Dobutamine-Masked Myxedema Coma Mimicking Acute Coronary Syndrome: A Rare Case of Cardiogenic Shock and Diagnostic Challenges

Document Type

Abstract

Publication Date

9-1-2025

Abstract

Description: Case Report: A 55-year-old woman with hypothyroidism presented with a 1-week history of dyspnea and limb swelling. Initial evaluation revealed bradycardia with first-degree atrioventricular block, elevated troponins, and brain natriuretic peptide. She was treated for non-ST-elevation myocardial infarction with heparin while continuing levothyroxine. Later, she developed cardiogenic shock. Random cortisol levels were normal. Dobutamine drip was started, and cardiac catheterization revealed no coronary artery disease. Laboratory tests showed a thyroid-stimulating hormone (TSH) of 40.6 mIU/mL (0.465-4.680) and a free T4 of 0.4 ng/dL (0.8-1.9). Echocardiography demonstrated global hypokinesis with an ejection fraction of 30%. Myxedema coma was identified as the underlying cause, with TSH levels inappropriately elevated in relation to the severity of hypothyroidism. Discussion: The interpretation of thyroid function tests in critical illness is challenging due to the effects of drugs like dobutamine. Although dopamine’s effect on TSH suppression is well established, the impact of dobutamine, commonly used in critical care, is less well understood. Dobutamine suppresses TSH secretion by acting on thyrotroph cells, which can mask severe hypothyroidism and delay diagnosis, as seen in this case. Conclusion: Myxedema coma can precipitate severe cardiac dysfunction, including cardiogenic shock, and may mimic acute coronary syndromes. Dobutamine therapy, while supportive, can suppress TSH levels, potentially obscuring the diagnosis of hypothyroidism. Early recognition and appropriate management of myxedema coma are crucial to improving outcomes.

Publication Title

Endocrine Practice

Volume

31

Issue

9 Supplement

First Page

S164

Last Page

S164

Comments

AACE Annual Meeting 2025 held 2025-05-15 to 2025-05-17 in Orlando, FL, USA

Link to Full Text

Open Access

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