Two years before admission	Diagnosed with autoimmune hyperthyroidism. Received treatment with stand-alone thionamide (carbimazole) for two months before it was discontinued due to neutropenia.
Four weeks before admission	Signs and symptoms of hyperthyroidism (free thyroxine (T4): 79 pmol/L, free triiodothyronine T3: 47 pmol/L), prescription of thionamide and a non-selective beta-blocker.
Two days before admission	Thionamide was discontinued again due to neutropenia.
Day 0	Admitted to her local hospital with fever, tachycardia, neutropenia, tonsillitis, suspected sepsis and a diagnosis of thyroid storm.
Day 1-3	Treatment with beta-blocker, antibiotics, glucocorticoids and (commencing on day 3) iodine solution.
Day 4	Sudden circulatory collapse with pulseless electrical activity (PEA). Cardiopulmonary resuscitation (CPR) was started and return of spontaneous circulation (ROSC) was obtained after 4 minutes. Transferred to tertiary care university hospital. Echocardiography demonstrated severe biventricular cardiac failure (severely hypokinetic left ventricle with ejection fraction <20%). Inotropic support with dobutamine was ineffective. Recurrent cardiac arrests, with PEA. Established on V-A ECMO support. Iodine solution dosages were increased and levosimedan infusion was started.
Day 7	Complete recovery of myocardial function. V-A ECMO circuit was discontinued and she was extubated the next day
Day 12	Surgery with total thyroidectomy
Day 28	Discharged without cognitive sequelae and with normalized cardiac function. Close follow-up by endocrinologist