# Cardiac Tamponade as a Harbinger of Hypothyroidism

## TL;DR

A case of cardiac tamponade caused by undiagnosed hypothyroidism is presented, showing improvement with levothyroxine treatment.

## Contribution

This case highlights hypothyroidism as a rare but important cause of cardiac tamponade.

## Key findings

- The patient showed regression of pericardial effusion after levothyroxine treatment.
- No invasive pericardiocentesis was needed following thyroid hormone replacement.
- Severe hypothyroidism was identified as the underlying cause of cardiac tamponade.

## Abstract

Cardiac tamponade is a rare complication of hypothyroidism. In rarer cases, hypothyroidism may initially present with tamponade. Cardiac tamponade is an emergency condition that usually requires urgent intervention. However, guidelines for tamponade secondary to hypothyroidism are not optimal, and cases have been managed variably (ranging from levothyroxine alone to pericardiocentesis followed by thyroid hormone replacement) with diverse outcomes. Here, we report a case of a 42-year-old male with no medical history who presented with exertional dyspnea, lower leg swelling, facial puffiness, constipation, and weight gain. He had low blood pressure (80/60 mm Hg), normal heart rate with sinus rhythm, normal oxygen saturation, and was afebrile. Apart from a mildly raised creatinine, his test results were normal. An echocardiogram revealed features of tamponade. Further laboratory tests showed severe hypothyroidism. Following the initiation of levothyroxine, he demonstrated significant improvement. Coronary angiography revealed 95% stenosis in the mid-left anterior descending artery, treated with stenting. Serial echocardiograms showed regression of the pericardial effusion, stabilizing his condition without the need for invasive pericardiocentesis. This case highlights the importance of prompt diagnosis and management of hypothyroidism-related tamponade to prevent severe cardiac compromise. Hence, it may be necessary to consider hypothyroidism in the differential for patients with unexplained cardiac tamponade.