Ventricular Septal Defect

A Ventricular Septal Defect is also known as a VSD or “hole in the heart”. It is a type of congenital heart defect, which means it was present at the time of birth. It can be an isolated defect or can be associated with other cardiac defects. The abnormal opening or “hole” is in the septum between the two lower chambers of the heart called ventricles. The defect can vary in size from pinhole to a complete absence of the septum resulting in a common ventricle. Because of this opening, blood can flow from the oxygen-rich left ventricle to the oxygen-poor right ventricle. The blood is mixed and goes back out to the lungs to pick up more oxygen. Because too much blood is trying to get into the lungs, sometimes it gets pushed back into the right ventricle and this can result in an enlarged right ventricle. This increased blood flow makes a “whooshing” sound, called a murmur. It can be heard by listening with a stethoscope.

Causes

A congenital defect occurs during fetal development. The heart is developed during the 5th week of pregnancy. VSD is the most common congenital cardiac malformation. Sometimes, birth defects can be caused by exposure to a poison in the environment, an infection, uncontrolled diabetes, alcohol or drug abuse, or chromosomal abnormalities (extra or missing pieces of genetic material). But most of the time, the cause of a congenital heart defect is simply unknown.

Signs/Symptoms

The size of the defect and its location along the septum determines the symptoms. The defect can be located in the membrane or the muscle. Kids with small defects often have no symptoms and those VSDs will usually close on their own. Babies with moderate to large VSDs may show symptoms such as:

  • Faster breathing
  • Tiring easily with feeds
  • Sweating or crying, especially with feeds
  • Slow weight gain

These types of symptoms often mean that the defect is not closing on its own and cardiac surgery may be needed. It is common for this type of surgery to be done within the first 3 months of life so that further complications can be prevented. However, a cardiologist may prescribe certain medications to lessen some of the symptoms so the baby can grow and be the healthy before having surgery.

Diagnosis

A murmur is often noted on a routine physical exam by the child’s pediatrician. The doctor should refer the patient to a pediatric cardiologist (a doctor who is a specialist in diagnosing and treating childhood heart conditions & diseases) for further evaluation. In addition to performing a complete exam and taking a full history, the cardiologist will most likely order a variety of tests such as:

  • Chest X-ray (CXR) – shows the heart, lungs and surrounding organs.
  • Electrocardiogram (EKG) – records the electrical activity of the heart and shows if the right side of the heart is enlarged due to increased blood flow.
  • Echocardiogram (Echo) – similar to an ultrasound; uses sound waves to bounce off the structures of the heart and produces a picture of the heart; shows the volume and direction of flow through the heart itself. This is generally the gold standard for diagnosis of a VSD.
  • Cardiac Catheterization (Heart Cath) – performed only if further information is needed; provides information about the heart’s structures, blood pressure & oxygen levels within the heart itself.

Treatment

Treatment of a VSD depends upon the age and size of the child as well as the location and severity of the defect. A cardiologist will regularly follow a patient with small defects who are asymptomatic to be sure that there are no concerns. Most of the time, a small defect will close on its own without surgery. If it remains open and doesn’t get any larger or cause problems, these kids will usually not have to restrict their physical activities.

If surgical correction is necessary, there are several options.

  1. Pulmonary artery banding: In infants, a band can be placed around the pulmonary artery to restrict the flow of blood into the lungs. This is sometimes done if there are multiple VSDs or more complex anatomy, and it is only palliative (a temporary “fix” to prevent damage to the lungs). A more corrective surgery will be needed once the baby grows.

  2. Complete repair: Open heart surgery is the procedure of choice. A cardio-thoracic surgeon will make an incision in the center of the chest (sternum) to expose the heart. The patient will be on a heart-lung bypass machine for a short period of time while the surgeon is performing the repair. Small defects are repaired by stitching the defect closed. For larger defects, a patch of knitted Dacron is sewn over the opening. The tissue of the heart will grow over the stitches or patch within about 6 months. The child will spend several days in the hospital, first in the cardiac ICU, then on a special cardiac unit where the doctors, nurses, and other staff will closely monitor for arrhythmias, breathing concerns, infection or poor eating. Generally, the younger the child is, the less pain they have during the recovery period. This is mainly because the sternum in infants and younger children is more pliable.

    These kids will have activity restrictions for 6 weeks post-op to prevent injury to the sternum. The parent will be instructed on Systemic Bacterial Endocarditis (SBE) Prophylaxis. This means that the child should have antibiotics before any routine dental work or surgical procedure to prevent an infection on the inside of the heart from occurring. The risk of this usually diminishes after 6 months. All risks and complications are discussed prior to a cath procedure or heart surgery.

  3. Cardiac Catheterization: Some of the smaller VSDs may be closed in the cath lab. This is being done in some facilities under investigational protocols. A catheter (a thin, flexible tube) is inserted into a blood vessel in the groin. It is threaded up into the heart to where the hole is located. A special implant made of flexible mesh is positioned over the hole to cover and seal the defect permanently from both sides. The patient’s own tissue grows over the mesh and completely covers it in about 6 months. This procedure usually requires only an overnight hospital stay. These patients will need to take a low-dose of aspirin for 6 months because of a small risk of clots forming on the device until the tissue grows over it. The child shouldn’t have a sit-down tub bath or swim for 3 days following the procedure, and they are usually kept out of gym class or sports for approximately one week or until cleared by their doctor. These kids should also have regular follow-ups with their cardiologist.

Prognosis

Most kids who have had a VSD repair recovery quickly and without further problems. Doctors will continue to monitor them regularly for any changes or concerns in their overall health. These kids generally have a normal life expectancy and go on to lead active and healthy lives.