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Heart Murmur

What is a heart murmur?

A heart murmur is an extra or unusual sound that can be heard when your healthcare provider listens to your heart. The sound is a whooshing or swishing sound that is made as blood flows through the heart valves. A heart murmur does not necessarily mean that there is something wrong with the heart.

What is the cause?

Murmurs may be normal and innocent, or they may be abnormal.

Innocent murmurs are common in young children. Innocent murmurs may come and go during childhood. Some innocent murmurs start in early infancy and last less than 6 months. Other innocent murmurs last until the teens. In all cases of innocent murmurs, the heart structure is normal. They may happen when the heart beats faster and changes the rate and amount of blood moving through the heart.

Some of the conditions that might cause your child's heart to beat faster are:

  • Anemia
  • Fever
  • Physical activity
  • Stress

Abnormal murmurs are usually caused by heart defects or heart disease, such as:

  • Abnormal heart structures, such as abnormal valves or defects in the walls of the heart, which your child may have had since birth
  • Damaged or overworked heart valves resulting from medical problems, such as rheumatic fever or heart infection

What are the symptoms of heart problems that may cause a murmur?

Heart problems that cause heart murmurs may not cause any symptoms for many years. When they do cause symptoms, the symptoms may include:

  • Shortness of breath
  • Lightheadedness
  • Fast or slow heart rate
  • Chest pain
  • Unusual tiredness when your child exerts himself, like when playing or climbing stairs

How is it diagnosed?

A heart murmur is usually discovered when your healthcare provider listens to your child’s heart. Your healthcare provider can usually tell the difference between an innocent murmur and a murmur that may be caused by a medical problem.

Your provider will ask about your child's growth and may ask if your child is able to exercise as much as other children of the same age. Usually no tests are needed when an innocent murmur is diagnosed.

If your provider thinks the murmur may be a sign of a problem, your child may have other tests to look for the cause of the murmur, such as:

  • An ECG (also called an EKG or electrocardiogram), which measures and records your child’s heartbeat
  • A chest X-ray to look for an enlarged heart, signs of heart muscle failure, and birth defects
  • An echocardiogram, which uses sound waves (ultrasound) to see how well your child’s heart is pumping. The images may show a hole in the wall of the heart or an abnormal valve.

How is it treated?

Innocent murmurs do not need treatment. Children with innocent murmurs can safely participate in sports and other activities. Your child may need medicine or surgery to treat other causes of heart murmurs.

How can I help take care of my child?

Follow your healthcare provider's instructions. Ask your provider:

  • How and when you will hear your child’s test results
  • If there are activities your child should avoid and when he can return to his normal activities
  • How to take care of your child at home
  • What symptoms or problems you should watch for and what to do if your child has them

Make sure you know when your child should come back for a checkup. Keep all appointments for provider visits or tests.

How can I help prevent a heart murmur?

Little is known about how to prevent the birth defects that cause heart murmurs. However, a healthy lifestyle may prevent or lessen heart problems later in life.

Developed by RelayHealth.
Pediatric Advisor 2015.3 published by RelayHealth.
Last modified: 2015-03-01
Last reviewed: 2013-10-20
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright ©1986-2015 McKesson Corporation and/or one of its subsidiaries. All rights reserved.
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