What causes ventricular septal defect?
The heart is forming during the first 8 weeks of fetal development. It begins as a hollow tube, then partitions within the tube develop that eventually become the septa (or walls) dividing the right side of the heart from the left. Ventricular septal defects occur when the partitioning process does not occur completely, leaving an opening in the ventricular septum. Some congenital heart defects may have a genetic link, either occurring due to a defect in a gene, a chromosome abnormality, or environmental exposure, causing heart problems to occur more often in certain families. Most ventricular septal defects occur sporadically (by chance), with no clear reason for their development.
