In order to determine whether Cx43 and [Ca2+]i are involved in the mediation of the anti-arrhythmic effect produced by EA pretreatment, the arrhythmia score, resting [Ca2+]i concentration, calcium oscillations, the content of total Cx43 protein and the content of non-phosphorylated Cx43 in cardiac myocytes isolated from the heart subjected to the simulative global ischemia-reperfusion (SGIR) were measured in the present study. The gene discussed is GJA1; the disease is cardiac arrhythmia.