Wolff-Parkinson-White ablation after a prior failure: a 7-year multicentre experience.

Aims: Catheter ablation for Wolff-Parkinson-White syndrome (WPW) can be challenging and is associated with failure in approximately 1-5% of cases. We analysed the reasons for failure.
Methods and Results: All patients (89 patients, 28 +/- 16 years old) referred for WPW ablation after a prior failure were studied. Reasons for the prior failure as well as for the acute success were analysed. The repeat procedure was successful in 81 (91%) patients. Multiple (2.7 +/- 0.9) or large accessory pathways (APs) were seen in 13 patients. For left lateral APs, inaccurate mapping and lack of transseptal access during the index procedure accounted for failure (n = 15). An irrigated-tip catheter was required for epicardial APs (n = 7). In addition, seven posteroseptal APs required bi-atrial and coronary sinus (CS) applications in order to succeed. For parahisian and midseptal APs, radiofrequency was cautiously titrated from 5 to 30 W, eliminating the AP in three patients. Cryoablation was used in seven patients (acute success in six but delayed recurrences in three of these). For patients with CS AP, irrigated ablation in the CS was crucial to deliver adequate power. For anteroseptal and right lateral APs, a successful outcome was achieved with long sheaths (n = 5) or a left subclavian approach (anteroseptal, n = 4).
Conclusion: Failure in WPW ablation may be due to a variety of reasons but catheter manipulation and inaccurate mapping remain the two major causes. Knowledge of the reasons for failure depending on the location of the WPW may facilitate a successful outcome.