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Home > Events & Health Information > Diseases & Conditions > Heart Conditions > Innocent Murmur

Innocent Murmur


 

Signs & Symptoms

A heart murmur simply means a noise is heard when a doctor listens with a stethoscope. Most of these children have a murmur with a particular sound that we call an innocent murmur.

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What causes it

There are various theories why normal hearts may make a noise but the most likely explanation is that as the blood circulates through the heart and arteries it causes minor vibrations which make the noise. This is similar to the mechanism that generates the noise water often makes when it comes out of the tap. This also explains why innocent murmurs are louder when the child has a fever as the heart beats faster, blood circulates quicker and the vibrations are louder.

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About the condition

Heart murmurs are very common in children - about three in every ten children will have a heart murmur from time to time. Most of these children have a murmur with a particular sound that we call an innocent murmur. In these children the heart is completely normal heart and it is not a sign of heart disease. Innocent murmurs are especially noticeable if a child is unwell with a fever. Generally they become harder to hear as children grow older but they are often still heard in adults. They have been given several names that all mean the same thing - innocent, vibratory, functional, Stills (after Dr Still who described it) or venous hum.


Innocent murmurs are not the only type of murmur. Some murmurs are caused by blood passing through a hole or a narrowed or leaky valve. These however make a different sound to innocent murmurs and are usually easy to distinguish. If there is any doubt then a heart scan test will be able to confirm whether the murmur is innocent or not.

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Diagnosis and Treatment Options

Endocarditis prophylaxis is not necessary for an innocent murmur.

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Care tips

If you have been told that your child has an innocent murmur then it is important for you to realise that your child does not have a heart problem. They can take part in all activities and sports. When they visit a dentist it is not necessary for them to have antibiotics beforehand. Further medical check-ups are unnecessary.


Dental Care

Children and adults with congenital heart disease are at an increased risk of having a heart infection. Whilst this is rare the chances of it occurring can be reduced by taking precautions.


Infections in the heart can occur for no apparent reason but are more common if the teeth are rotten - germs spread into the blood stream and infect the heart. Good dental hygiene is therefore important as are regular visits to the dentist.


If dental treatment is required then some procedures can cause germs to spill into the blood and infect the heart.


It is therefore important that the dentist is informed about the heart condition before treatment. The usual method of avoiding this problem is to give a single dose of antibiotics one hour prior to the treatment to kill any germs beforehand.


Exercise

Exercise is important even in those with heart disease. It improves the heart function and general sense of well being. It is associated with increased life expectancy and a reduced risk of heart disease in later life. In addition physical activity helps with controlling weight and reducing blood pressure.


There are different types of exercise. In static exercise the muscles contract but there is little joint movement eg weight lifting. In dynamic exercise the muscles contract and also move the joints eg running. Each places a different stress on the body and cardiovascular system. In general most types of sports are a mix of the two


Children usually take part in more rigorous exercise at school as they grow older. In Singapore physical education (PE) tends to teach games skills rather than competitive sports. However pupils may take sport for their co-curricular activities (CCA) when training is more intense and competitive. Training for the NAPFA test is also intensive and some pupils with heart problems may have difficulty with the 2.4k run as they often perform less well at endurance type activities.


As always parents or patients must seek the advice of their own doctor when deciding how much exercise and to what level is safe - particularly as there are no published guidelines for activity levels in children


The Bottom Line

  • Most children with heart conditions (even following surgery) can safely participate in sport at all levels
  • Some children with complex heart problems should restrict themselves to certain sports only
  • For a few children competitive sport should not be undertaken
  • For all a certain level of fitness is healthy and should be encouraged


Vaccination

Most children with heart disease can have all the normal vaccinations at the appropriate time.

However some children with an immune deficiency (DiGeorge syndrome or an isomerism) and those who are receiving immunosuppression - for example following transplantation require a different vaccination schedule.


Travel Advice

Before travelling anywhere unusual or a long distance make sure that you:

  • have a recent medical check up
  • have appropriate insurance cover
  • have an adequate supply of medicine
  • are aware of the quality and access to local health care
  • carry the relevant documentation about the heart condition 


Those with cyanotic heart disease ("blue" due to reduced oxygen in the blood) can still travel but aircraft at altitude have less oxygen in the air than at ground level and so the blueness may be more apparent. This does not usually cause symptoms but if necessary airlines can arrange for additional oxygen to be available on the aircraft.


For long aircraft flights it is sensible to use the support stockings and take aspirin or an equivalent unless your doctor advises against it.


Diet

Special diets are not normally necessary for those with heart disease. As with everyone it is important to have a balanced diet and not to eat to excess. It is however important to maintain a normal weight - excess weight means more work for the heart.


Infection

Most children with heart disease are no more prone to infections than any other children. Some however are likely to get chest infections - particularly those with holes in the heart (ASD, VSD, PDA).

In addition some heart diseases are also associated with an immune deficiency and infections therefore are more common. The majority of childhood infections are viruses and get better without antibiotics. In any case of doubt professional medical help should be sort and the doctor will decide if antibiotics are necessary.


Medication

Most children with heart disease do not require medication. Some however need them to:

  • reduce the body fluids
  • assist the pumping action
  • control rhythm problems
  • thin the blood


The majority of these medicine have been used for many years and are very safe but like all drugs side effects may occur - especially if there is another illness or a change in other medication. If unusual symptoms or side-effects occur whilst on medication it is important to inform the doctor immediately.


Pregnancy

Most women with heart disease are able to undergo a normal pregnancy and delivery.


The exceptions are those with severe cyanosis when there is usually insufficient oxygen in the blood supply to the placenta to sustain the baby. Most of these pregnancies  spontaneously abort.


Women with pulmonary hypertension (high lung artery pressure) are not usually advised to get pregnant as there is a serious danger to their life.



As with any medical problem it is essential that medical advise is taken - preferably before the event so that the pregnancy can be monitored and if treatment is necessary it can be undertaken early.


If a women herself has a heart problem then there is an increased risk that her child will have a problem too. The risk is around 6%. If a man has a heart problem then the risk is 2%. If the couple have had a previously affected child then the risk is about 2%. The risks quoted above are averages - the actual risk varies considerably between the various heart conditions. There is also some evidence that taking vitamins for 3 months prior to and the first 3 months of the pregnancy can reduce the chance of heart disease occurring in the baby.

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