Background: Ablation of right free wall accessory pathways (RFWAP) is sometimes difficult due to the catheter instability at the tricuspid valve annulus (TVA) and the lack of anatomic guidance such the coronary sinus for left AP`s.
Methods: For the last 4 years, we have been systematically using a duodecapolar (DD) mapping catheter (St Jude) in which the proximal 10 electrodes are in close contact with the TVA with the hope it will facilitate mapping and ablation of RFWAP located at the TVA.
Results: Eight consecutive pts (4 M, 4 F, aged 19-34 years), suffering from palpitations (suspected SVT) in the presence of manifest WPW (n=4 pts), LBBB-tachycardias mediated by a Mahaim fiber (n=3) as well as 1 asymptomatic WPW pt were included. Three pts had undergone prior ablation procedures. With the DD catheter deployed at the TVA, the AP location was rapidly identified: a) in pts with AVRT using the sites of earliest ventricular activation in sinus rhythm, or earliest atrial activation during AVRT or ventricular pacing (5/5 pts); b) in pts with atriofascicular Mahaim fiber by the recording of a "Mahaim potential" in sinus rhythm (2/3 pts). In all these 7 pts, AP`s were ablated after positioning the ablation catheter close to these areas. In 1 pt with Mahaim, the AP was ablated empirically. Successful ablation was achieved with 1 RF pulse (5 pts), 3 RF (2 pts) and 9 RF (1 pt). AP locations were: anterior (n=1), lateral (n=2), antero-lateral (n=1), postero-lateral (n=3), and posterior (n=1). One pt with AVRT required an additional procedure. All pts have remained free-symptoms with no AP recurrence after a mean follow-up of 19±18 months.
Conclusion: A DD catheter positioned at the TVA facilitates fast localization of RFWAP and guides their successful ablation.
