FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

KIDS WITH "INNOCENT" HEART MURMURS CAN PLAY SPORTS

Question: I recently took my child for a physical examination so that he could participate in sports at school. The doctor said that he has a heart murmur and needs to be seen by a cardiologist before it is OK to play sports. How serious is having a heart murmur?

Answer: A murmur is an abnormal sound made by the heart, but it does not necessarily indicate that there is an abnormality of the heart. Normally, as the heart pumps blood it creates a "Lub-Dub, Lub-Dub" sound that can easily be heard with a doctor's stethoscope. When a murmur is present, the doctor hears a swishing or hissing noise produced by turbulent blood flow in addition to the Lub-Dub sound produced by normal heart action. There are a number of conditions that cause a heart murmur. I'll talk about the most common one first. Children often have "innocent" or "benign" murmurs. These are murmurs that are not associated with any heart disease. They occur with fever, nervousness, or other conditions that make the heart beat rapidly and forcefully. The relatively thin chest wall of a child easily transmits the sounds of blood vigorously "swishing" out of the heart, thereby creating the murmur. Anemia and a few other conditions also produce "innocent" murmurs. Innocent murmurs only pose a problem because they must be differentiated from murmurs caused by serious problems of the heart or great vessels.

Defects in the heart can cause murmurs. Abnormal openings between the low pressure "filling chambers" (atria) of the right and left sides of the heart create a condition called atrial septal defect (ASD). A similar hole connecting the more powerful "pumping chambers" the ventricles is called a ventricular septal defect (VSD). These conditions produce murmurs that indicate the serious nature of the underlying heart defects.

Abnormal operation of any of the four heart valves, and narrowing of the great vessels leaving the heart can also cause murmurs. These conditions, along with ASD and VSD, are serious because without treatment they will lead to premature death due to heart failure.

The process of differentiating innocent murmurs from those associated with heart defects requires several steps. History of the mother's pregnancy with this child, including use of prescription and recreational drugs, is important. The history of blood relatives who experienced heart defects when they were babies is also important. A somewhat slowed rate of growth and development may also indicate that the child has heart trouble, although this is a very general sign that can also result from many non-heart related difficulties. The next step in identifying the cause of a murmur is the physical examination. Different heart defects cause murmurs that have subtle differences in their timing within the heart beat cycle and in the area of the chest where they are loudest. The way the murmur varies with change in body posture, exercise and breathing are also studied by the doctor. Differences in pulses between the arms and legs can also help narrow the list of possible causes.

Now I'll address your specific concerns about your son. The purpose of school sports physical examinations is to select those student who may have a health problem that could be made worse by playing sports. The doctor identified that your son has a murmur a condition that may or may not indicate a heart defect that would be worsened by sports. So, the murmur may be serious or it may not. Your son's doctor has asked for a consultation with a cardiologist though many family doctors are also skilled at doing this type of evaluation to identify the specific cause of the murmur, just as he or she should.

The cardiologist will obtain a thorough history as well as perform a physical examination. This may be all that is needed to clarify the cause of the murmur, but often additional tests such as an electrocardiogram, an echocardiogram or even more specialized heart tests are required. Knowing the specific cause of the murmur will enable the cardiologist to advise your son about participation in sports as well as any treatment that may be necessary for the underlying cause of the murmur.

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.