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Alternative names Return to top
Chest sounds - murmurs; Heart sounds - abnormalDefinition Return to top
Murmurs are blowing, whooshing, or rasping sounds produced by turbulent blood flow in or near the heart. Often, they are caused by turbulent blood flow through the heart valves.Considerations Return to top
A doctor can evaluate heart sounds by listening with a stethoscope. They can be further evaluated with an echocardiogram to see what the exact cause of the murmur is.
The heart has four chambers -- two upper chambers (called atria) and two lower chambers (ventricles). The heart has valves that temporarily close to permit blood flow in only one direction. The valves are located between the atria and ventricles, and between the ventricles and the major arteries from the heart.
Normal heart sounds are called S1 and S2. They are the "lubb-dupp" sounds that are thought of as the heartbeat. These sounds are produced when the heart valves close.
Because the heart is also divided into a "right side" and a "left side," sometimes these sounds may be somewhat divided -- most commonly noted is a "split S2," caused when the right and left ventricles contract at very slightly different times. This is normal, but occasionally the nature of the split can indicate an abnormality such as enlargement of one of the ventricles.
Murmurs are blowing, whooshing, or rasping sounds. They are the result of vibrations caused by turbulent blood flow patterns. This can happen when a valve does not close tightly (such as with mitral regurgitation), or when the blood is flowing through a narrowed opening or a stiff valve (such as with aortic stenosis).
A murmur does not necessarily indicate a disease or disorder, and all heart disorders do not cause murmurs. Murmurs are classified ("graded") depending on their ability to be heard by the examiner. The grading is on a scale with grade I being barely detectable. An example of a murmur description is a "grade II/VI murmur." (This means the murmur is grade 2 on a scale of 1 to 6).
In addition, a murmur is described by the stage of the heartbeat when the murmur is heard. The following are important clues to the cause of the murmur:
For example, a presystolic murmur is heard just BEFORE systole and is usually caused by narrowing of the mitral or tricuspid valve (the valves between the atria and the ventricles).
The location where the health care provider hears the murmur loudest is also often noted.
Common Causes Return to top
Murmurs can be caused by:Call your health care provider if Return to top
This finding is usually detected during examination by a health care provider.What to expect at your health care provider's office Return to top
This finding is usually discovered by a health care provider during a physical examination. The patient may or may not have been aware of its presence. The physical examination will include careful attention to heart sounds.
The doctor may ask the following questions:
Diagnostic testing to determine the cause of a "new" murmur or other abnormal heart sound may include:
Update Date: 10/6/2003 Updated by: Elena Sgarbossa, M.D., cardiologist and freelance editor. Review provided by VeriMed Healthcare Network.
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Page last updated: 28 October 2004 |