Background: Hyperthyroidism is one of the common causes of atrial fibrillation (AF), and AF is associated with increased morbidity and mortality due to thromboembolism. The sinus rhythm maintenance rate of hyperthyroidism-induced AF patients after conversion to sinus rhythm is excellent. The present study was undertaken to assess the efficacy and safety of bepridil, a multichannel blocker, in patients with hyperthyroidism-induced persistent AF.
Methods and results: Sixty-two patients with hyperthyroidism-induced persistent AF were treated with bepridil. Oral bepridil therapy resulted in conversion to sinus rhythm in 32 (51.6%) of the 62 patients. There were no significant differences in clinical characteristics between the responders and non-responders. At the observation period of an average of 23.9 months, the sinus rhythm maintenance rate was found to be 81.3%. Adverse effects consisted of abnormal QTc prolongation in 3 patients and sinus bradycardia in 10 patients. There was one death in which a causal association with bepridil could not be ruled out.
Conclusions: Bepridil is as beneficial treatment to convert AF for the patients with hyperthyroidism-induced persistent AF as it is for the patients with AF due to other causes. However, bepridil should be used with caution to avoid serious side effects.