The Journal of Thoracic and Cardiovascular Surgery, Vol 77, 202-211, Copyright © 1979 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
The spectrum of Ebstein's anomaly of the tricuspid valve
JR Zuberbuhler, SP Allwork and RH Anderson
The structure of the tricuspid valve in 14 cases of Ebstein's malformation
is described and compared with that in the normal heart. The anomalous
hearts showed a spectrum of malformation, varying from minimal displacement
of the adjacent parts of the septal and inferior leaflets of the tricuspid
valve to presence of an imperforate membrane or muscle shelf between the
inlet and trabecular zones of the right ventricle. In "typical" Ebstein's
anomaly the anterosuperior leaflet was abnormally attached so as to
partially obstruct the route from right atrium to distal right ventricle,
the communication between these chambers being between the abnormally
attached leaflet and its malformed neighbors. In two hearts, a muscular
shelf produced stenosis between inlet and trabecular portions, but a
competent valve was produced at this site, the atrialized part of the right
ventricle being of normal thickness. The significance of these findings is
considered with regard to possible methods of repair. Description of the
anomaly is facilitated by considering the right ventricle as possessing
inlet, trabecular, and outlet portions. The essence of the anomaly is
displacement of the tricuspid orifice to the junction of the inlet and
trabecular ventricular zones.