A heart murmur is an extra, unexpected, or abnormal sound that is caused by the flow of blood through the heart.
Except in unusual cases, a heart murmur is only noticed by a healthcare professional when he or she listens to the heart with a stethoscope. The heart normally makes certain sounds while beating. However, extra, unexpected, or abnormal sounds may also be heard. These are called murmurs. A murmur can be normal, or it can indicate the presence of a serious heart disease.
Heart murmurs often have no symptoms and usually are noticed only during a physical exam. Symptoms may include: chest painrapid heartbeat, known as tachycardiaa pounding heartbeat, also known as palpitationsbreathlessness, or shortness of breathfatiguedizzinessweaknessfevercoughcyanosis, a paleness or bluish color in the skin
The loudest heart murmurs can be heard without a stethoscope.
Normal or "innocent" heart murmurs are caused by normal blood flow. They are not a cause for concern.
Causes of abnormal heart murmurs include: anemia, or low red blood cell countshigh levels of thyroid hormone, called hyperthyroidismrheumatic fever, a complication of strep throat that can damage heart valvesendocarditis, an infection of the heart that can also damage heart valvesother types of heart valve damage or changes, such as stiffened valves from calcium deposits, which are common in the elderly. Damaged valves are often described as "leaky," which is called regurgitation, or "narrowed," which is also called stenosis. A heart attack can also cause a murmur from heart valve changes.artificial heart valvescongenital heart disease, or heart defects present at birth, which can cause holes in the heart or deformed heart valvesmitral valve prolapse, which is a "leaky" heart valve that often has no known cause and is usually not seriouspregnancythickening of the heart muscles or enlargement of the heart, which can occur due to high blood pressureheart failure, also called congestive heart failure
Other causes are also possible.
Prevention is related to the cause. Treatment of strep throat with antibiotics can prevent cases due to rheumatic fever. Treatment of high blood pressure can prevent many cases due to congestive heart failure. Many cases cannot be prevented.
Heart murmurs are usually detected during a physical exam when the healthcare professional. The type of sound heard, and its timing during the heartbeat cycle, can usually help suggest the cause of the murmur.
Other tests may also be done to help figure out the cause of the murmur. An electrocardiogram (ECG), is commonly done. A chest x-ray may also be performed to see if the heart is enlarged or abnormal. An echocardiogram, an imaging test that uses sound waves to view the heart, may also be done. Blood tests may be used as well. A test called an arterial blood gas, for example, can measure the level of oxygen in the blood.
The long-term effects of heart murmurs depend on the cause. Innocent heart murmurs are normal and have no long-term effects. If the heart murmur is due to a serious cause, such as a heart attack or congestive heart failure, the underlying condition may cause death if not treated. In other cases, such as anemia or hyperthyroidism, treatment will often stop the murmur, and there may be no long-term effects.
Heart murmurs are not contagious and pose no risk to others.
Treatment for heart murmurs will depend on the cause. Normal heart murmurs need no treatment. If hyperthyroidism is causing the murmur, medications or surgery may be needed to treat the thyroid condition. Anemia may be treated with iron supplements, blood transfusions, or other therapy, depending on the cause of the anemia. Mitral valve prolapse often needs no treatment. High blood pressure may be treated with blood pressure medications. Heart infections may be treated with antibiotics or surgery. If congenital heart disease is present, open heart surgery may be needed to repair the heart. Heart valve surgery can repair or replace damaged valves. Other treatments are also possible.
Side effects depend on the treatments used. For example, antibiotics can cause stomach upset, allergic reactions, or other effects. Blood pressure medications may cause sleepiness or erectile dysfunction. Surgery can be complicated by bleeding, infection, or reactions to anesthesia.
This depends on the cause of the murmur and the response to treatment. If anemia or hyperthyroidism are the cause and these are treated, the murmur may be "cured." However, these conditions may need further follow up or treatment. Someone who has a valve replaced may need to take medications to thin the blood, called anticoagulants, for life. A person with an artificial or damaged heart valve may also be advised to take antibiotics before any dental work or surgery. This is thought to reduce the risk of heart valve infections.
Heart murmurs may need close monitoring by a healthcare professional. Someone with a leaky or narrowed valve, high blood pressure, or congestive heart failure will need lifelong monitoring. A person should seek medical attention for any worsening or recurring symptoms.
Mayo Clinic Family Health Book, David E. Larson, 1996/ Professional Guide to Signs and Symptoms, Springhouse, 1997.