[Radiofrequency ablation of accessory atrioventricular pathways]

Abstract

Since its introduction at the beginning of the 1980s, radiofrequency ablation of accessory atrioventricular pathways has become method because of its excellent results and the indications have increased to cases in which only symptomatic improvement is the objective. These advances have been made possible by technical innovations to the generators of the radiofrequency current and, above all, to the ablation catheters which enable mapping nearly all the perimeter of the atrioventricular rings and reach all the accessory pathways irrespective of their site. The approach depends on the localisation of the accessory pathway but the criteria of mapping are the same: detection of a specific accessory pathway potential, precession or concordance (depending on the topography) of the initial peak of the endocavitary ventriculogramme and the onset of the delta wave on the surface ECG, QS morphology of the ventriculogramme on monopolar recording, shortest VA' interval in orthodromic reciprocating tachycardia for latent kent bundles. In specialised centres, the global success rate is 90 to 98% but certain sites, especially the right lateral pathways, are more difficult to attain. The complication rate is about 4% but it tends to decrease with the experience of the operating teams and close monitoring of the patients. However, there persists an uncertainty concerning potentially arrhythmogenic effects of the lesions induced which justifies restricting the indications in young children.