Cardiomyopathy associated with Graves' disease.

Cardiovascular changes associated with Graves' disease are generally considered to be secondary to the increased levels of thyroid hormone. We describe a case of Graves' disease in a 25-year-old man, who developed cardiomyopathy with severe heart failure. Pathological examination of the myocardial biopsies showed fibroblast infiltration and degenerative changes. After the cardiomyopathy subsided the patient developed a goitre and signs of hyperthyroidism, followed by Graves' ophthalmopathy, which was treated successfully with a combination of high-dose corticosteroids and orbital radiotherapy. These findings suggested a common pathogenesis for the cardiomyopathy and ophthalmopathy, and prompted us to investigate the expression of TSH receptor (TSH-R) in human heart. TSH-R mRNA was identified in human heart using the reverse transcriptasepolymerase chain reaction (RT-PCR) and DNA sequencing. Taken together, these data suggest that autoimmunity against the TSH-R might contribute to both the cardiomyopathy and ophthalmopathy in similar cases of Graves' disease.