Ebstein's anomaly.

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.33 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 Ebstein'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 malformation 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