Epicardial Ablation of Persistent Junctional Reciprocating Tachycardia in an Infant With Tachycardia-Induced Cardiomyopathy

A 3-month-old infant who developed persistent junctional reciprocating tachycardia (PJRT)–induced cardiomyopathy that was successfully treated with radiofrequency ablation. To our knowledge this is the youngest reported patient with a successful epicardial lesion placed in a diverticulum off the coronary sinus and also the first report of a PJRT connection located at an epicardial site distinct from the mitral and tricuspid valve annulus. We use this case to highlight how low-power lesions in the coronary sinus in the youngest of patients can achieve results safely. (Level of Difficulty: Advanced.)