ObjectiveTo evaluate the efficacy of the epicardial circumferential left atrial ablation (CLAA) with pulmonary vein isolation (PVI) in curing atrial fibrillation (AF). MethodsThirty experimental pigs, weight from 60-78 kg, were divided into 3 groups with the method of random sampling:a group of AF (AF group, n=10), a group of PVI (PVI group, n=10), and a group of CLAA and PVI (CLAA+PVI group, n=10). AF mode was induced by rapid atrial pacing. After AF was induced, no ablation was performed for pigs in the AF group, PVI was performed for pigs in the PVI group with bipolar radiofrequency ablation clamp, and the CLAA+PVI group underwent CLAA after accepted PVI with bipolar radiofrequency ablation clamp. After ablation, we applied electrovert on AF pigs to recover to sinus rhythm, then we tested the vulnerability and lasting time of AF in all 3 groups. ResultsAll pigs developed a stable and sustained AF by rapid left atrial pacing. The pigs of the PVI group and the CLAA+PVI group successfully underwent ablation with the beating heart. Isolated PVI terminated AF in 3 of 20 pigs, and CLAA with PVI terminated AF in 5 of 8 pigs (15% vs. 62.5%, P=0.022). After all pigs recovered to the sinus rhythm, compared with the AF group (10/10), the incidence of sustained AF by burst pacing was statistically decreased in the PVI group (3/10, P=0.003) and the CLAA+PVI group (0/10, P<0.001). There was no statistical difference between the PVI group and the CLAA+PVI group (P=0.211). There was a statistical decreasing of AF duration in the PVI group (P=0.003) and the CLAA+PVI group (P<0.001) compared with the AF group and there was a statistical decreasing of AF duration in the CLAA+PVI group compared to that of the PVI group (P=0.008). ConclusionCompared with isolated PVI, CLAA+PVI may effectually stop the lasting of AF, restrain the recurrance of AF, and improve the treatment effect of AF.