Ventricular septal defect

A ventricular septal defect is a hole between the heart’s two lower chambers, or ventricles. In a normally developed heart, the ventricles are separated by a wall of muscle and tissue known as a septum. Although a hole exists between the two chambers during fetal development, it should close by birth. If not, the child has the condition known as VSD.

Definition & Facts

The heart consists of four chambers, each with its own separate function. The right atrium and left atrium are the upper chambers into which blood is received. The right ventricle and left ventricle are the lower chambers and are responsible for pushing blood out of the heart. The left ventricle pushes oxygenated blood to tissues throughout the body, while the right ventricle pumps deoxygenated blood to the lungs. A VSD allows blood from the two chambers to mix and flow into the pulmonary arteries.

The pressure generated during contractions in the left ventricle is greater than that in the right ventricle. A hole in the separating septum will thus result in blood flow from the left to the right. The right ventricle must work harder due to the excess volume of blood. The lungs consequently receive too much blood under too much pressure, which can permanently damage the pulmonary arteries.

Symptoms & Complaints

In many cases, the only symptom is a heart murmur that is detected through a routine physical examination. The murmur may or may not be present in the early weeks of life. 

In other cases, however, the hole is sufficiently large that the child’s lungs and heart will need to work harder; in severe cases, this can lead to congestive heart failure. In early infancy, the most telling sign of severe VSD may be the child’s inability to gain weight or grow normally. Other symptoms may include:

• Fast breathing
• Rapid heartbeat
• Sweating
• Discolored skin

In adolescents or adult patients who have VSD, the risks are a bit different. Typically, those with severe VSD or a large hole have received treatment to repair it. For those with a small hole where treatment was not recommended or the location of the hole made treatment impractical, there is a danger of a heart infection called endocarditis and the possibility of leakage developing in the aortic valve.

Causes

VSD is a relatively common congenital heart defect occurring in approximately one in 500 births. Its causes are unknown, but like many other conditions, genetics seem to play a role and perhaps, environmental factors may contribute as well. Congenital heart defects typically arise from problems with the heart in early development, and it is not uncommon for an individual afflicted with VSD to also have other heart abnormalities. 

Diagnosis & Tests

As indicated, the detection of a heart murmur is typically the first clue a VSD may be present, but additional testing is required to confirm that suspicion and either eliminate or confirm other potential health concerns. Most patients are initially given a chest X-ray to determine the size of the heart and amount of blood flow to the lungs. X-rays given over a period of time can monitor the progress or stability of the individual’s condition.

An electrocardiogram is often performed if the chest X-ray is inconclusive or if there is the possibility of some other heart defect. Cardiac catheterization can be employed to provide the physician with more detailed information regarding how much blood is flowing onto the lungs. Echocardiograms may be conducted, which are ultrasound tests of the anatomical structure of the heart using sound waves.

Treatment & Therapy

For the least severe instances of VSD, nothing needs to be done to treat the condition, although regular check-ups are advised to monitor the situation. Medications can be prescribed to strengthen the heart muscle to enable it to handle its increased workload or to help reduce the volume of fluids in the body so the heart doesn’t have to work as hard.

Surgery may be recommended for large VSDs. The surgical procedure essentially covers the hole with a patch that is sewn into the wall of the septum. Occasionally, a transcatheter procedure is employed, whereby surgical instruments are passed through catheters inserted near the heart to close the septal defect.

The age and overall health condition of the patient will dictate the type of treatment suggested, including when surgery, if necessary, should be performed. If the patient is deemed to not be a good candidate for surgery, recommendations to relieve the symptoms of VSD as much as possible, should be followed. 

Due to the risk of endocarditis, VSD patients who have either not required surgery or those who have successfully completed surgery should take antibiotics before any dental procedures, including routine cleanings, as well as prior to any surgical procedures involving the throat or mouth. 

Prevention & Prophylaxis

A patient with mild to moderate symptoms of VSD may need to curtail certain activities that involve excessive exertion. Once successful surgery has been completed, there should be no need for any restrictions on activities. There are rarely surgical complications related to VSD, but in a small percentage of cases a patch leak has occurred after the surgical repair, so precautions must be made by a patient's medical team in anticipation of that possibility.