How Are Heart Murmurs Diagnosed?

Doctors use a stethoscope (STETH-uh-skope) to listen to heart sounds and hear murmurs. They often notice innocent heart murmurs during routine checkups or physical exams.

Doctors may also find abnormal murmurs during routine checkups. Murmurs caused by congenital heart defects are often heard at birth or during infancy. Doctors may hear murmurs caused by other heart problems at any age.

Doctors usually refer people with abnormal murmurs to a heart specialist (a pediatric cardiologist for children or a cardiologist for adults) for further evaluation and testing.

Physical Exam

Doctors listen carefully to the heart with a stethoscope to help decide if a murmur is innocent or abnormal. They listen to the loudness, location, and timing of the murmur to classify and describe the sound. This helps the doctor begin to diagnose the cause of the murmur.

The doctor also:

• Takes a medical and family history
• Does a complete physical exam, looking for signs of illness or physical problems (such as blue coloring of the skin, delayed growth, and feeding problems in an infant)
• Asks about symptoms, such as chest pain, shortness of breath (especially with exercise), dizziness, or fainting

Evaluation of Murmurs

When evaluating a heart murmur, the doctor pays attention to a number of things, including:

• How faint or loud the sound is. The doctor grades the murmur on a 1–6 scale (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 can also be heard in the neck or back.
• Whether the sound has a high, medium, or low pitch.
• How long the sound lasts.
• How breathing, exercise, or change of body position affects the sound.

Classification of the Murmur

Doctors classify murmurs as:

• Systolic—heard when the heart is squeezing and pumping blood out of the heart.
• Diastolic—heard when the heart is relaxing and filling with blood. Diastolic murmurs are often a sign of a heart defect or heart disease and should be further evaluated.
• Continuous—heard during the entire heartbeat. These are often a sign of a heart defect or heart disease and should be further evaluated.

Tests

When doctors hear a murmur that might be abnormal, they order tests, such as:

• Chest x ray. A chest x ray takes a picture of your heart and lungs. It can show if the heart is enlarged, and it can show some problems of the heart and lungs.
• EKG (electrocardiogram). This test is used to measure the rate and regularity of your heartbeat. The EKG can help rule out a variety of heart problems.

A heart specialist—a pediatric cardiologist or a cardiologist—will most likely do the followup testing. These tests might include:

• Echocardiogram. This test uses sound waves to create a moving picture of your heart. Echocardiogram provides information about the size and shape of your heart and how well your heart chambers and valves are functioning. The test also can identify areas of poor blood flow to the heart, areas of heart muscle that are not contracting normally, and previous injury to the heart muscle caused by poor blood flow.
• There are several different types of echocardiograms, including a stress echocardiogram. During this test, an echocardiogram is done both before and after your heart is stressed either by having you exercise or by injecting a medicine into your bloodstream that makes your heart beat faster and work harder. A stress echocardiogram is usually done to find out if you have decreased blood flow to your heart (coronary artery disease).
• Cardiac catheterization and angiography. Cardiac catheterization is a procedure in which a thin, flexible tube (catheter) is passed through an artery or vein in your upper thigh (groin) or in your arm to reach the heart, after you are sedated. This allows measurement of pressure inside the heart and blood vessels. Angiography involves injecting a dye that can be seen by using x ray. This helps the doctor see the flow of blood through the heart and blood vessels.