J Korean Soc Endocrinol.  1995 Mar;10(1):52-57.

Atrial Fibrillation in Patients with Hyperthyroidism

• Lee JY
• Song CH
• Yu BS
• Chung CH
• Chung YS
• Kim HM

Abstract

Hyperthyroidism is a well known cause of atrial fibrillation. It is also known that control of hyperthyroidism can usually curb thyrotoxic atrial fibrillation and restore sinus rhythm. In this study, 282 patients with hyperthyroidism were investigated to quantify the incidence of atrial fibrillation, and to identify the vulnerable groups. In addition, we compared two groups of subjects with atrial fibrillation-one group with hyperthyroidism and the other group without - to study their reversion rate to sinus rhythm. Lastly, we investigated the factors affecting reversion to sinus rhythm in patients with thyrotoxic atrial fibrillation.The results were follows;1) Among 282 patients with hyperthyroidism, 35 cases(12.4%) had atrial fibrillation. Atrial fibrillations were more prevalent among male patient(19.4%) and elderly patients(42.9%) than female patients(10.0%) and young patients(10.0%).2) Reversion to normal sinus rhythm in patients with thyrotoxic atrial fibrillation(39.3%) was significantly higher than that in patients without hyperthyroidism(17.4%, p<0.001).3) Reversion to normal sinus rhythm was achieved within 28 weeks from the beginnig of antithyroid treatment in patients with thyrotoxic atrial fibrillation. Although there were no significant differences in mean age, sex ratio, and initial and follow-up thyroid hormone levels between the reversion group and non-reversion group, associated heart diseases were more prevalent in the latter group(18.2% vs. 47.1%).It can be concluded that thyrotoxic atrial fibrillations were more common in male patient and elderly patient groups, and could be frequently reverted to normal sinus rhythm by antithyroid treatment. We also suggest that the duration of artrial fibrillation(from intial onset of the condition), and associated heart diseases, may be important predictive factors for the reversion of atrial fibrillation in patients with hyperthyroidism.

MeSH Terms

Aged
Atrial Fibrillation*
Female
Follow-Up Studies
Heart Diseases
Humans
Hyperthyroidism*
Incidence
Male
Sex Ratio
Thyroid Gland