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Heart murmurs and other sounds

Contents of this page:


Heart, section through the middle
Heart, section through the middle

Alternative Names    Return to top

Chest sounds - murmurs; Heart sounds - abnormal

Definition    Return to top

Murmurs are blowing, whooshing, or rasping sounds produced by turbulent blood flow through the heart valves or near the heart.

Considerations    Return to top

A doctor can check heart sounds by listening with a stethoscope over the surface of the chest. An echocardiogram can find the exact cause of the murmur.

The heart has four chambers: two upper chambers (atria) and two lower chambers (ventricles). The heart has valves that close with each heart beat, causing blood to flow in only one direction. The valves are located between the atria and ventricles, and between the ventricles and the major vessels 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 occur when the heart valves close. Normally, there is no sound when the heart valve opens. In a person with congenital heart disease or heart valve disease, a "click" sound may be heard during a physical exam.

Because the heart is also divided into a "right side" and a "left side," sometimes these sounds may be divided. Most commonly noted is a "split S2." This is caused when the right and left ventricles relax and the valves close at slightly different times. It is normal. But occasionally, the split can be a sign of an abnormality, such as enlargement of one of the ventricles or narrowing of a valve.

Murmurs occur when a valve does not close tightly (such as with mitral regurgitation) and blood leaks backward. They also can occur when the blood flows through a narrowed or stiff valve (such as with aortic stenosis).

The health care provider can often identify the valve involved and whether you have regurgitation or stenosis during the exam. The location, quality, and timing of the murmur are all important. 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.

A murmur does not necessarily mean that you have a disease or disorder, and not all heart disorders cause murmurs.

Murmurs are classified ("graded") depending on their ability to be heard by the examiner. The grading is on a scale. Grade I can barely be heard. An example of a murmur description is a "grade II/VI murmur." (This means the murmur is grade 2 on a scale of 1 - 6).

In addition, a murmur is described by the stage of the heartbeat when the murmur is heard. When a murmur is more prominent, the doctor may be able to feel it with the palm of the hand over the heart.

The following are important clues to the cause of the murmur:

For example, a presystolic murmur is heard just BEFORE systole. It 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.

Causes    Return to top

Significant murmurs can be caused by:

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

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

What to Expect at Your Office Visit    Return to top

The health care provider will usually discover a heart murmur during a physical examination. You 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:

References    Return to top

Otto CM, Bonow RO. Valvular Heart Disease. In: Libby P, Bonow RO, Mann DL, Zipes DP. Libby: Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Philadelphia, Pa: Saunders Elsever; 2007:chap 62.

Fang JC, O'Gara PT. The History and Physical Examination: An Evidence-Based Approach. In: Libby P, Bonow RO, Mann DL, Zipes DP. Libby: Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Philadelphia, Pa: Saunders Elsever; 2007:chap 11.

Update Date: 5/15/2008

Updated by: Alan Berger, MD, Assistant Professor, Divisions of Cardiology and Epidemiology, University of Minnesota, Minneapolis, MN. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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