Episodes of Atrial Fibrillation and Atrial Vulnerability After Successful Radiofrequency Catheter Ablation in Patients with Wolff-Parkinson-White Syndrome

Unlabelled: Episodes of atrial fibrillation occur in patients with WPW syndrome but frequently disappear after successful radiofrequency ablation.

Aims: To analyze the incidence of atrial fibrillation before and after successful ablation and the presence of increased atrial vulnerability.

Methods And Results: Fifty-four of 183 WPW patients had at least one documented episode of atrial fibrillation before ablation. During a follow-up of 24 +/- 12 months 13/54 patients (24%) experienced atrial fibrillation. At baseline, the patients with atrial fibrillation were more often men (74%) vs 53%, P=0.007), were older (45 +/- 15 vs 34 +/- 16 years, P=0.0001), more often had pre-excitation during sinus rhythm (87% vs, 73%, P=0.04) and had increased atrial vulnerability (41%, vs 18%, P<0.001). Only patients with atrial fibrillation before, developed atrial fibrillation after ablation. The 13 (of 54) patients who relapsed were also older (53 +/- 13 vs 42 +/- 15 years, P= 0.03), had increased atrial vulnerability at baseline (77% vs 29%, P=0.002), and were more symptomatic, (13 +/- 21 vs 1 +/- 3 arrhythmia attacks/month, P=0001). No patient without atrial fibrillation before ablation developed atrial fibrillation after treatment.

Conclusions: The accessory pathway was important for the development of atrial fibrillation. Frequent tachycardias seem to promote an electrical remodelling and an increased atrial vulnerability to atrial fibrillation, whereas after successful ablation the majority of patients remain free of atrial fibrillation.