What is a ventricular septal defect (VSD)?
A ventricular septal defect is an opening in the ventricular septum, the dividing wall between the two lower chambers of the heart known as the right and the left ventricles. VSD is a congenital (present at birth) heart defect. They are the most commonly occurring type of congenital heart defect.
What are the different types of VSD?
There are two basic types of VSD:
- Perimembranous VSD - an opening in the upper section of the ventricular septum, near the valves. This accounts for 75 percent of all VSD cases.
- Muscular VSD - an opening in the lower section of the ventricular septum that occurs in upto 20 percent of all VSD cases.
What are the causes?
The heart develops during the first 8 weeks of fetal development. It begins as a hollow tube. Partitions then develop within the tube 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.
What are the symptoms?
The size of the ventricular septal opening affects the type of symptoms noted, the severity of symptoms, and the age at which they first occur. A VSD permits extra blood to pass from the left ventricle through to the right side of the heart, and the right ventricle and lungs become overworked as a result. The larger the opening, the greater the amount of blood that passes through and overloads the right ventricle and lungs.
Symptoms often occur in infancy. The following are the most common symptoms of VSD. However, each child may experience symptoms differently. Symptoms may include:
- rapid breathing
- congested breathing
- disinterest in feeding, or tiring while feeding
- poor weight gain
What is the treatment?
Specific treatment for VSD is determined by the child's physician based on:
- the child's age, overall health, and medical history
- extent of the disease
- the child's tolerance for specific medications, procedures, or therapies
Small ventricular septal defects may close spontaneously as the child grows. A larger VSD usually requires surgical repair. A VSD has to be repaired if it has not closed on its own. The treatment includes:
- Medical management Some children have no symptoms, and require no medication. However, most children may need to take medications to help the heart work better, since the right side is under strain from the extra blood passing through the VSD. Medications that may be prescribed include the following: Digoxin - a medication that helps strengthen the heart muscle, enabling it to pump more efficiently. Diuretics - the body's water balance can be affected when the heart is not working as well as it should. These medications help the kidneys remove excess fluid from the body.
- Adequate nutrition
Infants with a larger VSD may become tired when feeding, and are not able to eat enough to gain weight. Options that can be used to ensure that the baby will have adequate nutrition include the following:
- high-calorie formula or breast milk Special nutritional supplements may be added to formula or pumped breast milk that increase the number of calories in each ounce, thereby allowing the baby to drink less and still consume enough calories to grow properly.
- supplemental tube feedings
Feedings given through a small, flexible tube that passes through the nose, down the oesophagus, and into the stomach, can either supplement or take the place of bottle feedings. Infants who can drink part of their bottle, but not all, may be fed the remainder through the feeding tube. Infants who are too tired to bottle-feed may receive their formula or breast milk through the feeding tube alone.
- Infection control
Children with certain heart defects are at risk for developing an infection of the inner surfaces of the heart (known as bacterial endocarditis). Certain procedures, like dental check-up, may increase the risk of the heart infection. However, giving antibiotics before these procedures can help prevent this. It is important that the medical personnel are informed that the child has a VSD so they may determine if the antibiotics are necessary before a procedure.
- Surgical repair
The goal is to repair the septal opening before the lungs become diseased from too much blood flow and pressure. Repair is indicated for defects that are causing symptoms, such as poor weight gain and rapid breathing. The child's cardiologist will recommend when the repair should be performed based on echocardiogram and cardiac catheterization results.
The child's VSD may be repaired surgically. Another method currently being used to close some VSDs is the use of a device called a septal occluder. During this procedure, the child is sedated and a small, thin flexible tube is inserted into a blood vessel in the groin and guided into the heart. Once the catheter is in the heart, the cardiologist will pass the septal occluder into the VSD. The septal occluder closes the ventricular septal defect providing a permanent seal.
The type of procedure (surgical vs septal occluder) is individualized depending on various factors including anatomy of the VSD. Postoperative care:
In most cases, children have to spend time in the intensive care unit (ICU) after a VSD repair. During the first several hours after surgery, the child will most likely be drowsy from the anaesthesia that was used during the operation, and from medications given to relax him and to help with pain.
Most children who have had a ventricular septal defect repair will live healthy lives. Activity levels, appetite, and growth return to normal in most children. The child's cardiologist may recommend that antibiotics be given to prevent bacterial infections for a specific time period after discharge from the hospital.