Abstract
We discuss an adolescent with Marfan syndrome and a previous aortic valve-sparing root replacement who was found to have mitral annular disjunction on surveillance cardiac imaging in the setting of recurrent palpitations. Ambulatory heart rate monitoring incidentally captured a fatal ventricular arrhythmia, a well-recognized but underappreciated cause of sudden cardiac death in patients with Marfan syndrome. (Level of Difficulty: Advanced.).