RYR2 and atrial fibrillation: In fact, AF has been shown to occur in individuals with structurally normal hearts including those with catecholaminergic polymorphic ventricular tachycardia (CPVT)10, 11 which is linked to inherited mutations in the intracellular Ca2+ release channel/ryanodine receptor (RyR2) that cause intracellular Ca2+ leak12, 13, 14.