Causes and Treatment of Heart Murmurs

A heart murmur is an extra or abnormal sound that is heard when listening to your heart through a stethoscope (also known as cardiac auscultation). A heart murmur may be congenital (something you are born with) or a condition that develops later in life.

A heart murmur can sometimes be harmless and pose no risk to your health. Other heart murmurs may be a sign of heart disease, particularly if they develop (or worsen) later in life and are accompanied by symptoms like fatigue, shortness of breath, and chest pain.

If there is a serious cause of a heart murmur, surgery or medications may help correct the problem.

This article describes the symptoms and causes of a heart murmur. It also explains how heart murmurs are diagnosed and what can be done to fix or manage a serious heart murmur.

What Does a Heart Murmur Sound Like?

When listening through a stethoscope, a normal heartbeat will sound like "lub-DUB" as the atrioventricular heart valves open and shut. When there is a heart murmur, the heartbeat may be accompanied by a whooshing or swishing sound if the valves don't shut properly and blood is propelled out of the heart turbulently.

Heart murmurs affect people of all ages from newborns to elderly adults. A heart murmur can begin at any age and may change throughout a person's life.

Many heart murmurs, called "innocent" murmurs, are not associated with any underlying heart problems. Other murmurs, called "abnormal" murmurs, are associated with heart problems that could cause serious health issues.

A heart murmur caused by heart disease may cause symptoms like:

• Severe fatigue
• Chest pain
• Lightheadedness or dizziness
• Shortness of breath, especially with physical exertion
• Heart palpitations
  

What Are the Causes of a Heart Murmur?

Abnormal heart murmurs can be caused by a variety of heart diseases. The most common causes vary based on a person's age.

Older Adults

Abnormal murmurs are most common among adults over 60. They can be caused by:

• Mitral valve prolapse (caused by the bulging of the valve)
• Aortic valve stenosis (caused by the narrowing of the valve)
• Mitral regurgitation (caused when blood backflow into the heart)
• Endocarditis (a type of heart infection)
• Arrhythmias (an abnormal heart rhythm)
• A previous heart attack

Babies and Children

A murmur may be the result of a congenital heart defect, such as:

• Tetralogy of Fallot (a birth defect that affects blood flow through the heart)
• Ventricular septal defects (a birth defect that causes an abnormal connection between the lower chambers of the heart)

A heart murmur may be serious if it is heard right at birth. Babies born with a heart murmur may have bluish skin, especially on the fingers or lips. These are signs of a medical emergency.

Children with a congenital heart murmur may experience slow weight gain and be shorter than their expected height. They often have exercise intolerance and will complain that they don't like sports or gym class.

Young Adults

A murmur could be due to a structural problem not diagnosed in childhood. Or, it could be due to a heart condition that developed later in life (including those that cause heart murmurs in older adults).

The most common type of murmur in young adults is a harmless "innocent murmur," also known as a flow murmur.

Pregnant People

It is not common to develop serious heart disease during pregnancy. Pregnancy may cause an innocent murmur due to the increased volume of blood flowing through blood vessels as the baby grows. Once the child is delivered, the heart murmur will disappear.

How to Tell if a Heart Murmur Is Serious

Your healthcare provider or a heart specialist called a cardiologist may detect a heart murmur during your routine medical examination.

A heart murmur can be louder or last longer than other heart sounds. Others are quiet and difficult to hear. Others still can come and go.

Generally speaking, a heart murmur is presumed innocent if you are younger and experience no other symptoms. However, this is not always the case as some murmurs can get progressively worse over time. For this reason, your healthcare provider may want to regularly monitor your heart sounds.

If a heart murmur is accompanied by symptoms of heart disease (or you are older and have risk factors for heart disease), your provider may order tests to help pinpoint the cause. The same may apply if you are young and your heart murmur is especially loud or irregular.

These tests may include:

• Electrocardiogram (ECG): An ECG is a non-invasive test that is used to assess heart rhythm. Wires are placed on your chest to produce a tracing that reflects your heart rhythm.
• Echocardiogram: An echocardiogram, often referred to as an echo, is a non-invasive ultrasound of the heart. A small device is placed on your chest, which produces a video of your heart in action. Your heart rhythm and its anatomical structure (including the valves) can be evaluated using this test.
• Cardiac catheterization: This is an interventional diagnostic test that allows your medical team to look inside your heart. During this procedure, a wire is used to guide a catheter into a blood vessel (usually in the arm or groin) and up into the heart. Dye is then injected through the catheter and into the heart arteries. Detailed information about the valves, blood vessels, and blood pressure can be obtained using this test.
• Cardiac magnetic resonance imaging (MRI): Magnetic resonance imaging allows healthcare providers to view the structure of the heart in detail. This form of imaging is noninvasive, though there may be adverse effects associated with the contrast agent used. It may also not be appropriate for people with any form of metal implant, such as a pacemaker.
• Cardiac computed tomography (CT): This form of imaging uses multiple X-rays to create a three-dimensional image of internal organs and structures.

In most cases, the cause of a heart murmur is diagnosed with a non-invasive echocardiogram.

How Is Heart Murmur Fixed?

Some heart murmurs are caused by conditions that require surgery and/or medical management, while some do not require any intervention at all.

Treatment and/or follow-up care will depend on the type of heart murmur you have.

Surgery

In some situations, emergency surgery may be necessary for a heart murmur. This is especially true for babies born with a severe congenital heart defect. Some defects (like hypoplastic left heart syndrome) will need to be repaired in stages using several surgeries. Some children may have to wait until they are physically bigger before having a heart defect repaired.

Heart surgery for children and adults can involve open-heart surgery, in which the chest is opened to access the damaged valve or chamber. In some instances, a minimally invasive procedure called cardiac catheterization can be used to repair the heart by assessing the heart through a blood vessel in your groin, arm, or neck.

Medical Management

There are some medical approaches for treating heart problems that cause murmurs.

Sometimes medications are used to prevent complications, but cannot treat the underlying problem. For example, some people with valve disease or arrhythmias may need an anticoagulant (blood thinner) to prevent blood clots.

Summary

A heart murmur is an abnormal whoosing or swishing sound that is heard when listening to your heartbeats on a stethoscope. A murmur can be something you are born with or something you acquire later in life due to heart disease. The cause can usually be diagnosed with an echocardiogram and ECG.

Some heart murmurs are "innocent" and don't cause any problems. Others associated with heart disease usually cause symptoms and may require treatment with medications or surgery.