Endomyocardial fibrosis (EMF) is a restrictive cardiomyopathy characterized by abnormal fibrous endocardial thickening of either or both ventricles. Associated with high mortality. The origin of the disease is unknown, and cases occur almost exclusively in regions within 15 degrees of the Equator. In these regions, EMF is a common cause of heart failure, with most cases occurring in adolescents and young adults. In temperate climates, Loeffler disease (see endocarditis) is a nearly identical presentation. Signs and symptoms of EMF include atrioventricular valve regurgitation, enlarged ventricle(s), dyspnea, facial or limb edema, orthopnea, and fatigue. Comorbidities include ascites, pleural / pericardial effusions, and atrial fibrillation / arrhythmia.