Ebstein’s Anomaly of Tricuspid Valve

Transcript of the video: Ebstein’s Anomaly is one of the cyanotic congenital heart disease in which survival to adult life is common. In Ebstein’s anomaly, there is downward or apical displacement of posterior and septal tricuspid leaflets. The anterior leaflet is not displaced, but is elongated to meet the other leaflets, so that when it closes, a loud sound, tricuspid sound, is produced, which is called as the sail sound. Ebstein’s anomaly may be associated with atrial septal defect or a patent foramen ovale, in about 50% of cases. The cyanosis in Ebstein’s anomaly, is usually not due to pulmonary hypertension, but because tricuspid regurgitation jet is directed across the atrial septal defect.

This is the diagrammatic representation of distal displacement of septal tricuspid leaflet. Anterior leaflet is elongated and sail like. This distance, between the anterior mitral leaflet and septal tricuspid leaflet, is usually only about 5 mm during echocardiography. When it is displaced much, then it is diagnostic of Ebstein’s anomaly. In Ebstein’s, portion of the right ventricle here, is atrialized. This portion is known as atrialized right ventricle. This is the regular right atrium, this is the atrialized portion of right ventricle. This can be a source of cardiac arrhythmia as well.

This atrialized portion of right ventricle will have electrocardiographic features of right ventricle and pressure tracing of right atrium. This is known as Hernandez sign, which is detected using a special catheter known as Zucker catheter. Zucker catheter has both an electrode as well as a pressure channel. So that can be used to detect Hernandez sign.

Hernandez sign is intracardiac pressures in this region showing right atrial pressure tracing, while intracardiac electrogram using the Zucker catheter will show ventricular type of electrogram.

An important cause of arrhythmias in Ebstein’s anomaly is the presence of a right sided accessory atrioventricular pathway or WPW syndrome. Normally, ECG of Ebstein’s anomaly shows an incomplete right bundle branch block pattern. But presence of an accessory right sided pathway, will cause this RBBB pattern to disappear. So, in fact, if an ECG of a person with Ebstein’s anomaly does not show incomplete right bundle branch block pattern, then an accessory pathway is suspected. Electrophysiological study will show that, and this pathway can be ablated. This is one important cause of supraventricular tachycardia in Ebstein’s anomaly. A huge right atrium can also predispose to supraventricular arrhythmias in Ebstein’s anomaly.

Ebstein’s anomaly may present with a murmur for evaluation in the pediatric age group or in adults with arrhythmias or heart failure with cyanosis and exercise intolerance. Auscultatory hallmarks of Ebstein’s anomaly the multiple heart sounds and a superficial scratchy precordial murmur. Striking X-ray feature of Ebstein’s anomaly in an adult, is ahuge enlargement of cardiac silhouette, contributed mainly by large right atrium, and the atrialized portion of the right ventricle. Characterisitic ECG finding in Ebstein’s anomaly are right atrial overload, and polyphasic or splintered QRS complexes, which are also called fragmented QRS complexes. An Ebstein’s type of anomaly can also occur in the left sided tricuspid valve in L- transposition of great arteries. This is an important cause of left sided AV valve regurgitation in congenitally corrected transposition of great arteries.

A modern surgical procedure for symptomatic Ebstein’s anomaly is Cone Procedure, which involves detachment of tricuspid leaflets, division of chordae, plication of the tricuspid annulus, rotation of leaflets and final re-insertion of leaflets in the modified tricuspid valve annulus. As cone procedure has become an effective hemodynamic intervention for Ebstein’s anomaly, late mortality due to arrhythmias assume more importance. Periprocedural electrophysiological study and ablation of potential arrhythmic circuits, have been suggested as a preventive strategy.