Clinical Features and Diagnosis of Cardiac Sarcoidosis

Abstract

Cardiac sarcoidosis (CS) is an unusual, but potentially harmful, manifestation of systemic sarcoidosis (SA), a chronic disease characterized by organ involvement from noncaseating and nonnecrotizing granulomas. Lungs and intrathoracic lymph nodes are usually the sites that are most frequently affected, but no organ is spared and CS can affect a variable portion of SA patients, up to 25% from post-mortem studies. The cardiovascular involvement is usually associated with a bad prognosis and is responsible for the major cause of death and complications, particularly in African American patients. Furthermore, the diagnosis is often complicated by the occurrence of non-specific clinical manifestations, which can mimic the effect of more common heart disorders, and imaging and biopsies are the most valid approach to avoid misdiagnosis. This narrative review summarizes the main clinical features of CS and imaging findings, particularly of CMR and 18-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG PET) that can give the best cost/benefit ratio in terms of the diagnostic approach. Imaging can be very useful in replacing the endomyocardial biopsy in selected cases, to avoid unnecessary, and potentially dangerous, invasive maneuvers.

Keywords: 18F-FDG PET; biopsy; cardiac sarcoidosis; imaging; magnetic resonance imaging.

Figure 1

The images show a case of typical Cardiac Sarcoidosis characterized by the presence of LGE of all basal segments of both ventricles (yellow arrows in c,d,f) with the predominantly transmural distribution involving more than one coronary territory and the right ventricular side of the interventricular septum (red arrow in c). Bright blood cine sequences show the thinning of the basal septum (yellow arrows in a,b). Coronal computed tomography (CT) scans show the typical perilymphatic distribution of micronodules with upper lobe predilection (yellow arrows in g) and hilar and mediastinal bilateral lymphadenopathy (yellow arrows in h). The 18F-fluorodeoxyglucose positron emission tomography (e) revealed an increased uptake in the septal and lateral left ventricle myocardial segments in a patient with systemic sarcoidosis.

Figure 2

T2-weighted (a) and Late Gadolinium Enhancement (LGE; b) images show a case of atypical presentation of the acute phase of Cardiac Sarcoidosis, characterized by the presence of edema (yellow arrow in a) and LGE (yellow arrow in b) of the inferolateral wall of the right ventricle with the transmural distribution.