Axial cineangiographic evaluation of the posterior ventricular septal defect.

The posterior or inlet ventricular septal defect may occur as an isolated anomaly or in combination with other defects. Axial cineangiography is the best means to delineate the anatomy of this defect as well as to exclude the presence of other ventricular septal defects. The posterior ventricular septal defect can be recognized in the four chamber view by obliteration of the septum by contrast medium flowing across the defect. Anterosuperior extension into the perimembranous region is identified by obliteration of the septum in the long axial oblique view. The presence of a posterior ventricular septal defect can be suspected on the basis of a two dimensional echocardiogram or electrocardiographic left axis deviation. When this is the case, the four chamber view should be performed first so that contrast material in the liver blood pool from a previous injection does not interfere with image quality.