Abstract
We present a case of a 45-year-old male with symptomatic supraventricular tachycardia. Electrophysiology study and 3-dimensional (3D) electroanatomic mapping showed a focal atrial tachycardia originating from a large left atrial diverticulum. Due to the unusual anatomy, 3D printing models were used to aid successful catheter ablation of the atrial tachycardia.