Expert Webinar Series: Pediatric Cardiology & Donor Management

Simpson Webinar

[00:00:00] Laura Carroll: Welcome again to many of you who’ve attended before. And on behalf of the CompuMed team, we’d like to welcome you to another in our series of expert webinars. Today, we are honored to have expert pediatric cardiologist, Dr. Scott Simpson. He’s a medical director of pediatric non-invasive imaging at Children’s of Mississippi and University of Mississippi Medical Center.

[00:00:24] Dr. Simpson has also led standards for CompuMed’s reading of echoes for pediatric donor cases. His unwavering dedication to working with the OPOs, including speaking with many of you at 2:00 AM to discuss pediatric donor cases is invaluable. We are extremely grateful for his passion to share his knowledge and experience with the OPO and transplant community today.

[00:00:46] So thanks again for attending, and Dr. Simpson, it’s all yours. Thank you.

[00:00:51] Dr. Scott Simpson: Thanks for having me here, and so I’m gonna showcase what a pediatric cardiologist does that’s different than an adult cardiologist. And I am also, as was mentioned, I’m a non-invasive imaging specialist. So, I have additional training compared to some of my peers with regard to echocardiography, whether that’s transthoracic echocardiography or transesophageal echocardiography. And I’ll try and highlight some points in my mind, how that helps facilitate in this situation with transplant how it helps match the donor with the recipient.

[00:01:33] Okay, so this is briefly what we’re gonna go over today. Our list of why we’re here, some things about donor selection from the transplant cardiologists, some basic stuff about echocardiography, particularly with a vet towards pediatric cardiology, some common congenital malformations, and then some very specific scenarios and discussion related to heart transplant, and then we’ll have questions at the end.

[00:02:00] So why not start off with a question for the audience? So why are you here? This is where I’m gonna pause and ask every single person. Not really, but what I want to drive is one of the blessings and amazing things about being involved with healthcare is that we are interacting with families in some of the most times uh, in their life. And you all in this audience definitely are involved with that in the transplant realm. And in this setting, as you all know, we have a patient that is uh, throughout the talk, I’m going to speak more for pediatrics than just transplant in general. But so we have a patient that has some sort of illness where they require a heart transplant. Obviously, there’s family in this setting that is extremely upset, distraught. Their loved one is ill and is facing potential mortality. So it’s a very significant and severe situation for them. On the other side of the spectrum, we have a family that also is going through a exceedingly tough time where they have a fatal injury to loved one in their family.

[00:03:04] And so you guys and everybody in the transplant realm is kind of in this world in depth. And so you have a situation where this family is praying for a miracle and this family is facing their worst fears, but then through donation is hoping to help pay it forward and help other families.

[00:03:19] And that’s where the OPO in this role CompuMed can help where we provide high quality assessment of echocardiography to more accurately and rapidly assess the ventricular performance and, the suitability of an organ for transplant, which then hopefully leads to, at least, a benevolent outcome for both parties, if possible.

[00:03:42] One major thing is there’s a significant, and this is discussed in literature, there’s a significant problem in the world, really not just the United States problem with wait list mortality and pediatrics, about 25% of infants that have made it to the transplant list, die while on that list. About 15% of children and adolescents also die on the waiting list. And so, above that mix, about 22% of those patients that have congenital heart disease end up meeting the rigorous evaluation for transplant, but end up unfortunately passing while they’re waiting for a donor heart. And then about 18 to 14%, depending on which type of cardiomyopathy, also have mortality while they’re awaiting transplant. This has been well recognized and I’m not directly a transplant cardiologist, so I’ll try and stay in my lane with imaging in relation to transplant cardiology, but it’s something that’s definitely recognized, and I think there’s a lot of efforts to look to how can we utilize more organs? How can we reduce some of these numbers on this slide? 

[00:04:45] So when you look at uh, thousands of variables that the transplant center is looking at, um, you know, whether it’s anything from gender to race, to size of the patient, mechanism of death, ischemic time, a lot of literature is distilling down to five main things. One is the ischemic time. The mechanism of death, with stroke being a big negative as a cause of death, the donor recipient height, or in a more larger, sense, the donor recipient size match, the renal function, and then the ventricular performance in the realm of cardiac transplantation and the the ventricular performance or the LV ejection fraction. And the number that has come up on several different studies has been an ejection fraction less than 50 is considered a pretty significant risk factor for postoperative mortality. And there even is some data that’s coming out that shows that even beyond all the other variables, including the ones on this chart, that really the main one is the ejection fraction of being less than 50 being a significant risk factor. So most of these things we can’t really influence. I would say that in some settings we can augment or help the heart to recover or allow time for the heart to recover, so we can get to a position where the ventricular performance, the LV ejection fraction is above 50, and then it could be considered a viable draft.

