Definition

A heart murmur is a 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 benign (harmless) and are not caused by abnormalities in the heart. However, some heart murmurs can signal an underlying heart problem.

Heartbeat: Anatomy of the Heart
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Causes

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:

Risk Factors

Normal heart murmurs are more common in children 3-7 years old. Pregnant women are also at increased risk.

Risk factors for abnormal heart murmurs include:

  • Rheumatic fever
  • Atherosclerosis
  • High blood pressure
  • Autoimmune disease
  • Congenital heart defects or disease

Symptoms

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 symptoms.

Signs and symptoms of abnormal heart murmurs can include:

  • Rapid breathing or trouble breathing
  • Blue lips (cyanosis)
  • Lightheadedness
  • Chest pain
  • Rapid or irregular heartbeat
  • Exercise intolerance
  • Inability to gain weight 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.

Diagnosis

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.

Your bodily fluids may be tested. This can be done with blood tests.

Images may be taken of your heart. This can be done with:

Your heart's electrical activity may be tested. This can be done with electrocardiogram (ECG).

Treatment

Benign heart murmurs do not require treatment. Treatment of other heart murmurs depends on the underlying cause and extent of the problem.

Treatments include:

Medication

Medications can either treat the cause of the heart abnormality associated with the murmur or help compensate for its dysfunction:

  • Diuretics, angiotensin-converting enzyme inhibitors, digitalis—to treat heart failure
  • Antibiotics—to prevent or treat endocarditis

Surgery

Surgery is often necessary to treat severe heart abnormalities:

  • Replacement of defective heart valves with artificial ones
  • Correction of congenital heart defects
  • Removal of heart tumors

Prevention

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:

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.

Revision Information

  • American Heart Association

    http://www.heart.org

  • CardioSource—American College of Cardiology

    http://www.cardiosource.org

  • Canadian Cardiovascular Society

    http://www.ccs.ca

  • The College of Family Physicians of Canada

    http://www.cfpc.ca

  • Antibiotic prophylaxis. American Dental Association website. Available at: http://www.ada.org/2157.aspx. Accessed September 29, 2014.

  • Heart murmurs. American Heart Association website. Available at: http://www.heart.org/HEARTORG/Conditions/More/CardiovascularConditionsofChildhood/Heart-Murmurs%5FUCM%5F314208%5FArticle.jsp.Updated September 3, 2014. Accessed September 30, 2014.

  • Heart murmurs and your child. Kids Health—Nemours Foundation website. Available at: http://kidshealth.org/parent/medical/heart/murmurs.html. Updated May 2013. Accessed September 30,2014.

  • Heart murmur in children. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated December 14, 2012. Accessed September 30, 2014.