Heart Murmur

Understanding a Heart Murmur

Understanding a Heart Murmur

Cross section of heart showing valves.

The heart makes sounds as it beats. These sounds occur as the heart valves open and close to allow blood to flow through the heart. A heart murmur is an extra noise heard during a heartbeat. The noise is caused when blood does not flow smoothly through the heart. Heart murmurs can be innocent (harmless) or abnormal (caused by a heart problem).

What causes a heart murmur?

An innocent heart murmur can be a normal finding for many people. It may also be caused by:

  • Fever

  • Exercise

  • Pregnancy

  • Anemia

  • Overactive thyroid gland

An abnormal heart murmur can be caused by heart problems such as:

  • A damaged or diseased valve. The valve may be too narrow for blood to flow through easily. Or it may have problems opening or closing, and may leak blood backward.

  • A hole in the heart (septal defect). This is a problem with the heart’s structure that a person is born with (congenital). It causes blood to leak through the wall that normally divides the left and right sides of the heart.

What are the symptoms of a heart murmur?

Heart murmurs do not usually cause symptoms. They tend to be found when your healthcare provider is listening to your heart for another reason. People with an abnormal heart murmur may have symptoms of the problem causing the murmur. Symptoms can include:

  • Feeling weak or tired

  • Shortness of breath, especially with exercise

  • Chest pain

  • Fast, pounding, or skipping heartbeat

  • Swollen ankles, feet, abdomen

  • Feeling dizzy or faint

  • Poor feeding and failing to grow normally (babies only)

How is a heart murmur treated?

An innocent heart murmur does not usually need treatment unless there is a clear cause, such as anemia. In such cases, treating the underlying cause should cure the murmur. In some cases, an innocent heart murmur may go away on its own.

Treatment for an abnormal heart murmur depends on the cause. Options may include:

  • Medicines to help relieve symptoms

  • Procedures or surgery to fix or replace a diseased or damaged heart valve

  • Procedures or surgery to fix a hole in the heart

What are the complications of a heart murmur?

An innocent heart murmur has no complications. Complications of an abnormal heart murmur will vary depending on the cause. Possible complications include:

  • Heart failure. This problem occurs when the heart is so weak it no longer pumps blood well.

  • Infection of the heart’s valves or inner lining (infective endocarditis)

  • Blood clots and stroke

  • Fainting

  • Heart attack

  • Sudden cardiac arrest. This problem occurs when the heart suddenly stops beating.

When should I call my healthcare provider?

Call your healthcare provider right away if you have any of these:

  • Chest pain

  • Shortness of breath

  • Fever of 100.4°F (38°C) or higher, or as directed

  • Symptoms that don’t get better with treatment, or symptoms that get worse

  • New symptoms

When your Child has a Heart Murmur

When Your Child Has a Heart Murmur

Healthcare provider listening to boy's chest with stethoscope.

The heart makes sounds as it beats. These sounds occur as the heart valves open and close to allow blood to flow through the heart. A heart murmur is an extra noise. When blood does not flow smoothly through the heart or heart valves, it causes the noise. This is called turbulence. Heart murmurs can be harmless (innocent) or caused by a heart problem (pathologic).

What causes a heart murmur?

An innocent heart murmur is caused by mild turbulence in blood flow within the heart. A pathologic heart murmur is often caused by a structural heart defect. This can include:

  • Septal defects (holes in the dividing walls of the heart that allow blood to pass through)

  • Heart valve problems (valve has trouble opening or closing)

  • Artery-vein fistulas (abnormal connections between a blood vessel on the left side of the heart and a blood vessel on the right side of the heart)

  • Backflow of blood through the valve due to pressure or blood flow abnormalities

What are the symptoms of a heart murmur?

Innocent heart murmurs cause no symptoms. Symptoms related to a pathologic heart murmur depend on the underlying cause of the murmur.

How is a heart murmur diagnosed?

Your child's doctor or healthcare provider may detect a heart murmur during a physical exam. He or she can hear heart noises with a stethoscope. A heart murmur is classified by how loud it is, its location, when it occurs during the heart’s pumping cycle, the way it changes through the heart beat, and its sound qualities. If the doctor suspects the murmur is pathologic, your child may be referred to a pediatric cardiologist. This is a doctor who diagnoses and treats heart problems in children. The following tests may be done:

  • Chest X-ray. This test takes a picture of the heart and lungs. The picture can show your child’s heart size and shape. It can show some problems that may occur in the heart or lungs.

  • Electrocardiogram (ECG or EKG). During this test, the electrical activity of the heart is recorded to check for abnormal heart rhythms (arrhythmias) or problems with heart structure.

  • Echocardiogram (echo). During this test, sound waves are used to create a picture of the heart. This test can show problems with heart structure or heart function. This includes showing how well the heart pumps, if the heart is enlarged, or if there are any valve problems.

How is a heart murmur treated?

An innocent heart murmur requires no treatment because it’s not caused by a heart problem. Treatment for a pathologic murmur depends on the underlying cause. The cardiologist will evaluate your child’s condition and discuss treatment options with you if needed.

What are the long-term concerns?

Most innocent murmurs usually go away by the time children become adolescents or young adults. A murmur may also become louder or more noticeable, or even return if a child has a fever or another cause of a fast heart rate. If pathologic heart murmurs aren’t diagnosed or treated, severe symptoms may result and cause serious health problems. These can include heart failure, arrhythmias, or respiratory problems.

Saint Luke's Cardiovascular Consultants

A leader in cardiac care, Saint Luke’s Cardiovascular Consultants treats patients throughout the Kansas City area and surrounding communities. Our medical team consists of both board-certified clinical cardiologists as well as physicians certified in specialty areas of cardiology including interventional cardiology, echocardiography, nuclear cardiology, preventive cardiology, and electrophysiology.