In patients with paroxysmal atrial fibrillation (AF), the P-wave signal-averaged electrocardiogram often demonstrates a low-amplitude potential at the terminal part of filtered P-wave (atrial late potential: ALP), which would originate from delayed pulmonary vein (PV) potentials. The aim of this study was to investigate the impact of PV isolation on P-wave morphology, and explore the association between ALP and AF recurrence after ablation.Methods and results
We enrolled 88 consecutive paroxysmal AF patients scheduled for ablation. The signal-averaged electrocardiogram was obtained at baseline and 1 day after ablation. An ALP was defined as a P-wave duration of ≥130 ms and a root-mean-squared voltage of the terminal 20 ms of ≤2.0 μV. A pre-procedural ALP was found in 37 (42%) patients and a post-procedural ALP was found in 26 (30%) patients. We completed PV isolation in all patients and followed them for 16 ± 4 months. The AF recurrence rate was 30% (26 patients) and was similar between patients with and without pre-procedural ALP (27 vs. 31%, respectively, P = 0.66); however, AF recurrence was significantly higher in patients with than without post-procedural ALP (54 vs. 19%, respectively, P = 0.001). In multivariate logistic regression analysis, post-procedural ALP was independently associated with AF recurrence (odds ratio = 4.22, 95% confidence interval = 1.52—11.7).Conclusion
Pulmonary vein isolation can modify ALP in a substantial number of patients with paroxysmal AF. Post-procedural ALP is associated with increased risk of future AF recurrence.