Right ventricular endomyocardial fibrosis (2013 Grover Conference series)

Abstract

Endomyocardial fibrosis (EMF) is a restrictive cardiomyopathy of unknown origin, affecting predominantly the right side of the heart. Its highest prevalence is in poor regions of sub-Saharan Africa, where it is usually found in children and adolescents. In areas where it is endemic, EMF is a major cause of heart failure and premature death. EMF of the right ventricle has unique clinical, electrocardiographic, and echocardiographic signs. Several features of advanced disease are not fully understood, the most striking being the presence of severe ascites with little or no pedal edema. Echocardiography is the main diagnostic tool and supports management of the disease in most patients, as it allows assessment of the severity and extension of endocardial fibrosis, the quality of the right atrioventricular valve, and the presence of intracardiac thrombi. Pulmonary hypertension in the setting of right EMF is related to chronic thromboembolism, through the chronic thrombi present in the severely enlarged right atrium found in advanced disease. The management of right EMF is difficult. Treatment of symptomatic patients should be surgical. However, as the disease is usually detected in late stages, with severe and advanced lesions, surgery cannot be performed without a very high risk of death and complications. New surgical approaches addressing several components of the structural cardiac abnormalities have been attempted, with promising results. EMF remains one of the most neglected diseases worldwide, and research into its pathophysiological mechanisms will probably improve outcomes and alter the natural history of the disease. This requires improvement in the health systems in areas of endemicity as well as the design of international collaborative research projects.

Keywords: endomyocardial fibrosis; pulmonary hypertension; sub-Saharan Africa.

Figure 1

Echocardiographic features of bilateral endomyocardial fibrosis, with predominance of right-heart lesions. Notice the massive reduction of the dimension of the right ventricle, retraction of the leaflets of the tricuspid valve, and aneurysmal dilatation of the right atrium. A typical right apical notch and pericardial effusion confirm advanced disease. Mural thrombi and spontaneous contrast are seen in the right atrium.

Figure 2

Doppler image of pulmonary regurgitation that allows the estimation of pulmonary pressures in a patient with free tricuspid regurgitation.

Figure 3

Right atrial appendage tissue resected during surgery, showing several thrombi attached to the wall.

Figure 4

Image of endocardial resection, showing the removal of the fibrous plaque that releases the right ventricular myocardium.