Endomyocardial fibrosis

Abstract

Endomyocardial fibrosis (EMF) is an idiopathic disorder of the tropical and subtropical regions of the world. It is the commonest cause of restrictive cardiomyopathy and affects an estimated 10 million people worldwide mainly children and adolescents from Africa, South America, and Asia.The etiology and pathogenesis of EMF remain unknown, since none of the factors that have been postulated for its origin can fully explain the occurrence worldwide. EMF might be caused by one or several environmental factors acting upon genetically predisposed individuals. Attempts to relate the condition to infections, dietary factors, and toxic agents failed to unveil the exact etiology and pathogenesis.The pathological hallmark of EMF is the deposition of a thick layer of fibrous tissue underneath the endocardium, which interferes with the diastolic and systolic function of one or both ventricles, and thickening and fibrosis of the components of the atrioventricular valves causing valve malfunction. Mild tissue inflammation, predominant in the interface between the endocardium and the myocardium, is a common feature.To date, there are no specific drugs to treat EMF. Endocardial decortication and atrioventricular valve repair/replacement seems to be beneficial in a subset of patients, but surgery is associated with high morbidity and mortality. Surgery is technically and financially very demanding and has been performed in only few centers treating a small number of patients, which leads to slow improvement in knowledge about the condition. The rate of recurrence after surgery is controversial. The overall prognosis is poor.EMF is probably the most neglected disease in cardiovascular medicine. Despite constituting a big burden to the families and health systems in endemic areas, due to its preponderance in poor sectors of the society, few human and material resources are made available for research onto its mechanisms. However, there is need to fully understand the pathogenesis and pathophysiology of EMF in order to improve the management and outcome of the affected patients.