Both these situations lead to impaired Ca2+ homeostasis and enhanced RyR2 sensitivity to cytosolic Ca2+ activation [108,136,146,147,148], which in turn couples with the development of CPVT, a highly severe hereditary arrhythmogenic disorder [103,149,150,151]. The gene discussed is RYR2; the disease is catecholaminergic polymorphic ventricular tachycardia.