In this condition there is narrowing of the valve letting blood flow from the heart to theartery feeding the body with blood (the aorta). Almost all patients with aortic stenosis will need major heart surgery at some stage in their life, but the age at which surgery is necessary is very variable. If the valve is severely narrowed treatment may be necessary within the first few weeks of life, but if the narrowing is slight treatment may not be necessary until later adult life. The timing of treatment depends on how badly narrowed the valve is, how it changes as time goes by (it almost always gets worse with increasing age), and how well the heart is coping with the extra work of pumping blood through the narrow valve. When the aortic valve is narrow the muscle of the main pumping chamber of the left side of the heart (the left 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 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 can even cause death if it is not treated.
Usually only simple tests such as an ultrasound scan of the heart ("echocardiogram") are needed to make the diagnosis but it is helpful to also have occasional electrical recordings of the heart’s activity (electrocardiogram or ECG) and Xray pictures of the chest. None of these tests are unpleasant or painful.
All patients with aortic stenosis will need an operation to replace the valve at some stage, but we try hard to avoid this during childhood because replacement valves do not grow and repeated operations would be needed to put a larger valve in place. When the valve is badly narrowed in childhood we can usually help to delay valve replacement 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 artery at the top of the leg (or the arm in babies) and feeding it up into the heart and across the narrow valve. Using Xray pictures, the balloon is positioned in the narrow valve and is blown up, stretching the valve open. This never makes the valve normal and it is not always successful, but in many cases it can reduce the severity of the narrowing so surgery can be put off until the patient is older.
Mitral balloon Valvoplasty
Sometimes balloon valvoplasty can be repeated as the patient grows to further delay the need to replace the valve. Usually only one night’s stay in hospital is necessary after the balloon procedure. Sometimes the 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 (called a "valvotomy"). Usually about 7 to 10 days stay in hospital is necessary after surgical valvotomy. All treatment for aortic stenosis has potentially serious risks for the patient. Balloon valvoplasty and surgical valvotomy both carry a risk of death (about 1 in 100 in children but higher in very young babies) as well as a small risk (also about 1 in 100) of stroke or other forms of brain damage. Stretching or cutting the valve open helps to reduce the narrowing but almost always makes the valve leak. It is never possible to predict how bad the leak will be - but it is worth trying these procedures in the hope that it will be possible to delay valve replacement. If the leak is severe it may be necessary to replace the valve early in life after all.
General advice for the future
Occasional visits for checkups in the outpatient clinic are very important even if the patient appears perfectly well. Unless the valve is only slightly narrowed, it is usually best to avoid really competitive sporting activities. In most cases swimming, PE, football, netball and similar sports can continued to be enjoyed but more intensive exercise such as cross country races and squash should be avoided. Your cardiologist will answer any questions you have about individual recommendations for you or your child. Patients with aortic stenosis will be at 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.