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Great Ormond Street Hospital for Children NHS Foundation Trust: Information for Families
Mitral valve stenosis
This information sheet from Great Ormond Street
Hospital explains the causes, symptoms and treatment
of mitral valve stenosis and where to get help.
Mitral valve stenosis is usually a
congenital heart defect – that is, it was
present when the child was born. Around
eight in every 1000 babies born have a
congenital heart defect.
The normal heart
The heart consists of four chambers – two
upper filling chambers (atria) and two
lower pumping chambers (ventricles).
In between each atrium and ventricle is a
valve that stops blood flowing backwards.
There is also a valve where the pulmonary
artery and aorta join the heart.
The function of the heart is to pump
blood around the body.
Blood comes into the right atrium from
the body and goes through the tricuspid
valve into the right ventricle. From here, it
is pumped up the pulmonary artery to the
lungs to pick up oxygen.
Oxygen-rich blood comes back to the
heart through the pulmonary veins into
the left atrium. It flows through the
mitral valve into the left ventricle. This
pumps the blood into the aorta and from
there around the body.
Mitral valve stenosis
Aorta
Pulmonary
artery
Left
atrium
Mitral
valve
Right
atrium
Tricuspid
valve
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The right and left sides of the heart are
divided by a thick wall of heart muscle
called the septum.
Left
ventricle
Ref: 2013F1108
Mitral valve stenosis is usually a
congenital heart defect – that is, it was
present when the child was born. Around
eight in every 1000 babies born have a
congenital heart defect.
Congenital mitral valve stenosis means
that the valve between the left pumping
chamber (left ventricle) and left filling
chamber (left atrium) is narrower than it
should be. Blood flows from the left atrium
into the left ventricle and then on to the
© GOSH NHS Foundation Trust October 2013
rest of the body. As the valve is narrow,
blood collects 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 congenital
mitral valve stenosis?
The heart is formed early in pregnancy
but doctors do not fully understand why
some children’s hearts do 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.
What are the signs and
symptoms of congenital
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 may be feeding difficulties
which lead to poor weight gain and
breathlessness after exertion.
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Ref: 2013F1108
If the problem progresses, the child’s
nails, lips and skin may develop a blue
tinge as there is not enough oxygenrich blood circulating around the body.
Gradually the heart becomes weaker as it
has to work much harder to pump blood
around the body.
How is congenital mitral
valve stenosis normally
diagnosed?
A child’s defect may have been diagnosed
antenatally by our foetal team and will
be confirmed on admission. Doctors will
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.
How is congenital mitral
valve stenosis treated?
Doctors will suggest 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.
© GOSH NHS Foundation Trust October 2013
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 older children treatment
carried out using a catheter (thin plastic
tube) threaded through the blood vessel
system to the heart might be possible.
Further information
and support
Contact one of the support organisations
below:
British Heart Foundation
Tel (Heart Help Line): 0300 330 3311 (calls
charged at local rate)
Website: www.bhf.org.uk
Heartline
Tel: 03300 224 466 (local rate number)
Website: www.heartline.org.uk
What happens next?
All children who have had mitral valve
stenosis will need to come to hospital for
regular check ups. This will usually involve
repeat Echo scans to check that the valve
is not becoming narrower. Other tests
such as an ECG might also be needed.
If the valve has been replaced, this will
involve life long follow-up. A manmade
valve will need lifelong blood thinning
medicine to prevent the valve clotting.
Notes
Compiled by the Web team in collaboration with the Child and Family Information Group
Great Ormond Street Hospital for Children NHS Foundation Trust
Great Ormond Street
London WC1N 3JH
www.gosh.nhs.uk
Sheet 3 of 3
Ref: 2013F1108
© GOSH NHS Foundation Trust October 2013