[00:06:08] So, every pediatric cardiologist – sorry, I got a little blurry there – this is a ruler, has an adage that not every kid is just a small adult. Just as though you wouldn’t expect this child to be able to balance this checkbook, their organs and the brain and the whole body is still in development even after their in utero time. And so to be able to perform an echocardiogram on a two week old baby or an adult 20 year old patient, just measuring things, doesn’t really tell you the whole story because two centimeters on a baby could be adequate sized and two centimeters on adult sized patient would be dramatically small. And so beyond just subjectivity, we often use some metrics, which I’m gonna show here in just a second. 

[00:06:55] One of the things to note is that on our end of the spectrum, in the pediatric realm in cardiology, that congenital cardiac malformations are common. And of all of the malformations that we see, the cardiac malformations are the most common. And when you look at the numbers, about one out of a hundred births has some sort of cardiac malformation. Clearly, a lot of those are gonna be very where we consider simple problems, like a small hole in the top chambers or things like that, but it’s a very frequent thing. So everybody on this panel or on this webinar knows somebody that’s definitely had a cardiac malformation as a child, maybe even themselves personally. However, though, one out of a hundred, depending on how you look at that, 1% can either be a big number or a small number. So, most cardiac anatomy is basically normal, but there could be small differences. In some settings the small differences can be a big deal for the transplant center and for the transplant surgeon, and so lack of awareness of small differences could have a big effect down the road. 

[00:07:54] As I had alluded to earlier, when we’re trying to compare size of patients, what we use and lean on pretty heavily in pediatric cardiology is what’s called a Z score; all that is, is, simply taking the absolute measurement. So I measure whether it’s the aortic valve, the left ventricular in diastolic dimension, the aortic root, whatever the measurement could be. And there are uh, multiple population studies to create normative data such as the diagram or the, graph on the right to create a sort of build of distribution of sizes. What we do with those absolute measurements is we divide it by the body surface area. So, accounting for the height and weight to calculate a body surface area, and then that’s what we call an index measurement, so it’s related to the size of that patient. So that way I can then take that absolute measurement in a two week old or a 20 year old. And by indexing, I can find some equivalency. Then beyond that, what we then do is we then have statistical norms so that we can say, okay, we accept that greater two standard deviations, negative to two standard deviations positive from the mean, which would about 95% of the population we’re gonna consider normal. And things on the outside, we’re gonna consider abnormal when indexes for body surface area. Clearly that could be, that means there’s 2.5% on each side that are technically, potentially normal, but this is the way we, approach it in our field to move beyond just subjective measurements and subjective assessment of the cardiac anatomy to more objective measurements.

[00:09:23] Okay. So just to get us all on the same page, just take you back to your school days, we’ll just review briefly the typical heart structures and flow of how things go. We have our blue deoxygenated blood coming back from the upper body and lower body through the superior vena cava, inferior vena cava, and they both collect in the right atrium. Then, as we fall the red blood cell around the heart, the right atrium squeezes, the blood passes through a tricuspid valve, one of the atrium ventricular valves, into a right ventricle and then the right ventricle squeezes, that blood goes out through the pulmonary valve, through the main pulmonary artery. Roughly 50% goes to the left lung, 50% to the right lung. We breathe in and out, goes from deoxygenated blue blood to oxygenated red blood and comes back through at least four pulmonary veins to the left atrium, the top chamber on the left side; and then is then squeezed from the left atrium through the mitral valve, the other AV valve, atrium ventricular valve, into the left ventrical, out through an aortic valve, and then out the aortic arch; where then sends nourishment, oxygen nutrients to our arms, our brain; turns the corner and then sends nourishment to our lower body, our intestines and everything in between. And then it goes through the capillary bed and then deoxygenated blood vent comes back through the cycle.

[00:10:41] To assess that, then we have some standard views and these are gonna mirror the adult world fairly similar. So we have a para sternal view of on the chest which is highlighted here, and I’m gonna show you some specific examples. We have an apical view, which is on the left, lower sternal border, a little bit towards the left side, which gives this kind of view here. We have the subxiphoid or subcostal views, which are very helpful, particularly in a baby this size would be very helpful, cause you can really see everything from down there and you don’t have the interference from the lungs or the ribs. We can sometimes do high parasternal, which is this view on the right side of the sternum. And then the suprasternal, which is all the way up at the base of the neck, where we can look at the aortic arch, the superior vena cava, and some structures in that area.

