208 Reappearance of the preexcitation syndrome after ablation; significance

Accessory pathway (AP) ablation is the treatment of choice of symptomatic patients (pts) with a Wolff-Parkinson-White (WPW) syndrome or pts with a malignant form at electrophysiological study (EPS). WPW can reappear after ablation. The purpose of the study was to look for the risk factors of AP reappearance and the clinical consequences.MethodsAP ablation was performed in 327 pts aged from 8 to 77 years (37±16), with a WPW. Ablation failed in 6 pts. In other pts, the anterograde and retrograde conduction disappeared after AP radiofrequency ablation. Reappearance of AP occurred in 48 pts from several hours to several years. Their data were studied.ResultsThere were no significant clinical differences between pts with and without reappearance of AF, concerning the age (33±16 years vs 36±16), the gender (male gender 28/48 vs 166/280), the reason of ablation (spontaneous malignant form: 10/48 vs 70/280; spontaneous AV reentrant tachycardia (AVRT): 29/48 vs 176/280, asymptomatic with electrophysiological signs of malignancy: 9/48 vs 38/280), the location of AP (left lateral AP: 21/48 vs 125/280, posteroseptal AP: 22/47 vs 119/280, anteroseptal: AP 5/47 vs 27/280). During the follow up, among 9 of 45 pts asymptomatic before ablation but with only inducible rapid AF at EPS, 2 pts became symptomatic and had inducible AVRT at the control. 29 of 202 pts with spontaneous AVRT presented recurrences of AVRT, except one and a 2nd procedure was required. Among 10 of 79 with syncope and signs of malignancy or spontaneous rapid AF, 2 pts have lost the signs of malignancy at 2nd EPS; 2 pts who presented only with rapid AF, had an AP with long refractory period but developed incessant AVRT's; 6 pts had still signs of malignancy, requiring a second procedure.ConclusionsThere was no significant clinical or electrophysiological cause that explains the reappearance of AP after ablation. The reappearance of conduction is generally associated with reappearance of all properties of AP associated with malignancy or AVRT, except in some cases. Pts without AVRT before ablation may become symptomatic and develop this AVRT after AP ablation