How to Use Imaging: Cardiac Sarcoidosis

Sarcoidosis is characterized by noncaseating granulomatous inflammation that involves the lungs or lymph nodes in 90% of cases. The prevalence of cardiac involvement in patients with sarcoidosis is thought to be between 5% and 25%. However, cardiac sarcoidosis can also present without extracardiac disease (known as clinically isolated cardiac sarcoidosis) or with previously unrecognized extracardiac disease. The principal manifestations of cardiac sarcoidosis are heart failure or left ventricular systolic dysfunction, high-grade atrioventricular nodal disease, or ventricular arrhythmia. Cardiovascular imaging plays a crucial role in making the diagnosis, partly due to the low yield of endomyocardial biopsy in cardiac sarcoidosis. Cardiovascular imaging is also used for risk stratification for ventricular arrhythmia, to identify patients who may benefit from immunosuppressive therapy, and for longitudinal follow-up on and off therapy. It can also be used to identify alternative diagnoses to cardiac sarcoidosis. This review will discuss how to use imaging in the diagnosis and management of patients with suspected or known cardiac sarcoidosis.