Cardiac Sarcoidosis: Oldies but Not Goodies

Cardiac involvement in sarcoidosis is being increasingly noted since it has been recognized in the early 20th century and is associated with poor prognosis. Cardiac sarcoidosis is rare but is potentially fatal with a wide spectrum of clinical manifestations ranging from an incidentally discovered, benign condition to fatal cardiomyopathy, arrhythmias, and even sudden cardiac death.1)2) Cardiac involvement may occur at any point during the course of sarcoidosis, may occur in the absence of pulmonary or systemic involvement, and may be a presenting feature.1-3) Arrhythmias or conduction defects are the most common cardiac manifestations reflecting granulomatous infiltration within the conduction system or ventricular walls and are the most common causes of death due to cardiac sarcoidosis; however, progressive heart failure due to massive granulomatous infiltration of the myocardium accounts for at least 25% of deaths.1)3)4) Sarcoidosis can involve any part of the heart, including myocardium, endocardium, and pericardium.3)4) The areas of involvement in descending order of frequency are the left ventricular free wall, ventricular septum, papillary muscles, right ventricle, and atria.3) Obliteration of the sinoatrial node, atrioventricular node, or the bundle of his may occur.4) Valvular dysfunction may result from localized involvement of the papillary muscles causing significant valvular insufficiency in rare cases.4)