Endocrine Abstracts

Background: Thyrotoxicosis is a common disorder with a prevalence of 3% in females and 0.3% in males in iodine replete areas. The prevalence may be higher in areas of iodine deficiency. It is known to induce many cardiovascular effects. The most important complication of thyrotoxicosis is atrial fibrillation. We aimed to assess thyroid function in patients with atrial fibrillation and determine the frequency of thyrotoxicosis in this group.

Methods: We studied medical history of 107 patients with atrial fibrillation (34 males and 73 females, mean age 61.7±9.7 yr). The time interval was January 2004 to August 2005. Thyroid function was assess by serum TSH concentration (normal range 0.4–4.0) and data of ultrasonographic examination.

Results: 12 patients (11.2%) had thyrotoxicosis, TSH 0.1±0.12 mU/l. 13 patients (12.1%) had hypothyroidism, TSH 9.1±6.4 mU/l. 82 patients (76.7%) had euthyroidism (normal serum TSH values). Among 12 subjects of the first group were 8 (66.6%) with a nodular goiter.

Conclusion: The frequency of thyrotoxicosis in patients with atrial fibrillation was 11.2%. A nodular goiter was found in 66.6% subjects of this group. Serum level TSH level should be measured in all patients with atrial fibrillation.