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Q&A: Congenital Heart Defects

For Congenital Heart Defect Awareness Week we asked CHD specialist & pediatrician Dr. Evan Zahn a few questions about the disease.

Congenital heart defect or disease (CHD) occurs when the heart and major blood vessels don't form correctly. About 1 out of 100 babies born in the US are affected, according to the CDC.

Most of the time, the physical problems with the heart or blood vessels can be repaired and CHD patients can lead full, normal lives, but that wasn't always the case.

"For the vast majority of patients born with CHD, we do not know what causes the problem."

"When I started in this field in the late 1980s, we were telling the parents of certain children with congenital birth defects that they should take their child home and love them because there was nothing we could do," says Dr. Evan Zahn, director of the Smidt Heart Institute's Guerin Family Congenital Heart Program.

"Fast forward to now, and the survival rate of patients at congenital heart programs in the US hovers around 98%."

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Evan M. Zahn, MD

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Guerin Children's

Evan M. Zahn, MD

Peds - Cardiology
Guerin Children's
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What should parents know about congenital heart defect?

Dr. Zahn: Having a congenital heart defect is not uncommon and most kids will go on to lead very normal, healthy, happy, and active lives.

They may need special doctors and occasionally a procedure, but the survival rate is excellent. There is virtually no congenital heart defect that we can't offer therapy for and successfully treat.

Will all defects require surgery?

Dr. Zahn: Some infants and children will require surgery.

But for the past 3 decades, many of us have worked on less invasive ways to treat certain defects so we can minimize the trauma of surgery. As a result, we've been able to perform minimally invasive transcatheter procedures for premature infants as small as 1.5 pounds.

What's been great is that the technology has finally caught up to what a lot of us had been imagining. We are now able to offer many of these procedures on the tiniest and sickest patients as well as older children and adults.

How many types of congenital heart defects are there?

Dr. Zahn: It's really infinite. No two patients are the same, and that also goes for defects. In fact, I've been doing this for 30 years and I'm still seeing different types of congenital heart defects for the first time.

Do we know what causes congenital heart defects?

Dr. Zahn: Some congenital heart disorders can be traced back to genetic causes.

Other disorders may result from an illness of the mother, such as diabetes or rubella (a form of measles), exposure to certain drugs or alcohol, fetal alcohol syndrome, or combinations of all of these. But for the vast majority of patients born with CHD, we do not know what causes the problem.

I see a lot of parents who feel guilty that maybe they did something wrong, and that's rarely the case.

If we think about how the heart is formed, it goes from a simple cell, to a tube, to a four-chambered beating organ. There are so many steps that have to go just right for it to do that, and in the process something can go wrong.

Are there any misconceptions about congenital heart defects that you'd like to clear up?

Dr. Zahn: Yes: the idea that once your child has been treated, they are permanently cured. The reality is that while the children we care for overwhelmingly lead normal lives, essentially all will require care by a congenital heart specialist throughout their lifetime.

That doesn't mean that they'll be sick all the time or that they can't be a professional athlete. It just means that these conditions—even when repaired—need monitoring over the course of an entire lifetime.

Is seeing a cardiologist enough?

Dr. Zahn: While we do work with general adult cardiologists and want our patients to have one, it is not enough. That is not just my opinion either—that opinion is supported by the March of Dimes, the American Heart Association, American College of Cardiology, and others.

Unfortunately, at this point in time, 75% of adults who were born with a congenital heart defect are not getting the right care. In order to help address this in the greater Los Angeles region, we have added a new specialist to our Congenital Heart Program who solely cares for adults with congenital heart defects.