Heart Murmurs

A heart murmur is an abnormal heart sound detected when a doctor listens to the heart through a stethoscope. Some heart murmurs are signs of heart defects, such as a hole between two chambers of the heart or a malformed heart valve. In children, however, the vast majority of heart murmurs arise from no known cause—and, fortunately, have no medical significance. These benign murmurs are known as innocent murmurs, and doctors estimate that up to 70 percent of active, healthy children develop them at some time. Furthermore, long-term studies of people who had such murmurs during childhood indicate that they are not associated with an increased risk of adult heart disease or any other lasting complications.

The vast majority of murmurs detected in childhood disappear by the time the child is ten to 14 years old. In about ten percent of cases, an innocent murmur persists into adulthood. Even in an adult, however, such a murmur does not indicate serious disease.

WHEN SHOULD I SUSPECT THAT MY CHILD HAS A HEART MURMUR?
Heart murmurs are usually detected when a doctor examines the child with a stethoscope. Pediatricians often discover them during routine school screenings or in presport or precamp examinations.

Because newborns have rapid heart rates, their heart murmurs are harder to detect. To hear all the heart sounds, the pediatrician listens from several angles, including the armpit and the back.

WHAT CAUSES HEART MURMURS?
Innocent heart murmurs arise as part of the normal functioning of the heart. They may, for example, be due to vibrations of the heart muscle.

Murmurs also may be organic, arising from a variety of abnormalities in the heart's structure. For example, they may be present if a valve does not open properly or, conversely, if a valve leaks.

IS MEDICAL ATTENTION NECESSARY?
Your pediatrician will determine if the murmur is innocent or requires further evaluation. Innocent murmurs require no medical attention. If the pediatrician determines that the murmur may signal a more complicated condition, the child will be referred to a pediatric cardiologist or a pediatrician experienced in heart disease for an examination. In fact, murmurs are by far the most common reason children are referred to cardiologists for evaluation.

HOW CAN THE PEDIATRICIAN TELL IF MY CHILD HAS HEART MURMURS?
By listening to the heart with a stethoscope, an experienced pediatric cardiologist can usually tell whether the murmur signals the presence of a defect. The doctor may also feel the child's chest and abdomen, tap on the chest and take the child's pulse. To support the diagnosis, imaging studies of the child's heart may be needed, particularly echocardiography, which is a kind of ultrasound.

WHEN DOES A CHILD WITH A HEART MURMUR REQUIRE TREATMENT?
Although the majority of murmurs turn out to be innocent, sometimes they do signal the presence of heart disease. In such cases, treatment depends on the underlying problem. If the structural deformity is severe, surgery may be required.

In some cases, no treatment is necessary, but certain precautions must be taken. For example, a murmur may signal that the child's heart contains a structural defect that is not dangerous in itself but makes the heart more prone to infection than a totally normal heart. Children with these types of defects may need to take special measures—such as taking antibiotics before dental work—to prevent such infection.

GETTING HELP
Call your doctor if:
A baby or child who has been diagnosed as having a heart murmur develops any signs of heart malfunction. Signs to look for include:

• Poor sucking ability

• Extreme fatigue

• Bluish skin or lips

• Slowed growth and weight gain

Excerpt from THE DISNEY ENCYCLOPEDIA OF BABY & CHILD CARE, © 1995 DSH Communications, Inc. This material is based on current medical research and, to the best of the editors' knowledge and understanding, is accurate and valid. However the reader should not use information contained in this material to alter a medically prescribed regimen or as a form of self-treatment, without seeking the advice of a licensed physician.