Affiliation:
1. University Department of Medicine, Gardiner Institute, Western Infirmary, Glasgow
Abstract
In 50 of 96 patients, atrial fibrillation spontaneously reverted to sinus rhythm following treatment for thyrotoxicosis with radioiodine. Reversion to sinus rhythm did not occur, however, until the patient was euthyroid. Forty-seven per cent of the patients required more than one dose of 131I, 10 per cent receiving 4 doses, and 23 per cent took longer than one year before they were rendered permanently euthyroid. The incidence of hypothyroidism was 43 per cent. Thus radioiodine is not ideal treatment in patients with atrial fibrillation and thyrotoxicosis. We suggest that patients with thyrotoxicosis and atrial fibrillation be treated with antithyroid drugs in the first instance as these result in rapid control of the thyrotoxicosiss.