My son was just diagnosed with a heart murmur. he just turned 3. aren't murmurs diagnosed at birth?

Worst usually are: If I listen to a kid often enough in his or her childhood I will hear a slight murmur in all of them. Murmurs reflect the sounds made by blood flow and or the dynamic action of the heart. Although they can suggest structural defect in some, most are innocent.(not indicative of disease) most simple murmurs have nothing to do with later risk.