In this condition the valve letting blood flow from the heart to the arteries in the lungs is narrowed. In most cases it is not a serious problem. In the normal heart blood passes from the main pumping chamber on the right side of the heart (the right ventricle) to the artery feeding the lungs with blood (the pulmonary artery). When the valve letting blood out of the right ventricle (the pulmonary valve) is narrow the muscle of the right ventricle has to work harder than normal and the muscle gets thickened, just like other muscles in the body if they are worked hard. If the pulmonary valve is only mildly narrowed the heart copes very well, but if the narrowing is very severe the heart cannot pump normally and this can limit how much exercise the patient can manage and very rarely can even cause death if it is not treated. Many patients have only mild pulmonary stenosis and do not need any treatment at all, but the valve can become more narrow as the patient grows, so occasional visits for checkups in the outpatient clinic will be necessary even if the patient appears perfectly well.
Usually only simple tests such as an ultrasound scan of the heart ("echocardiogram") are needed.
If the valve is severely narrowed treatment will be needed, but it is very rare nowadays to need open heart surgery. Most cases can be treated by stretching the narrow valve open with a balloon (called "balloon valvoplasty"). This is done under general anaesthetic and involves passing a long tube with a collapsed balloon on the end of it (a balloon catheter) into the vein at the top of the leg and feeding it up into the heart and across the narrow valve. Using X-ray pictures, the balloon is positioned in the narrow valve and is blown up, stretching the valve open. This is usually a very effective form of treatment and is very low risk - the chance of death during the procedure is less than 1 in 100, even in babies. Usually only one night’s stay in hospital is necessary. Sometimes if the narrowing is only partly relieved by the balloon it is worth repeating the procedure at a later date. Because the thickened heart muscle (due to the narrow valve) itself can cause some narrowing, it is not always possible to tell straight after the procedure exactly how successful it has been - sometimes we have to wait for a few weeks for the thickened heart muscle to return to normal. In a small proportion of patients the thickened heart muscle doesn’t return to normal and if this causes important narrowing inside the heart surgery is needed to remove some of the muscle.
Sometimes the pulmonary valve cannot be stretched open using a balloon and open heart surgery will be needed. This involves opening the chest (usually in the middle at the front) and the function of the heart and lungs being taken over by a machine so the surgeon can open the heart and cut the narrow valve open. There is a very small risk of death (less than 1 in 100) and a very small risk of major complications such as brain damage (less than 1 in 100). Other complications such as fluid collecting around the heart or lungs can occur after the operation but these are very rarely serious. After operation the patient needs to stay in hospital for about 5 days, although a longer stay might be necessary if there are any complications.
The long term future
Patients who have not needed any treatment by the time they are fully grown usually don’t ever need treatment for their pulmonary stenosis, but in rare cases the valve can become more narrow in later adult life. Balloon treatment is usually effective in adult life just as it is in children. Patients who have a good result from balloon stretching of the valve or surgery usually do not need any further treatment. However, after any kind of treatment for pulmonary stenosis, the pulmonary valve never works completely normally, and will leak to some extent (some of the blood pumped out of the heart to the lungs flows back into the heart through the valve). This leak is very rarely important, but there is a very small chance that some patients might need surgery to replace or repair the valve in later life.
General advice for the future
Most children with pulmonary stenosis, whether they have had treatment or not, lead completely normal lives and can exercise normally too. Patients with pulmonary stenosis will be at a small risk of infection in the heart (called endocarditis), both before and after treatment. Such infections may be caused by infections of the teeth or gums or even by routine treatment at the dentist. It is important to visit the dentist regularly and to remind the dentist at each visit of the heart abnormality. You will be given an information card to help you with this. Ear or body piercing and tattooing are best avoided as they also carry a small risk of infection which may spread to the heart.
How to interpret the survival funnel plots
These graphs show the national average survival after specific procedures for treating congenital heart disease. The national average is shown as a horizontal grey line. Two control limits are shown; a warning limit (Green line, 98%) and an alert limit ( Red line 99.5%). Unit performances are shown as identifiable coloured symbols. If a unit's symbol is above the green line then the performance is no different from the national average. If a unit’s survival rate is below the warning limit, their performance will be closely monitored in subsequent years. If a unit’s survival rate is below the alert limit, an investigation into possible reasons and remedial actions will be launched by the appropriate professional and regulatory bodies.