Table 4. Heart Rhythm Society (HRS) consensus statement for diagnosis of cardiac sarcoidosis.

Histological diagnosis of cardiac sarcoidosis

Endomyocardial biopsy specimens with non-caseating epithelioid granulomas and no alternative cause identified

Clinical diagnosis of probable cardiac sarcoidosis

Histologic diagnosis of extracardiac sarcoidosis and one or more of the following is present while reasonable alternative cardiac causes other than CS have been excluded:

Corticosteroid or immunosuppressive therapy responsive cardiomyopathy or heart block

Unexplained reduced LVEF (<40%)

Mobitz type two second degree heart block or third degree heart block

Depressed left ventricular ejection fraction <50%

Patchy uptake on cardiac FDG-PET in a pattern consistent with CS

Late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging in a pattern consistent with CS

Positive gallium uptake in a pattern consistent with CS

Adapted from (7). “Probable Cardiac Sarcoidosis” defined as >50% likelihood. LVEF, left ventricular ejection fraction; FDG PET, fluorodeoxyglucose positron emission tomography; CS, cardiac sarcoidosis.