Ebstein's anomaly.

Four cases of Ebstein's anomaly are described, revealing that the clinical features permit diagnosis in the majority of instances and that cardiac catheterization affords precise confirmation of the diagnosis. The occurrence of this anomaly in acyanotic adults is pointed out. and the similarity to acquire(I valvular rheumatic heart disease is stressed. r 'HE congenital cardiac defect known as Ebstein's anomaly has been recognized as a pathologic entity for 90 years.1 The first 80 years of this period constituted a relatively dormant era characterized by sporadic descriptions of the lesion at postmortem examination and by intimation that clinical recognition of this anomaly was not possible.2 Knowledge regarding Ebstein's anomaly has accumulated rapidly following the introduction of cardiac catheterization. A rapidly expanding body of information has accumulated in the literature in the past 10 years that has totally dispelled the myth of the diagnostic impregnability of Ebstein's anomaly.3-3 This recent experience has permitted the establishment of a definitive pattern of diagnostic clinical features. These features, when applied in the younger age patients, should lead promptly to the recognition of this anomaly. The less well described occurrence of Eb-stein's anomaly is in adults without cyanosis. This type of patient with Ebstein's anomaly constitutes a more formidable diagnostic challenge than does the cyanotic child in view of the possible confusion with acquired cardiac lesions. A description of the congenital mal-formation first described by Ebstein in 1866 is considered to be pertinent at this time. Although the details in the individual case have varied somewhat, in general this malformation consists of an abnormality of the leaflets and origin of leaflets of the tricuspid valve. This consists of a fusion of the leaflets, particularly 210 the septal and posterior leaflets, into a mem-branous structure extending into the cavity of the right ventricle and separating the right ventricle into a proximal and distal chamber. The proximal portion, which consists of the sinus of the right ventricle, is continuous with the right atrium, while the distal portion, composed of the outflow tract of the right ven-tricle, functions as the right ventricle. The anterior leaflet of the valve is frequently normal ; however, the septal and posterior leaflets are deformed and may be completely fused with the endocardium of the ventricle and not attached to the annulus fibrosus. A defect in the atrial septum is almost invariably present and may consist of all anatomically patent foramen ovale or true …