PDA: The Hole You’re Born With In Your Heart
Did you know that essentially everyone is born with a hole in the heart? When people hear about “holes in the heart,” they instantly think of major heart problems. But I’m here to assuage some of the worry. One particular hole, called the Patent Ductus Arteriosus (a.k.a., PDA) is a life-saving necessity in utero. The thing that changes the hole from being normal to abnormal is when and if it closes.
Quick anatomy background
You’ll probably remember from high school biology, the basics about blood flow. Blood (with little oxygen) comes from the body to the heart. The heart pumps the blood to the lungs to get oxygen. The blood, now full of oxygen, comes back from the lungs to the heart. The heart then pumps the blood back to the rest of the body.
When a woman is pregnant, a baby’s lungs aren’t really working. They are full of fluid. So the heart has a little hole, essentially a little bypass system to skip the lungs, when the baby is inside mom.
What exactly is a PDA?
A PDA is a patent ductus arteriosus. Meaning the duct (a.k.a, hole) that allows the heart to pump blood past the lungs stays patent or open (when it should have closed). Technically speaking the ductus connects the aorta and the pulmonary artery.
Why does it happen?
When a baby is born, the baby takes his/her first great grand breath. The fluid in the lungs moves out and there is a big pressure shift. Essentially these forces all act at once (like a change in pressure), to close the hole in the heart.
Sometimes, birth doesn’t go exactly as planned in nature. Sometimes the birth is very fast (so there isn’t time for the fluids to shift exactly like they are supposed to). Sometimes we cut babies out (C-Section) which isn’t exactly “natural” either. In no way am I saying that docs shouldn’t do C-sections (in fact, they are often life-saving), but they can create a few new sets of problems. In these sets of circumstances what usually happens is that over the course of the first few days of life, the hole gradually closes (instead of dramatic close right at birth). The pediatrician will note this by stating that a particular sounding heart murmur, noted at birth, goes away with time.
How is it diagnosed?
A PDA is a usually a clinical diagnosis. An experienced pediatrician will listen to your baby and the nature of the murmur will alert the doctor to the condition. The murmur often sounds like a continuous machine, but can change volume throughout also (a crescendo, decrescendo). The murmur is a systolic one (meaning that it happens during the contracting phase of the heart pumping). It can be confirmed by an echocardiogram (a.k.a., echo) if there is question about the diagnosis. An echo is essentially an ultrasound of the heart; so it is non-invasive test and there is zero radiation.
Is there a treatment?
Treatment of a PDA depends on lots of factors. In full-term infants, most of the PDAs close on their own in the first 72 hours of life. If they don’t close spontaneously, we generally suggest closing them with a procedure to prevent long-term problems. PDAs can be closed with either cardiac catheterization (essentially fishing the closure device up through a blood vessel) or a surgical ligation (opening the chest to access the heart).
If the affected infant was born premature, then the significance of the PDA (because everything may not be exactly matured/formed like it was supposed to) becomes a bit more complicated. In those circumstances, sometimes a medication (called Indomethacin) is used and sometimes surgery is performed. The individual circumstances of the premie play into the decision on how to treat.
How worried should I be?
The short answer is that it depends. Typical, small PDAs that close up on their own are nothing to worry about. However, if they don’t close or are really big, then that is when you can run into more serious problems. Generally speaking, if you’re going to have a heart issue, this is not a bad one to have (as it often clears up on its own or is fixable). Just make sure that your pediatrician helps you manage it and decides when and if you need to see a cardiologist.