Thyrotoxicosis-induced cardiomyopathy treated with venoarterial extracorporeal membrane oxygenation

Abstract

A 37-year-old woman with no past medical history presented with longstanding untreated hyperthyroidism and consequentially developed thyrotoxicosis-induced cardiomyopathy. Upon admission, she was noted with a heart rate of 172 beats per minute and an EKG consistent with supraventricular tachycardia which was unresponsive to adenosine. Shortly after the initiation of a non-cardioselective beta-blocker for the treatment of persistent tachycardia, she developed profound cardiogenic shock refractory to vasopressors and inotropes. She was diagnosed with thyroid storm, which was ultimately attributed to Graves' Disease and controlled with propylthiouracil, potassium iodide drops, and hydrocortisone. Extracorporeal membrane oxygenation (ECMO) was successfully used as a temporizing measure while her thyroid hormone level normalized and cardiac function recovered. Patients with longstanding untreated hyperthyroidism may be dependent on the induced hyperadrenergic state to compensate for low-output cardiac failure, therefore it is important to exercise caution when initiating beta-adrenergic blockade. Given the expected disease time-course in cases of acute decompensation, ECMO remains a viable option for short-term mechanical circulatory support.

Keywords: Cardiomyopathy; Extracorporeal membrane oxygenation; Graves’ disease; Hyperthyroidism.