Value of P-wave signal averaging to predict atrial fibrillation recurrences after pulmonary vein isolation

AIMS: Recurrences of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA) are usually caused by pulmonary vein (PV) re-conduction, by foci outside the PV or by previous electrical remodelling. Substrate alterations with conduction delays may be detected by signal-averaged P-wave analysis (SAPW). This study was conducted to assess the value of the SAPW to predict recurrences after RFCA in patients with paroxysmal or persistent AF. METHODS AND RESULTS: One hundred and two patients (59 ± 10 years, 83 males) underwent a first RFCA procedure for paroxysmal (n = 61) or persistent/long-standing persistent (n = 41) AF. A SAPW recording with measurement of total filtered P-wave duration (FPD), P-wave integral, and terminal root mean squared voltage was obtained immediately after the ablation procedure and the patients were prospectively followed. During a mean follow-up of 12 ± 7 months, recurrences occurred in 36 of 102 (35.3%) patients, 17 of 61 with paroxysmal AF, and 19 of 41 with persistent AF (P = 0.06). The FPD was significantly longer in patients with recurrences compared to those without (158 ± 22 vs. 140 ± 18 ms, P = 0.0008). The FPD was shorter in patients with paroxysmal AF compared with patients with persistent AF (142 ± 28 vs. 153 ± 20 ms, P = 0.03). A FPD of 140 ms was found to discriminate patients prone to recurrences (log-rank test, P = 0.008) with a sensitivity of 69%, a specificity of 53%, a positive predictive value of 45%, and a negative predictive value of 76%. CONCLUSION: A FPD >140 ms is a marker of AF recurrences after RFCA and probably reflects the extent of atrial remodelling.