CAMK2G and Arrhythmia: Analogously, the Na+ channel opener ATX-II induces spontaneous diastolic Ca2+ release from the SR and DADs in myocytes (Song et al., 2008) and arrhythmia in Langendorff perfused hearts (Yao et al., 2011), which is attenuated with CaMKII or INaL inhibition.