What Is a Heart Murmur?
When your heart beats, it typically makes a distinct rhythmic sound, the well-known “lub-dub.” These sounds occur when your heart valves close with each beat. In people with a heart murmur, there are extra sounds created in the heart that sound like whooshing or swishing, explains George J. Philippides, MD, a Mass General Brigham cardiologist and chief of Cardiology at Newton-Wellesley Hospital. “These sounds may be created by choppy or turbulent flow of blood through abnormal heart valves.”
Most heart murmurs are benign, which means they’re harmless and don’t cause health problems or put you at risk for other conditions. However, some heart murmurs are more serious and require treatment.
What causes heart murmurs?
“It’s easiest to think of heart murmurs by splitting them into two categories: murmurs that are innocent or harmless, and murmurs that are associated with significant heart diseases,” says Dr. Philippides. He explains the causes of each category:
Benign heart murmurs
Heart murmurs are common in children, and most are harmless. “Up to 75% of children have a heart murmur at some point,” says Dr. Philippides. “These tend to be benign, and they’re just caused by high blood flow inside a healthy heart.”
Other causes of high blood flow that may lead to a benign heart murmur include:
Anemia
Fever
Intense exercise
Overactive thyroid (hyperthyroidism)
Rapid growth in children and teenagers
“Murmurs caused by these types of conditions or states are typically harmless and don’t require monitoring or treatment,” says Dr. Philippides. A benign heart murmur is often temporary.
Serious heart murmurs
“Some murmurs can be caused by significant heart or heart valve problems,” says Dr. Philippides. Causes of serious heart murmurs include:
Calcium deposits on heart valves due to the aging process
Congenital heart conditions such as valve abnormalities or holes in the heart
Infections of the heart lining or valves that cause damage to the heart
Rheumatic fever
In addition, certain factors raise your risk of developing a heart murmur, such as:
Aging
Family history of heart defects or heart valve problems
History of an infection that affected your heart
Intravenous (IV) drug use, which increases the risk of valve infections
What are heart murmur symptoms?
Heart murmur symptoms typically depend on whether the murmur is benign or serious. “In many people with a murmur, there are no symptoms,” says Dr. Philippides. “That’s usually because the heart valve problem is very mild.”
Mild murmurs are often first discovered during a routine health appointment when your provider listens to your heart using a stethoscope (a tool used to listen to your heartbeat and breathing). With a heart murmur, your provider will hear the telltale whooshing sound as your heart beats.
If the valve problem causing the murmur is more severe, you may have symptoms such as:
Shortness of breath
A cough that doesn’t go away
Swelling in the abdomen, ankles, or neck
Reduced capacity for physical activity
In infants who were born with a problematic heart murmur, signs may include:
Blue or gray fingernails
Lack of growth
Poor appetite
What are the tests for a heart murmur?
“The first and most important test for a heart murmur is to have your health care provider perform a very careful examination of your heart by listening to it through a stethoscope,” says Dr. Philippides. “Your provider will listen closely to different parts of your chest and heart.”
If your provider diagnoses the murmur as benign, you typically don’t need any further medical care for it. If your provider is concerned the murmur may be serious, you’ll have additional testing.
“The most common test your provider would order is an echocardiogram, also called a cardiac ultrasound,” says Dr. Philippides. “This test uses sound waves to look at different structures of the heart and how blood is flowing through the valves.”
You may need additional imaging tests if the echocardiogram doesn't give enough information about the murmur.
What are the treatments for heart murmur?
A benign murmur doesn’t require treatment, but a murmur due to a heart problem requires ongoing monitoring and care. “Depending on how severe the heart problem is, your provider will want to see you at regular intervals, usually at least yearly,” says Dr. Philippides. “Your provider will ask you if you have any new symptoms that are worrying, and they’ll listen to your heart to see if the murmur has changed or gotten worse. You also may need a periodic echocardiogram.”
Medications for heart murmurs caused by valve problems or other conditions
Treatment depends on your underlying heart valve problem and other conditions. You may need medications such as:
Antiarrhythmic medications to control an irregular heart rhythm
Blood pressure medication
Blood thinners to prevent blood clots from forming in the heart and lower the risk of stroke
Diuretics to decrease the fluid buildup that can happen with heart valve problems
Surgery for heart valve conditions
If the heart valve problem progresses, you may need surgery. The valve may require repair, or you may need a procedure to replace it with a healthy one. Newer procedures allow a cardiologist or surgeon to perform a valve repair or replacement through a catheter, which is much less invasive than standard surgery.
Dr. Philippides notes that some people with heart valve conditions, such as those that cause murmurs, are at higher risk of heart infections. Infections can happen when bacteria enter your bloodstream and cause an infection of your heart valve. If you have a heart valve condition, ask your provider if you should take preventive antibiotics before dental work or other procedures.
Learn about Mass General Brigham Heart services