[Atrial fibrillation and thyroid gland].

Many diseases can lead to atrial fibrillation and one of these is thyroid disfunction. The prevalence of atrial fibrillation does not differ between subclinical and overt hyperthyroidism. Hypothyroidism also can be associated to atrial fibrillation. Low-T3 syndrome is considered a risk factor in cardiac patients. In 100 patients affected by atrial fibrillation we studied the thyroid function and performed ultrasound examination of the thyroid gland. 30 patients had a low-T3 syndrome, 66 (38 > or =10 mm) patients had thyroid nodules, while just 10 patients had an abnormal thyroid function. So, in patients affected by atrial fibrillation, we suggest to study the levels of thyroid hormones and, even if these are normal, to perform an ultrasound examination of the gland.