Unexpected Case of Cardiac Sarcoidosis in a Caucasian Male

Abstract

Cardiac sarcoidosis (CS) is an underappreciated diagnosis in healthy patients presenting with recurrent syncope. This may be particularly limited in patients who do not meet common epidemiology and manifestations of sarcoidosis, which are typically African American women and pulmonary, respectively. In our case, we have a previously healthy middle-aged Caucasian American male who presented with recurrent syncope for one week. Initial electrocardiogram showed a right bundle branch block with a normal P-R interval. A few days into admission, the patient suffered another episode of syncope precipitated by micturition, and repeat electrocardiogram revealed evolution to complete atrioventricular block, necessitating emergent placement of a temporary permanent pacemaker. Transthoracic echocardiogram showed preserved left ventricular ejection fraction of 55%-60% with normal heart valves. Chest computerized tomography revealed few pulmonary nodules, prompting a weak concern for infiltrative disease, e.g. sarcoidosis. To evaluate for possible cardiac structural abnormalities, a cardiac magnetic resonance imaging (MRI) study was considered but precluded by the presence of the MRI-incompatible temporary pacemaker. Despite low suspicion, a fluorodeoxyglucose-positron emission tomography was obtained which unexpectedly revealed hypermetabolic lymph nodes in the perihilar, supraclavicular, and mediastinal regions as well as an area along the interventricular septum, consistent with atrioventricular (AV) conduction pathways. As the patient met major criteria for CS per Japanese Circulation Society guidelines, a tentative diagnosis was made, and a Biotronik single-chamber implantable cardiac defibrillator was ultimately placed. On outpatient follow-up, endobronchial ultrasound-guided fine needle biopsy of perihilar lymph nodes revealed only rare epithelioid histiocytes, rare alveolar macrophages, and benign bronchial cells, consistent with benign nodal tissue. Further attempts for histological confirmation were aborted due to profound calcification and location of affected lymph nodes. A decision was made to defer further biopsy, including the gold standard of diagnosis endomyocardial biopsy, due to the risks outweighing the benefits. He initiated medical therapy with prednisone and mycophenolate, as well as trimethoprimsulfamethoxazole for Pneumocystis prophylaxis. Unlike general sarcoidosis, which is often considered a benign systemic disease, CS has high potential for severe complications including arrhythmia, systolic heart failure, and sudden cardiac death. In general, males carry a higher risk of CS than females, especially those who are of African American descent as they carry a higher incidence of nonspecific sarcoidosis. Expectations related to our patient's demographic initially delayed diagnostic workup for infiltrative disease, primarily focusing on intracranial, orthostatic, and infectious causes. This case serves to inform clinicians on early manifestations of CS, raise awareness of its incidence in unexpected dem...