Abstract 16928: Amiodarone For Atrial Fibrillation In The Setting Of Cardiogenic Shock And Thyroid Storm

Case Presentation: A 29-year-old man with a history of hyperthyroidism presented to an outside hospital with altered mentation and palpitations in the setting of non-adherence to thyroid medications. He was found to be in atrial fibrillation with rapid ventricular response. Initial vital signs included a heart rate of 165 beats/min, respiratory rate of 43 breaths/min, blood pressure of 134/115 mmHg, and O2 saturation of 94% on 2L of oxygen. Point of care ultrasound showed an EF of 10% and a dilated IVC. Labs showed a creatinine of 0.7 mg/dL, total bilirubin of 3.9 mg/dL, ALT of 39 IU/L, AST of 62 IU/L, ALP of 181 IU/L, lactate of 7.6 mMol/L, TSH of < 0.01 uIU/mL, free T4 of > 5.00 ng/dL, and a T3 of > 30.00 pg/mL. He was treated with methimazole and then switched to propylthiouracil (PTU). Esmolol and diltiazem resulted in worsening cardiogenic shock and PEA arrest twice requiring VA ECMO cannulation. Upon transfer to our facility, he was started on potassium iodide (SSKI). He had electrical cardioversion twice with reversion back to atrial fibrillation. He was then started on amiodarone and digoxin. He remained in atrial fibrillation but achieved rate control with heart rates in the 100s. Discussion: Amiodarone is typically avoided in atrial fibrillation in the setting of thyrotoxicosis due to its high iodine content which can precipitate further thyroid hormone synthesis. However, in the setting of cardiogenic shock, treatment options are limited. We learned from our endocrinology colleagues that amiodarone can be beneficial when patients are treated with PTU and SSKI as amiodarone blocks the conversion of T4 to T3. Amiodarone should be started after PTU as PTU prevents thyroid hormone synthesis and blunts the effect of the iodine load of amiodarone. In conclusion, amiodarone can be considered earlier for the treatment of atrial fibrillation in the setting of thyrotoxicosis especially if treatment options are limited by cardiac dysfunction granted the patient has been started on PTU.