How does VSD (Ventricular Septal Defect) occur?

A VSD is the most common heart defect present at birth. It often occurs as a single defect with no known cause but is also found in children with multiple problems.

About one in three children with a heart abnormality discovered at birth has a VSD. VSDs account for one in five heart abnormalities found during childhood and for one in 10 found in adults.

A VSD may occur when a heart attack weakens the muscle of the septum. Blood pressure in the left ventricle breaks opens the weakened septum, pushing blood into the right ventricle through the new opening. Rarely, trauma to the heart may cause a VSD.