A heart murmur is a blowing, whooshing, or rasping sound heard during a heartbeat. The sound is caused by rough blood flow through the heart valves or near the heart.

Chest sounds - murmurs; Heart sounds - abnormal; Murmur - innocent; Innocent murmur; Systolic heart murmur; Diastolic heart murmur

Many heart murmurs are harmless. These types of murmur are called innocent murmurs. They will not cause any symptoms or problems. Innocent murmurs do not need treatment.

Significant murmurs can be caused by:

• Aortic regurgitation
• Aortic stenosis
• Hypertrophic cardiomyopathy (idiopathic hypertrophic subaortic stenosis)
• Mitral regurgitation - acute
• Mitral regurgitation - chronic
• Mitral stenosis
• Pulmonary regurgitation (backflow of blood into the right ventricle, caused by failure of the pulmonary valve to close completely)
• Pulmonary stenosis
• Tricuspid regurgitation
• Tricuspid stenosis

Significant murmurs in children are more likely to be caused by:

• Anomalous pulmonary venous return (an abnormal formation of the pulmonary veins)
• Atrial septal defect (ASD)
• Coarctation of the aorta
• Patent ductus arteriosus (PDA)
• Ventricular septal defect (VSD)

Children often have murmurs as a normal part of development. These murmurs do not require treatment, and may include:

• Pulmonary flow murmurs
• Still's murmur
• Venous hum

A doctor or nurse can listen to your heart sounds using a tool called a stethoscope, which is placed over your chest. You will be asked questions about your medical history and symptoms, such as:

• Have other family members had murmurs or other abnormal heart sounds?
• Do you have a family history of heart problems?
• What other symptoms do you have, such as:
  • Bluish skin color (cyanosis)
  • Chest pain
  • Distended neck veins
  • Fainting (syncope)
  • Liver enlargement
  • Lung sound changes
  • Shortness of breath
  • Swelling
  • Weight gain

The doctor may ask you to squat, stand, or hold your breath while bearing down or gripping something with your hands to listen to your heart.

The following tests may be done:

• Chest x-ray
• ECG
• Echocardiography

Goldman L. Approach to the patient with possible cardiovascular disease. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24thed. Philadelphia, PA: Saunders Elsevier; 2011:chap 50.

Sabatine MS, Cannon CP. The history and physical examination:an evidence-based approach. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald'sHeart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 12.

Bonow RO, Carabello BA, Chatterjee K, de Leon AC Jr., Faxon DP, Freed MD, et al. 2006 Writing Committee Members; American College of Cardiology/American Heart Association Task Force. 2008 Focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1998 Guidelines for the Management of Patients with Valvular Heart Disease): endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. Circulation. 2008;118:e523-e661.