Location of accessory pathways and its radiofrequency ablation in Wolf-Parkinson-White syndrome

Abstract

Radiofrequency ablation (RFA) of accessory pathways (AP) is the first line therapy in symptomatic patients with preexcitation syndrome, resistant to medical therapy. To evaluate the influence of AP location on RFA effectiveness. The study compared RFA results of AP located on the left side, right side, and in septal area of the heart in the first 101 consecutive patients treated at Dedinje Cardiovascular Institute in Belgrade. There was no significant difference between the right-, left- and septal-AP in relation to primary success rates (66.7%, 84.3%, 73.7%, respectively, p = 0.285), recurrence rates (12.5%, 6.97%, 14.3%, p = 0.591), and final success rates (66%, 84.3%, 78.9%, p = 0.37). Maximally achieved interface temperature was lowest at right-sided AP (49.8 +/- 1.9 degrees C) as compared to the left (53.0 +/- 3.5 degrees C) or septal AP (52.9 +/- 3.0 degrees C) (p < 0.01). Fluoroscopy time did not differ significantly (p = 0.062), while total procedure time and the number of applied RF pulses was higher in the left-sided AP as compared to other two (104.6 +/- 44.9 for the left, 98.9 +/- 47.5 for the right and 80.7 +/- 39.8 minutes for the septal AP, p < 0.05; 11.0 +/- 8.8 pulses for the left, 6.5 +/- 3.8 for the right and 6.4 +/- 5.0 for septal AP, p < 0.01). Two major complications developed: one third-degree AV block after ablation of midseptal AP, and one pericardial effusion without tamponade, with spontaneous regression. The success rate of RFA of the right-, left- and septal-AP was similar. Heating of the tissue was weakest during RFA of the right-sided AP.