Background: Identification of patients at risk for PAF recurrence after AP ablation is important because of the necessity for additional therapies.
Objectives: To determine whether Maximum P-wave duration (Pmax) and P-wave dispersion (Pd ) detected on surface ECG after successful accessory pathway (AP) ablation can predict the recurrence of paroxysmal atrial fibrillation (PAF).
Methods: Seventy-eight patients with Wolff-Parkinson-White (WPW) syndrome who had at least one documented PAF episode and underwent catheter ablation were enrolled. Pmax, minimum P-wave duration (Pmin) and Pd were determined on a surface ECG recorded on a high resolution computer screen on day 2 after ablation of the AP.
Results: There was no significant difference in terms of basic clinical data and electrophysiological findings between patients with (Group-1, n = 19) and without (Group-2, n = 59) recurrence of PAF during follow-up of 21 +/- 10 months. Pmax and Pd were significantly higher in Group-1 than Group-2 (120 +/- 15 vs. 96 +/- 10 ms and 47 +/- 12 vs. 25 +/- 7 ms, respectively; p < 0.001 for both). Pmin didn't differ significantly. A Pmax value of > or = 103 ms separated Group-1 from Group-2 with a sensitivity of 84.2%, specificity of 72.9%, positive predictive value of 50%, and negative predictive value of 93.5%. A Pd value of > or = 32.5 ms separated Group-1 from Group-2 with a sensitivity of 89.5%, specificity of 84.7%, positive predictive value of 65.4%, and negative predictive value of 96.2%. Pmax (p < 0.010) and Pd (p < 0.001) were found to be significant univariate predictors of PAF, whereas only Pd remained significant in multivariate analysis (p = 0.037).
Conclusion: Pd > or = 32.5 ms and Pmax > or = 103.0 ms predict the recurrence of PAF after ablation with acceptable positive and negative predictive values. Pd > or = 32.5 ms is an independent predictor of recurrence of PAF after catheter ablation in patients with WPW syndrome.