The degree of scooping of the interventricular septum influences electrocardiographic findings in atrioventricular septal defect

The aim of this study was to clarify those morphological features and hemodynamic stress factors which influence the electrocardiographic findings in atrioventricular septal defect. In 64 patients with the incomplete form of atrioventricular septal defect (separate valvar orifices) with usual atrial arrangement, the length from the left ventricular apex to the aortic valve (outlet dimension), to the so-called cleft (scoop dimension), and to the lowest point of the left atrioventricular valve (inlet dimension) were measured by biplanar cineangiography. The size of the ostium primum defect, the ventricular pressure ratio, and the pulmonary/systemic flow ratio were also evaluated. The results showed that the lower the scoop/outlet ratio (r=0.60, p