(275) Pericardial Squeeze and Thyroid Freeze: Cardiac Tamponade as a Complication of Myxedema Coma

Introduction: If the severe risks of myxedema coma aren’t urgent enough to warrant immediate treatment, the rare complication of cardiac tamponade should be. Myxedema coma is a life-threatening emergency requiring prompt intervention, with a high mortality rate even with aggressive treatment. This report presents a critical case in which myxedema coma was complicated by pericardial tamponade.

Description: A 71-year-old female with a history of hypothyroidism was admitted to the hospital with altered mental status, urosepsis, and acute kidney injury. The following day, she was urgently transferred to the intensive care unit due to hypotension and deteriorating mental status, necessitating mechanical ventilation. Clinical examination revealed hypothermia, bradycardia, and the need for vasopressor support to maintain adequate blood pressure.
Diagnostic evaluation revealed a markedly elevated thyroid-stimulating hormone (TSH) level (>100 µIU/mL) and undetectable T4. The patient was promptly initiated on high-dose T3/T4 replacement therapy. Bedside ultrasound identified a significant pericardial effusion with a concern for cardiac tamponade.
Cardiology intervention involved emergency drainage of approximately 800 cc of pericardial fluid, resulting in restored cardiac function and decreased pressor requirements. The fluid analysis was non-specific.

Discussion: The diagnosis of myxedema coma can be difficult, often distracting the clinician with non-specific symptoms. In the United States, there are approximately 2.6 cases of myxedema coma per million persons annually.
Although rare, severe hypothyroidism can increase pericardial membrane permeability, leading to protein leakage into the pericardial space and subsequent fluid accumulation.
Given the widespread availability of ultrasound technology, prompt assessment of the pericardial space in patients with suspected myxedema coma, particularly those in shock, can be critical for diagnosing a concurrent life-threatening pathology ultimately improving patient outcome.