RYR2 and cardiac arrhythmia: In addition, SR overload during myocardial I/R induces spontaneous Ca2+ release and leak mediated by RyR2, a term previously defined as store overload‐induced Ca2+ release (SOICR), leading to spontaneous Ca2+ waves in cardiomyocytes, which induce cardiac arrhythmias 20, 21, 22.