Comparison of radiofrequency versus cryothermy catheter ablation of septal accessory pathways.

Approximately 30% of all accessory pathways are located in the “septal” area. As these pathways are close to the atrioventricular node, there is an increased risk of right bundle branch block or inadvertent complete atrioventricular block during catheter ablation. Lesions created by radiofrequency (RF) energy inevitably involve some degree of tissue disruption and are irreversible. As cryothermy energy has the ability to reversibly show loss of function of tissue with cooling (“ice mapping”) at less negative temperatures, and progressive ice formation at the catheter tip causes adherence to the adjacent tissue, this ablation method potentially has advantages over RF for safe ablation of septal accessory pathways. In this retrospective study we compare transvenous RF with cryoablation in patients with septal accessory pathways.