Echocardiography in Ebstein's anomaly

In this thesis the value of echocardiography is evaluated for the diagnosis of Ebstein's anomaly of the tricuspid valve. This congenital heart defect, first described in 1866 by Wilhelm Ebstein, is characterized by an apical displacement of the septal and inferior tricuspid valve leaflets and by dysplasia of the tricuspid valve apparatus. Since the publication of Ebstein, this congenital heart defect had been recognized and documented several times but only on the basis of postmortem studies. T ourniaire and coworkers ( 1949) were the first to diagnose Ebstein 's anomaly in the living patient. Ultrasound techniques, introduced in the early seventies, appear to be a major step forward in establishing the diagnosis non-invasively. This thesis describes the value of both M-mode and two-dimensional echocardiography for the diagnosis of Ebstein's anomaly. The study is restricted to patients and heart specimens with situs solitus of the atria, concordant atrioventricular and ventriculo-arterial connections. Knowledge regarding the anatomy of Ebstein's anomaly is essential in order to fully appreciate and understand the echographic information. During the course of this study we investigated this congenital heart disease in 23 selected patients and in 21 heart specimens. In the first part of this thesis (chapter 2) an extensive review is presented of the literature relevant for this study. The anatomic spectrum of the anomaly is described. The degree of apical displacement of the leaflets varies from little to pronounced and the degree of valye dysplasia may present a similar spectrum. Ebstein 's anomaly may be associated with other congenital heart defects, such as atrial septal defect, ventricular septal defect, pulmonary valve stenosis and Wolff-Parkinson-White syndrome. A review of the echocardiographic literature reveals that a prolonged time interval between mitral and tricuspid valve closure is the most important M-mode criterion. Two-dimensional echocardiography has introduced the possibility of demonstrating the displacement of the septal tricuspid valve leaflet towards the right ventricular apex.