Cardiovascular effects of thyroxine in combination with methimazole in premenopausal female Graves' disease patients: case-control study.

Aim: To evaluate cardiovascular consequences of combined treatment in Graves' disease patients with addition of thyroxine (LT4) to antithyroid drugs in doses sufficient to suppress serum thyrotropin (TSH) levels below normal.

Methods: Eleven premenopausal female patients who reached subnormal TSH levels (<0.3 microIU/mL) under the combined therapy were evaluated by equilibrium radionuclide ventriculography at rest, and during the peak stage of fixed moderate exercise workload (75W) initially at diagnosis and after at least 8 months of stable euthyroidism, as judged by peripheral free thyroxine and triiodothyronine.