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Heart murmurs

Show Alternative Names
Chest sounds - murmurs
Heart sounds - abnormal
Murmur - innocent
Innocent murmur
Systolic heart murmur
Diastolic heart murmur

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

Considerations

The heart has 4 chambers:

  • Two upper chambers (atria)
  • Two lower chambers (ventricles)

The heart has valves that close with each heartbeat, causing blood to flow in only one direction. The valves are located between the chambers.

Heartbeat - Animation

The heart is a four-chambered organ with four main vessels, which either bring blood to or carry blood away from the heart. The four chambers of the heart are the right atrium, the right ventricle, the left atrium, and the left ventricle. The great vessels of the heart include the superior and inferior vena cava, which bring blood from the body to the right atrium, the pulmonary artery, which transports blood from the right ventricle to the lungs. The last of the great vessels is the aorta, the body's largest artery, which transports oxygen-rich blood from the left ventricle to the rest of the body. If we remove some of the tough fibrous coating of the heart and great vessels, you can get a better look at the heart beating. If you look carefully, you can see a series of one-way valves that keep the blood flowing in one direction. If we inject dye into the superior vena cava, you can watch it pass through the heart as it goes through the cardiac cycle. The blood first enters the heart into the right atrium. Blood passes from the right atrium through the tricuspid valve and into the right ventricle. When the right ventricle contracts, the muscular force pushes blood through the pulmonary semilunar valve into the pulmonary artery. The blood then travels to the lungs, where it receives oxygen. Next, it drains out of the lungs via the pulmonary veins, and travels to the left atrium. From the left atrium, the blood is forced through the mitral valve into the critically important left ventricle. The left ventricle is the major muscular pump that sends the blood out to the body systems. When the left ventricle contracts, it forces the blood through the aortic semilunar valves and into the aorta. From here, the aorta and its branches carry blood to all the tissues of the body.

Murmurs can happen for many reasons, such as:

  • When a valve does not close tightly and blood leaks backward (regurgitation)
  • When blood flows through a narrowed or stiff heart valve (stenosis)

There are several ways in which your health care provider may describe a murmur:

  • Murmurs are classified ("graded") depending on how loud the murmur sounds with a stethoscope. 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 to 6).
  • In addition, a murmur is described by the stage of the heartbeat when the murmur is heard. A heart murmur may be described as systolic or diastolic. (Systole is when the heart is squeezing out blood and diastole is when it is filling up with blood.)

When a murmur is more noticeable, the provider may be able to feel it with the palm of the hand over the heart. This is called a "thrill" and means the murmur is grade 4 or higher.

Things the provider will look for in the exam include:

  • Does the murmur occur when the heart is resting or contracting?
  • Does it last throughout the heartbeat?
  • Does it change when you move?
  • Can it be heard in other parts of the chest, on the back, or in the neck?
  • Where is the murmur heard the loudest?

Causes

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

Other heart murmurs may indicate an abnormality in the heart. These abnormal murmurs can be caused by:

  • Problems of the aortic valve (aortic regurgitation, aortic stenosis)
  • Problems of the mitral valve (chronic or acute mitral regurgitation, mitral stenosis)
  • Hypertrophic cardiomyopathy
  • Pulmonary regurgitation (backflow of blood into the right ventricle, caused by failure of the pulmonary valve to close completely)
  • Pulmonary valve stenosis
  • Problems of the tricuspid valve (tricuspid regurgitation, tricuspid stenosis)

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

Multiple murmurs may result from a combination of heart problems.

Children often have murmurs as a normal part of development. These murmurs do not need treatment. They may include:

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

What to Expect at Your Office Visit

A provider can listen to your heart sounds by placing a stethoscope on 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?
  • Do you have chest pain, fainting, shortness of breath, or other breathing problems?
  • Have you had swelling, weight gain, or bulging veins in the neck?
  • Does your skin have a bluish color?

The provider 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:

Review Date: 5/8/2022

Reviewed By

Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

References

Fang JC, O'Gara PT. History and physical examination: an evidence-based approach. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 13.

