Atrial fibrillation as a presenting symptom of Cardiac Sarcoid.

We submit an unusual presentation of spontaneous atrial fibrillation in a young fit active-duty U.S. military African-American male without evidence of structural heart disease. His atrial fibrillation was refractory to several ablation treatments over the course of 3 years. Subsequently he was diagnosed with extracardiac sarcoidosis and fluorodeoxyglucose-positron emission tomography (FDG-PET) scan identified bi-atrial hypermetabolic lesions, concerning for cardiac sarcoidosis. Given the low incidence of atrial fibrillation in patients < 45 years-of-age, this case report aims to underscore consideration of cardiac sarcoidosis as a subclinical contributor towards developing atrial fibrillation in the appropriate patient population. Broadly more investigations are needed to explore the role of cardiac sarcoidosis with atrial involvement and the likelihood of developing atrial arrhythmias.