Electrocardiogram characteristics of P wave associated with successful pulmonary vein isolation in patients with paroxysmal atrial fibrillation: Significance of changes in P‐wave duration and notched P wave

BACKGROUND: The mechanisms involved in changes in P wave following catheter ablation for atrial fibrillation (AF) are uncertain. This study aimed to assess the relationship between changes in P‐wave morphology and pulmonary vein (PV) reconnection following ablation by the assessment of 12‐lead surface electrocardiogram and signal‐averaged electrocardiogram. METHODS: This retrospective study included 115 consecutive patients with paroxysmal AF that underwent repeat ablation for recurrence following initial ablation. We investigated changes in P‐wave morphology between baseline and repeat procedure in patients with and without PV reconnection. The study also included as validation group without recurrence (n = 67) following initial ablation. RESULTS: The maximum P‐wave duration (PWD) was significantly decreased from baseline to just after the procedure in all groups. However, for the PV reconnection group (n = 100), the maximum PWD was significantly increased again at the repeat procedure. In contrast, the maximum PWD was significantly reduced between baseline and repeat procedure in the non‐PV reconnection group (n = 15). The signal‐averaged PWD was significantly decreased from baseline to repeat procedure in the non‐PV reconnection group, but, conversely, was increased in the PV reconnection group. In the non‐PV reconnection group, the disappearance of notched P wave was detected in 8 of 15 patients (53%), which was significantly higher than in other groups (p = .001). A new or delayed notched P wave was identified in the PV reconnection group only. These results were confirmed in the validation group. CONCLUSIONS: The reverse dynamics of PWD after initial shortening directly following ablation were significantly associated with PV reconnection.