The echocardiographic anatomy of ventricular septal defects

Many of the controversies surrounding the description of ventricular septal defects arise from differences in the perspectives from which they are viewed. In this review, we analyse these defects as seen in cross-sectional echocardiographic images, correlating them with morphologic specimens. The classification we advocate, which now has a suitable pedigree, is a simple descriptive method distinguishing between perimembranous, muscular, and doubly committed types of defects. The approach is to categorise the defects as seen from the right ventricle, the usual port of access for surgeons. The term 'perimembranous' highlights the proximity of the atrioventricular conduction axis to the margin of the defects in which the remnant of the membranous septum forms a direct border. This system is applicable to all interventricular communications, no matter how malformed the heart may be in which they are enclosed.