Angiographic differentiation of types of ventricular septal defects.

A retrospective study of 40 patients with 41 surgically repaired ventricular septal defects was performed in order to correlate the anatomic findings with the angiographic features seen by axial angiography. In 39 patients there were 32 perimembranous, three muscular, and four subarterial defects. One patient had both perimembranous and inlet muscular ventricular septal defects. Perimembranous defects as seen on left ventriculograms on long axial view are in continuity with the aortic valve. The relation of the defect to the tricuspid valve allows distinction of the extension of the perimembranous defect toward the inlet, trabecular, or infundibular zones. This relation was determined angiographically, using the course of the contrast medium from the left ventricle through the ventricular septal defect opacifying the right ventricle. Muscular defects are separated from the semilunar and atrioventricular valves. Subarterial defects are related to both semilunar valves, and they are best demonstrated by the elongated right anterior oblique view of the left ventriculogram. This study demonstrated that with axial views an experienced angiographer can define the location, size, and relations of the ventricular septal defects with high accuracy. In only two of the 41 defects there were differences between the retrospective angiographic prediction and the previous surgical findings.