Question special

In some cases of amiodarone-induced thyrotoxicosis, it can be difficult to distinguish between Type 1 and Type 2 at the time of diagnosis. Furthermore, some patients who are on long-term amiodarone for recurrent arrhythmias may not have any other suitable alternative to amiodarone and may not be amenable to ablation therapy.

How would you approach management for a patient who been recommenced on high dose amiodarone for management of recurrent cardiac arrhythmias (e.g. VT storm) who has previously had amiodarone-induced thyrotoxicosis (of which the aetiology is unclear)? How often would you monitor their thyroid function tests? How would you approach management if they developed thyrotoxicosis again, particularly if they are unable to discontinue amiodarone and if their cardiac function precludes them from a surgical thyroidectomy due to high perioperative risk?