Our main findings were that, following prolonged administration, UDCA: (1) reduced ischaemia-induced arrhythmia incidence with no effect on reperfusion-induced arrhythmias, (2) attenuated ischaemia-induced CV slowing in the early stage with no effect on APD90 shortening, (3) maintained phosphorylation of Cx43 during acute ischaemia and (4) increased cardiac wavelength (WL) during acute ischaemia. The gene discussed is GJA1; the disease is Arrhythmia.