Incidence
The prevalence of multiple defects in the muscular ventricular septum is
low, occurring in less than one-fifth of patients in whom deficiency of
the ventricular septum is the main finding, and in no more than 2% of
those with co-existing lesions such as discordant ventriculo-arterial
connections, tetralogy of Fallot, or atrioventricular septal
defect.35,36