What Is A Heart Murmur?

What is a heart murmur? To understand what a heart murmur is, you must understand the basic structure and functioning of the heart. The heart is an organ (formally called the cardiac muscle) that supplies blood to various parts of the body by continuous, repeated contractions. It is made up of four valves that regulate the flow of blood through the heart. These include two semilunar valves (SL) and two atrioventricular valves (AV).

The average human heart beats at a constant rate of 72 bpm (beats per minute). A heart murmur is any irregularity in the heartbeat. It is caused when the rate of flow or the amount of blood flowing through the heart changes.  Most heart murmurs are harmless and require no medical attention, while others are due to the flow of blood through an overworked or damaged heart valve, heart valve disease, rheumatic fever, infective endocarditis, or a heart attack – and require urgent treatment.

There are many types of heart valve diseases, including aortic stenosis, aortic sclerosis, mitral valve prolapse and aortic regurgitation. Other potential causes include anemia, pregnancy, an overactive thyroid gland, high blood pressure, and fever.

A heart murmur can be detected by a physical exam, electrocardiogram (ECG), chest x-ray and echocardiography. Treatment options depend on the cause of the heart murmur. While heart murmurs in many adults and children are harmless and do not indicate heart disease or require any form of treatment, others require periodic checkups. Diseased heart valves are treated by drug therapy (vasodilators, beta-adrenergic blockers, diuretics, antiarrhythmics and anticoagulants) or surgery.  

References:

Synopsis of Cardiac Physical Diagnosis; Jonathan Abrams; 2001

U.S. Department of Health and Human Services - What is a Heart Murmur