An Unusual Cause of Unstable Angina: Endomyocardial Fibrosis

Although rare globally, endomyocardial fibrosis (EMF) is the leading cause of restrictive cardiomyopathy in some tropical countries. However, its aetiology and pathogenesis remain unclear. Epidemiology data are limited but the highest prevalence has been reported in tropical regions, specifically sub-Saharan Africa. EMF is characterized by apical filling with fibrotic tissue in one or both ventricles, often associated with thrombus and calcification. Most often it extends to the posterior leaflet of the mitral valve, papillary muscle or chordae tendineae, causing atrioventricular valve dysfunction. Transthoracic echocardiography is the first-line modality for assessment, but magnetic resonance imaging has emerged as a more accurate tool for the tissue characterization of this disease.

Consider endomyocardial fibrosis in patients with restrictive cardiomyopathy and a tropical origin or eosinophilia.Cardiac magnetic resonance imaging is essential for non-invasive diagnosis and assessment of fibrosis, calcification, and ventricular involvement.Microvascular angina may be an unusual initial presentation of endomyocardial fibrosis.