The noncoronary cusp as a site for successful ablation of accessory pathways: electrogram characteristics in three cases.

Radiofrequency ablation is the treatment of choice to cure symptomatic patients with atrioventricular accessory pathways (APs). Septal APs are challenging because of the proximity of the normal conduction system. In some patients, despite aggressive lesion creation on the right anteroseptal region pathway, ablation is unsuccessful. We report 3 cases where the successful ablation site was in the noncoronary cusp of the aortic valve and discuss possible defining features of this variant of septal APs and an approach for successful ablation.