Heart murmurs are sounds during your heartbeat cycle — such as whooshing or swishing — made by turbulent blood in or near your heart. These sounds can be heard with a stethoscope. A normal heartbeat makes two sounds like "lubb-dupp" (sometimes described as "lub-DUP"), which are the sounds of your heart valves closing.
Heart murmurs can be present at birth (congenital) or develop later in life. A heart murmur isn't a disease — but murmurs may indicate an underlying heart problem.
Often, heart murmurs are harmless (innocent) and don't need treatment. Some heart murmurs may require follow-up tests to be sure the murmur isn't caused by a serious underlying heart condition. Treatment, if needed, is directed at the cause of your heart murmur.
If you have a harmless heart murmur, more commonly known as an innocent heart murmur, you likely won't have any other signs or symptoms.
An abnormal heart murmur may cause no obvious other signs or symptoms, aside from the unusual sound your doctor hears when listening to your heart with a stethoscope. But if you have these signs or symptoms, they may indicate a heart problem:
- Skin that appears blue, especially on your fingertips and lips
- Swelling or sudden weight gain
- Shortness of breath
- Chronic cough
- Enlarged liver
- Enlarged neck veins
- Poor appetite and failure to grow normally (in infants)
- Heavy sweating with minimal or no exertion
- Chest pain
- Dizziness
- Fainting
Causes (Heart Murmurs)
There are two types of heart murmurs: innocent murmurs and abnormal murmurs. A person with an innocent murmur has a normal heart. This type of heart murmur is common in newborns and children.
An abnormal heart murmur is more serious. In children, abnormal murmurs are usually caused by congenital heart disease. In adults, abnormal murmurs are most often due to acquired heart valve problems.
Innocent heart murmurs
An innocent murmur can occur when blood flows more rapidly than normal through the heart. Conditions that may cause rapid blood flow through your heart, resulting in an innocent heart murmur, include:
- Physical activity or exercise
- Pregnancy
- Fever
- Not having enough healthy red blood cells to carry adequate oxygen to your body tissues (anemia)
- An excessive amount of thyroid hormone in your body (hyperthyroidism)
- Phases of rapid growth, such as adolescence
Innocent heart murmurs may disappear over time, or they may last your entire life without ever causing further health problems.
Abnormal heart murmurs
The most common cause of abnormal murmurs in children is when babies are born with structural problems of the heart (congenital heart defects).
Common congenital defects that cause heart murmurs include:
Holes in the heart or cardiac shunts. Known as septal defects, holes in the heart may or may not be serious, depending on the size of the hole and its location.
Cardiac shunts occur when there's an abnormal blood flow between the heart chambers or blood vessels, which may lead to a heart murmur.
- Heart valve abnormalities. Congenital heart valve abnormalities are present at birth, but sometimes aren't discovered until much later in life. Examples include valves that don't allow enough blood through them (stenosis) or those that don't close properly and leak (regurgitation), such as mitral valve prolapse.
Other causes of abnormal heart murmurs include infections and conditions that damage the structures of the heart and are more common in older children or adults. For example:
- Valve calcification. This hardening or thickening of valves, as in mitral stenosis or aortic valve stenosis, can occur as you age. Valves may become narrowed (stenotic), making it harder for blood to flow through your heart, resulting in murmurs.
Endocarditis. This infection of the inner lining of your heart and valves typically occurs when bacteria or other germs from another part of your body, such as your mouth, spread through your bloodstream and lodge in your heart.
Left untreated, endocarditis can damage or destroy your heart valves. This condition usually occurs in people who already have heart valve abnormalities.
- Rheumatic fever. Although now rare in the United States, rheumatic fever is a serious condition that can occur when you don't receive prompt or complete treatment for a strep throat infection. It can permanently affect the heart valves and interfere with normal blood flow through your heart.
Treatments and drugs (Heart Murmurs)
An innocent heart murmur generally doesn't require treatment because the heart is normal. If innocent murmurs are the result of an illness, such as fever or hyperthyroidism, the murmurs will go away once that condition is treated.
