RYR2 and hydrops fetalis: In conclusion, the present study supports our hypothesis that the pathological RyR2 primed state is a key common mechanism underlying diastolic SR Ca2+ leak that leads both to the arrhythmic events in HF and arrhythmogenic disorders like CPVT and atrial fibrillation, and to the reduction in cardiac function observed in HF patients caused by depleting the SR Ca2+ store.