This patient presented with chest pain and breathlessness on a background of weight loss and lethargy. Further history revealed a sub-acute history of heat intolerance and fine tremor. There was a family history of over-active thyroid.

The main finding in this patient's blood tests was abnormal thyroid function: free T4 (45), elevated free T3 and thyroid receptor antibodies and fully suppressed TSH.

This biochemical and clinical scenario was consistent with thyroid storm.

There were a number of management steps this patient required in the emergency setting:

• control of heart rate: the patient was in uncontrolled AF and was loaded with digoxin and given thiazide diuretics and propranolol

• echocardiogram: severe left ventricular dysfunction, moderate mitral regurgitation, ejection fraction 10%

• treatment of hyperthyroid state: commenced on propylthiouricil and steroids

When the heart rate was better controlled, a repeat echo confirmed the above findings and the patient underwent DC cardioversion to good effect.

Case contributed by Dr Gilly Fleming