Cardiac involvement in sarcoidosis

Cardiac sarcoidosis is a challenging diagnostic entity. Manifestations range from an incidentally discovered, benign condition to fatal cardiomyopathy and arrhythmias. In this review, we discuss the salient clinical features, diagnostic evaluation, treatment, and prognosis of cardiac sarcoidosis. A definitive histologic diagnosis of myocardial sarcoidosis is difficult, and treatment may be necessary in some patients with suspected cardiac involvement even in the absence of histologic confirmation. Optimal strategies to diagnose cardiac involvement have not been clarified. Thallium(201) radionuclide scintigraphy has been most extensively studied; 2-D echocardiography is less sensitive, but may have a complementary role. Additional radionuclide techniques (e.g., gallium(67) or technetium(99)) may have a role in complex cases. Given the life-threatening nature of cardiac involvement, prompt and aggressive treatment with corticosteroids or immunosuppressive agents, or both, is warranted. Long-term, possibly lifelong, therapy may be required. Serious, recurrent tachyarrhythmias may require implantation of an automatic cardioverter-defibrillator. Recognizing cardiac sarcoidosis and selecting a sensible management strategy remain the major obstacles facing clinicians.