Sarcoidosis is a multisystem inflammatory disease. It frequently manifests as noncaseating granulomas, predominantly in the lungs and intrathoracic lymph nodes. The presentation and sequelae of sarcoidosis vary significantly between individuals. Approximately 50% of patients present with pulmonary complaints ranging from dyspnea to cough or chest pain, 45% present with systemic complaints such as anorexia and fevers, and the remaining 5% are asymptomatic.1 The classic pulmonary, ocular, and dermatologic manifestations of sarcoidosis are the disease manifestations which commonly come to mind when thinking of this entity. However, up to 5% of patients with sarcoidosis can have cardiac manifestations, which can range from relatively benign incidental findings to life threatening depending on the location and extent of granulomatous inflammation.
The most common sequelae of cardiac sarcoidosis is complete heart block. Patients may initially develop first-degree heart block due to lesions in the atrioventricular node or bundle of His, but these can progress to complete heart block, which often manifests as episodes of syncope.2, 3 Histologic evaluation of the myocardium, which can be done via myocardial biopsy or seen on autopsy, demonstrates noncaseating granulomas.
Given the patient's presentation with multiple witnessed episodes of syncope, EKG findings of both right bundle branch and left anterior fascicular block, and histologic evaluation of the myocardium demonstrating noncaseating granulomas near the AV nodal tissue, complete heart block secondary to sarcoidosis, combined with the patient's severe preexisting atherosclerotic cardiovascular disease, are most likely responsible for his cause of death.
The second most common cardiac manifestation of sarcoidosis is ventricular arrhythmias. These can manifest as sustained or intermittent premature ventricular beats or as ventricular tachycardia. Granulomas within the myocardium become foci for abnormal automaticity. They can also disrupt ventricular activation and recovery, which results in re-entrant arrhythmias. In addition to conduction defects, cardiac sarcoidosis can also result in cardiomyopathy and congestive heart failure.
Sudden cardiac death, due to either conduction blocks or ventricular tachyarrhythmias, is a common cause of death in patients with cardiac sarcoidosis.4, 5 It is important to assess patients with known systemic sarcoidosis for EKG changes suggestive of arrhythmias or conduction abnormalities.
The current guidelines developed in 2006 for diagnosing cardiac sarcoidosis require either:
Interventions for cardiac sarcoidosis include aggressive control of inflammation to prevent further fibrosis in the myocardium. Corticosteroids have been used empirically to prevent further granulomatous inflammation of the myocardium, and are still used as the primary treatment for cardiac sarcoidosis. In addition to immunosuppression, intracardiac devices and pacemakers have been used to combat the potential for sudden death due to ventricular tachyarrhythmias or conduction block, as these account for more than half of the deaths in cardiac sarcoidosis.7
Although the prognosis for all patients with cardiac sarcoidosis is not well-defined, patients who have symptomatic cardiac manifestations of their disease in addition to pulmonary findings have increased morbidity and mortality and require aggressive treatment of their sarcoidosis.
Contributed by Michelle Stram, MD and Jeffrey Nine, MD