A ventricular septal defect (VSD) is a congenital heart defect that occurs during fetal development. Babies born with a VSD have a hole in the septum (wall) that separates the heart’s lower chambers, or the right and left ventricles.
An intact ventricular septum helps ensure that oxygen-rich blood from the lungs doesn’t mix with oxygen-poor blood returning from the body. A ventricular septal defect allows blood to travel from the left to right ventricle, meaning that oxygen-rich blood from the lungs can mix with unoxgenated blood and get sent back to the lungs instead of out to the body. This makes the heart muscle work harder.
Newborns with ventricular septal defects can have one or more holes in the septum. Some of the more common ventricular septal defect types include:
- Cono-ventricular, in which the septal hole occurs just below the aortic and pulmonary valves;
- Peri-membranous, a hole in the upper ventricular septum;
- Inlet, a hole close to where blood enters the heart through the tricuspid and mitral valves (this defect might be part of an atrio-ventricular septal defect); and
- Muscular, the most common ventricular septal defect type, characterized by a hole located in the muscular, lower ventricular septum.
Ventricular septal defects are estimated to affect 42 in every 10,000 babies born in the US. Why this defect occurs is not yet known, but researchers suspect genetics, as well as the pregnant mother’s environment, and what she eats, drinks, and takes (medicines, for example) could have an impact on the unborn baby’s heart.
Children who have small defects might not need treatment. In fact, the opening often closes naturally with time. The only abnormal finding in children with small defects might be a heart murmur.
Large ventricular septal defects are more likely to cause symptoms and problems. Infants with this condition can have trouble feeding (because they tire so easily) and, therefore, grow at a slower rate than normal. Infants with the defect might breathe harder and faster than normal or sweat while feeding.
Parents who notice these symptoms should report them right away to their physicians. A pediatrician can determine if the problem is a ventricular septal defect with a clinical exam and an echocardiogram.
Babies with large ventricular septal defects are at risk for developing dangerous symptoms, as well as long-term complications. Since more blood than normal is being pumped to the lungs, the added pressure can eventually damage the lung blood vessels. Physicians, therefore, might recommend open-heart surgery early in children’s lives to repair the holes. The surgical procedure involves sewing a permanent patch to completely close the defect. Surgeons may be able to close some holes by way of a catheter through a vein in the leg instead of open-heart surgery.
The treatment for children who are very sick might be to first do a temporary operation to reduce blood flow to the lungs before performing open-heart surgery to permanently repair the hole when the child is older.
The long-term prognosis for children with ventricular septal defect is good. Pediatric cardiologists often monitor these children for signs of heart problems, such as leaky aortic valves. However, most lead normally healthy lives with no need for additional surgery or medications.
Reviewed by Dr. Sara Connolly, August 2019
- A ventricular septal defect is a hole in the septum (wall) that separates the heart’s right and left ventricles.
- Small holes might not cause any symptoms and often close naturally.
- Larger holes can stress the heart and lungs and often require surgery or catheterization.