Cardiac involvement in patients with sarcoidosis is being increasingly recognised and is associated with poor prognosis. Although environmental and genetic factors have been implicated in its pathogenesis, the aetiology of cardiac sarcoidosis remains obscure. Clinical manifestations include advanced heart block, arrhythmias, and congestive heart failure. To date, cardiac sarcoidosis has been extremely difficult to diagnose clinically because the clinical manifestations are non-specific, and the sensitivity and specificity of diagnostic modalities are limited. The optimal management of cardiac sarcoidosis has not been well defined. Although corticosteroids remain the mainstay of treatment, there is little evidence for the optimal initiation, dosage, or duration of therapy. This article will update the reader on the clinical manifestations and pathophysiology of cardiac sarcoidosis, with a special focus on recent diagnostic and therapeutic modalities.

HISTORICAL PERSPECTIVE

Although Jonathan Hutchinson described the first case of cutaneous sarcoid in 1869,^w1 the illness was named by Boeck, a Norwegian dermatologist, who in 1899 described nodular skin lesions of epithelioid cells. He thought that these cells resembled sarcoma cells; hence the designation “sarcoid”.^w2 It took an extra 60 years to achieve recognition that sarcoid can involve the heart. Bernstein, in 1929, was the first to recognise cardiac involvement in a patient with systemic sarcoidosis.^w3 In 1952 Longcope and Freiman were the first to describe myocardial involvement in 20% of 92 necropsied cases of sarcoidosis.^w4

EPIDEMIOLOGY

Sarcoidosis most commonly involves granuloma formation in the lungs. Other commonly involved organ systems include the lymph nodes, skin, eyes, heart, and the nervous, musculoskeletal, renal, and endocrine systems. The disease is more commonly seen in young and middle aged adults. In the USA, African Americans have a three- to fourfold greater risk for disease compared with whites. Estimates of the prevalence of sarcoidosis range from 10.9 per 100 000 population for whites to …