A heart murmur is a sound produced as blood flows through the chambers and large blood vessels of the heart during the cardiac cycle of contraction and relaxation.
Some murmurs are benign or harmless and are more of a finding than a condition. A benign murmur is not associated with any significant underlying abnormality of the heart or its vessels. Many young people can have benign flow murmurs and still have normal cardiac structure and function.
A pathologic heart murmur is one associated with a structural or functional abnormality of the heart. Most murmurs are produced as blood flows past the cardiac valves, which separate the chambers of the heart, or through the valves that lead to the great vessels of the lungs and the systemic circulation.
If the flow is excessive or turbulent, a murmur may be manifest. Blood flowing through a tight valve will produce a murmur. Blood that is leaking back across an improperly sealing valve also can cause a murmur. Occasionally, abnormal communications (holes) between chambers of the heart can result in the presence of a murmur.
Diagnosing a heart murmur begins with auscultation of (listening to) the heart-usually with a stethoscope. The location, quality, pitch and variation in the sound are all important clues to whether the murmur is benign or pathologic. One of the most useful tests in evaluating a murmur is an echocardiogram. This is a sound wave test that produces a real-time image of the beating heart and is very good in assessing the status and function of the cardiac valves and chambers. Sometimes further studies, such as cardiac catheterization, will be required to further track down the specific abnormality and its significance, and to determine which cases will require treatment.
Cardiac valve disease can have several causes. Congenital valve defects are those that an individual is born with. Some may be evident early in life while others may not cause symptoms until many years later. Acquired defects are those that are caused by a specific disease process. Rheumatic fever is a leading cause of valve-related illness. Infection of the heart valves, endocarditis, is, also a major contributing factor. Other valve problems can be the result of aging, when the valve tissue may degenerate or thicken and calcify, impairing its ability to function normally. By altering the function of the support structures of the mitral valve, blockage of the coronary arteries can cause valvular heart disease even if the valve tissue is normal.
Some valve problems can be treated with medicine. More severe problems usually require correction, often with surgery. Operations for valve disease usually involve either repair of the defective valve or replacement with a biologic or mechanical prosthesis (artificial valve).
Evaluation of a heart murmur should be done by your doctor or primary health care provider. When it comes to murmurs, they can give you sound advice.
Daniel J. Waters, D.O., FCCP
Cardiovascular Surgery
641-494-5300