic polymorphic ventricular tachycardia.