Eosinophilic myocarditis: two case reports and review of the literature

Abstract

Background: Eosinophilic myocarditis is a rare and often under-diagnosed subtype of myocarditis with only around 30 cases published in the medical literature. In this article we present two patients with eosinophilic myocarditis with the aim to demonstrate the often elusive nature of the disease and present the current scientific literature on this topic.

Case presentation: A 76 years old Caucasian gentleman and a 36 years old Aboriginal gentleman both presenting with heart failure symptoms were eventually diagnosed with eosinophilic myocarditis after extensive evaluation. Their presentation, assessment, and medical management is explored in this article.

Conclusions: Eosinophilic myocarditis remains a rare and likely under-diagnosed subtype of myocarditis. The key features of this disease include myocardial injury in the setting of non-contributory coronary artery disease. Endomyocardial biopsy remains the definitive gold standard for diagnosis of noninfectious eosinophilic myocarditis. Non-invasive cardiac imaging in the setting of peripheral eosinophilia can be strongly suggestive of eosinophilic myocarditis with potential for earlier diagnosis. Failure to diagnose eosinophilic myocarditis and the delay of therapy may lead to irreversible myocardial injury. Therapies for this disease have yet to be validated in large prospective studies.

Figure 1

Magnetic resonance imaging with arrow depicting circumferential subendocardial delayed enhancement on the short axis view.

Figure 2

Magnetic resonance imaging with arrow depicting subendocardial delayed enhancement in the 4 chamber axial view.

Figure 3

Endomyocardial biopsy of a patient with eosinophilic myocarditis (infiltrating eosinophils depicted by arrows).