Pediatricians know that one of the most terrifying single words they can say to a parent, particularly in the newborn period, is “heart.” This is especially true if the word “normal” or “good” is not in the same sentence. The problem is, there is such a wide variety of heart findings early on. Some things that show up may be serious and need immediate attention. Others may mean an uncertain path even to experienced doctors—anything from “definitely follow this up soon” to “it’s probably OK.”
Fortunately, medical science has gotten better and better in diagnosing and treating heart disease in early infancy. Congenital heart disease—the term is used for heart defects that babies are born with—sometimes doesn’t show signs right away. In recent years new tools to pick up these defects have arrived on the scene, and fewer babies are being discharged with an undetected cardiac problem. And treatments have come a long way; many are less invasive and produce better results than before.
Following is a description of a few things new parents might encounter related to their little one’s heart. We’ll touch on what happens with more obviously urgent issues as well as how providers screen for more subtle defects.
The Newborn Heart: What’s Normal, and What Can Go Wrong
In a recent blog, Dr. Wyszynski described the structure of a normal heart. Obstetricians will be the first to look at the structure of the heart to make sure everything looks normal. They do this by ordering an ultrasound on a pregnant woman. Most of the time a problem isn’t detected; however, the ultrasound may show a heart that doesn’t appear normal. In this case the obstetrician may suspect congenital heart disease in a baby.
Congenital heart disease shows up in about 1 in 100 babies. However, about 1 in 500 will have critical congenital heart disease (CCHD). This term refers to the most severe heart problems—the ones that need more immediate care. Some of these problems will be picked up on prenatal ultrasound; the obstetrician can then arrange for the baby to be born in or near a center specializing in pediatric heart disease.
Unfortunately, only about half of major heart defects show up on prenatal ultrasound. Thus, despite the best of prenatal and newborn care, some babies show up with CCHD when it’s not expected. Many of the signs of CCHD are not very specific—they include:
- Difficulty breathing. This can start right after birth but may not be present for several days, even weeks.
- Poor feeding.
- A bluish color. This is known as cyanosis.
None of these signs mean that a newborn has CCHD. However, they are red flags that compel the newborn’s provider to look for problems both cardiac and non-cardiac.
Heart Disease in the Healthy-Appearing Newborn
Most heart defects will not result in a very sick newborn. Some defects are not severe and do not cause major problems in infancy. Others take days or even weeks to show up, if they cause symptoms or signs at all. This is because many of the signs that something is going on with the heart depend on other factors: the baby’s size, the flow of blood within the heart and the body, even their increased nutritional requirements at they grow.
Pediatricians look for certain clues related to disease during those first physical examinations. They’ll listen for a heart murmur—a sound that occurs in between heartbeats. However, many murmurs are normal, particularly the first day of life. These occur due to natural “holes” or passages in between the chambers of an unborn baby’s heart or between major blood vessels. These holes normally close up shortly after birth.
In order to pick out murmurs that aren’t normal and need more attention, the physician will listen for clues such as an abnormally loud murmur, a murmur that occurs at a less typical time between heartbeats, or one that persists after the first day. They’ll also look for other clues such as pulses that are either too strong or too weak, or an abnormal color.
However, an examination only goes so far in terms of diagnosing heart disease in a newborn. Newborns will now usually undergo a different test known as pulse oximetry. In this test, a monitor is fastened to the baby’s right wrist and also to one foot. The monitors measure the amount of oxygen in the blood. Problems show up when the oxygen is too low, or when there is a big difference between the two monitors, meaning that the blood may not being pumped correctly by the heart. This test has been effective in picking up heart disease that might otherwise not show up until the baby is home. Since early detection and treatment is important, many states now require this test in newborns.
Heart Defect Suspected! What Now?
The answer to this question depends on a lot of factors. Certainly anytime CCHD is suspected, a baby will be promptly referred to a pediatric cardiologist and undergo an echocardiogram (ultrasound picture of the heart). Ill-appearing babies and those that fail the oxygen test are usually referred immediately.
However, those with more subtle or questionable signs—say, a murmur in an otherwise well-appearing baby with a normal oxygen test—might be followed up in the pediatric provider’s office first. Although eventually most providers would probably refer a young infant with any sign of potential heart disease to a cardiologist, some healthy babies visit the specialist for the first time as an outpatient. And after the first few weeks, if a murmur shows up in an otherwise healthy-looking infant, there’s usually a little more time to get this accomplished.
Finally, although heart defects do show up in older infants and children, many murmurs happen in absolutely normal hearts—a murmur is a sound, not a disease. In fact, 1/3 of all children will have a heart murmur at some point. So outside of young infancy, if the word “heart” is mentioned, it may not be a reason for alarm!