A heart murmur is an abnormal sound made by turbulent
blood flow in the heart. It sounds like whooshing or
swishing with each heartbeat. Some adults and many
children have incidental heart murmurs that are harmless
(benign) and are not caused by abnormalities in the
heart. At least 30% of children may have an innocent
heart murmur at some point during childhood. However,
some heart murmurs can signal an underlying heart
Heartbeat: Anatomy of the Heart
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Benign murmurs are caused by the normal flow of blood
through the heart and large vessels near the heart. The
murmur may come and go over time. Some things that can
increase blood flow and cause a benign heart murmur to
be heard include:
Abnormal heart murmurs can be due to:
Structural abnormalities of the heart
valves (most common)—These may be
present from birth (congenital). The
structural abnormalities may also be
acquired later in life due to certain
conditions, such as:
Abnormal holes in the structure of the
heart persisting after birth:
—connection between the
—connection between the
major artery and vein
near the heart
Structural abnormality of the heart
Congenital defects (eg,
Acquired (eg, myocardial
infarction , heart
failure , long-standing
high blood pressure )
Other congenital heart conditions, such
Coarctation of the aorta
Hypoplastic left heart
Tetralogy of Fallot
Endocarditis —infection of the inner
lining of heart valves and chambers
Cardiac myxoma—a benign soft tumor
within the heart (rare)
Risk factors for normal heart murmurs include:
Age: 3-7 years old
Risk factors for abnormal heart murmurs include:
High blood pressure
Congenital heart defects or disease
Benign heart murmurs usually cause no symptoms. Patients
with mitral valve prolapse sometimes complain of vague
chest discomfort and other symptoms. It remains unclear
whether or not the valvular abnormality is causing the
Signs and symptoms of abnormal heart murmurs can
Rapid breathing or trouble breathing
Blue lips (cyanosis)
Palpitations (feeling of rapid or
Failure-to-thrive in children
When Should I Call My Doctor?
If you think that you or your child has a heart
murmur, you should see the doctor.
Most benign heart murmurs are diagnosed during the
course of a routine physical exam with a stethoscope.
Some abnormal heart murmurs are also discovered this
way. Other abnormal heart murmurs are discovered
initially by their symptoms.
Tests may include:
Electrocardiogram —a test that records
the heart's electrical activity using
electrodes attached to the surface of
the chest. This does not diagnose the
cause of the murmur but can provide
other useful information about the
condition of the heart.
Chest x-ray —an x-ray to determine the
approximate size and shape of the heart,
and the presence of associated lung
swelling (pulmonary edema)
Echocardiogram —a test that uses
high-frequency sound waves (ultrasound)
to examine the size, shape, and motion
of the heart
Cardiac catheterization —a tube inserted
into the heart through an artery
(usually in the groin) to detect
problems with the heart's structure,
function, and blood supply
Blood tests—to check for evidence of a
recurrent heart attack or other diseases
that may affect the heart (eg, kidney
disease, infections, autoimmune
Benign heart murmurs require no treatment. Treatment of
other heart murmurs depends on the underlying cause and
extent of the problem.
Medicines can either treat the cause of the
heart abnormality associated with the murmur or
help compensate for its dysfunction:
inhibitors, digitalis—to treat
Antibiotics—to prevent or treat
Surgery is often necessary to treat
severe heart abnormalities:
Preventing benign heart murmurs is unnecessary. To help
reduce your risk of developing an abnormal heart murmur:
Get prompt testing and treatment for
strep throat to prevent rheumatic fever.
Reduce your risk of atherosclerosis to
help prevent valvular heart disease in
the distant future. To do this:
Eat a healthy diet with
plenty of fruits and
Get regular exercise.
If you smoke, quit.
If you have high blood
pressure or diabetes,
follow your treatment
Although not routinely recommended for every type of
heart murmur, you may need to take antibiotics before
and after some medical or dental procedures that could
allow bacteria to enter your bloodstream. Ask your
doctor if you need to take preventive antibiotics (eg,
if you have a high-risk condition).
American Heart Association http://www.heart.org/
Heart Information Network http://www.heartinfo.org/
Canadian Cardiovascular Society http://www.ccs.ca/
Canadian Family Physician http://www.cfpc.ca/
American Dental Association. Antibiotic prophylaxis. American Dental
Association website. Available at: http://www.ada.org/2157.aspx .
Accessed August 30, 2010.
American Heart Association. New guidelines regarding antibiotics to
prevent infective endocarditis. American Heart Association website.
Available at: http://www.americanheart.org/ . Accessed August 30, 2010.
Berkow R. The Merck Manual of Medical Information . New York, NY:
Heart murmur in children. EBSCO DynaMed website. Available at:
http:www.ebscohost.com/dynamed/ . Updated October 17, 2011. Accessed
February 9, 2012.
Heart murmurs. American Heart Association website. Available at:
http://www.americanheart.org/presenter.jhtml?identifier=4571 . Accessed
July 6, 2009.
Heart murmurs. Mayo Clinic website. Available at:
http://www.mayoclinic.com/health/heart-murmurs/DS00727 . Updated April
9, 2010. Accessed February 9, 2012.
Heart murmurs and your child. KidsHealth website. Available at:
http://kidshealth.org/parent/medical/heart/murmurs.html . Updated August
2010. Accessed February 9, 2012.
Medical dictionary: heart disease and stroke. Harvard Medical School
Consumer Health Information website. Available at:
Accessed July 6, 2009.
Review Date: 06/2012
Update Date: 00/61/2012