If you or your child has an abnormal heart murmur, treatment may not be necessary. Your doctor may want to monitor the condition over time. If treatment is necessary, it depends on what heart problem is causing the murmur and may include medications or surgery.
Medications
The medication your doctor prescribes depends on the specific heart problem you have. Some medications your doctor might give you include:
- Medications that prevent blood clots (anticoagulants).Your doctor may prescribe anticoagulants, such as aspirin, warfarin (Coumadin, Jantoven) or clopidogrel (Plavix). An anticoagulant prevents blood clots from forming in your heart and causing a heart attack or stroke.
- Water pills (diuretics). Diuretics remove excess fluid from your body, which can help treat other conditions that might worsen a heart murmur, such as high blood pressure.
- Angiotensin-converting enzyme (ACE) inhibitors. ACE inhibitors lower your blood pressure. High blood pressure can worsen underlying conditions that cause heart murmurs.
- Statins. Statins help lower your cholesterol. Having high cholesterol seems to worsen some heart valve problems, including some heart murmurs.
- Beta blockers. These drugs lower your heart rate and blood pressure. They're used for some types of heart valve problems.
Surgery
Many valve conditions can't be treated with medications alone. Depending on your heart condition, your doctor may recommend one of these options to treat a damaged or leaky valve:
Valve repair
To repair a valve, your doctor may recommend one of the following procedures:
- Balloon valvuloplasty. This procedure is performed to relieve a narrowed valve. During a balloon valvuloplasty, a small catheter containing an expandable balloon is threaded into your heart, placed into the valve and then expanded to help widen the narrowed valve.
- Annuloplasty. In this procedure, your surgeon tightens the tissue around the valve by implanting an artificial ring. This allows the leaflets to come together and close the abnormal opening through the valve.
- Repair of structural support. In this procedure, your surgeon replaces or shortens the cords that support the valves (chordae tendineae and papillary muscles) to repair the structural support. When the cords and muscles are the right length, the valve leaflet edges meet and eliminate the leak.
- Valve leaflet repair. In valve leaflet repair, your surgeon surgically separates, cuts or pleats a valve flap (leaflet).
Valve replacement
In many cases, the valve has to be replaced. Options include:
Open-heart surgery. This is the primary surgical treatment for severe valve stenosis. Your surgeon removes the narrowed valve and replaces it with a mechanical valve or a tissue valve.
Mechanical valves, made from metal, are durable, but carry the risk of blood clots forming. If you receive a mechanical valve, you'll need to take an anticoagulant medication, such as warfarin (Coumadin, Jantoven), for life to prevent blood clots.
Tissue valves — which may come from a pig, cow or human deceased donor — often eventually need replacement. Another type of tissue valve replacement that uses your own pulmonary valve (autograft) is sometimes possible.
Transcatheter aortic valve replacement (TAVR). A less invasive approach, TAVR involves replacing the aortic valve with a prosthetic valve via an artery in your leg or in a small incision in your chest.
In some cases, a valve can be inserted via a catheter into a tissue replacement valve that needs to be replaced (valve-in-valve procedure).
TAVR is usually reserved for individuals with severe aortic valve stenosis who are at increased risk of complications from aortic valve surgery.
Doctors used to recommend that most people with abnormal heart murmurs take antibiotics before visiting the dentist or having surgery due to possible complications from a bacterial infection that affects the lining of your heart (infective endocarditis).
Doctors no longer recommend antibiotics before procedures, except for people at highest risk of complications of infective endocarditis, such as those who have an artificial heart valve or people with certain congenital heart defects.
Prevention (Heart Murmurs)
While there's not much you can do to prevent a heart murmur, it is reassuring to know that heart murmurs are not a disease and are often harmless. For children, many murmurs go away on their own as children grow. For adults, murmurs may disappear as the underlying condition causing them improves.
Cardiomyopathy
