Localization and radiofrequency catheter ablation of accessory AV pathways in Wolff-Parkinson-White syndrome.

Abstract

Direct catheter recordings of accessory pathway activation were utilized to localize accessory atrioventricular (AV) pathways for radiofrequency catheter ablation in 187 patients with Wolff-ParkinsonWhite syndrome. Closely spaced bipolar catheter electrodes (1.5-2.5 mm center-to-center) were positioned perpendicular to the mitral anulus (orthogonal electrodes placed circumferentially around the catheter) and the tricuspid anulus (conventional ring electrodes), and recordings were obtained at low gain « 1 cm/mV). The small recording range of the close bipolar electrodes minimized the recording of distant atrial or ventricular potentials occurring simultaneously with accessory pathway activation and enabled differentiation of accessory pathway activation potentials from local atrial and ventricular potentials. For ablation, a special large tip electrode (7F, 4 mm long, 27 mrrr' surface area) was positioned against the mitral or tricuspid anulus at a site guided by direct recordings of accessory pathway activation. The large tip electrode was positioned either beneath or above the leaflet, and radiofrequency current (power approximately 30 watts) was delivered for approximately 45 seconds to the large tip electrode using a large skin lead for the return electrode .