Innocent murmurs tend to be louder in certain situations such as with fever or after crying. Very quiet murmurs can go undetected until the child is old enough to be cooperative enough for your doctor to hear. However, some pathologic murmurs initially may not be audible, but will become louder if the condition worsens over time. Also, although some loud murmurs suggest more serious problems, loud doesn't necessarily mean bad: the tiniest holes in the heart cause the loudest murmurs, but are generally of little consequence with respect to a child's health and often spontaneously close. Evaluation of heart murmurs by a pediatric cardiologist will include a thorough physical examination and may include other tests such as a chest x-ray, electrocardiogram (ECG) and/or an echocardiogram. Some murmurs can be classified as innocent by examination alone. An echocardiogram is an ultrasound examination which provides moving images of the structure and function of the heart, allowing detection of congenital defects and other heart problems. After the evaluation is complete the doctor will go over the findings and explain in detail what your child's murmur means.

"In many cases, this will be good news, but even if the murmur is pathologic your pediatric cardiologist can still provide good treatment options for your child," Bezold said.

Source: University of Kentucky College of Medicine