Cardiac sarcoidosis masquerading as ventricular tachycardia storm: a challenging diagnosis

A 67-year-old African-American woman with remote history of complete heart block (s/p pacemaker 3 years ago) and recent onset of ventricular tachycardia (VT) (s/p VT ablation and cardiac resynchronisation therapy defibrillator upgrade 3 months ago) presented to the hospital with VT storm. Workup showed newly reduced left ventricular ejection fraction with global hypokinesis (20%) and restrictive physiology. Positive technetium pyrophosphate scan was suspicious for TTR amyloid while serological workup revealed a monoclonal gammopathy. Cardiac MRI was contraindicated given remote brain aneurysm clip. Given clinical suspicion for cardiac sarcoidosis and divergent non-invasive workup, endomyocardial biopsy was performed which showed non-necrotising granulomas consistent with cardiac sarcoidosis. She was started on steroids with clinical improvement. Cardiac sarcoidosis is a challenging clinical diagnosis, particularly in patients without extracardiac manifestations. This case highlights the importance of a detailed and thorough workup of non-ischaemic cardiomyopathy and being cognizant of infiltrative disease as it can change patient management and outcomes.