[00:11:25] So to have a good, detailed assessment of a heart, particularly a pediatric heart, when we know there’s a higher risk of congenital malformations, we really need to see all these views or at least a good portion of them. In all of the standard protocols to evaluate a heart by echocardiography, there’s always some sort of overlap, so that way we can look at structure from different angles. And the analogy I like to use is that the heart is a very complex three-dimensional structure, similar to, say a car. And if you were to look at the car just from the front, it’s very different than it looks from the front then it does from the bottom, or the top. So we really wanna get pictures all the way around to get a good three dimensional assessment of the structure and function of that organ.

[00:12:11] So I’m just gonna briefly walk you through some images. This is one of the views from the parasternal long axis view. And essentially you can think of the head on the, this side, over here, the foot over here, this would be anterior towards the chest and then posterior towards the spine here. This is that left atrium. We can see the mitral valve opening and closing here; the rip cord, like attachments to the mitral valve. This is the powerhouse left ventricle. It’s gonna be really important in all patients. And we see that in the walls moving, and that’s gonna be a lot of what we’re gonna talk about in a second. And then the blood will then leave through the left ventricular outflow tract, LV OT through the aortic valve, and then through the asin aortic, which is not really well shown here. And then we get a tiny little snippet of the right ventricle right here. 

[00:12:57] So with all echocardiography, we can then also look with color doppler. This will imply the direction and velocity of blood. And so we can see here this little blue dot here is, could potentially be very, trivial mitral regurgitation. And if it was much more significant, then that would be something of note. This would be just a sort of a minimal amount and not of consequence, but with colored doppler we can assess for that. We can also look for things like septal defects, like a ventricular septal defect, which often can be in this territory here. And if that’s here, the surgery would definitely want to know about it. I don’t think typically would preclude transplant, but they would want to know about that for sure, so they could take care of that as they’re doing the the transplant.

[00:13:37] If we would go from that same parasternal long axis view, we then pan posteriorly, we see the tricuspid valve; this is the very bottom of the heart. This is the IVC coming in from the back of the screen, essentially. And the coronary sinus is right here. And then the blood’s gonna come in from the lower body and the upper body here, which is not shown to cross into the right ventricle through the tricuspid valve. We can again, assess the chamber size, the wall motion or the right ventricle. We can do the same color assessment. Everyone has a little bit of leakage of their tricuspid valve. This would be considered just trivial and, just what we call physiologic, meaning just normal variation. We do that same view and then we pan all the way anterior, we can see our first or not, I guess not our first, but another look at one of the great vessels, one of our pulmonary valves. So this is the right ventricular outflow tract here, and here’s the pulmonary valve. And we can see it, a portion of that going into the MPA, which would then divide into the two branch pulmonary arteries, going to the right lung and a left lung. And again, we can look with color. We see again, there’s very trivial insufficiency, which I would just consider physiologic would not really hardly make it on my echo report, cause we see that so much and it would be inconsequential. 

[00:14:48] All right, and then a really important view. So now we are essentially the same view. We’ve turned 90 degrees to give an alternate view of the heart, which is this short access view. This is a great view to look at the ventricular function. This is the left ventricle here, and we see a crest shaped, right ventricle; it’s not fully shown. And then this would be the interventricular septum. And this would be normal function and often we do not see normal function such as this. 

[00:15:14] I’m gonna have a dedicated slide just for this, but this is where we derive from that same view. If you were to take that picture, think of that same circle and then just take a single slice where this line is, and then watch that slice over time. It’s gonna give you a picture like this. This is the septum coming in during systole and diastole, and this is the LV free wall coming in during systole and diastole. And this is how we’re gonna derive a lot of what the OPO coordinators are gonna be seeking, which is our left ventricular in diastolic dimension and our ejection fraction or shortening fraction. And that’s what derived from this image. I’m gonna have a dedicated slide to that in just a second. 

[00:15:52] From that same view if we move up towards the base of the heart, we can look at the aortic valve to look for fairly common lesions, such as bicuspid aortic valves. Instead of a nice three part valve here, we can have just a two part valve or a bicuspid valve. We can also get a hint of a left coronary and a right coronary here in this image. And we get a small little picture of the pulmonary valve. 

