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 can result from:

• Abnormal heart structures, such as oddly shaped or narrowed heart valves, or blood vessels or heart chambers that are larger than normal. You may have had the abnormal heart structure since birth, or it may have been caused by a medical problem, such as rheumatic fever, heart attack, injury, or heart infection.
• A heart valve that does not close properly, which may cause your blood to flow backwards.
• An increased flow of blood moving through your heart valves. This can happen with a fast heart rate and normal heart valves or heart valves with a narrowed opening. Some of the conditions that can increase your heart rate or the amount of blood are:
  • Anemia
  • High blood pressure
  • Fever
  • Stress
  • Thyroid problems
  • Pregnancy

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
• Feeling more tired than normal when you exert yourself, like when you climb stairs or even make a bed

How is it diagnosed?

A heart murmur is usually discovered when your healthcare provider listens to your heart. Your healthcare provider can usually tell the difference between a harmless 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, tests to look for the cause of the murmur may include:

• An ECG (also called an EKG or electrocardiogram), which measures and records your 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 heart is pumping. The images may show a hole in the wall of the heart or an abnormal valve.
• Cardiac catheterization, which uses dye injected into a vein and X-rays to look at blood flow through the blood vessels or chambers of the heart. This procedure also allows measurement of the pressures in the heart chambers and of valve function.

How is it treated?

Most murmurs are not caused by a heart problem, don’t cause any problems, and don’t need treatment. Murmurs that start in childhood usually go away in adulthood. Most heart murmurs during pregnancy are harmless if you do not have a history of heart problems. They usually go away a week or so after delivery.

If the murmur is caused by a heart problem, the treatment depends on:

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

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

How can I help take care of myself?

If you have heart disease, high blood pressure or another medical problem, follow your treatment plan. Be sure to take all medicines as prescribed by your healthcare provider.

Try to have a heart-healthy lifestyle.

• Eat a healthy diet.
• Keep a healthy weight. If you are overweight, talk to your provider about losing weight.
• Stay fit with the right kind of exercise for you.
• If you smoke, try to quit. Talk to your healthcare provider about ways to quit smoking.
• If you want to drink alcohol, ask your healthcare provider how much is safe for you to drink.

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 if there may be a risk of complications during your pregnancy. Even though most heart murmurs are harmless for you and your baby, you should always tell your healthcare provider if you have problems with breathing or doing your usual activities–especially if you cannot catch your breath after you sit or lie down.

Ask your healthcare provider:

• How and when you will hear your test results
• How long it will take to recover
• What activities you should avoid and when you can return to your normal activities
• How to take care of yourself at home
• What symptoms or problems you should watch for and what to do if you have them

Make sure you know when you should come back for a checkup.

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.