Michael Smith, MD (Host): Welcome to Pediatrics in Practice, A CME podcast. joining me today is Pza Doctor, a medical doctor from Children's Mercy. Today we're diving into an important topic, hypoplastic left heart syndrome, key insights for pediatricians. Thanks for joining me today. I want to dive right into this and ask you what are the key prenatal indicators of hypoplastic left heart syndrome?

Pezad Doctor, MD: Thanks for having me on this podcast. in terms of prenatal diagnosis, as the name suggests, hyperplastic left heart syndrome is usually when the left side of the heart, That is mainly the left ventricle, mitral valves. The aorta is, small and underdeveloped. And. Sometimes the spectrum can be that it can be completely absent.

It's usually detected, prenatally these days when there is a routine antenatal scan done at the ob GYNs office. And when there's always a suspicion that they cannot see all the four chambers of the heart, that's when, these children or these fetal moms are refer to cardiology where a fetal cardiologist, performs the study and, confirms the diagnosis.

Michael Smith, MD (Host): So how can pediatricians support families during this process? This is a hard diagnosis to hear, right? So any, tips. Ideas you can give pediatricians, for helping their families go through that diagnostic process.

Pezad Doctor, MD: yes. it's extremely stressful situation from the time that there may be something wrong with the baby's heart in neutral, and by the time they see the fetal cardiologist, it could be sometimes the next day or it could be sometimes weeks. And in the meantime, the parental anxiety can be, really, striking and nerve wracking.

So, in terms of coordinating care with their. Primary pediatrician that they know of from their other siblings, or if they have someone, in mind who is close to their, location to the area. It's definitely helpful for the pediatrician to talk to them about the basic nuances of what this, condition means for the child.

And what are the. few palliative surgeries that this child may need eventually, in the future. but just to summarize that This is, a stressful situation for the parents and having a pediatrician, to, uh, explain them, the nuances of this diagnosis, is really important.

Michael Smith, MD (Host): What is the prevalence of hypoplastic left heart syndrome?

Pezad Doctor, MD: It is one of the rare congenital heart defects. Overall, we maybe see like one in, every 5,000 alive births. in terms of all the congenital heart diseases, it's one in a hundred. So, let's say out of five or 10,000 live births, one may have hypoplastic left.

Michael Smith, MD (Host): So what should pediatricians know about the stage? Surgical approach to this And what role do they play in coordinating care between surgeries?

Pezad Doctor, MD: in Sharon with this condition, there is, drastic changes in their hemodynamics throughout their palliative surgeries. they mainly have three surgical palliations, starting from a normal procedure That is soon after the birth in the newborn period. it's to ensure, a stable source of systemic and pulmonary blood flow. So since the left ventricle is underdeveloped, the right ventricle is fashioned to supply both the circulations.

after that procedure, the children, at about six months of age undergo the next operation called the Glen Procedure. so in between those first stage and second stage palliative, is called the Interstage period, which is really, high-risk mortality in this age period. So it's important to maintain, Good balance between the systemic and pulmonary blood flow.

And the best way is by assessing their oxygen saturations. So we guide pediatricians to make sure when they routinely see these children every other week with the cardiologists, that's been the practice, during the end-stage period to make sure they're gaining weight so that we know that there is good systemic blood flow.

They're feeding well, And the oxygen saturations are where we expect them to be between 75 and 85%.

Michael Smith, MD (Host): So gaining weight, watching oxygen saturation, Those are the key things during this very important time period.

Pezad Doctor, MD: Exactly. so we have, parents note down how much feeds they have been taking. Sometimes fa failure to feed or feeding intolerance can also suggest, compromise.

Michael Smith, MD (Host): If a child comes out of this like very important phase, does the outcome become better?

Pezad Doctor, MD: Yes, absolutely. previously, in this inter staged, mortality was close to 30%. but due to, implementing of home monitoring programs and, you know, with the help of CLO coordination with the pediatrician And the cardiologist, we have. Been able to significantly bring down this mortality, to close to now 2%. as you said, once they have that, second stage where it's a more stable form of pulmonary blood flow, the mortality, is much lower.

Michael Smith, MD (Host): So 30% down to 2%. that's significant.

Pezad Doctor, MD: Absolutely. it's, all thanks to this close monitoring that we do in these children along with the care of pediatricians.

Michael Smith, MD (Host): Yeah, I wanna talk about that. So the main app that's used now is called Champ, right? That's a, remote monitoring app. How is that, guess you're saying that's had like some of the biggest. Impacts and outcomes. Huh?

