A heart murmur is simply an extra sound heard when listening to the heart. The normal sounds a heart makes are from the valves closing. If there is turbulence, or disturbance, in the flow of blood through the heart or major blood vessels around the heart, a murmur may be heard.

Types of Heart Murmurs

Heart murmurs can generally be divided into two categories:

• Murmurs that are not due to structural problems in the heart, also called "innocent murmurs" or "functional murmurs." These types of murmurs do not usually require follow-up visits with a cardiologist.
• Murmurs that are due to a structural problem of the heart (such as a hole in the heart, a narrowed heart valve or a leaky heart valve). These murmurs require further evaluation and follow-up with a cardiologist.

Common Questions and Answers

Our pediatrician heard a murmur in our child and has recommended that we see a pediatric cardiologist. What happens next?

Most murmurs can be categorized into one of the above two categories with a careful evaluation by a pediatric cardiologist. The doctor will ask questions about your child's growth, development, illnesses, and family history of heart disease.

The doctor will perform a thorough examination of your child, including careful listening to the heart with a stethoscope. Usually the pediatric cardiologist will obtain an electrocardiogram (ECG or EKG), or a test that records the heart's electrical activity as part of the evaluation of a heart murmur.

There are many sounds the heart can make that will help classify if a murmur as "innocent" or not. Occasionally, it can be hard to characterize a heart murmur on the basis of a physical examination and electrocardiogram. In these cases, an ultrasound of the heart, called an echocardiogram, may be performed to look at the structure of the heart in detail.

We have been told that our child has an innocent murmur. Could this become a problem as they grow up?

Innocent heart murmurs do not make the child more likely to have heart attacks or high blood pressure later in life. Your child's physical activities should not be restricted because of the heart murmur. The best way to ensure a healthy heart in the adult years is to develop good exercise and eating habits as a child. Generally, a child with an innocent heart murmur will be discharged from further cardiology follow up.

How common are innocent heart murmurs in children?

Innocent murmurs are very common! Some pediatric cardiologists estimate a heart murmur can be heard in 90% of children with anatomically normal hearts between the ages of 4-7 years.

What if my child has a murmur that is not innocent?

Even if your child has been diagnosed with a heart murmur that is due to a structural problem of the heart, this does not necessarily mean that your child will need heart surgery. Some murmurs are due to small holes between the two lower chambers of the heart. These holes do not get bigger and often close by themselves.

Other murmurs are due to narrowing or leaking of one of the valves of the heart, however this may be mild. Many children with structural heart disease lead normal active lives through adulthood.

Our dentist asked about the presence of a heart murmur in our child. What does that mean?

If your child has been diagnosed with an innocent murmur, no special precautions are needed for dental procedures or other invasive medical procedures since your child has a structurally normal heart.

However, people who have structural heart problems (such as a hole in the heart or an abnormal heart valve) are at higher risk for developing an infection of the heart (endocarditis) following routine teeth cleaning and other dental procedures such as fillings.

Endocarditis can also develop after invasive medical procedures (for example, procedures that use a lighted scope to examine the stomach, colon or bladder). Taking appropriate antibiotics as directed by your doctor or dentist at the time of these procedures can prevent endocarditis.

If your child requires antibiotics for such procedures because of a heart condition, your pediatric cardiologist will make note of that in the consultation letter that is sent to your primary care doctor. Most primary care doctors are comfortable prescribing the needed antibiotics prior to dental procedures, but our team can help if needed. 

It is very important that these recommendations be followed, as endocarditis is a serious infection that can be fatal.