Sarcoidosis is a multisystem granulomatous disease of unknown etiology characterized by the presence of noncaseating granulomas in the involved organs. The prevalence is 10-40/100,000 persons in the United States and Europe with an increased prevalence of sarcoidosis in African-Americans compared to Caucasians with a ratio ranging from 10-17 : 1 [1
]. The Scandinavian population has a higher prevalence of sarcoidosis than other whites [2
Sarcoidosis is more prevalent in women than in men. Virtually any body tissue may be involved. Organs commonly involved with sarcoidosis include lymph nodes, skin, lung, central nervous system, and eye. Although many patients may not manifest symptoms at the time of diagnosis, some patients present with systemic symptoms such as fatigue, anorexia, weight loss, and fever. Many patients report dyspnea on exertion, retrosternal chest pain, and cough. In 20% to 50% of patients with more acute presentations, the constellation of erythema nodosum, bilateral hilar lymphadenopathy, and polyarthralgia (Lofgren’s syndrome) is seen. In the United States, more than half of patients present with chronic respiratory symptoms and few constitutional symptoms [2
Cardiac involvement in sarcoidosis occurs in 20-30% of patients in pathology series [3
]. Cardiac involvement in patients with sarcoidosis is being increasingly recognized and is associated with a poor prognosis. Silverman et al.
reviewed 84 autopsy cases of pulmonary sarcoidosis and found myocardial granulomas in 27% of patients [4
]. Cardiac involvement may be high as 58% in Japanese patients with sarcoidosis [5
] and may be responsible for as many as 85% of deaths of Japanese patients with sarcoidosis [6
]. Despite these findings, only 5% of patients with sarcoidosis have clinical manifestations of cardiac disease, and only 40-50% of patients with cardiac sarcoidosis at autopsy have the correct diagnosis made during their lifetime.
The etiology of cardiac sarcoidosis remains unknown. Environmental, occupational, and infectious causes have been hypothesized. These agents may act as immunologic triggers in genetically predisposed individuals. A multicenter case controlled study did not discover a single predominant cause of sarcoidosis, but identified several exposures that were linked to sarcoidosis risk including agricultural employment and exposure to insecticides or microbial bioaerosols [8
]. A number of infectious organisms, including Mycobacteria
, and Herpes virus
have been implicated as possible etiologies of sarcoidosis [9
]. A provocative pilot study reported the empiric use of anti-fungal agents with corticosteroids for 3-6 months in 18 patients resulted in improvement of clinical symptoms, chest X-ray infiltration, and pulmonary function [10
]. The role of infectious organisms in the etiology of sarcoidosis remains to be clarified. Myocardial sarcoidosis affects young and middle-aged patients without sex predilection. Myocardial involvement may occur in 25% of patients with sarcoidosis in the United States, and may account for as many as 13-25% of deaths from sarcoidosis.