The relevance of looking for right bundle branch block in catheter ablation of Ebstein's anomaly.

INTRODUCTION: Ebstein's anomaly is the most commonly occurring congenital defect associated with the Wolff-Parkinson-White syndrome. In patients with Ebstein's anomaly and supraventricular tachycardia, the absence of right bundle branch block (RBBB) in sinus rhythm is a highly sensitive and specific indicator of the presence of an ipsilateral accessory AP.

CASE: We present an electrophysiology case of a patient with Ebstein's anomaly and 3 ipsilateral accessory pathways. After ablation was performed, RBBB was evident.

CONCLUSION: In patients with Ebstein's anomaly and supraventricular tachycardia, the absence of a RBBB pattern in the surface ECG after RFCA should raise suspicion for the presence of multiple accessory pathways.