The complex post-surgical anatomy after the Senning procedure presents several challenges for catheter ablation. Transbaffle approach allows access to the pulmonary venous atrium and better catheter manipulation. However, this modified transseptal puncture can be challenging to perform. The authors present the case of a 29-year-old woman who underwent a Senning procedure for dextro-transposition of the great arteries. The patient had recurrent episodes of atrial flutter despite adequate antiarrhythmic therapy and was referred for catheter ablation. […]