Case Presentation: Patient is a 29 year old female with no significant past medical history who presented to our hospital with an unintentional 60 pound weight loss over 3 months and 4 days of palpitations, shortness of breath, leg swelling, and orthopnea. Physical exam revealed 4+ pitting edema, tachycardia (130 beats/minutes) and jugular venous distention to the jaw. Lab work revealed the patient was in thyroid storm with an undetectable TSH, free T4: 6.2, T3: 292, and a Burch-Wartofsky score of 60. She was started on appropriate medical therapy, however the following morning the patient went into PEA cardiac arrest. After successful resuscitation she was transferred to the ICU. Bedside ultrasound was consistent with biventricular failure. An intra-aortic balloon pump was placed, but MAPs remained in the 40s despite maximum inotropic and pressor support. Swan-Ganz catheter was placed and showed a severely depressed cardiac index which was consistent with cardiogenic shock. Her condition continued to deteriorate and it was decided to place the patient on Veno-Arterial Extracorporeal Membrane Oxygenation (VA ECMO). After a prolonged 2 week hospital course she was able to be decannulated and extubated with full mental recovery. Repeat echocardiogram showed improvement in left ventricular (LV) function. At 4 month follow up she continued to show signs of improved physical conditioning.
Discussion: Thyrotoxic cardiomyopathy is one of the most catastrophic complications of hyperthyroidism with mortality as high as 30%. The goals of care in thyrotoxic cardiomyopathy are the same as thyroid storm: to maintain adequate tissue perfusion and oxygenation and return the patient to a euthyroid state. This is achieved with multiple medications including beta-blockers, anti-thyroid medications, inorganic iodide, and corticosteroid therapy. However, medical management alone often requires hours to days to be effective, during which time adequate perfusion and oxygenation needs to be maintained. VA ECMO, also known as cardiac ECMO, can achieve this by drawing deoxygenated blood from the venous system, running it through an artificial lung and then returning oxygenated blood to the arterial system. This can be maintained for critically ill patients with cardiovascular collapse for days to weeks. As was the case with our patient, patients with thyrotoxic cardiomyopathy and in thyroid storm are at higher level of cardiovascular collapse. Therefore, early support with VA ECMO should be considered in these patients.
Conclusions: Thyrotoxic cardiomyopathy with refractory cardiogenic shock and circulatory collapse is often fatal. However, VA ECMO and antithyroid medications can help to avoid this outcome. As was the case with our patient, even with aggressive medical treatment additional cardiovascular support is often required. Therefore, aggressive circulatory support with VA ECMO should be considered in these patients and if unavailable they should be transferred to centers who offer ECMO for higher level of care and patient safety.