Echocardiographic Features of Endocardial Cushion Defects

The echocardiographic features of endocardial cushion defects were defined in 28 patients. Two basic characteristics, common to both complete and incomplete forms of endocardial cushion defects, were found. First, the mitral valve excursion was not seen best in the usual location as defined by intraventricular landmarks. Secondly, the mitral valve echoes in cases where there are dense attachments of the mitral leaflet to the crest of the interventricular septum may be traced to the rightward and anterior border of the left ventricular outflow tract. This is the echocardiographic representation of the characteristic “goose-neck’ deformity seen angiographically.Two additional paterns were recognized in patients with complete atrioventricular (A-V) canal. In Pattern I, a large, single, A-V valve was found occupying a central location between the two ventricles. During diastole, the superior segment moved anteriorly into the right ventricle and the inferior segment posteriorly into the left ventricle. In Pattern II, a large single A-V valve moved from the left ventricle in systole into the right ventricle in diastole. This pattern was specific to patients with common A-V valve leaflets.