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[Dysplasia of both the components of the atrioventricular valve in atrioventricular septal defects].

BACKGROUND
A spectrum of anomalies of the atrioventricular valves, characterised by decreasing grades of leaflet differentiation from the tension apparatus and the ventricular wall, is included under the common heading of "Atrioventricular Valve Dysplasia". This concept has been further supported by the observation that tricuspid and mitral valve dysplasia frequently occur in the same heart. Although the general features of valvular dysplasia are the same in the two atrioventricular valves, there are side-specific patterns such as grade III dysplasia (and Ebstein's anomaly as well) in the right valve and mitral arcade in the left one.


CLINICAL CASE
The common nature of "Atrioventricular Valve Dysplasia" was confirmed by the observation of a newborn infant affected by atrioventricular septal defect with separate orifices. By means of both pre- and post-natal echocardiography, a diagnosis of Ebstein-like dysplasia of the right atrioventricular component, and of marked regurgitation of the left one was made. At the post-mortem examination, a diagnosis of grade III dysplasia of the right valvular component and of grade II dysplasia of the left one was confirmed.


REVIEW OF THE LITERATURE
Revision of the cases of atrioventricular septal defect with Ebstein-like dysplasia of the right valvular component disclosed that regurgitation of the left component frequently occurred, and that in one instance it was so severe as to require surgery. It may be inferred that in some cases, as in the one herein reported, such regurgitation could be due to a valvular dysplasia.


CONCLUSIONS
The simultaneous presence of dysplasia of both valvular components of a common atrioventricular orifice further validates the concept of "Atrioventricular Valve Dysplasia". Pediatric cardiologists observing patients with atrioventricular septal defect and Epstein-like dysplasia of the right atrioventricular component should be aware of the possibility of a pathologic change in both the valvular components and accordingly plan the correct surgical approach.