ECHOCARDIOGRAPHIC EVALUATION OF ATRIOVENTRICULAR ORIFICE ANATOMY IN CHILDREN WITH ATRIOVENTRICULAR SEPTAL-DEFECT

In atrioventricular (AV) septal defect, the common AV valve can have a common orifice or can be divided by bridging leaflet tissue into two separate orifices. To determine the accuracy of a two-dimensional echocardiographic technique devised specifically for evaluation of the number of AV valve orifices, all 69 children undergoing surgical repair of AV septal defect from April 1987 to August 1990 were examined prospectively. The presence of bridging leaflet tissue and the number of AV valve orifices were determined with use of a subcostal imaging plane. From a standard subcostal four-chamber view, the plane of sound was rotated 30-degrees to 45-degrees clockwise until the AV valve was seen en face. The plane of sound was then tilted from a superior to an inferior direction so that cross-sectional views of the AV valve were examined from the inferior margin of the atrial septum to the superior margin of the ventricular septum. Of the 69 patients, 6 (9%) were excluded because the appropriate subcostal images were not obtained (in 3 because of obesity and in 3 as a result of operator failure). The remaining 63 children, ranging in age from 1 day to 13.5 years and in weight from 1 to 55 kg, constituted the study group. Echocardiographic results were compared with surgical observations in 62 patients and with autopsy findings in 1 patient. With the two-dimensional echocardiographic technique, 32 of 33 patients with a common orifice and 28 of 30 patients with two separate AV valve orifices were correctly identified. By chi-square analysis, the echocardiographic technique allowed correct identification of a common orifice valve with 94% sensitivity and 97% specificity. For correct identification of two separate orifices, the echocardiographic technique had 97% sensitivity and 94% specificity. The positive predictive value of the echocardiographic technique was 97% for a common orifice and 93% for two separate orifices. Thus, in patients with AV septal defect, the presence of bridging leaflet tissue and the number of AV valve orifices can be accurately determined with use of a subcostal two-dimensional imaging plane.