Undiagnosed myocardial sarcoidosis presenting as life threatening cardiac dysrhythmia

Sarcoidosis is a systemic disorder of unknown aetiology characterised by its pathological hallmark of non-caseating granuloma. Definitive diagnosis requires compatible clinical and imaging features as well as pathogenic identification of non-caseating granulomas in at least one organ. The disease has a wide variety of clinical and radiological manifestations but is associated with low mortality. However, cardiac involvement which is clinically only identified in 5% significantly worsens prognosis due to complications such as congestive heart failure, ventricular tachyarrhythmia, pulmonary hypertension or conduction disturbance leading to sudden death. Cardiac involvement is implicated in 77-85% of deaths directly related to sarcoidosis. Autopsy series in sarcoidosis patients show cardiac involvement with sarcoidosis in up to 79% cases. This case details the clinical course of a 56-year-old female who had experienced refractory cardiac dysrhythmias for many years in the context of also having biopsy proven pulmonary sarcoidosis. She had failed multiple antiarrhythmics as well as pacemaker and implantable cardioverter defibrillator placement. It was not until she presented as a potentially fatal ventricular tachycardia that the possibility of cardiac involvement from her sarcoidosis was entertained as the aetiology of her cardiac problems. Confirmation of myocardial sarcoidosis with PET CT imaging and subsequent treatment with prednisone resulted in her clinical improvement.