Pathophysiology and clinical management of cardiac sarcoidosis.

Cardiac sarcoidosis is a potentially life-threatening condition characterized by formation of granulomas in the heart, resulting in conduction disturbances, atrial and ventricular arrhythmias, and ventricular dysfunction. The presentation of cardiac sarcoidosis ranges from asymptomatic with an abnormal imaging scan, to palpitations, syncope, symptoms of congestive heart failure, and sudden cardiac death. Screening for cardiac sarcoidosis has not been standardized, but the presence of cardiac symptoms on medical history and physical examination, and an abnormal electrocardiogram (ECG), Holter monitoring, or echocardiogram has been shown to be highly sensitive for detecting cardiac sarcoidosis. A signal-averaged ECG might also have a role in screening for cardiac sarcoidosis in asymptomatic patients. Although endomyocardial biopsies are highly specific for the diagnosis of cardiac sarcoidosis, procedural yield is very low and appropriate findings on cardiac MRI or PET are, therefore, often used as diagnostic surrogates. Treatment for cardiac sarcoidosis usually involves immunosuppressive therapy, particularly corticosteroids. Additional therapy might be required, depending on the clinical presentation, including implantation of an internal defibrillator, antiarrhythmic agents, and catheter ablation.