- Most common type of Congenital Heart Disease (CHD)
- Comprises approximately 25% of all Congenital Heart Diseases
- More frequent in males
- Failure of proliferation of endocardial tissue from the right edge of endocardium cushions to fuse with aorticopulmonary septum and the muscular part of the intraventricular septum.
- Large ventricular septal defects with excessive pulmonary blood flow and pulmonary hypertension leading to dyspnea and cardiac failure.
- A ventricular septal defect is an abnormal opening in the wall between two ventricles.
- Intramembranous ventricular septal defect is the commonest type of ventricular septal defect.
- A large ventricular septal defect has a left-to-right shunt.
- It's a failure of the membranous part to develop.
- Muscular ventricular septal defects are less common.
- Sometimes multiple perforations - like "Swiss Cheese"
- Whether it's a single ventricle or common ventricle - failure of intraventricular septum to develop leads to a 3-chambered heart (Cor triloculare biatrium).