Heart Murmur

What is a heart murmur?

A heart murmur is a sound that occurs between beats of the heart. The sound is made by blood flowing through the heart. It is similar to the sound water makes as it flows through a hose. A heart murmur does not necessarily mean that there is something wrong with the heart.

What is the cause?

Murmurs can result from:

• the shape of the heart
• abnormal heart structures, such as the valves or the walls of the heart, which you may have had since birth
• damaged or overworked heart valves resulting from medical problems such as rheumatic fever, heart attacks, or infective endocarditis

When your heart beats faster, it changes the rate and amount of blood moving through your heart. This, or an increased amount of blood in your body, can cause heart murmurs. Some of the conditions that can cause your heart to beat faster are:

• anemia
• high blood pressure
• pregnancy
• fever
• stress
• thyroid problems

Most heart murmurs are heard in people with normal hearts. These innocent heart murmurs—also called functional, normal, vibratory, or physiologic murmurs—do not cause any problems. They are common in children. Most murmurs go away for good as a child nears adulthood.

Many women develop a heart murmur during their pregnancy. These normal heart murmurs usually go away a week or so after delivery. Most heart murmurs during pregnancy are harmless as long as you have no previous history of heart problems.

What are the symptoms?

Innocent heart murmurs do not cause any symptoms.

If you have a heart problem that is causing the murmur, possible symptoms of a heart problem are:

• shortness of breath
• lightheadedness
• decreased ability to exert yourself, for example, during activities such as climbing the stairs or even making a bed
• frequent experiences of a rapid heart rate
• chest pain

Heart problems that cause heart murmurs may not cause any other symptoms for many years.

How is it diagnosed?

A heart murmur is usually discovered when your healthcare provider listens to your heart with a stethoscope. Innocent murmurs have a distinctive sound. Your healthcare provider can usually tell the difference between an innocent murmur and a murmur that may be caused by a medical problem.

If your provider thinks the murmur may be a sign of a problem, the following tests may be done to look for the cause of the murmur:

• An electrocardiogram, which records the heart's electrical activity.
• A chest X-ray to look for an enlarged heart, signs of heart muscle failure, and birth defects.
• An echocardiogram, which uses sound waves to create images of the heart structure. The images may show a hole in the wall of the heart or an abnormal valve.
• Cardiac catheterization, which uses dye injected through a thin tube and into your heart so that your healthcare provider can see the blood vessels or chambers of your heart on X-ray film. This procedure also allows measurement of the pressures in the heart chambers and of valve function.

How is it treated?

Innocent murmurs do not need treatment.

Treatment of heart problems that cause murmurs depends on:

• your symptoms
• the cause of the murmur
• the risk of heart damage over time if the abnormality is not corrected
• the risk of sudden complications, such as stroke or cardiac arrest (the heart suddenly stops beating)

If the murmur is caused by high blood pressure, lifestyle changes, such as a low-fat, low-salt diet and more exercise, may help. Medicines may also be prescribed to lower blood pressure. If the murmur is caused by a valve problem, you may need surgery.

How can I help take care of myself?

• Keep a healthy weight.
• Eat a healthy diet that is low in sodium and saturated and trans fat.
• Get regular exercise, as recommended by your healthcare provider.
• Do not smoke.
• If you are pregnant and have a murmur that is caused by a heart problem that you have had since birth, ask your healthcare provider whether your baby may be at increased risk for a heart complication during pregnancy. Even though most heart murmurs are harmless for you and your baby, you should always tell your healthcare provider if you start having problems with breathing or doing your usual physical activities--especially if you cannot catch your breath after you lie down.
• Call your healthcare provider if you notice that your heart is beating very fast, especially if you feel faint and are having trouble breathing.

How can I help prevent a heart murmur?

Little is known about how to prevent the birth defects that cause heart murmurs. However, you may be able to prevent or lessen problems such as coronary artery disease or hypertension, which can cause heart muscle damage, by having a healthy lifestyle:

• Keep a healthy weight.
• Eat a healthy diet that is low in sodium and saturated and trans fat.
• Stay fit with the right kind of exercise for you.
• Decrease stress.
• Don’t smoke.
• Limit your use of alcohol.

Also, be sure to get prompt treatment for strep infections. This will help prevent rheumatic heart disease, which can damage the heart.