Thyroid storm in a patient with Wolff-Parkinson-White syndrome.

A 44-year-old woman with no medical history presented to the emergency department with a 2 h history of sudden onset chest pressure, palpitations, diaphoresis and shortness of breath. She reported a 90-pound unintentional weight loss, increased appetite, irritability, night sweats and palpitations for 2 months. Physical examination revealed a heart rate (HR) of 269 bpm and a blood pressure of 116/94 mm Hg. Her ECG revealed a wide-complex tachycardia with right bundle branch morphology and an HR of 265 bpm. Intravenous adenosine was administered with resolution of the arrhythmia and symptoms. Her subsequent ECG revealed sinus tachycardia with δ waves, which was consistent with Wolff-Parkinson-White (WPW) syndrome. Laboratory findings confirmed thyroid storm and treatment began with intravenous hydrocortisone, methimazole, metoprolol, amiodarone and iodine drops. Graves' disease was confirmed based on the presence of serum thyroid-stimulating hormone receptor antibody. The patient underwent successful WPW accessory tract ablation 6 weeks after initial presentation.