Heart Murmurs

An auditory exam of the heart is performed with a stethoscope. The normal sound for a heart beat is “LUB-DUB”. The dominant sounds are made by the four valves as they close. The first two sounds can provide a health practitioner with information about the patient’s heart rate and heart rhythm. Abnormal heart sounds indicate abnormalities of the heart valves or chamber walls. Heart murmurs can be present at birth or develop later in life.

The murmur itself is not a disease process but rather an indication that there may be an underlying heart condition. Not all murmurs require intervention. These types of murmurs are often referred to as innocent murmurs. An individual with a heart murmur does not have an underlying heart disorder. An innocent heart murmur can often occur because the blood is flowing more rapidly through the heart. Innocent heart murmurs can be very common in infants and children. Some common conditions that can be associated with innocent heart murmurs are

• Pregnancy
• Physical exertion
• Low red blood cell counts
• Fever

Abnormal heart murmurs can also occur in children and adults. In children, an abnormal heart murmur is usually indicative of a congenital heart defect. In adults, it typically is because of acquired heart valve problems. Infections or conditions that can cause damage to the heart and then the development of a heart murmur are;

• Rheumatic Fever – from an untreated strep infection
• Endocarditis – an infection of the inner lining of the heart and valves
• Valve calcification – hardening or thickening of the valves

When a health care practitioner hears a murmur, the following steps are used to determine if the murmur is innocent or abnormal:

• How loud is the murmur
• Where in the heart is the murmur being heard
• What is the pitch – high, medium, low
• Can body position or exercise affect the sound of the murmur
• When does the murmur occur and for how long can it be heard

If upon hearing the murmur the health care practitioner determines that the murmur is abnormal there are additional diagnostic tests that can be done to further exam and then diagnose the murmur:

• Chest X-Ray
• Electrocardiogram(ECG or EKG) recording of electrical signals used to determine if there are irregularities in the rhythm of the heart and structure
• Echocardiogram(ECHO) an ultrasound of the heart that provides a picture of the structure and function of the heart
• Cardiac Catheterization – a catheter is placed in the patient in order to visualize the chambers of the heart, to look at the pressure measurements and to look at the blood flow to the heart

References:
MayoClinic(2006). Heart murmurs. Retrieved July 2007 from http://www.mayoclinic.com/health/heart-murmurs/DS00727/DSECTION=2

McCance K.L. and Huether, S.E.(2003) Pathophysiology: The Biologic Basis for Diseases in Adults and Children(5th ed). Mosby: St. Louis