A heart murmur is an extra or unusual sound heard during a heartbeat. Heart Murmurs range from very faint to very loud. They sometimes sound like a whooshing or swishing noise.
Normal heartbeats make a "lub-DUPP" or "lub-DUB" sound. This is the sound of the heart valves closing as blood moves through the heart. Doctors can hear these sounds and heart murmurs using a stethoscope.
Overview of Heart Murmurs
There are two types of heart murmurs: innocent (harmless) and abnormal.
People who have innocent heart murmurs have normal hearts. They usually have no other signs or symptoms of heart problems. Innocent murmurs are common in healthy children. Many, if not most, children will have heart murmurs heard by their doctors at some time in their lives.
People who have abnormal murmurs may have other signs or symptoms of heart problems. Most abnormal murmurs in children are due to congenital heart defects. These are heart defects that are present at birth.
In adults, abnormal murmurs are most often due to heart valve problems caused by infection, disease, or aging.
A heart murmur isn't a disease, and most murmurs are harmless. Innocent murmurs don't cause symptoms or require you to limit physical activity. Although an innocent murmur may be a lifelong condition, your heart is normal and you likely won't need treatment.
The outlook and treatment for abnormal heart murmurs depends on the type and severity of the heart problem causing them.
Signs and Symptoms
Most people who have heart murmurs don’t have any other signs or symptoms of heart problems. These murmurs usually are innocent (harmless).
Some people who have heart murmurs do have signs or symptoms of heart problems. The signs and symptoms may include:
- Blue coloring of the skin, especially on the fingertips and inside the mouth
- Poor eating and abnormal growth (in infants)
- Shortness of breath
- Excessive sweating
- Chest pain
- Dizziness or fainting
- Fatigue (feeling very tired)
Signs and symptoms depend on the problem causing the murmur and how severe that problem is.
Doctors use a stethoscope to listen to heart sounds and hear heart murmurs. They often notice innocent heart murmurs during routine checkups or physical exams.
Doctors also may find abnormal heart murmurs during routine checkups. When a congenital heart defect causes a murmur, it’s often heard at birth or during infancy. Abnormal murmurs caused by other heart problems can be heard in patients of any age.
Doctors usually refer people who have abnormal murmurs to cardiologists or pediatric cardiologists for further care and testing.
Cardiologists are doctors who treat adults who have heart problems. Pediatric cardiologists treat children who have heart problems.
Your doctor will carefully listen to your heart or your child’s heart with a stethoscope to find out whether a murmur is innocent or abnormal. He or she will listen to the loudness, location, and timing of the murmur to classify and describe the sound. This will help your doctor diagnose the cause of the murmur.
Your doctor also may:
- Ask about your medical and family histories.
- Do a complete physical exam. He or she will look for signs of illness or physical problems. These may include blue coloring of the skin and delayed growth and feeding problems (in infants).
- Ask about your symptoms, such as chest pain, shortness of breath (especially with physical activity), dizziness, or fainting.
Evaluating Heart Murmurs
When evaluating a heart murmur, your doctor pays attention to many things, such as:
- How faint or loud the sound is. Your doctor will grade the murmur on a scale of 1 to 6 (1 is very faint and 6 is very loud).
- When the sound occurs in the cycle of the heartbeat.
- Exactly where the sound is heard in the chest and whether it also can be heard in the neck or back.
- Whether the sound has a high, medium, or low pitch.
- How long the sound lasts.
- How breathing, physical activity, or change of body position affects the sound.
Classifying Heart Murmurs
Doctors classify murmurs as systolic, diastolic, or continuous.
A systolic murmur is heard when the heart is squeezing and pumping blood out of the heart.
A diastolic murmur is heard when the heart is relaxing and filling with blood. Diastolic murmurs often are a sign of a heart defect or heart disease, and further checking is likely needed.
A continuous murmur is heard during the entire heartbeat. These murmurs often are a sign of a heart defect or heart disease, and further checking is likely needed.
Diagnostic Tests and Procedures
If your doctor suspects you or your child has an abnormal heart murmur, he or she may order one or more of the following tests.
Chest X Ray
A chest x ray is a painless test that creates pictures of the structures inside your chest, such as your heart and lungs. This test is done to find the cause of symptoms, such as shortness of breath and chest pain.
An EKG (electrocardiogram) is a simple test that detects and records the electrical activity of the heart. An EKG shows how fast the heart is beating, the heart’s rhythm (steady or irregular), and where in the body the heartbeat is being recorded.
An EKG also records the strength and timing of electrical signals as they pass through each part of the heart.
This test is used to detect and locate the source of heart problems. The results from an EKG also may be used to rule out certain heart problems.
Echocardiography (EK-o-kar-de-OG-ra-fee) is a painless test that uses sound waves to create pictures of your heart. The test gives information about the size and shape of your heart and how well your heart’s chambers and valves are working.
The test also can find areas of heart muscle that aren’t contracting normally due to poor blood flow or injury from a previous heart attack.
There are several different types of echocardiography, including stress echocardiography. This type is done both before and after a cardiac stress test. During this test, you exercise or take medicine (given by your doctor) to make your heart work hard and beat fast. Stress echocardiography shows whether you have decreased blood flow to your heart (a sign of coronary artery disease).
If your doctor thinks that your or your child’s abnormal heart murmur is due to a heart problem, such as a congenital heart defect, he or she may want you to have a procedure called cardiac catheterization (KATH-e-ter-i-ZA-shun).
For this procedure, a long, thin, flexible tube called a catheter is put into a blood vessel in your arm, upper thigh (groin), or neck and threaded to your heart. Through the catheter, your doctor can perform diagnostic tests and treatments on your heart.
Innocent Heart Murmurs
Healthy children who have innocent heart murmurs don’t need treatment because they have normal hearts. If your child has an innocent murmur, alert his or her doctor during regular checkups.
Pregnant women who have innocent heart murmurs due to extra blood volume also don’t need treatment.
You may have an innocent heart murmur due to an illness or condition, such as anemia, hyperthyroidism, or fever. The murmur will go away once the illness or condition is treated.
Abnormal Heart Murmurs
Treatment for abnormal heart murmurs depends on the heart problems causing them. For example, treatment for a congenital heart defect depends on the type and severity of the defect. Treatment may include medicine or surgery. (For more information, see the Diseases and Conditions Index Congenital Heart Defects article.)
When an infection or disease causes a heart murmur, treatment depends on the type, amount, and severity of the heart damage. Treatments may include medicine or surgery.