RYR2 and cardiac arrhythmia: Isoproterenol treatment has also been demonstrated to result in delayed afterdepolarizations (DADs) and arrhythmias in conditional RyR2 KO mice resulting in a 50% decrease in RyR2 expression, significantly decreasing the beat rate and cardiac output (ml/min) in comparison to wild type controls (Bround et al., 2012).