Arrhythmias in cardiac sarcoidosis: diagnosis and treatment.

PURPOSE OF REVIEW: Sarcoidosis is a granulomatous disease of unclear cause and variable presentation. Cardiac involvement can result in life-threatening conditions including heart block, ventricular tachycardia, sudden cardiac death, and heart failure. There is no consensus on the diagnosis and management of cardiac sarcoidosis and a practical update is needed to provide clinicians with guidance.

RECENT FINDINGS: Three recent studies have described cardiac manifestations as the first presentation of sarcoidosis. In one study, cardiac sarcoidosis was found to be the underlying cause in 19% of adults aged less than 55 years presenting with new onset unexplained atrioventricular block. Also, there are increasing reports of patients with isolated cardiac sarcoidosis (i.e., without sarcoid in other organs). Finally, advances in imaging have enhanced our ability to detect myocardial involvement and perhaps follow response to treatment.

SUMMARY: Cardiac sarcoidosis should be considered in patients aged less than 55 years presenting with unexplained atrioventricular block and in patients with idiopathic cardiomyopathy and sustained ventricular tachycardia. Much remains to be learned about the condition, including the role of steroids and devices in treatment, and the place of advanced imaging in following the response to treatment. Collaborative multicenter studies are required to answer these important clinical questions.