Apathetic thyrotoxicosis.

A previously fit 37-year-old woman was admitted with acute left ventricular failure, atrial fibrillation and a left-sided thromboembolic stroke. Her ventricular rate progressively increased despite full digitalisation. She had a cardiac arrest and was successfully resuscitated. Investigations revealed evidence of hyperthyroidism and she was treated for thyrotoxic crisis. She has made a complete recovery from the hemiparesis and is now in sinus rhythm. She denied any symptoms of hyperthyroidism. This patient had apathetic thyroid crisis, which is exceedingly rare in the young.