Blockade of angiotensin II improves hyperthyroid induced abnormal atrial electrophysiological properties

► These results demonstrated benazepril or irbesartan could improve abnomal atrial electrophysiology properties underlying hyperthyriod, and further reduce AF vulnerability. ► RAS blocker could prevent abnomal atrial electrophysiology properties underlying hyperthyriod by improving atrial ion channel, gap junction, and structural remodeling. ► RAS may play an indirect role in regulating the LCC and Ito currents related subunit. ► RAS blocker improve gap junction remodling mainly due to prevent the abnormal distribution of gap junction.