[00:16:13] Moving to that apical four chamber view, this is the easiest one for people that aren’t super familiar with echocardiography. This is as though the patient is facing us in this image, this is the left atrium. This is the mitral valve, the left ventricle and the interventricular septum, the right ventricle. We don’t see the right ventricle free wall, all that. This is right up against the chest wall on the interior side there. So it’s sometimes hard to see tricuspid valve, and then the right atrium and then the atrial septum right here. I’m gonna get hints of those veins, bringing that oxygen, rich blood back to the heart in the left atrium here. And again, we can assess the ventricular performance ventricular function from this view very well. And then again, not to over call this, but it would been also assess the ventricular function with both color and with doppler. And so for any of these, I didn’t put slides of this, cuz I thought it’d be excessive. But with all of these valves, we can also then, right where this equal sign is, have the machine tell us what is the direction and velocity of the blood in that specific location using ultrasound. And that can tell us a lot about the valve function, if there’s stenosis or insufficiency, if there is a downstream problem, such as ventricular dysfunction, that’ll alter this pattern that we see here, and there are a lot of data points that we can track and trend with this.

[00:17:34] Moving up to the super sterile notch. This is right at the bottom of the neck here. We’re looking down at the one of the great vessels, the aorta. This is the ascending aorta that’s coming up towards our head, turns the corner into the transverse arch, like the candy cane, and then turns southbound and to go down to our toes. And these are some of those head and neck vessels that are coming up our neck, that you could feel your heartbeat in your neck, through your carotid artery. This typically isn’t a huge area of interest for transplant; usually, aside from the recipient, having a pathology here, usually, is not used in tissue donation, but we sometimes utilize it in pediatrics.

[00:18:13] Okay. So we went through the normal cardiac anatomy and physiology, but sometimes there’s not all normal things. And so you can have, as I mentioned, the blue blood coming through the right sided, superior vena cava. There can be a mirrored structure called the left sided vena cava, which outside of undergoing cardiac surgery is really considered mostly a normal variation of anatomy. It shouldn’t leave lead to dysfunction or problems, however, in a transplant situation or when in a patient that has to undergo cardiac pulmonary bypass, the surgeons are gonna want to know about this, cuz it’ll alter their cannulation strategy. They’re gonna have more blood coming back to the heart once they think they’ve emptied it. And so knowledge of this can be of importance. I don’t think it would be a deal breaker for a transplant, but a surgeon would definitely want to know about it ahead of time so they can make some plans during a transplant. And so I have a couple real world pictures we have. This is some of the subtleties that I think highlights the importance of having a pediatric cardiologist that’s trained in imaging, cuz this, you could say it looks very similar to that last parasternal picture with the left atrium, mitral valve, left ventricle, aortic valve. However, if you look really closely, this is the coronary sinus of one of the venous structures of the heart, and this is significantly larger than it should be. And that is because there is that persistent left sided vena cave present, almost always. And then here’s another picture from that same patient. The coronary sinus is much larger as they’re panning back towards the tricuspid valve. And then with color, it confirms it that the direction of the blood is coming from the direction we suspect it is. So, this patient had a left sided vena cava. 

[00:19:49] Very common things that we seek is a hundred percent of people when we’re in utero, the way we survive that time period, where we’re floating in fluid and not breathing yet, is that we have some additional structures we typically don’t have once we’re out here breathing in the world. One of those is a patent ductus arteriosis, which connects the two great arteries. And the other one is a patent foramen ovale, which is a small pin size hole communication between the left atrium and the right atrium. And typically patients are essentially all of us when we’re a fetus, have both of these at the same time. Cause then they are utilized to shunt blood away from the lungs since our lungs aren’t being used at that point. Very commonly, these can persist after we’re born. So you can have really no symptoms, normal oxygen levels, not be blue, not have any problems, and potentially have a residual communication here or potentially a smaller PDA here. Probably the PDA is not, to be completely honest, is gonna play a huge role in the transplant realm, but a septal defect such as a PFO probably would not again, be a deal breaker for the surgeon, but they might wanna know about it because they may want to close it while they’re there. And then sometimes we can have both those together. Plus, the edit feature of a gap in the bottom chambers between the septum, between the two ventricles, which is a ventricular septal, defector VSD. These are all very common things that we see in pediatric cardiology. 

