Objective: The aim of this paper was to evaluate our results of radiofrequency catheter ablation (RFCA) of accessory pathways in patients with WPW syndrome.
Study patients: We studied 100 consecutive patients with WPW syndrome, 52 men and 48 women, mean age 37 +/- 15 years who underwent RFCA. All patients were symptomatic, with documented episodes of supraventricular tachycardia and 9% of patients had underlying cardiac disease.
Methods: The RFCA was performed without antiarrhythmic drugs in the same session of the electrophysiologic diagnosis. The location of the accessory pathway site was obtained by catheter mapping, based on the premature and/or the presence of Kent potentials. According to the location of the accessory pathway, the ablation catheter was introduced either by the femoral vein or artery with mapping of the tricuspid or mitral ring. In the first cases performed energy application was manually controlled and thereafter was temperature guided with an upper temperature limit of 70 degrees C. We considered primary success criteria the disappearance of the delta wave in the surface ECG and the absence of ventricular preexcitation under atrial pacing and after adenosine injection. Clinical success was defined as the absence of clinical recurrence of tachycardia during the follow-up period.
Results: The primary success rate achieved was 88%; 91% in the left free wall pathways, 100% in the right free wall and 85% in the septal pathways (antero-septal-83%; right postero-septal-76.5%; left postero-septal-92%). A second ablation procedure was performed in seven of the twelve patients with primary unsuccess obtaining a final success rate of 93% (left free wall-94.5%; septal pathways-91.6%). After a mean follow-up period of 8 +/- 7 months clinical recurrence occurred in 9% (eight patients), five of which are under anti-arrhythmic therapy (62.5%). Clinical success rate at the end of the follow-up period was 88%.
Conclusions: In our experience RFCA has shown to be safe and with a high success rate in patients with symptomatic pre-excitation. In this group of patients it was an effective therapy.