(291) Myxedema Coma Associated With Torsades de Pointes Cardiac Arrest

Introduction: Hypothyroidism is a common condition that is easily treated with thyroid hormone replacement. Although severe hypothyroidism is rare, it can be life threatening. Here we present a rare case of myxedema coma presenting with torsades de pointes cardiac arrest.

Description: A 66 year old male with past medical history significant for COPD, recurrent DVT on Eliquis, retroperitoneal fibrosis, hypothyroidism, and peripheral vascular disease on Plavix. He was brought to the hospital after being unresponsive at home. In the emergency department, he was hemodynamically stable with altered mental status. He was found to have a severe respiratory acidosis with pcO2 >103. Due to his worsening mentation, he was intubated. Shortly after intubation, he was found to be pulseless and CPR was initiated. Rhythm was polymorphic ventricular tachycardia. IV magnesium was given and he was defibrillated twice with ROSC achieved. On workup for causes of cardiac arrest, patient was found to have severe hypothyroidism with TSH 46.8 and Free T4 0.12. He had not been taking levothyroxine for at least 6 months. No other significant electrolyte abnormalities were seen prior to arrest, and the admission EKG had a mildly prolonged corrected QT interval of 484 by Bazett calculation. He was not given any medications with significant QT prolonging potential. Head imaging was negative for stroke and had CT angiogram of the chest was negative for pulmonary embolism. Left heart catheterization was without significant coronary artery disease, and echocardiogram was unremarkable. IV levothyroxine was initiated, QT interval improved, and no further arrhythmias occurred. Myxedema coma was likely the cause of QT prolongation and subsequent torsades de pointes.

Discussion: Although easily treatable, hypothyroidism poses significant morbidity and mortality if unrecognized. Hypothyroidism is known to have various cardiac manifestations including bradycardia, pericardial effusion, and AV nodal blocks. QT prolongation has been reported in severe hypothyroidism and improves with levothyroxine treatment. Similar improvement was seen with this patient. Thyroid function testing should be considered in all patients for post cardiac arrest care as prompt treatment can prevent further arrhythmias.