Glossary for Adult Congenital Heart Disease, E—E

Ebstein anomaly

An anomaly of the tricuspid valve in which the basal attachments of both the septal and the posterior valve leaflets are displaced apically within the RV. Apical displacement of the septal tricuspid leaflet of >8mm/M2 is diagnostic (the extent of apical displacement should be indexed to body surface area). Abnormal structure of all three leaflets is seen, with the anterior leaflet typically large with abnormal attachments to the right ventricular wall. The pathologic and clinical spectrum is broad and includes not only valve abnormalities but also myocardial structural changes in both ventricles. Tricuspid regurgitation is common, tricuspid stenosis occurs occasionally, and right-to-left shunting through a patent foramen ovale or atrial septal defect is a regular but not invariable concomitant. Other congenital lesions are often associated, such as VSD, PS, and/or accessory conduction pathways.

Ehlers-Danlos syndrome (EDS)

A group of heritable disorders of connective tissue (specifically, abnormalities of collagen). Hyperextensibility of the joints and hyperelasticity and fragility of the skin are common to all forms; patients bruise easily.

• Ehlers-Danlos types I, II and III, which demonstrate autosomal dominant inheritance, are the commonest forms, each representing about 30% of cases. The cardiovascular abnormalities are generally mild, consisting of mitral and tricuspid valve prolapse. Dilatation of major arteries, including the aorta, may occur. Aortic rupture is seen rarely in type I, but not in types II and III.
• Ehlers-Danlos syndrome type IV is also autosomal dominant, but frequently appears de novo. This is the "arterial" form, presenting with aortic dilation and rupture of medium and large arteries spontaneously or after trauma. It is due to an abnormality of type III procollagen, and comprises about 10% of cases of Ehlers-Danlos syndrome.
• There are 6 other rare types of Ehlers-Danlos syndrome.

Eisenmenger syndrome

An extreme form of pulmonary vascular obstructive disease arising as a consequence of pre-existing systemic to pulmonary shunt, wherein pulmonary vascular resistance rises such that pulmonary pressures are at or near systemic levels and there is reversed (right to left) or bi-directional shunting at great vessel, ventricular, and/or atrial levels. See Heath-Edwards classification and pulmonary hypertension.

Ellis-van Creveld syndrome

An autosomal recessive syndrome in which common atrium, primum ASD and partial A-V septal defect are the most common cardiac lesions.

endocardial cushion defect

See atrio-ventricular septal defect. The term endocardial cushion defect has fallen into disuse because it implies an outdated concept of the morphogenesis of the atrio-ventricular septum.

erythrocytosis

Increase in red blood cell concentration secondary to chronic tissue hypoxia, as seen in cyanotic CHD and in chronic pulmonary disease. It results from a hypoxia-induced physiologic response resulting in increased erythropoeitin levels, and affects only the red cell line. It is also called secondary erythrocytosis. The term "polycythemia" is inaccurate in this context, since other blood cell lines are not affected. Erythrocytosis may cause hyperviscosity symptoms. See also polycythemia vera and hyperviscosity.

Eustachian valve

A remnant of the right valve of the sinus venosus guarding the entrance of the inferior vena cava to the right atrium.

extracardiac Fontan

See Fontan procedure.