BAX and atrial fibrillation: Here, we found that high mechanical tension significantly increased cell apoptosis ratio and caspase-3 activity, up-regulated gene/protein expression of Bax, caspase-3, cleaved caspase-3, and cleaved PARP, and down-regulated gene expression of Bcl-2 in AF cells compared with the low mechanical tension and control group, indicating that high mechanical tension promotes AF cell apoptosis compared with the low mechanical tension.