An ECG Index of P-Wave Force Predicts the Recurrence of Atrial Fibrillation after Pulmonary Vein Isolation

Background: Although several prognostic factors of atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) have been investigated, the accurate prediction of AF recurrence remains difficult. We propose an electrocardiogram (ECG) index, the P-wave force (PWF), which is the product of the amplitude of the negative terminal phase of the P wave in the V1 electrode and the filtered P-wave duration, obtained by a signal-averaged P-wave analysis. This study was conducted to evaluate the impact of the PWF on the recurrence of AF after PVI. Methods: We retrospectively evaluated 79 paroxysmal AF patients (64 +/- 9 years, 56 males) who underwent PVI by cryoballoon ablation. Standard 12-lead ECG and a P-wave signal-averaged electrocardiogram (SAECG) were recorded the day before and 1 month after the PVI procedure. Results: During the mean follow-up of 10.2 months, AF recurred in 11 (14%) patients. The PWF 1 month after ablation was significantly higher in the recurrence group compared to that in the nonrecurrence group (8.8 +/- 3.1 mVms vs 6.5 +/- 2.9 mVms, P = 0.017). The patients with a PWF value >= 9.3 mVms had a significantly greater risk of recurrence after the ablation compared to the patients with a PWF value <9.3 mVms (log-rank test, P <0.001). Conclusion: Higher PWF after cryoballoon ablation was associated with poor prognosis during follow-up. The PWF may be a useful and noninvasive marker to predict the recurrence of AF.