A female in her early 30s with a previous history of postpartum granulomatous hypophysitis presented with palpitations and a syncopal episode. She was haemodynamically unstable on arrival with a heart rate of 180 bpm and a blood pressure of 80/60 mm Hg. Electrocardiography revealed polymorphic ventricular tachycardia (VT), requiring immediate defibrillation. Her baseline ECG showed a markedly prolonged corrected QT (QTc) interval of 581 ms. Despite antiarrhythmic therapy, she experienced a VT storm, necessitating multiple defibrillations, and progressed to moderate left ventricular systolic dysfunction and cardiogenic shock. Laboratory investigations revealed profound central hypothyroidism with severely reduced triiodothyronine (T3) and thyroxine (T4) levels. Other common causes of QTc prolongation were excluded. Initiation of thyroid hormone replacement therapy with oral T3 and T4, along with oral steroids, led to complete resolution of arrhythmias and rapid recovery of ventricular function.
Sundaram et al. (2026) studied this question.