We report a pediatric patient with persistent left superior vena cava and a D-transposition of great arteries, which is an uncommon relation. It is crucial to know the anatomy of the persistent left superior vena cava and the dilated coronary sinus to plan the mapping techniques in cases of posterior accessory pathways.
Keywords: Wolff-Parkinson-White; coronary sinus; pediatric accessory pathway; persistent left superior vena cava; radiofrequency ablation.