Heart Murmurs and Your Child (continued)

Maternal health also plays a role. At a higher risk of having a baby with a heart defect are pregnant women who:

• contract rubella (German measles)
• have uncontrolled or poorly regulated diabetes
• have PKU (phenylketonuria, a genetic error of the body's metabolism)

Common Heart Defects

Several different categories of heart problems can present with heart murmurs. These include septal defects, valve abnormalities, abnormalities of flow between the heart chambers and the exits (outflow tract obstruction), and heart muscle disorders.

• Septal defects involve the walls (or septum) between the upper or lower chambers of the heart. A hole in the septum can result in blood flowing through it into the heart's other chambers. This extra blood flow may cause a murmur. It can also make the heart work too hard and may cause the heart to enlarge. Some holes may be large enough to produce symptoms in addition to a heart murmur; others are smaller and may close on their own in time.
• Valve abnormalities are caused by heart valves that are narrow, too small, too thick, or otherwise abnormal. Valves that are misshapen don't allow smooth blood flow across them, and this creates turbulent flow. Sometimes, abnormal valves may allow backflow of blood within the heart. Either condition will cause a murmur. Outflow tract obstruction may be caused by extra tissue or heart muscle that blocks the smooth flow of blood through the heart.
• Heart muscle disorders (cardiomyopathy) can make the heart muscle abnormally thick or weak. This can impair the heart's ability to pump blood to the body normally.

A heart murmur is an exam finding, not a disease. Your doctor and pediatric cardiologist can determine if the murmur is innocent (which means your child is perfectly healthy) or if there is a specific heart problem. If there is a problem, a pediatric cardiologist will know how to best take care of it.

Reviewed by: Steven B. Ritz, MD
Date reviewed: November 2007
Originally reviewed by: Terrence U. H. Chun, MD