The following are two distinct conditions:
Heart Murmur in the First 24 Hours
The doctor just told you your baby has a heart murmur, but he didn't even seem worried. Why not? Chances are your baby is still under 24 hours old. It is very common to hear heart murmurs in new babies, especially in the first 24 hours.
A heart murmur is an extra sound that occurs when your (or your baby's) heart beats. "Murmur" is a general term that doesn't say anything about what might or might not be causing the extra sound. It could be totally normal, or it could be a major problem.
The way a baby's blood circulates inside of Mom is really different from how it circulates once he is born and breathing air. Inside the uterus, the majority of his blood is shunted away from his lungs. After birth, some passages must close down, and others must open up. The process can take up to 24 hours in a healthy, normal baby. In healthy babies under 24 hours old, nine times out of ten, a heart murmur is totally normal. We usually wait until after the first 24 hours before calling a specialist.
Heart Murmur at over 24 Hours Old
If your baby is over 24 hours old, and he still has a heart murmur, I call the pediatric cardiologist (heart specialist).
At our hospital in Albuquerque, we have the luxury of knowing there is a pediatric cardiologist in the hospital every morning, checking the babies and children who are in intensive care. When they are done taking care of the critically ill children, they will come to the normal nursery to check newborn babies if needed.
Either before or during the cardiologist's visit, a specially trained cardiac echo technician will do a cardiac echo on your baby. The technician uses the same technology that was used to get pictures of your baby when he was still inside your uterus. The equipment is specially adapted for checking hearts, but it is the same, safe, sound-wave technology that was used during your pregnancy.
The technician and the cardiologist are trained to interpret the echo pictures to see the details of the heart. This includes the major blood vessels leading to and from the heart, the four heart chambers, how the heart is pumping, and where the blood is flowing.
With this information, the doctor can tell exactly what is causing your baby's heart murmur. Then she can tell you what to do about it.
Thanks to Janelle Aby MD, Stanford School Of Medicine, Newborn Nursery, and Lucille Packard Children's Hospital for the use of occasional photographs.