For example, mutations leading to spontaneous Ca2+ release from RYR2 (ryanodine receptor 2; OMIM: 180902) sarcoplasmic reticulum (SR) Ca2+ release channels result in catecholaminergic polymorphic ventricular tachycardia (CPVT) and atrial fibrillation (AF). This evidence concerns the gene RYR2 and catecholaminergic polymorphic ventricular tachycardia.