Ventricular Septal Defect (Large)

A ventricular septal defect is a hole in the wall between the two main pumping chambers of the heart (the ventricles). Some patients have more than one VSD.

In the normal heart the left ventricle works at high pressure and pumps blood to the body and the right ventricle works at low pressure and pumps blood to the lungs. When there is a hole between the two ventricles (a VSD), blood flows from the left ventricle to the right ventricle through the hole. This causes the blood flow and the blood pressure in the right ventricle and in the arteries feeding the lungs (the pulmonary arteries) to be increased.

Babies with a VSD usually appear perfectly well in the first week or so of life, but many gradually become breathless over the first month or so after birth because the increased blood flow to the lungs makes the lungs congested. Babies who are very breathless often cannot feed normally and may not gain weight well because they put so much energy into breathing. Even quite big VSDs can gradually get smaller or even close off completely on their own as the child grows. However if the VSD remains large enough to cause high blood pressure in the lungs for a long time (more than a year or so) there is a serious risk that the arteries in the lungs will become permanently damaged by the high blood pressure.

This is a very serious complication (“pulmonary vascular disease”) as there is no effective treatment and the child will gradually become more and more breathless and blue over a period of some years and will eventually die because of the damage to the lungs.

In most patients a simple test such as an ultrasound scan of the heart (“an echocardiogram”) is required to measure the size of the VSD and level of blood pressure in the lungs.

Sometimes medicines can help to make the patient less breathless, but medicines cannot make the VSD smaller. If the VSD stays big as the child grows, surgery will be necessary.

In most cases it is possible to close the hole (or holes) but sometimes an operation, called a pulmonary artery band, is performed to reduce the amount of blood flowing to the lungs so that the bigger operation to close the hole can be delayed until the child is bigger. The operation to close the VSD involves opening the chest (usually down the middle at the front) and sewing a patch of material over the VSD while the heart is stopped and its function is taken over by a machine (cardiopulmonary bypass). The operation takes about 4 hours and usually involves a stay in hospital of about 5-7 days, as long as they are feeding well. Most children are completely back to normal activities within 6 weeks after the operation.

Risks and complications of treatment
Although most patients who have an operation to close a VSD do well and go on to lead completely normal lives, there is a very small risk (less than 1%) of dying at the operation and very small risks of major complications such as brain damage, kidney damage and respiratory infections such as pneumonia. There is also a small risk (around 1%) of the heart’s electrical system being damaged at operation; if this happens the child’s heart rate will be much slower than normal and a further operation is required to implant a pacemaker to make the heart beat faster. There are other minor risks involved, such as fluid collecting around the lungs or the heart after surgery.

Long term future
It is rare to need further treatment after surgery. Some patients will require medicines but this is usually only for a short time. Occasional outpatient visits are usually recommended even if the patient is well, to make sure that the repair remains satisfactory as the child grows.

Most children lead completely normal lives after surgery to close a VSD.

General advice for the future
All patients with a VSD will be at risk of infection in the heart (called endocarditis) before surgery and if there is a small residual VSD after the operation there will still be a small risk of infection in the heart. Such infections may be caused by infections of the teeth or gums. It is important to look after your child’s teeth and visit the dentist regularly (every 6 months). Ear or body piercing and tattooing are best avoided as they also carry a small risk of infection which may spread to the heart.