Update on cardiac sarcoidosis.

Cardiac sarcoidosis is an inflammatory myocardial disease of unknown etiology. It is characterized by the deposition of non-caseating granulomas that may involve any part of the heart. Cardiac sarcoidosis is often under-diagnosed or recognized partly due to the heterogeneous clinical presentation of the disease. The three most frequent clinical manifestations of cardiac sarcoidosis are atrioventricular block, ventricular arrhythmias, and heart failure. A definitive diagnosis of cardiac sarcoidosis can be made with histology findings from an endomyocardial biopsy. However, the diagnosis in the majority of cases is based on findings from the clinical presentation and advanced imaging due to the low sensitivity of endomyocardial biopsy. The Heart Rhythm Society (HRS) 2014 expert consensus statement and the Japanese Ministry of Health and Welfare criteria are the two most commonly used diagnostic criteria sets. This review article summarizes the available evidence on cardiac sarcoidosis, focusing on the diagnostic criteria and stepwise approach to its management.