Echocardiography in atrioventricular canal defect: a clinical spectrum.

Echocardiographic examinations were performed in 30 children with atrioventricular (A-V) canal defect to determine the diagnostic value of recording A-V valve motion. Although a wide spectrum of abnormal movement was observed, four main diagnostic types emerged. Type 1, prolonged mitral-septal approximation during diastole, resulted from anterior displacement of the cleft anterior mitral leaflet. Type 2, the most diagnostic motion, was recorded when the common anterior A-V leaflet traversed the interventricular septum. Type 3 motion reflected posterior displacement of the septal tricuspid leaflet, which appeared to arise from the interventricular septum. Normal posterior diastolic motion of the septal leaflet was never recorded. Type 4, double contour of the mitral valve during systole and marked duplication of the systolic image, corresponded to irregularities in the mitral valve. When these patterns are recorded in a patient with congenital heart disease the diagnosis of A-V canal defect can be made with confidence.