Bradycardic Tamponade: The Myxedema Pitfall.

Document Type

Article

Publication Date

2-21-2026

Publication Title

Cureus

Abstract

Severe, untreated hypothyroidism can produce large, slowly accumulating pericardial effusions; progression to cardiac tamponade is uncommon and may present without tachycardia because of blunted sympathetic tone. We report a middle-aged woman with long-standing hypothyroidism who presented with dyspnea and hypotension but a low resting heart rate. Transthoracic echocardiography demonstrated a large circumferential effusion with right ventricular diastolic collapse and marked respiratory variation in tricuspid inflow, confirming tamponade physiology. She underwent urgent, echo-guided pericardiocentesis with the removal of a large volume of straw-colored fluid, followed by short-term catheter drainage and the initiation of thyroid hormone replacement. Cultures and cytology were negative, and the clinical course, with rapid hemodynamic recovery and resolution of the effusion, supported hypothyroidism as the most likely etiology after excluding infectious, malignant, and autoimmune causes. This case underscores a practical pitfall: bradycardia does not exclude tamponade in severe hypothyroidism. Diagnosis should be anchored in echocardiographic findings, and timely pericardial drainage coupled with endocrine management can achieve rapid stabilization and help prevent recurrence.

Volume

18

Issue

2

First Page

e104017

ISSN

2168-8184

PubMed ID

41878168

Link to Full Text

Share

COinS