Dr. Kaitlin Ryan, a pediatric cardiologist at Le Bonheur Children’s Hospital
It’s a fitting sentiment for the month of Valentine’s Day: “I fell in love with pediatric hearts,” says Dr. Kaitlin Ryan, discussing her pediatric residency training in Washington, D.C., and the career path that led her to Le Bonheur Children’s Hospital.
A graduate of the State University of New York at Albany, Ryan completed medical school at Temple University, finished her fellowship at Georgetown University, then applied for a cardiology fellowship with the UT Health Science Center and Le Bonheur. That turned into a full-time staff position with the hospital in 2018. As an attending pediatric cardiologist, she specializes in cardiomyopathy, heart failure, and heart transplant medicine at Le Bonheur while also working with the cardio-oncology service at St. Jude Children’s Research Hospital.
“I feel very lucky to be part of an incredible group,” she says, “who work so well together to provide excellent care for the children of this area.”
With its four chambers, valves, veins, arteries, muscles, nerves and electrical pathways, the human heart is an incredibly complex organ that circulates oxygen-carrying blood from the lungs to every part of the body. With so many components having to work in perfect synchronization, there’s always the chance something may go wrong — at any age, even before birth.
“Parents may notice their baby doesn’t finish his bottle, doesn’t have any appetite, or they’re not gaining weight. That’s because all these activities take energy, and because their hearts are not providing oxygen, they just don’t have the energy they need.” — Dr. Kaitlin Ryan
“The heart actually begins developing before many women even know they are pregnant,” says Ryan. “There’s still some muscle development over time, but the chambers are formed and the coronary connections are the way they should be within eight to 12 weeks of gestation.”
Some pediatric heart conditions are considered minor. The most common is a septal defect, a small opening between two chambers that is supposed to close before birth, but in one out of a hundred children, it doesn’t. As a result, the heart pumps inefficiently, and parents report vague symptoms: Their child seems more tired than other babies, doesn’t eat as much, or acts irritable.
The good news is that treatment for this problem is relatively simple: A device called an occluder — basically a plug made of metal alloy — is threaded inside the heart through a catheter inserted in a leg vein and placed in the opening. “It stays in place for life,” says Ryan. “Obviously, it doesn’t grow as the child’s heart grows, but it gets incorporated into scar tissue that forms around it, and it keeps the hole closed.”
A far more serious complication is a transposition of the major arteries, where the blood vessels linking the heart to the lungs are reversed. This causes the so-called “blue baby” syndrome, since the child isn’t getting enough oxygen to thrive, and the skin actually takes on a blue color. In the past, children with this condition weren’t given much hope for survival. Today, thanks to better imaging and surgical techniques, outcomes have dramatically improved.
“Catheter-based advancement over the past 10, 20, or 30 years has constantly been moving forward,” says Ryan. “We’re now able to save these ‘blue babies’ that otherwise didn’t have any option and can do complex palliative procedures that can give these children a life they otherwise wouldn’t have.”
Even though open-chest surgery may be the best option, Ryan is impressed with advances in catheter interventions — working on the heart by threading tiny instruments inside the organ through arteries in the legs and arms. “A child can come in, we insert a plug for a septal defect, and they go home maybe two days later,” she says, “instead of having to be in the hospital for a week after major open-chest surgery.”
A fetal echocardiogram can look at the anatomy of a baby’s heart long before birth. A more advanced technique, a cardiac MRI, can provide very detailed information about heart function.
The new procedures aren’t just a benefit for the young patient. “It’s a lot less stressful for the parents and family,” Ryan says. “It’s hard when a child has to go under anesthesia of any kind, because of the risks associated with that. So if we can lessen the concern of something bad happening to their child, that’s something we always try to aim for.”
Other procedures that can now be performed by catheter include heart-valve replacement and cardiac ablations to correct problems with the heart rhythm. Atrial fibrillation, a chaotic beating of the upper chambers rather common in adults, is usually not a problem with children. They can, however, develop more serious arrhythmias such as ventricular tachycardia, normally detected by simply checking a child’s pulse, which can be treated by an electrophysiologist (a specialist in heart rhythm disorders), who threads catheters inside the heart to correct aberrant electrical pathways that are interfering with the normal heartbeat.
“It’s obviously patient-dependent,” says Ryan, “but you’d be surprised how small of a patient you can actually treat with catheter procedures.”
Can babies have heart attacks? Not in the usual sense, Ryan explains, where the problem is the result of an artery blocked by plaque formation. But a child of any age can have a wide range of heart conditions that are not immediately obvious.
“Parents may notice their baby doesn’t finish his bottle, doesn’t have any appetite, or they’re not gaining weight,” says Ryan. “That’s because all these activities take energy, and because their hearts are not providing oxygen, they just don’t have the energy they need.” The tiny patients themselves often can’t vocalize how they feel, and some symptoms don’t immediately appear to be heart-related. She remembers one little boy, brought to the hospital because he seemed to have gastrointestinal problems. The other members of the family had caught a “stomach bug” weeks earlier but had all recovered; the child was still not feeling well.
