Children's Hospital Colorado

Heart Murmur

What is a heart murmur in children?

A heart murmur is a noise that can be heard while listening to the heart using a stethoscope. Sometimes the murmur is simply the sound of normal blood flow moving through a normal heart (known as an innocent murmur). Other times, a murmur may be a sign of a heart problem (called an organic murmur).

The difference between innocent and organic heart murmurs in children

Heart murmurs are very common, occurring in up to 70% of kids by the time they are school age. Most murmurs are not a cause for concern and do not affect a child's health. These are called "innocent murmurs," which are produced by a normal, healthy heart. An innocent murmur can come and go throughout childhood, and usually goes away as the child gets older. Many kids will have a heart murmur at some point during their lives.

Other heart murmurs can indicate a problem with the heart. This type of murmur is caused by problems inside the heart, such as an abnormal valve or a hole in an inner wall separating the left from the right side of the heart. These murmurs are much rarer and occur in less than 1% of the population.

If your child's doctor hears a heart murmur and suspects your child may have a heart condition, he or she will order further tests. The treatment plan your cardiologist recommends will depend on the underlying heart condition.

What are the signs and symptoms of heart murmurs?

Usually, there are no visible signs of heart murmur symptoms. The most common way murmurs are diagnosed is during a routine pediatric checkup when your child's doctor listens to the heart. Innocent murmurs will have no other symptoms.

Murmurs are classified by how loud they are. Louder murmurs are usually more serious than quieter ones.

If your child has an abnormal heart murmur, there may be symptoms that indicate there is an underlying heart condition.

Heart murmur symptoms may include:

  • Shortness of breath
  • Trouble feeding and gaining weight
  • Sweating while feeding
  • Fatigue
  • Cyanosis (a blue tint to the lips and skin)

Please tell your doctor if you notice these symptoms in your child.

Diagnosing the cause of a heart murmur

A murmur is diagnosed when a doctor hears something extra or unusual in the sound of blood flow. If your child's pediatric cardiologist thinks a murmur might be abnormal, he or she will order an electrocardiogram (EKG) or echocardiogram (ECHO) to look at the structure of the heart and how it's functioning. These are safe and painless tests that use electrical signals from the heart and sound waves to produce a movie of the heart at work.

From the EKG and/or ECHO, our team will usually be able to diagnose what's causing the murmur and, if necessary, develop a treatment plan to fix it.

Heart murmur treatment at Children's Hospital Colorado

The specialists in our pediatric Cardiology Clinic are trained to differentiate innocent murmurs (which mean your child is perfectly healthy) from those more serious murmurs that may be a sign of a heart problem. Because murmurs are so common and frequently harmless, many families will be reassured after a thorough physical examination of your child.

Patients with more concerning heart murmurs will receive further evaluation. If a heart problem is found, our pediatric cardiology team will help create a heart murmur treatment plan designed specifically for your child. Some options include medication, electrophysiology, minimally invasive cardiac catheterization and surgery.

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