SAT-508 Oh My Thyrotoxic Heart! An Uncommon Presentation of High Output Heart Failure

Abstract

High output heart failure is an extremely rare manifestation of thyrotoxicosis in patients without heart disease. Thyroid hormone has a potent metabolic, vascular, positive chronotropic and inotropic effects. Thyrotoxicosis is accompanied by a reduction in systemic vascular resistance and an obligatory increase in cardiac output to compensate high metabolic state. Most of the patients had completed or near completed recovery of cardiac function after treatment to euthyroid status, if cut in time.Case of 70 y/o female with past medical history of hypothyroidism, hypertension and chronic smoker, came to emergency room due to lightheadedness, weakness, shortness of breath, palpitations and acute bedridden for one week ago. Denied fever, nausea, vomiting or chest pain. On examination patient presented with 122bpm, 23rpm and normotensive. She was in acute respiratory distress requiring BiPAP. Lungs auscultation bilateral crackles, decrease sounds in the bases. Cardiac exam significant for tachycardia, lower extremity edema and JVD +. Laboratories significant for CKD stage 2, chronic anemia and hypoxemia. EKG no ST changes neither T depressions. CXR day #1 reported no cardiopulmonary disease. Basing in these she was admitted with Suspected Pulmonary Embolism. Well’s score was moderate risk; a Chest CTA and full anticoagulation were ordered. Later, venous duplex reported no DVT and D-dimer levels 1.65μg/ml. TSH levels significant decrease 0.0002mU/L and T4 1.800ng/dL. CXR Day#2 reported pulmonary edema and pleural effusion. ECHO2D moderate LVH and preserved systolic function. Patient referred her doctor recently increased thyroid medications from 50 to 100 mcg. Instead of presenting with pulmonary embolism, she has hyperthyroidal state causing cardiac failure. Levothyroxine, heparin and Chest CTA scan were cancelled. She was started in Atenolol and diuretics. Patient symptoms improved and was discharged home to be followed in the clinic. After one week, TSH levels were in 0.008mU/L and one month later in 3.032mU/L. She was started in Levothyroxine 50mcg, to maintain patient euthyroid state.This case illustrates that sometimes tachycardia and tachypnea are symptoms which frequently presents as baffling diagnostic problems. The association of thyrotoxicosis and cardiovascular morbidity is well established. Thyrotoxicosis most common cardiac manifestation is high output heart failure. Patients presenting with heart failure may have thyrotoxicosis as the underlying cause. Treatment of the thyrotoxicosis can restore normal heart function. Hyperthyroidal state may be take into consideration as a differential of tachycardia and tachypnea even if it’s not one of the common causes. Awareness of this presentation may help identify patients with reversible dilated cardiomyopathy and other complications.