Mitral Valve Stenosis
Mitral valve stenosis is generally a congenital heart disorder i.e. it was present when the child was born. Around 8 in every 1000 babies born are having a congenital heart disorder.
Congenital mitral valve stenosis means that the valve between the left ventricle and left atrium is narrower than it should be.
Blood regulates from the left atrium into the left ventricle and further on to the rest of the body. As the valve is narrow, blood get collected in the left atrium, builds up pressure and may flow back to the lungs.
Even if the mitral valve is the main problem, some children with mitral stenosis have other abnormalities on the left side of the heart, perhaps in the aortic valve area or in the aorta as it leaves the heart.
What causes mitral valve stenosis?
The heart is formed early in pregnancy but doctors has not fully understand why some children’s hearts does not develop properly. For the majority of babies born with congenital mitral valve stenosis, doctors never find a cause.
However, the chance of a child having this condition increases a little if one or both parents had a congenital heart defect. Occasionally some conditions such as diabetes or medicines taken during pregnancy can also increase the risk.
Congenital heart defects are more common in children with other congenital conditions.
How mitral valve stenosis is normally diagnosed?
A child’s defect may have been diagnosed antenatally by our foetal team and will be confirmed on admission. Doctors would like to
use chest X-rays, electrocardiograms (ECG) and echocardiograms (Echo) to diagnose congenital mitral valve stenosis.
An ECG measures the electric current passing through the heart. An Echo is an ultrasound of the heart and shows not only the structure of the heart but the blood flow through it.
Some children also have a cardiac magnetic resonance imaging (MRI) scan which uses a strong magnetic field, radio waves and a computer to make a very detailed image of the heart.
What are the signs & symptoms of mitral valve stenosis?
Symptoms are often present from birth when the baby can be seriously ill or symptoms can develop within the first two years of life.
There can be feeding difficulties available which lead to poor weight gain and breathlessness after exertion.
If the problem progresses, the child’s nails, lips and skin may develop a blue tinge as there is not enough oxygen-rich blood circulating around the body. Generally, the heart becomes weaker as it has to work much harder to pump blood around the body.
How is mitral valve stenosis treated?
Doctors will advise treatment depending on the narrowness of the mitral valve stenosis and the results of the diagnostic tests. Some mild mitral valve stenosis, where the valve is only a little narrower than normal, might not need any treatment but will still need to be assessed regularly.
If the narrowing is severe enough to interfere with a child’s progress the treatment options will depend on the severity, the size and age of the child and whether other valves or blood vessels need attention.
In young children, open heart surgery to repair or replace the valve may be the first option. In some of the older children, treatment carried out using a catheter (thin plastic tube) threaded through the blood vessel system to the heart might be possible.