Pezad Doctor, MD: Yes, absolutely. So initially, children, when they would be discharged from the hospital, they would sometimes be, not clear understanding of what is normal for these children. You know, these children are, as I said, very, high acuity, at least for decompensation. So with this monitoring, some people call it, so Children's Mercy kind of pioneered this champ, application where, parents are given An iPad and there is a portal where they can have to document the child's weight, the oxygen saturations, the feedings, And we closely monitor with the entire sham team on how they're doing.

if there is any concern, uh, them. Parent has about their child at home during this end-stage period, they can quickly shoot us a message and it comes as a page to our on-call cardiologist. we also now have the ability to record videos if they think the child is very blue, the child is grunting, the child is, we can all, yeah, we can remotely access that.

Michael Smith, MD (Host): and of course that helps you. It just speeds up the recognition of an issue that there's something going on, that's fascinating. what are realistic expect expectations? For growth, development activity levels in children with HLHS how do pediatricians play a role in, facilitating that counseling families? can you dive into that a little bit?

Pezad Doctor, MD: Absolutely. once they have the Fontan operation, That's the third final stage of their palliation. That happens usually at three to four years of age. so you can imagine that by the age of four years they've had multiple heart surgeries, some of which requiring a heart lung machine, long ICU stays, cat procedures.

and This is just a routine. if there are complications that may even, have more cath procedures. So, children's neurodevelopmental, That we have found that especially in older kids who are studying, we have found learning disabilities. We have found attention deficits And also an increased risk of, mental health issues like anxiety, depression in these groups.

So understanding that evaluating that, at the right time is really appropriate so that, we can guide them through therapies. talking about the physical activity, we. Know that since these children have one ventricle, which is doing the job of both initially, And then the final palliation is where we want the pulmonary blood flow to go passively to the lungs.

So the children's exercise capacity is reduced, but we encourage pediatricians and, through our Fontan clinic we have a multidisciplinary clinic where we closely monitor these children and continue to encourage them to participate in sports.

Michael Smith, MD (Host): What about supporting families emotionally not just the patient, but the parents, siblings. how can pediatricians work through that?

Pezad Doctor, MD: it's a very long journey, at the end of the road. And then, despite doing all these palliations, there is a lot of long-term issues these children can encounter and, I think supporting. First understanding what the parents, are hoping for their child to, finally succeed in whether it is, final graduation or it's the being able to participate in sports or, they're having other issues.

identifying them early on, where they have a close, bond with their pediatrician. and noticing that will really help us kind of guide them in the right. So, I mean, I really appreciate the pediatrician's role in identifying these, high stress or behavioral concerns in children and their parents.

Michael Smith, MD (Host): You know, when it comes to these, Air, congenital conditions. one of my favorite questions is talking a little bit about promising innovations, are there any things that are being studied, clinical trials that are going on that you would like to share with pediatricians that are kind of exciting? You?

Pezad Doctor, MD: Yeah, there are a few, actually. the one That is really exciting is the, reenergized trial That is going on and still actually enrolled. participants. So the idea is that, as I mentioned earlier, these children with fonta and palliation do not have adequate exercise capacity. And, when compared to children with a healthy heart, their capacity is about 40 or 50% of that, that we use the oxygen uptake as a on exercise stress test, as a marker of that.

And we have identified that a certain cohort of these, children with fontans have in fact near normal exercise capacity and are able to, perform as, any other child of that age group. And we found that these children, have been enrolled in competitive sports, athletics. they're pursuing, postgraduate education and they have more muscle mass.

So the theory is that since the fontan palliation is a method of sending passive blood flow to the lungs and augmenting cardiac output, perhaps their activity level, the secondary muscle in their legs is acting as that bump that they're deficient of in their heart. And. That is supplying more blood to their lungs, more cardiac output, and they're able to perform very well.

so coming to this clinical trial, they are actually providing an exercise prescription to these children. and, every, three weeks, they expect them to do certain activities for an hour. And then, they're again reassessing their exercise capacity and seeing if that, helps improve their exercise capacity as well as reduce any long-term, issues with their other organs, like liver failure, lymphatic failure.

Michael Smith, MD (Host): that's fascinating to me. that's an amazing, exciting, thing that's coming down the line. how do you see this playing out in the future? when does this become something that we'll be able to talk more about with the average patient with hypoplastic left heart syndrome.

Pezad Doctor, MD: This is really a great, breakthrough we have, through some retrospective studies, identified these findings that, you know, children with more muscle mass act. Are overall doing well, and now we need to implement a more randomized control trial to make sure the cause effect is appropriate. we had other studies in the past where, one of the other clinical trials was fuel study where they gave pulmonary vasodilators and tried to see if there's increased excess capacity in this children with very limited like.

Statistical significance. So I think this approach would be really, amazing to see if we are able to improve the quality of life overall. So more to come on this.

Michael Smith, MD (Host): Yeah. Very interesting. I'm sure you'll be watching all of this closely. This was great information. thank you so much. For coming on the show today and sharing your insights for more information, please visit CM KC link slash CME podcast. If you enjoyed this podcast, please share it and explore our entire podcast library for topics that may interest you.

This is Pediatrics in Practice. Thanks for listening.