Great Ormond Street Hospital for Children NHS Foundation Trust: Information for Families

Innocent heart murmur

This information sheet from Great Ormond Street
Hospital explains the causes, symptoms and treatment
of innocent heart murmurs and where to get help.

A heart murmur is an extra or unusual What causes

sound made by the heart. It is usually the
heart murmurs?
sound of the blood negotiating its way
around the tight bends inside a young Young children have small, slim chests so
child’s heart and resembles a “whooshing” their hearts are nearer to a stethoscope
or “swishing” noise. Murmurs are than those of teenagers and adults, and
sometimes also heard in the neck as blood their heart rate is faster.
streams back towards the heart. Blood has to negotiate two tight bends
Heart murmurs are very common in babies as it flows through the heart. The flow
and young children. In the vast majority of blood travelling through the heart
of cases the heart is working normally and and blood vessels in this way can also
there isn’t anything to worry about. make a noise, and this is known as an
‘innocent’ murmur. Innocent murmurs
In fact many young children have heart can sometimes come and go, becoming
murmurs and neither they nor their noisier if the heart is beating fast - after
parents will ever know anything about it. exercise or with a fever - and quieter as a
Occasionally though, a heart murmur child sleeps.
can be linked to a problem with the way As the years go by, the heart rate slows
that blood flows through the heart, or a and the heart grows and lies deeper
structural problem with the heart. Even if within the body. The normal bends within
an underlying problem is the reason for a the heart become less tight, and an
baby’s heart murmur, there is treatment innocent murmur therefore disappears.
available. A heart murmur very rarely
proves fatal. In rarer cases, a heart murmur can come
from abnormal blood flow within the
heart and blood vessels. This might be
related to either a narrow or leaking
valve, or a hole in the wall between the
two chambers of the heart or between
the two main arteries of the heart.

Sheet 1 of 2 Ref: 2012F0393 © GOSH NHS Foundation Trust April 2012

 What are the signs are not signs of a serious heart problem in
children with no other symptoms.
and symptoms of a
A child might be referred to a heart
heart murmur?
specialist for a thorough examination
There are no outward signs or symptoms
and possibly further investigations.
of an innocent heart murmur. Its presence
For instance an echocardiogram (an
is usually only detected during a routine
ultrasound scan of the heart) might be
doctor’s examination.
recommended. This scan is designed to
show the structure, function and blood
flow of the heart, and will aim to rule out
How are heart murmurs any underlying problem.
diagnosed?
A doctor can hear normal heart valves
closing and producing regular heart What happens next?
sounds by listening to the heart with In most cases, an innocent murmur
a stethoscope. In this way, the doctor disappears as a child gets older and the
will be able to detect the presence of a bends within the heart become less tight.
heart murmur.

Further help and advice

How are heart murmurs Talk to the child’s doctor or health visitor.
treated? Contact one of the support organisations
Some murmurs are clearly ‘innocent’ below:
when heard through a stethoscope. If
British Heart Foundation
the murmur is innocent, no follow-up or
Tel (Heart Help Line): 0300 330 3311 (calls
treatment is needed.
charged at local rate)
If the quality of the murmur suggests that Website: www.bhf.org.uk
it might be due to some sort of structural
Heartline
oddity, the cause of the murmur needs to
Tel: 03300 224 466 (local rate number)
be established. Even then, most murmurs
Website: www.heartline.org.uk

Notes

Compiled by the GOSH web team

Great Ormond Street Hospital for Children NHS Foundation Trust, Great Ormond Street, London WC1N 3JH

www.gosh.nhs.uk

Sheet 2 of 2 Ref: 2012F0393 © GOSH NHS Foundation Trust April 2012