Heart Murmurs and the Dentist

When your child goes to the dentist for the first time, one of the questions you will be asked is whether or not they have a heart murmur. Many parents do not know why the dentist is so concerned about the heart. Does it mean that dental procedures or anesthesia could have serious cardiac consequences such as heart damage or abnormal rhythms if a heart murmur present?

To understand this concern, parents should understand what having a murmur means. A murmur itself is merely a sound that is heard when the heart beats. Physicians listening to children''s hearts hear "normal, innocent" heart murmurs all the time. Since a murmur is produced by blood flow, and every beating heart has blood flow, it makes common sense that everyone could have a heart murmur at some time in their lives. Furthermore, all pumps make some noise, and the world''s greatest pump -the human heart- is no exception. A device that beats three billion times and pumps a half a billion gallons of blood in a lifetime is certainly allowed to make a little squeak once in a while! It is easier to hear heart murmurs in children because a youngster''s heart is very close to the chest wall, and there is less lung tissue, muscle, and fat to muffle the sound picked up the stethoscope The important point to remember is that there is nothing wrong with the heart in this instance-it merely makes a funny noise. These murmurs are usually called "innocent" or "functional."

The other reason for a heart murmur to be heard is that there is an anatomical defect of the heart. Common examples of these defects include an opening or hole in the wall that separates different compartments of the heart, and abnormally shaped valves between the chambers of the heart. When these defects are present, they cause the blood flowing through them to make an abnormal sound-a murmur.

When a dental procedure is performed on a child in which there is some bleeding bacteria from the mouth get into the bloodstream and travel throughout the body. This causes no problem because our normal defense mechanisms are able to destroy the germs as they course through our various organs. However, if there is an abnormal area inside the heart, such as an abnormal opening or a damaged heart valve, these bacteria can attach themselves to these areas, multiply, and cause an infection in the heart lining and muscle, called subacute bacterial endocarditis, or "SBE" for short. This is a very serious medical condition and requires several weeks of IV antibiotics to cure.

"SBE" is preventable if the dentist knows ahead of time that there is an abnormality in the heart. That is why the dentist wants to know if a heart murmur is present. He or she then will check with the child's pediatrician to determine if the murmur is "innocent" or represents some type of heart defect.

If it is an innocent murmur, no precautions are necessary. If the murmur is caused by an anatomical problem in the heart, then the dentist will recommend an antibiotic usually Amoxicillin (the "pink stuff") that is given about one hour before the procedure. Previously, a dose was also given six hours after the procedure but this is no longer required. This simple step - a dose of antibiotic one hour before the dental visit - will prevent the development of SBE.

As a reminder, this information should not be relied on as medical advice and is not intended to replace the advice of your child’s pediatrician. Please read our full disclaimer.