Incidence of hyperthyroidism among in-patients with atrial fibrillation.

Abstract

Background : The incidence of hyperthyroidism has been increasing in patients with atrial fibrillation. It is ranged from 1 - 32% in different populations.

Objective : To find the incidence of hyperthyroidism in-patients with atrial fibrillation at Prapokklao Hospital. Hence, we found out of the clinical clues for sending appropriate thyroid function test in patients with atrial fibrillation.

Design : Retrospective descriptive study.

Setting : Prapokklao Hospital, Chanthaburi Province.

Material and Methods : All hospitalized patients who were diagnosed with atrial fibrillation and had performed thyroid function tests in 2010 were recruited. The medical records were analyzed about the incidence of hyperthyroidism and the correlation between patient characteristics and the results of thyroid function test.

Results : The 130 in-patients with atrial fibrillation were reviewed. The incidence of hyperthyroidism was 16.2% (21 patients). Fifty fifth percent was female and the mean age was 69.9 ± 13.3. Newly diagnosed atrial fibrillation was 41.5%. The patients with hyperthyroidism were younger (58.5 yr vs. 72.2 yr; P = 0.009), had higher heart rates (123.1/min vs. 98.5/min; P = 0.047) and had more symptoms of atrial fibrillation e.g., palpitation (63.2% vs. 29.8%; P = 0.015) than AF patient with euthyoidism.

Conclusion : The incidence of hyperthyroidism among in-patients with atrial fibrillation in Prapokklao Hospital was significant, so thyroid function test should be done in all patients with atrial fibrillation. The patient who had symptomatic atrial fibrillation, rapid ventricular response and not elderly should be highly suspicious for hyperthyroidism.