RADIOFREQUENCY CATHETER ABLATION OF ATRIOVENTRICULAR ACCESSORY PATHWAYS - EXPERIENCE IN 179 PATIENTS

Radiofrequency catheter ablation was used to treat 179 patients aged 5 to 79 (37 +/- 17) years. Six patients had multiple accessory pathways. The total number of accessory pathways was 188, 47 conducting only retrogradely; among them, 8 had retrograde decremental properties. The location of the accessory pathways was: 81 at the left lateral position; 13 left posterior; 15 left posteroseptal; 24 posteroseptal; 16 midseptal, 16 right posteroseptal; 17 anteroseptal and 6 right lateral. All patients were symptomatic and six had congenital heart disease. Initial success was achieved in 159 patients (88.8%). Ten out the 20 patients in whom ablation failed underwent a second attempt and success was obtained in all but 3 patients. Final success was accomplished in 166 patients (92.7%). There were 14 recurrences (7.8%) all successfully ablated during a second procedure. The mean procedure duration time was 80 +/- 60 minutes, the mean radiation exposure time was 31 +/- 26 minutes and the mean number of radiofrequency applications was 9 +/- 10. Three patients developed complete atrioventricular block during the procedure requiring permanent pacing, one patient had a perforation of a previously unknown congenital aneurysm of the aorta solved by surgery and one patient had a transient amaurosis after the procedure attributed to microembolization. Radiofrequency ablation of accessory pathways is a safe and effective treatment.