Q: How serious are heart murmurs for kids?

A: A heart murmur is the sound of blood flowing through the heart. Everyone whose heart beats has a murmur. Murmurs can be normal (innocent) or abnormal.

We pediatric cardiologists spend lots of time learning to listen to heart murmurs with a special stethoscope.

When murmurs are normal, we don’t hear much. It sounds like a hose with the nozzle wide open, or like water flowing through a brook with no rocks in it.

When murmurs are abnormal, it sounds turbulent because blood flow is blocked or under high pressure — like the spray from a hose when you put your finger on the end of it.

We also listen for:

• Pitch: Is the tone higher or lower than it should be?
• Timing: Does blood flow only when the heart squeezes? (This shouldn’t happen when the heart relaxes.)
• Volume: How loud is it? A loud murmur may suggest a severe blockage. (You can hear really loud murmurs without a stethoscope and even feel them with your hand.)
• Subtle clicks: These suggest a valve closing or opening.

Abnormal heart murmurs range in severity. For some murmurs, the doctor may simply monitor children over time. For others, medication or surgery may be required.

—Elizabeth (Tess) Saarel, MD, Chairman, Pediatric Cardiology