Left atrioventricular valve after surgical repair in atrioventricular septal defect with separate valve orifices ("ostium primum atrial septal defect"): an echo-Doppler study.

Left atrioventricular (AV) valve dysfunction is the most frequent major postoperative hemodynamic complication in patients with AV septal defect. The anatomy and function of the left AV valve were investigated in 64 patients with separate valve orifices (ostium primum atrial septal defect) who had survived corrective surgery. M-mode and cross-sectional echocardiograms of the left AV valve were obtained. Doppler flow tracings were obtained at the left AV valve orifice to determine if regurgitation was present. The findings were related to the position of the commissures between the leaflets, the size of the 3 leaflets and the position of the papillary muscles. Left AV valve regurgitation was present in 29 of 51 patients (57%). These patients had a significantly different left AV valve leaflet configuration, characterized by a large mural leaflet and a small inferior bridging leaflet. The size of the superior bridging leaflet is not a determinant factor. Thus, the configuration of the left AV valve in AV septal defect is related to the postoperative functional result. Awareness of the echocardiographic anatomy may influence the surgical approach to this defect.