Ebstein's anomaly

Ebstein anomaly is a congenital heart defect in which the opening of the tricuspid valve is displaced towards the apex of the right ventricle of the heart. The annulus of the valve is still in the normal position. The valve leaflets, however, are to a varying degree, attached to the walls and septum of the right ventricle. There is subsequent 'atrialization' of a portion of the morphologic right ventricle (which is then contiguous with the right atrium). This causes the right atrium to be large and the anatomic right ventricle to be small in size. There is an enlargement of the aorta which may cause an increased risk of abnormality in infants of women taking lithium during the first trimester of pregnancy (though some have questioned...