PET-Driven, Voltage-Guided Atrial Endomyocardial Biopsy Clinches the Diagnosis of Cardiac Sarcoidosis

Endomyocardial biopsy (EMB) is used in diagnosing infiltrative and other suspected cardiomyopathies. We present a case in which positron emission tomography– and electroanatomic mapping-guided EMB of the atrial septum confirmed the diagnosis of cardiac sarcoidosis in a patient with negative findings on ventricular and lymph node biopsy. (Level of Difficulty: Advanced.)