New-Onset Graves' Disease Presenting As Thyro-Pericarditis.

Acute perimyocarditis is commonly preceded by viral illness and presents with non-specific complaints that can be a manifestation of serious cardiac complications such as arrhythmias and heart failure. While pericarditis is a known complication of thyrotoxicosis, termed "thyrotoxic pericarditis," concomitant new-onset perimyocarditis and Graves' disease, termed "thyro-pericarditis," has been reported. We present a case of thyro-pericarditis as the initial presentation of undiagnosed and untreated Graves' disease co-occurring with recent Coxsackievirus A and B infection. A 27-year-old male with a family history of undifferentiated hyperthyroidism presented with acute pleuritic chest pain and shortness of breath. Laboratory testing showed elevated cardiac troponin I with ST elevations and PR depressions on initial ECG. Left heart catheterization was normal, but transthoracic echocardiogram showed right ventricular systolic dysfunction and enlargement. Cardiac MRI demonstrated diffuse pericardial enhancement suggesting pericarditis. Thyroid function testing and thyroid ultrasound suggested auto-immune thyrotoxicosis. Serology noted abnormal Coxsackievirus A and B IgG antibody titers, suggesting prior infection. The patient was treated with colchicine, ibuprofen, methimazole, and metoprolol, with resolution of symptoms. Thyro-pericarditis is a rare concomitant presentation of both Graves' disease and myopericarditis, and it remains unknown whether there is an increased risk of adverse cardiac outcomes.