Hence, our study probed the specific role and mechanism of the ST1P1/Cx43 in RA with the use of an established isolated Langendorff‐perfused rat heart model and hypoxia/reoxygenation (H/R) cellular model, hoping to help attenuate the risk of I/R‐induced arrhythmias. Here, GJA1 is linked to cardiac arrhythmia.