Heart Murmurs in Children: What They Mean and When to Worry

Signs That Do Need Checking

The murmur itself rarely tells you how urgent things are. How your child is doing does. A heart problem shows itself differently in babies and in older children.

Coming to Limi in an emergency? Call 0813 408 5400 on the way so the team can prepare, and have someone else drive if you can. You can count a baby's breaths with our breathing counter.

What a Heart Murmur Is

A normal heartbeat has two main sounds, often described as "lub-dub", made by the heart's valves closing. A murmur is an extra sound between them: a whooshing or swishing noise made by blood flowing through the heart and the large blood vessels. The doctor hears it with a stethoscope.

Blood flow makes some noise in everyone. In children, the chest wall is thin and the heart is close to the stethoscope, so the sound of normal flow is easy to hear. That is why murmurs are so much more common in children than in adults.

Innocent Murmurs: Very Common, and Harmless

An innocent murmur (also called a normal, functional or flow murmur) is the sound of blood flowing through a normal heart. Studies suggest that half or more of all children have one at some time, most often between about 3 and 7 years. An innocent murmur:

• does not mean there is anything wrong with the heart;
• does not need treatment, medicine or a special diet;
• does not mean your child must avoid sport or play;
• can sound louder when your child has a fever, is anaemic, is excited or has just been running, and quieter when they are calm;
• may change when your child lies down or sits up;
• often becomes quieter or disappears as the child grows.

Hearing the word "murmur" frightens many parents, and relatives may call it "a hole in the heart". If the doctor says the murmur is innocent, your child's heart is healthy. Mention it at future check-ups so it is not investigated again.

What the Doctor Listens For

A doctor experienced with children can often tell an innocent murmur from one that needs a closer look by listening and examining. They think about:

• When in the heartbeat it happens. Most innocent murmurs happen while the heart squeezes. A murmur while the heart relaxes is more likely to need a scan.
• How loud and harsh it is. Soft, musical murmurs are usually innocent. Loud, harsh murmurs, or one that can be felt as a buzz through the chest wall, need a scan.
• Where it is loudest, and whether it spreads to the neck or back.
• Whether it changes when the child lies down, sits or stands.
• The rest of the examination: pulses in the arms and legs, the oxygen level, breathing, the liver size, growth and colour.
• The history: feeding, growth, breathlessness, fainting, chest pain, and heart problems in the family.

When a Heart Scan Is Needed, and What Happens

The doctor asks for a heart scan (echocardiogram, often called "an echo") if the murmur does not sound innocent, if it is found in a newborn, if the child has any of the signs above, if the oxygen level is low, or if the child has a condition that often comes with heart problems, such as Down syndrome. Sometimes a heart tracing (ECG) or chest X-ray is also done.

1. Your child lies on a couch with the upper body undressed, or in a gown. You can stay with them the whole time.
2. A little cool gel goes on the chest, and a smooth probe is moved over the chest and just under the ribs and neck.
3. Pictures of the heart show on a screen. The person scanning can see the chambers, valves, walls and blood flow, and measure them.
4. It takes a while. Often around 20 to 45 minutes. Your child needs to lie fairly still; a favourite toy, a video on your phone or a feed for a baby helps. Very occasionally a young child who cannot keep still is given a sleep medicine.
5. It does not hurt and uses no radiation. The gel wipes off. Your child can eat, play and go back to school straight after.

The care team tells you when the result will be ready, and a children's heart specialist (paediatric cardiologist) explains it. Ask what was found, whether anything needs to be done, and when (or whether) to come back.

Heart Conditions Children Are Born With

About 1 in every 100 babies is born with a heart condition (congenital heart disease). They range from tiny holes that close by themselves to complex conditions that need surgery in the first weeks of life. Nothing the mother ate or did is usually the cause. Some common ones, in simple terms:

Ventricular septal defect (VSD)

A hole between the two pumping chambers. Small ones are common, often make a loud murmur, and many close on their own in the first years. Larger ones can cause breathlessness and poor growth, and may need closing.

Atrial septal defect (ASD)

A hole between the two upper chambers. Often causes no symptoms in childhood and may be found only by a soft murmur. Some close on their own; larger ones are usually closed in childhood, often by a catheter procedure.

