Lethal arrhythmia and corticosteroid insufficiency.

We describe a case of isolated adrenocorticotropic hormone deficiency that showed ventricular fibrillation associated with QT prolongation. A 72-year-old man was admitted because of consciousness disorder caused by severe hypoglycemia. On the second hospital day, QT intervals were unexpectedly prolonged and ventricular fibrillation occurred. Electrical defibrillation was performed and restored hemodynamically stable condition without neurologic deficits. He was diagnosed with endocrine tests as having isolated adrenocorticotropic hormone deficiency. QT prolongation was improved after hydrocortisone replacement therapy. We considered the QT prolongation was caused by corticosteroid insufficiency. We should be aware that corticosteroid insufficiency may provoke QT prolongation responsible for sudden cardiac death.