RADIOFREQUENCY ABLATION OF RIGHT ACCESSOR Y PATHWAYS

Background: Accessory pathways are muscular connections between auricl es and ventricles, present in different points of mitral and tricuspid annuluses. These pathways participate in 50% of paroxysmal supraventr icular tachycardias and the definitive cure of the arrhythmia is their ablation. Aim: To report our experience in patients with right access ory pathways. Patients and methods: Fifty consecutive patients treated between 1990 and 1996 are reported. Eight had a history of syncope, t wo had a diagnosis of Ebstein disease and 36 had a pre-excitation in t he surface electrocardiogram. Results: Fifty four accessory pathways w ere identified, since four patients had two pathways. Twenty four path ways were posteroseptal, 15 were lateral, 9 were medioseptal and 6 wer e anteroseptal. One patient had also a nodal reentry tachycardia. Fulg uration was attempted in 39 patients and it was finally successful in 32. Three patients required more than one session. There were six rela pses and all were successfully ablated in a second session. A mean of 28 radiofrequency applications were done (range 1-76), mean laboratory time was 6 hours and mean radioscopy time was 70 min. Four patients h ad a transient atrioventricular conduction blockade. Conclusions: Radi ofrequency ablation of accessory pathways has a high degree of success and a low rate of complications.