الفهرس 
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Abstract
ventricular septal defect (VSD) is a hole or multiple holes in the interventricular septum.
There are two fundamental types of defects between the ventricles : the first is that due to deficiency in the septal substance in otherwise relatively normally (inter-related) ventricular septal components. This is the group referred to as isolated VSDs.
The second type includes numerous conditions in which the ventricular and conus septa are either not in line or are too far apart to fuse, and the intervening gap is defined as a VSD. This group includes defects seen in various types of dextroposition and transposition complexes (Grant et al., 1961).
VSD is the most common heart lesion. As an isolated anomaly, it occurs approximately once in every 1000 live births and represents about 25% of all congenital heart lesion (Keith, 1978).
This section deals specifically with isolated VSDs. Defects were observed in the area of membranous septum, termed perimembranous defects; within the muscular septum, termed muscular defects; or in the area of septum subjacent to the arterial valves, termeél subarterial infundibular defects (Soto et al, 1980).