THU660 Pericardial Effusion Secondary To Uncontrolled Hypothyroidism

Disclosure: G.D. Cain: None. D. Goldsmith: None. E. Ruel: None. Introduction: Hypothyroidism is an endocrine disorder that can effect multiple organ systems. Pericardial effusion is a rare but significant complication of hypothyroidism. Early diagnosis and management of the pericardial effusion is important to prevent progression to cardiac tamponade and hemodynamic instability. We present a case of pericardial effusion in a 62-year-old female with hypothyroidism and medication non-compliance. Case Presentation: A 62-year-old female with past medical history of hypothyroidism and hypertension presented to the emergency department due to altered mental status. Patient's family reported that she had a progressive decline in her speech for more than a month, until she became completely aphasic on day of presentation, which prompted them to call EMS. Patient had diminished exercise capacity, dyspnea on exertion, bilateral pedal edema over the past couple of months. Family also reported that the patient had been depressed and negligent of her health following the passing of her husband three years ago. She was not taking her medications including levothyroxine. In the ED, patient was hypertensive, blood pressure was 190/100. CT head stroke protocol did not show stroke. Chest x-ray showed massive cardiac enlargement. 2D-Echo confirmed a large pericardial effusion without cardiac tamponade. Thyroid function panel showed high TSH of 77, free T4 was undetectable. Pericardial effusion was most likely secondary to hypothyroidism. Myxedema coma was suspected due to patient's progressive mental deterioration. Patient also had myxedema of bilateral lower extremities. IV levothyroxine and hydrocortisone were started with improvement in her symptoms. A pericardial window was performed by the thoracic surgeon for her large pericardial effusion. Patient had large amounts of drainage from JP pericardial drain for more than two weeks following the surgery. JP drain was removed after the amount of drainage decreased to less than 100 ml a day. Cultures and cytology for malignancy were sent and all came back negative. Patient’s symptoms improved with treatment and the she was discharged on levothyroxine 137 mcg daily. Patient was counseled to take her medication regularly. Follow-up appointments were arranged with primary care provider and endocrinology. Discussion: Pericardial effusion is a rare complication of hypothyroidism, more likely to be seen in severe, untreated hypothyroidism such as in this case. The mechanism of pericardial effusion in hypothyroidism is through increased capillary permeability in heart and decreased lymphatic drainage of albumin, resulting in accumulation of fluid in the pericardial space. The effusion develops over time and patients can have large amounts of volume at the time of diagnosis without tamponade physiology. Early diagnosis is important to avoid tamponade and hemodynamic instability. Presentation: Thursday, June 15, 2023