Abstract
The authors present a case of a 54-year-old male patient with a history of shortness of breath and orthopnea. The echocardiogram showed an ejection fraction (EF) of 35%-40%. Diagnosis of hyperthyroidism was missed initially although the patient had bilateral exophthalmos and thyroid function tests suggesting it. Medical treatment of the hyperthyroid state reversed the cardiomyopathy within 6 months of treatment. Repeated echocardiograms after hyperthyroidism treatment showed a normalized EF.