[00:21:10] Just to kinda give a shout out. This is where I honestly spend a lot of my world, but it’s not really on a donor side of transplantation gonna be relevant for you guys, but these are very significant lesions. This is double inlet left ventricle where there’s essentially one left ventricle. This patient also has the malposition, the great artery. So instead of crisscrossing, like they’re supposed to they’re in a parallel fashion is a very common single ventricle physiology lesion. And then the feared hypoplastic left heart wherein the left sided structures in varying degrees, the mitral valve, the left ventricle aortic valve and ascending aorta are exquisitely small leading to again, a single ventricle utilization for pumping for the heart. So these could both be recipients that have these sort of lesions. And as they’ve progressed through their life, have problems that necessitate cardiac transplantation. But obviously we wouldn’t be transplanting this, from a donor perspective. 

[00:22:04] Okay. So to bring it back. The five main variables. Again the ejection fraction carries significant weight and really the number is greater than 50%. So this is a paper that came out in 2020, and it’s the who’s who of transplant pediatric transplant, cardiologists, and people from all over the country. I’m sure recognize people near them.

[00:22:23] This is a lot of the big players in pediatric cardiac transplantation and a direct quote from this paper that says that, “Donor function is often reduced on the initial echocardiogram after brain death because of autonomic storm.” So, in correlation with the official brain death, and “Recovery of function usually occurs with time. If the initial echocardiogram demonstrates decreased function, then it should be repeated to assess for recovery.” And that’s from, this is the hyperlink to it, but this is a paper you could just search under that for 2020, if you want to read further. So again, highlighting the importance of potential serial echoes, particularly if the LBEF is right at 50 there may be potential for additional recovery.

[00:23:12] Okay. And then this is a real world case that I read. So this is a apical four chamber review with left atrium, right atrium, rightventrical, left ventricle, mitral valve. And without any additional training, I think if you just kinda watch this left ventricle, you’ll agree it doesn’t look super spiffy, so it’s not really squeezing way we’d want. The heart’s moving, free wall is moving a little bit, but really it’s not squeezing the way we’d like to see. And, from an alternate view of the short axis view, I think that also is demonstrated here where you can see this left ventricle. It’s moving some, but really not getting with it.

[00:23:42] The right ventricle’s doing much better, dealing with whatever has happened and this left ventrical is not. And then when we go to that same exact patient, and this is unfortunately the best picture I could get to have the exact correlatives is that apical views a little off axis. We can see that particularly this region, we can see the ventricular septum is moving much better. We can’t see the free wall very well, but definitely when we go to the short axis, markedly improved left ventricular function. It’s playing a little slow right now, but if you just look at this the cardiac motion here it’s much better. So this was a better setting after just the time interval.

[00:24:16] So how do we assess ventricular performance? This is a hotly debated area in our field or active area of research. I wouldn’t say necessarily debated, but an active area of ongoing research. So it turns out that the first version, when the technology was literally developing, all of the echo looks like this, which is called M-mode, and it’s that same single slice of the left ventricle displayed over time. And because this is what we had historically back when my great grandpappy was doing echocardiography, then we would utilize this to then generate a left ventricular end diastolic dimension, which is this measurement here. We can generate a posterior wall thickness inter ventricular septal thickness in diastole. And then we can then do some of the same measurements in systole. And then if we simply take this number or subtract this number from this number, and then divide by this number, multiply it by a hundred, it gives us our shortening fraction, which is this one right here, 31% or on this picture is 32 from the same sort of analysis.

[00:25:20] So that was what first was on the scene with ventricular function. Then we can then if the heart is a typical shape, so there’s not a dilated cardiomyopathy or segmental wall motion abnormality, we can then correlate that with an ejection fraction, which on this patient was 58.6. And then this one, I guess didn’t, calculate on this image here. The problem with that, so a lot of places use this as the ejection fraction and that’s good, but, this only looks at the heart as it’s squeezing towards itself, the radial motion. And as we know, the ventricular function is much more sophisticated than that. It squeezes from the apex and the base together in the longitudinal fashion. There’s also circumferential motion. It’s like a raining of a towel as the heart squeezes, in addition to the radial motion where it’s just squeezing towards itself. Measurement can give you information, but it definitely can be fraught with error. There are much far superior ways that are data proven ways of assessing the ventricular performance. One is the what’s called the Simpson method, no relation, but and the best ways to do by playing, which is a mix of apical four chamber and an apical two chamber, which I didn’t show a picture of, but it’s just a 90 degree analysis of the same chamber. You do that both in systole and in diastole. And then you can get what’s called the summation of discs and you can get an ejection fraction. This is much more accurate as far as the ejection fraction when it’s compared to what it’s thought to be gold standard measurements. You can also do a five, six area length or an area length method, which I didn’t draw a picture of, but it’s similar to this, but a little bit easier and that it’s done properly is again, more accurate than the shortening fraction or the EF generated by the shortening fraction. 

