The Utility of Unipolar Electrogram Recording for Catheter Ablation of Accessory Pathways During Atrial Fibrillation

INTRODUCTION: Atrial fibrillation, a commonly occurring rhythm in patients with manifest accessory pathways, may prevent the usual mapping criteria for successful catheter ablation from being obtained. Unipolar electrogram recordings may be of value in this situation. METHODS: Unipolar recordings were obtained during atrial fibrillation in one patient with a manifest left-sided accessory pathway, and another patient with a septal accessory pathway with Mahaim-like properties. The timing of the intrinsic deflection, and the presence of a QS complex, were utilized as criteria to define the successful ablation site. RESULTS: Successful ablation of the accessory pathways was achieved during atrial fibrillation. CONCLUSIONS: The use of unipolar recordings can aid successful catheter ablation of the accessory pathways during atrial fibrillation, giving added information to the bipolar electrograms.