# Organ-Restricted Hypereosinophilic Syndrome: A Case of Recurrent Hypereosinophilic Myopericarditis

## TL;DR

A young man with asthma developed heart-related complications from a rare condition called hypereosinophilic syndrome, which was successfully treated with steroids.

## Contribution

This case highlights cardiac involvement as a rare initial presentation of hypereosinophilic syndrome.

## Key findings

- Hypereosinophilic syndrome can present with myopericarditis and cardiac tamponade.
- Corticosteroids and heart failure medications improved the patient's condition.
- EM should be considered in cases of acute heart failure with uncertain etiology.

## Abstract

Eosinophilic myocarditis (EM) is a rare inflammatory condition that is characterized by eosinophilic myocardial infiltration. We present a case of hypereosinophilic syndrome (HES) presenting as EM, complicated by cardiac tamponade.

A 22-year-old man with a history of asthma presented with hypotension and chest pain. Work-up revealed myopericarditis with tamponade, eosinophil-rich pericardial effusion, and infection with influenza A. Despite initial improvement, he had recurrent episodes with elevated troponin, eosinophilia, and reduced left ventricular ejection fraction. Extensive work-up excluded malignancy and revealed biopsy-confirmed EM suggestive of HES. He responded to corticosteroids and was managed with guideline-directed heart failure medications.

Cardiac involvement as the initial presentation of HES is uncommon and represents a major contributor to morbidity and mortality.

In patients presenting with acute heart failure and cardiac tamponade of uncertain etiology, a diagnostic work-up for EM should be initiated regardless of the presence of hypereosinophilia on the peripheral blood smear.