MRCP2-1286

A 36-year-old patient arrives at the emergency department via ambulance. Despite recently moving locally, she has not yet registered with a GP and has experienced a lapse in her supply of carbimazole for hyperthyroidism, which was diagnosed three months ago. She is currently in a very unwell state, reporting palpitations. Upon examination, she displays a raised JVP, bilateral crepitations upon auscultation, severe peripheral edema, and has become extremely breathless. Her temperature is 40.1 degrees C. Oxygen is administered. An ECG reveals a heart rate of 170 bpm in AF, while a chest X-ray shows pulmonary edema. What is the most appropriate immediate course of action?