Treatment of atrial fibrillation associated with hyperthyroidism by amiodarone and methimazole

We treated a 78-year-old patient with hyperthyroidism and atrial fibrillation with amiodarone 1200 mg/day for 3 days and methimazole 60 mg/day. Sinus rhythm was restored within 3 days and serum levels of triiodothyroxine returned to normal within 4 days. A transient increase in serum rT3 concentrations was observed. Amiodarone associated with methimazole was useful in the management of atrial fibrillation and hyperthyroidism in our patient.