THU601 Massive Pericardial Effusion As Sole Symptom For Uncontrolled Hypothyroidism.

Disclosure: D.A. Lopez: None. M. Caban: None. C. Camacho: None. Y. Fuentes: None. M. Sanchez: None. K. Velez: None. Hypothyroidism is a common endocrine disorder with worldwide prevalence resulting from deficiency of thyroid hormone that can affect multiple organs. It can be asymptomatic and subclinical or symptomatic with fatal complications. Hypothyroidism can present with symptoms such as fatigue, slow movement and slow speech, cold intolerance, constipation, weight gain, and bradycardia. Hypothyroidism can be the cause of pericardial effusion due to increase membrane permeability. Massive pericardial effusion or pericardial tamponade is rare. Pericardial effusion can also be caused by autoimmune conditions, infections, uremia, medications, iatrogenic, and trauma. This is a case of 68-year-old Hispanic female with past medical history of hypothyroidism that was admitted to the hospital due to large pericardial effusion. These findings were found incidentally by her primary care physician during a preoperative evaluation for cataract surgery. Chest X-ray showed massive enlargement of the cardiac silhouette. Echocardiogram was ordered presenting large circumferential pericardial effusion with moderate diastolic right atrial collapse reason why patient was sent to the hospital. Physical examination showed distant heart sounds but absent jugular venous distention. Vital signs were within normal limits. Beck's triad was absent. Electrocardiogram showed a sinus rhythm with low QRS voltage. Patient denied any recent procedure, trauma, myocardial infarction, malignancy, or fever. Complete blood count was without leukocytosis, normal hemoglobin levels and platelet count. Basic metabolic panel presented without electrolyte disturbances and preserved renal function. Evaluation for causes of pericardial effusion was made including autoimmune conditions. Results showed negative ANA, Rheumatoid factor, Anti-dsDNA antibody, Anti-Scl-70 antibody, anti-U1-ribonucleoprotein, anti-Ro, and anti-La. Inflammatory markers were within normal limits. TSH level were in 22.5μIU/mL (0.03-5.0μIU/mL) with undetectable Free T4 pointing towards uncontrolled hypothyroidism as the cause of her large pericardial effusion. Patient denied other symptoms of hypothyroidism. She agreed not being compliant with levothyroxine. Pericardiocentesis was done and 750ml of pericardial fluid was removed. A catheter was placed and 200ml of fluid was drained on the second day. Catheter was removed and Echocardiogram showed immediate resolution of the diastolic right atrial collapse. She was sent home with adequate medical therapy and intense education of hypothyroidism. As a take home message, this unique case presents the importance of being compliant to medical therapy since the initial presentation of uncontrolled hypothyroidism could be a fatal complication as pericardial effusion. This could’ve been prevented if compliance with medications was encourage since the beginning of this disorder. Presentation: Thursday, June 15, 2023