A new method for evaluating tricuspid valve displacement in children with Ebstein's anomaly: using the annulus and coronary sinus as a reference point.

This study aimed to investigate the reference point for the downward displacement of the posterior and anterior leaflets of the tricuspid valve using echocardiography in children with Ebstein's anomaly. This study enrolled 25 patients with Ebstein's anomaly. The extent of downward displacement of the posterior and anterior leaflets of the tricuspid valve was evaluated by echocardiography using the tricuspid annulus and the coronary sinus as reference points. These results were compared with the surgical findings. The findings showed displacement of the simple septal leaflet in 1 patient, displacement of both the septal and posterior leaflets in 22 patients, displacement of both the anterior and posterior leaflets in 1 patient, and displacement of all the leaflets in 1 patient. Because the septal and posterior leaflets were close to the apex or because the posterior leaflet was nearly absent, the displacement distance of the septal and posterior leaflets could not be measured accurately in two patients. The displacement distance of the septal and posterior leaflets in the remaining 22 patients were 2.08 ± 1.15 and 2.58 ± 1.06 cm, respectively. The displacement distances of the anterior leaflet in two patients were respectively 1.0 and 2.2 cm. These results were similar to those measured during surgery. The direction of the valvular regurgitation flow was anterolateral in the apical four-chamber and apical right heart two-chamber views in patients with the downward displacement of the anterior leaflet. The tricuspid valve annulus and the coronary sinus are ideal reference points for evaluating the downward displacement of the posterior and anterior leaflets of the tricuspid valve. It is critical to evaluate the downward displacement of the anterior leaflet that the direction of the tricuspid regurgitation flow is changed.