Reappraisal of radiofrequency ablation of multiple accessory pathways

Complete electrophysiologic study and radiofrequency ablation were performed in 145 consecutive patients with Wolff-Parkinson-White syndrome. Presence of multiple accessory atrioventricular pathways was documented in 20 patients (13.8%); 17 had two, two had three, and one had four accessory pathways. Location of accessory pathways was posteroseptal in 18, left free wall in 15, right free wall in nine, and right midseptal in two. Of the 44 pathways, 36 were found during baseline electrophysiologic study and eight were found after successful ablation of the initially attempted pathways. After delivery 20 +/- 23 pulses (per patient) of radiofrequency energy (37 +/- 6 W, 70 +/- 30 seconds), 43 accessory pathways were ablated successfully without complications. Duration of the procedure (4.5 +/- 1.7 vs 3.7 +/- 1.6 hours, p < 0.05) and radiation exposure time (53 +/- 30 vs 38 +/- 18 minutes, p < 0.05) were longer in patients with multiple pathways, whereas the success rate (95% vs 95%, p > 0.05) and incidence of recurrent conduction (11% vs 11%, p > 0.05) were similar in patients with single or multiple accessory pathways. These findings confirmed that multiple accessory pathways were common in patients with Wolff-Parkinson-White syndrome, and these pathways could be ablated successfully by radiofrequency energy with a success rate comparable to that of a single accessory pathway.