Patent ductus arteriosus (PDA)

A blood vessel that every baby has before birth, which normally closes in the first days. If it stays open it can cause a murmur and, if large, breathlessness. It is more common in premature babies.

Narrowed valves

A valve that does not open fully (for example pulmonary or aortic stenosis), making the heart work harder. Mild narrowing may only need checks; more severe narrowing can often be stretched with a balloon.

Coarctation of the aorta

A narrowing of the main blood vessel from the heart. It can cause weak pulses in the legs and high blood pressure, and needs treatment.

More complex conditions

Such as tetralogy of Fallot or transposition of the great arteries. These often cause blue colour (cyanosis) in the first days or weeks and need specialist surgery.

Children can also develop heart problems after birth, for example from rheumatic fever (see below), infections or, rarely, heart muscle diseases that run in families.

Pulse Oximetry Screening in Newborns

Some serious heart conditions cause no murmur and no obvious signs in the first days, but lower the oxygen level in the blood slightly. A quick, painless test called pulse oximetry can pick up many of them. A soft sensor wrapped around the baby's right hand and a foot shines a light through the skin to measure oxygen. It is usually done after 24 hours of age, before the baby goes home.

A low or uneven reading does not always mean a heart problem — breathing problems and infection can also lower it — but it always needs a doctor to look further, usually with an echo. A normal result is reassuring but does not rule out every heart condition, so the signs above still matter. If your baby was born at home or discharged early and did not have this test, ask for it at the first check.

What Treatment Can Involve

Treatment depends entirely on the condition. The team explains what they found, what they recommend and why. Nobody can promise an outcome, but many heart conditions in children are very treatable.

• Watchful waiting. Many small holes and mild valve problems only need checks with an echo every so often. Your child lives normally in between.
• Medicines, to help the heart pump, remove extra fluid or control the heart rhythm, as prescribed.
• Feeding support, because babies with heart conditions use a lot of energy. When a baby needs extra energy to grow, the team sets up fortified feeds or tube feeding.
• Catheter procedures. A thin tube is passed through a blood vessel in the leg to the heart, to close some holes with a small device or stretch a narrow valve with a balloon, without opening the chest.
• Heart surgery, for larger holes and complex conditions, sometimes in stages over years.

The team explains each option, the risks, where it is done and what recovery looks like. You can always ask for a second opinion.

Teeth and the Heart

Bacteria from the mouth can enter the blood, and in children with some heart conditions they can cause a serious infection of the heart lining (infective endocarditis). Healthy teeth and gums are the most important protection: brush twice a day with fluoride toothpaste, limit sugary drinks and snacks, and see a dentist regularly. Tell the dentist about your child's heart condition. A small number of children with certain high-risk conditions (such as artificial valves or previous endocarditis) need antibiotics before some dental treatment — the heart team will tell you if your child is one of them. Our guide to children's teeth has more.

Sore Throats and Rheumatic Heart Disease

Rheumatic heart disease is still common in Nigeria and much of Africa, and it is preventable. It starts with a throat infection caused by a bacterium called group A streptococcus, most often in children aged 5 to 15. In some children, the body's reaction to that infection causes rheumatic fever a few weeks later, which can permanently damage the heart valves.

• Get a sore throat with fever checked, especially in a school-age child with swollen neck glands and no cough or runny nose. If the doctor prescribes an antibiotic, give the full course, even when your child feels better.
• Know the signs of rheumatic fever: fever with painful, swollen joints that move from one joint to another, a new murmur, breathlessness, or jerky movements the child cannot control. See a doctor the same day.
• After rheumatic fever, children usually need regular penicillin for years to prevent another attack and more valve damage. Keeping to this schedule protects the heart.

Heart Care at Limi and CardioCare

At Limi Children's Hospital, the Little Hearts programme brings the paediatric team, paediatric cardiology and echocardiography under one roof, so a child with a murmur or a heart question is assessed, scanned and given a clear plan. CardioCare Multispecialty Hospital (cardiocare.ng) is part of the same group, The Limi Hospitals, caring for families since 1982. When a child needs a procedure, the team explains the options and coordinates the next steps with you. Read about our children's heart service.

Questions Parents Ask