My child has an innocent murmur. What do I need to do?

Suzanne Berman, M.D.

Actually, nothing. Think of an innocent murmur like freckles. Technically, it's an "abnormality" in the skin, but practically, it means nothing. Freckles don't require any special treatment or have any significance. So, children with innocent heart murmurs:

do not need any special tests or X-rays
can play sports or do any activity they want to do
do not have an increased risk of heart problems later in life
do need to take antibiotics before dental procedures or surgery
should be treated like any other child

Why has no one heard this heart murmur until now?

Parents are sometimes upset when they are told their 4-year-old child has a heart murmur, wondering how the doctor could have "missed it" all this time. However, innocent heart murmurs are often "discovered" much later than the newborn period because:

The murmur may not have been there before. Innocent murmurs tend to appear and disappear as children grow.
The murmur may be quite soft. and difficult to hear if the child is crying, or if the child's heart is beating very fast.
Certain things (like fever or a change in body position) can make murmurs easier or harder to hear. If the doctor had never listened to the child's heart during a certain circumstance before, the murmur might not have been audible.

What is causing this murmur?

See our page on what causes murmurs for more details and diagrams.

Will it go away?

Most innocent murmurs do go away as children get older -- which is why adults don't have them, even though so many children do. However, remember that, since it's harmless, it really doesn't matter whether an innocent murmur goes away or not.

How can you tell just from listening if the heart murmur is innocent or not?

The characteristics of the sound help classify it as good or bad. For instance, we listen for:

How loud the sound is
Where on the chest we hear the sound
What it most sounds like (a hum, a click, a honk, a whoosh, etc.)
When in the cardiac cycle the sound occurs (for example, right after the "lub," or with the "dub")
Whether the sound comes and goes

Also, there are other things which suggest that a murmur is harmless:

An otherwise normal circulation: a normal blood pressure, strong pulses, etc.
An otherwise normal body: no other physical problems with the ears, kidneys, limbs, etc.
Good growth and development.
No symptoms. Children who can run, jump, and play without chest pain, shortness of breath, or heart palpitations are much less likely to have a serious murmur.

Once in a while (about 1% of children), the murmur may sound unusual, or a child may have other issues which make us more suspicious of a heart problem. In those circumstances, we will refer the child to a pediatric cardiologist for evaluation.

For more technical information on the mechanical causes of murmurs, see our page on what causes different kinds of murmurs.