Isolated Cardiac Sarcoidosis Presenting as High-Degree Atrioventricular Block.

Isolated cardiac sarcoidosis is a rare phenomenon of systemic sarcoidosis, with presentation ranging from asymptomatic to sudden cardiac death. Controversy exists on diagnostic and therapeutic options, creating an ongoing challenge for clinicians in providing patient care. A 79-year-old male presented status post looposcopy and interval ureteral stent replacement with sinus bradycardia and high-degree atrioventricular block. A comprehensive examination was performed that conclusively ruled out common etiologies of atrioventricular block, including coronary artery disease, electrolyte abnormalities, and medications. This prompted an investigation using advanced cardiac imaging modalities that demonstrated cardiac sarcoidosis. Computed tomography of the chest was negative for lymphadenopathy or infiltrates indicative of pulmonary involvement. The lack of extracardiac manifestations, in combination with imaging findings, led to a probable diagnosis of isolated cardiac sarcoidosis. The patient underwent biventricular implantable cardioverter defibrillator placement and was started on oral corticosteroids.