Goldman L. Approach to the patient with possible cardiovascular disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 45.

Otto CM, Nishimura RA, Bonow RO, et al. 2020 ACC/AHA guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol. 2021;77(4):e25-197. PMID: 33342586 pubmed.ncbi.nlm.nih.gov/33342586/.

Swartz MH. The heart. In: Swartz MH, ed. Textbook of Physical Diagnosis: History and Examination. 8th ed. Philadelphia, PA: Elsevier; 2021:chap 14.

Disclaimer

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

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Heartbeat

Heartbeat

Animation

Heart - section through the middle - Illustration Thumbnail

Heart - section through the middle

The interior of the heart is composed of valves, chambers, and associated vessels.

Illustration

Heart valves - Illustration Thumbnail

Heart valves

The valves of the heart open and close to control the flow of blood entering or leaving the heart.

Illustration

 
Heartbeat

Heartbeat

Animation

 
Heart - section through the middle - Illustration Thumbnail

Heart - section through the middle

The interior of the heart is composed of valves, chambers, and associated vessels.

Illustration

Heart valves - Illustration Thumbnail

Heart valves

The valves of the heart open and close to control the flow of blood entering or leaving the heart.

Illustration

 
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Heartbeat - Animation

The heart has four chambers and four main blood vessels that either bring blood to the heart, or carry blood away.

The four chambers are the right atrium and right ventricle and the left atrium and left ventricle. The blood vessels include the superior and inferior vena cava. These bring blood from the body to the right atrium. Next is the pulmonary artery that carries blood from the right ventricle to the lungs. The aorta is the body's largest artery. It carries oxygen-rich blood from the left ventricle to the rest of the body.

Beneath the tough fibrous coating of the heart, you can see it beating.

Inside the chambers are a series of one-way valves. These keep the blood flowing in one direction.

Dye injected into the superior vena cava, will pass through all the heart's chambers during one cardiac cycle.

Blood first enters the heart's right atrium. A muscle contraction forces the blood through the tricuspid valve into the right ventricle.

When the right ventricle contracts, blood is forced through the pulmonary semilunar valve into the pulmonary artery. Then it travels to the lungs.

In the lungs, the blood receives oxygen then leaves through the pulmonary veins. It returns to the heart and enters the left atrium.

From there, blood is forced through the mitral valve into the left ventricle. This is the muscular pump that sends blood out to the rest of the body.

When the left ventricle contracts, it forces blood through the aortic semilunar valve and into the aorta.

The aorta and its branches carries the blood to all the body's tissues.

 

Heartbeat - Animation

The heart has four chambers and four main blood vessels that either bring blood to the heart, or carry blood away.

The four chambers are the right atrium and right ventricle and the left atrium and left ventricle. The blood vessels include the superior and inferior vena cava. These bring blood from the body to the right atrium. Next is the pulmonary artery that carries blood from the right ventricle to the lungs. The aorta is the body's largest artery. It carries oxygen-rich blood from the left ventricle to the rest of the body.

Beneath the tough fibrous coating of the heart, you can see it beating.

Inside the chambers are a series of one-way valves. These keep the blood flowing in one direction.

Dye injected into the superior vena cava, will pass through all the heart's chambers during one cardiac cycle.

Blood first enters the heart's right atrium. A muscle contraction forces the blood through the tricuspid valve into the right ventricle.

When the right ventricle contracts, blood is forced through the pulmonary semilunar valve into the pulmonary artery. Then it travels to the lungs.

In the lungs, the blood receives oxygen then leaves through the pulmonary veins. It returns to the heart and enters the left atrium.

From there, blood is forced through the mitral valve into the left ventricle. This is the muscular pump that sends blood out to the rest of the body.

When the left ventricle contracts, it forces blood through the aortic semilunar valve and into the aorta.

The aorta and its branches carries the blood to all the body's tissues.

 
 
 
 

 

 
 

 
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