© 2004 by European Society of Cardiology
Radioiodine ablation of the thyroid to prevent recurrence of amiodarone-induced thyrotoxicosis in patients with resistant tachyarrhythmias
aCardiology Department, Hôpital Sud, Centre Hospitalier Universitaire, University Hospital 80054 Amiens Cedex, France; bNuclear Medicine Centre, University Hospital Amiens, France; cEndocrinology Department, University Hospital Amiens, France; dBiophysics and Nuclear Medicine Unit, Jean Godinot Institute Reims, France
Amiodarone-induced thyrotoxicosis (AIT) is a common complication of amiodarone therapy. Although permanent withdrawal of amiodarone is recommended due notably to the risk of worsening of tachyarrhythmias, some patients may require the reintroduction of amiodarone several months after normalizing their thyroid function. We, retrospectively, assessed the effects of 131I therapy to prevent recurrence of AIT in euthyroid patients requiring reintroduction of amiodarone.
SUBJECTS AND METHODS: Amiodarone was required in 10 cases of recurrent symptomatic paroxysmal atrial fibrillation (AF) and in 5 cases of ventricular tachycardia (VT) (M=12, F=3, mean age: 63±14 years). The underlying heart disease was dilated cardiomyopathy (n=4), ischaemic heart disease (n=4), hypertensive heart disease (n=2), arrhythmogenic right ventricular dysplasia (n=2) and valvulopathy (n=1). Two patients had idiopathic paroxysmal AF.
RESULTS: A mean 131I dose of 579±183 MBq was administered 34±37 months after the episode of AIT. Amiodarone was reintroduced in 14 of 15 patients after a mean interval of 103±261 d. Fourteen patients developed definite hypothyroidism necessitating L-thyroxine but we observed no late recurrence of AIT. After a mean follow-up of 22±16 months, tachyarrhythmias were controlled in 12 of 14 patients.
CONCLUSION: 131I therapy appears to be an effective and safe approach to prevent the recurrence of AIT in a patient requiring the reintroduction of amiodarone for tachyarrhythmias.
Key Words: amiodarone, thyrotoxicosis, iodine radioisotope, tachyarrhythmia
*Corresponding author. Tel.: +33-322-45-58-75/+33-614-27-33-09; fax: +33-322-45-56-61/+33-825-17-46-19. E-mail address: hermida.jean-sylvain{at}chu-amiens.fr (J.-S. Hermida).