WHAT IS A HEART MURMUR?
Normally blood moves through the heart smoothly in a nearly fractionless fashion called laminar flow. However when the velocity of flow increases, flow becomes turbulent and friction increases making flow audible to the healthcare provider using a stethoscope. This noise is called a murmur. Some murmurs occur when flow velocity occurs in response to physical conditions such as pregnancy or fever and do not represent a heart problem. However many murmurs occur from heart valve abnormalities or congenital heart disease and should be evaluated. The most common abnormal heart conditions causing murmurs are when heart valves fail to open properly (called valve stenosis) or when heart valves leak (called valvular regurgitation).
IS IT SERIOUS?
Even if a heart murmur is due to a cardiac abnormality many are mild in nature and do not cause problems. However a murmur can indicate serious cardiac pathology that causes symptoms and/or abnormal heart enlargement. Symptoms of serious valve or congenital heart disease include shortness of breath during exercise, shortness of breath when lying flat to sleep at night, chest pain during exertion, blacking out during exertion, palpitation and swelling of the ankles. It must be emphasized all the symptoms noted above can be caused by a host of conditions other than valvular or congenital heart disease. Even so, these symptoms should be reported to the patient’s healthcare provider for evaluation.
WHAT SHOULD HAPPEN NEXT?
Although the provider may be able to tell that a given murmur is not associated with significant disease (benign murmur), in most cases even the most experienced provider may not be able to distinguish benign from more serious murmurs by physical examination alone. He/she may then order a chest x-ray and electrocardiogram (EKG). However the definitive test for diagnosing the origin and impact of most heart murmurs is the echocardiogram. During this non-invasive test that has no risks or side effects, the echocardiograph emits sound waves that return to the machine producing a detailed moving picture of the heart and its valves.
THE TEST SHOWS I HAVE A CARDIAC ABNORMALILITY: WHAT WILL THAT MEAN FOR ME?
If the abnormality is mild the only impact will be periodic check-ups to be sure that the condition isn’t worsening. If the condition has produced severe narrowing or leaking of a heart valve or a severe congenital abnormality, the condition will require referral to a cardiologist and eventual correction, especially if it has caused symptoms. Most treatment is provided during open heart surgery but some conditions can be treated less invasively using heart catheter techniques where the treatment device is placed through the skin into an artery or vein.
THE BOTTOM LINE
Learning that you have a heart murmur is not a cause for alarm. Most will require only careful watching by your healthcare provider. Even if therapy is required, and even if surgery is required, mortality risk is low and the outcomes are excellent.
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Blase A. Carabello, MD, is Chair of Cardiology at Mount Sinai Beth Israel, Medical Director of the Heart Valve Center at The Mount Sinai Hospital, and a member of the Senior Faculty of the Departments of Medicine and Cardiovascular Surgery at Icahn School of Medicine at Mount Sinai.