Endocrine Abstracts

Amiodarone is a potent and among cardiologists still very popular anti-arrhythmic drug. This case report describes severe course of amiodarone-induced thyrotoxicosis (AIT) which is one of the most serious side effects of the treatment. The patient (J S born in 1950) was first hospitalised in June 2012 for atrial fibrillation with rapid ventricular response and tachycardia-induced cardiomyopathy with a decreased ejection fraction (EF). Thyroid hormones were normal at that time and electric cardioversion was successfully performed and following echocardiography showed improving EF. Attending cardiologist added to the medication amiodarone which was after <6 months discontinued for symptomatic corneal deposits. The second hospitalisation for the same reason was in September 2013. According to laboratory findings, ultrasonography and scintigraphy we diagnosed a destructive type of amiodarone-induced thyrotoxicosis more than half a year after the withdrawal of this drug! We started treatment with combined antithyroid medication at higher doses (including parenteral forms of administration) and corticosteroids. The atrial fibrillation was resistant to standard doses of β-blockers even in combination with digoxin. However, despite the normalisation of thyroid hormones the patient had to be after 33 days of treatment moved to ICU with a serious heart failure. After administration of levosimendan, diuretics and after an electric cardioverison was carried out, the clinical condition began to improve. We had decided for a total thyroidectomy and afterwards we started a substitution therapy with levothyroxine. Recurrence of atrial fibrillation in October 2014 was without any major concern quickly solved by pharmacological cardioversion with amiodarone. Nowadays, the amiodarone treatment was discontinued, the patient keeps sinus rhythm and a radiofrequency ablation is planned. This case report draws attention to the risk of developing a serious AIT even after a long time since discontinuation of administering amiodarone.