After a thorough exam, Ryan says, “It turned out he had very poor heart function. He was sick to his stomach because he wasn’t getting enough oxygen and nutrients to digest food effectively.” He was treated successfully with medications.
In cases like that one, the problem is a disorder with the heart muscle. Some of these conditions are genetic, but Ryan admits, “We still don’t understand how all of them develop.” The most common conditions, which can develop at any age, are dilated cardiomyopathy, hypertrophic cardiomyopathy, and restrictive cardiomyopathy, but in very basic terms they mean the same: Either because the muscles are weak or the chambers are dilated, the heart is not pumping as strongly as it should.]
Dr. Kaitlin Ryan reviews digital scans of a 's heart. Years ago, physicians relied on EKGs and X-rays to diagnose heart problems. Advances in imaging allow pediatric cardiologists to detect problems early.
Advances in imaging allow cardiologists to detect these problems early. A fetal echocardiogram, for example, can look at the anatomy of a baby’s heart long before birth. A more advanced technique, a cardiac MRI, can provide very detailed information bout heart function. “This can tell us the volume of the chambers and what percentage of blood is being pumped from the heart,” says Ryan. “It can show us very precisely how much blood flow is going to the right lung, and how much is going to the left lung. It can also show us if there’s been any scarring or damage to the heart muscle.”
In many cases, the good news is that these conditions can be treated by medications. For more serious cases, surgeons implant battery-powered ventricular assist devices to help with heart function. Sometimes, however, it’s not that easy.
Children are born with congenital diseases that, despite all the advances we’ve made, we just don’t have good surgical options where they would have a long-term life expectancy,” says Ryan. “So that’s my area of expertise — managing patients with abnormal anatomy and physiology who need a heart transplant.”
Every week, Le Bonheur’s cardiology team meets to discuss pediatric patients with special challenges. “We’re a very collaborative group — congenital cardiologists, fetal cardiologists, interventional cardiologists, and the cardiothoracic surgeons — working together to explore potential treatment options.”
Ryan particularly remembers one patient, “and there was really no great palliative surgical options, so she was put on the transplant list once she was born.” The little girl was fortunate: A donor was found before she was two months old, and she received a heart transplant.
“She’s doing very, very well,” says Ryan, explaining that children often handle transplant procedures better than adults. “They are less likely to have organ rejection, which is your body’s way of trying to rid itself of something it considers foreign. But because infant immune systems are not as well developed, they tend to do much better in the long-term. I believe she was the youngest transplant that we’ve ever done.”
According to Ryan, Le Bonheur performs about a dozen heart transplants a year, and conducts more than 200 cardiac surgeries or procedures. Even though “pediatric” usually refers to children, in many situations these boys and girls remain patients for life, with the doctors at Le Bonheur following their progress when they transfer to an adult cardiologist — such as specialists at Stern Cardiovascular Center or Sutherland Cardiology Clinic — in their late teens or early twenties.
“We usually transition them over a couple of visits, so they and their families can gain that comfort level working with somebody new,” says Ryan, “and knowing that somebody is going to be providing that same level of impeccable care for their child.” Besides, as she points out, “It’s hard to let go of a relationship you’ve built over 20 years or more.”
Even though the specialists at St. Jude Children’s Research Hospital primarily focus on pediatric cancer, there is considerable crossover with the cardiologists at Le Bonheur. “A lot of cardiac disease can be associated with hematological disorders associated with cancer,” says Ryan, “and we know that some of the chemotherapies given to save their lives from cancer can be cardiotoxic.” She consults with the patient’s oncologist and then meets with the families to give them assurance their child is in good hands. “I tell the families that this is by far the most important treatment they can get. We know it can be potentially detrimental to the heart muscle, but it’s going to save your child’s life, and I have lots of medicines available to support the heart.”
Among other things, Ryan would like to see more advances in pediatric medicine. “Children are not just small adults,” she says. “I would like more things made available just for children. Everything seems to get looked at first for adults, and then for children, because — thankfully — fewer kids are sick. But there are a lot of things about children’s anatomy and physiology that are not met by simply making the devices smaller.
“We’ve recently seen the FDA approval of Entresto, originally developed for older patients, for use in pediatric heart failure, and that’s been a huge step for us,” she continues. “But I want to see more medicines that aren’t just given to children as an afterthought, as well as more mechanical support or devices that can help children specifically and improve their life quality and life expectancy.”
Less than a hundred years ago, “blue babies” didn’t have a chance for survival. Other cardiac conditions meant short lifespans for children. Recent years have seen impressive advances in education, awareness, medications, procedures, and overall treatment.
“The types of surgery that we do now are different from what we did 30 years ago,” says Ryan, “and having the knowledge that each patient is unique and their physiology is different is really important.”
The best part of her job, she says, is building relationships with families, especially as part of the transplant team. “I get to meet families, though it’s usually not under the best circumstances. I’m meeting them when they’ve been told something devastating about their child, who they thought was perfectly healthy.”
But then, says Ryan, “Being able to grow with them and see their child get through all that, and thrive and run around? That’s been such a special part of what I do.”
