In addition, flecainide has been shown to be effective in the treatment of catecholaminergic polymorphic ventricular tachycardia (CPVT), and its action has been attributed to an ability to reduce inappropriate release of Ca2+ from the sarcoplasmic reticulum (SR) by directly blocking open cardiac ryanodine receptor (RyR2) channels (Watanabe et al., 2009; Hilliard et al., 2010). This evidence concerns the gene RYR2 and catecholaminergic polymorphic ventricular tachycardia.