Our results showed that miR-27b-3p overexpression could reduce the incidence and duration of AF, alleviate atrial fibrosis, increase atrial CX43 expression, and decrease the expression of Collagen-I, a-SMA, Collagen-III, TGF-β1, Wnt3a, and p-β-Catenin. Here, GJA1 is linked to atrial fibrillation.