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

Abstract

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. 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%. A FPD >140 ms is a marker of AF recurrences after RFCA and probably reflects the extent of atrial remodelling.