Prediction of the efficacy of pulmonary vein isolation for the treatment of atrial fibrillation by the signal-averaged P-wave duration.

BACKGROUND: The noninvasive methods for predicting a successful pulmonary vein isolation (PVI) have not been well described. The aim of this study was to assess the usefulness of the P-wave signal-averaged electrocardiogram (P-SAECG) in predicting the chance of a successful PVI in patients with atrial fibrillation (AF).
METHODS: A P-SAECG was recorded before (pre), 1 day after, and 3-4 months after the PVI in 51 AF patients (41, paroxysmal AF; 10, persistent AF). Three-dimensional electroanatomic mapping (3D-EAM) of the right and left atria and left PVs was performed before PVI in 10 patients to analyze the biatrial conduction time (BAT).
RESULTS: Fifteen patients suffered from AF recurrences 3 months or more after the PVI. The pre-filtered P-wave duration (FPD) was significantly longer in patients with recurrence than in those without (166.8 +/- 14.8 ms vs 145.9 +/- 12.6 ms, P < 0.0001). In both patient groups, PVI shortened the FPD, which continued for 3-4 months. Multivariate analysis revealed that a pre-FPD >150 ms was a powerful predictor for recurrence, but persistent AF, the left atrial dimension, and structural heart disease were not predictors for recurrence. 3D-EAM showed that the delayed activation point was located within the left PVs and the BAT was identical to the pre-FPD.
CONCLUSIONS: The pre-FPD may strongly reflect atrial dysfunction, and thus may be useful for predicting a successful PVI. Shortening of the FPD after the PVI and similar FPD and BAT values suggest that the last component of the FPD represents the activation of the left PVs.