AF recurrence and other factors
AADs after RFCA were a strong confounding factor for an AF recurrence. In our study, the LA size in the patients with an output of > 5 J was larger than that in those with an output of ≤ 5 J. However, the IDF threshold remained as an independent predictor of an AF recurrence. These findings suggested that a greater AF substrate remained in the patients with an output > 5 J after the RFCA. On the other hand, there was no significant difference in the presence of non-PV foci between the patients with an output of ≤ 5 J and those with an output > 5 J. In addition, the LA size was not associated with AF recurrence, however, the LA size was larger in the patients with an output of > 5 J. Those findings suggested that not only eliminating AF triggers but also approaching the LA substrate were important, because those patients with an output of > 5 J had a higher rate of AF recurrence and greater AF substrate. Recent studies have demonstrated that the efficacy of substrate ablation is questionable.23, 24 In our study, AADs after the RFCA could not prevent AF recurrence especially in patients with an output of > 5 J. Therefore, further studies are need to study those patients with an output of > 5 J.