[00:27:04] And then we have even newer. So this is a, I would take as our next tier up in accuracy. And then the next one up is the hot one, which is 3D which in small patients is technically challenging sometimes, but the data would suggest this is the most accurate, and I do frequently see that. So I’ve had conversations with coordinators in the past where I’ll reference the EF the shortening fraction, or EF from M mode, the Simpson EF, and then I’ve gotten calls like why are you telling me the EF in so many different ways? Cause I think they don’t know where to put it on their sheet. And so really I’m just trying to supply the most information possible for the transplant center so they can see that hopefully the theme is that all these measurements all correlate and they’re all in a good position that gives you a lot more confidence if the ventricular performance is in a good place. And then I would say potential role for CompuMed again, from that same sort of huge statement paper that came out in 2020, they wrote and, this is in verbatim, “There are notable differences in echocardiographic interpretations between local and transplant center cardiologists, so every effort should be made to allow direct echocardiographic image evaluation by the recipient sites.” And I would say clearly they didn’t call out the role of CompuMed in this, but I would say, and as a imaging specialist, I think that even compared to my partners that specialize in electrophysiology or critical care or even transplant cardiology, we spend time just looking at these sort of questions of how, what is the structure and function of the heart. And, the analogy I would use is you want the right person for the job. And so you wouldn’t call your plumber to come do electrical work at your house; you’re gonna call the right person for that job. And I would then say that be a pediatric cardiologist with imaging specialty.

[00:28:50] And then getting back bringing it full circle to the transplant rate. There’s increasing susceptibility of donor hearts. Acceptability of donor hearts can be achieved by appropriately managing the potential donor and giving time if necessary recovery of heart function. And to maximize the opportunity for acceptance. And they also suggested dedicated teams with the necessary knowledge and expertise or training of current ICU teams and donor management can help achieve this. So I think potentially, the role of sequential or serial evaluation of hearts can be of benefit, and this was what they had highlighted in their paper. 

[00:29:29] So how do we help each other to help get the wait list and the mortality down. I think it’s easy for me to say sitting here, and again, I have to preface that I am not a Cardiac intensivists. I work with the ICU but I don’t work directly in the ICU, but I think just from a 3000 foot view, if you can try and keep all the vital signs normal, I’ve had echocardiograms where the heart rate’s like 180 in like a three year old; I actually read one very similar to that just recently. And that’s like trying to interpret a hummingbird heart, it’s beating so fast. I think if the blood pressure roll out, if you can back down off the epinephrine or something like that, which maybe is driving some of the chronotipic response, and chronotropic response and increasing your heart rate, that’s gonna help us, help me assess the ventricular performance.

[00:30:21] This is probably an obvious one, but try and reduce the pressure used. I think there’s always an asterisk. If I give a glowing report that the ventricle function was seven, had an EF of 70%. But then when we read that they’re on significant doses of vasopressin, epi and T4 or something. Yeah. I think the donor site understandably is probably gonna say why do we need all those medicines if the EF’s that high. So maybe that would where you would potentially back down and reassess. I really wanna try and get as high quality echo as possible, cause that’s gonna help me give high quality information back.

[00:30:51] So the quality in is the quality out. One thing for sure is that we always need to have a heightened weight provided so that we can generate that body surface area for Z scores. I think that’s usually done. It sounds like a no brainer, but if they have a lot of unnecessary attachments on the chest, particularly outside of the chest, like EKG stickers or things like that, that aren’t used when you’re trying to image and you have stuff in your way that makes you have to go from alternate views or makes it harder to acquire imaging and the standard location, or it can cloud the picture a little bit. I would argue that having pediatric specific trained sonographer fellow or techs would be helpful, because they’re gonna know some of these lesions and some of these subtle things that we’re gonna emphasize more in pediatric cardiology as compared to adult cardiology. And really to get that 360 view we need to complete study. So I think this is probably a little different than my adult counterparts, because we’re so used to looking at the heart from so many different views. I’m really expecting about 60 pictures or more. Sometimes it could be a hundred and twenty. I think a lot of times in the adult realm, they’ll do much more brief, because they’re not gonna expect to see some of the defects. They’re not gonna see those things, and so they don’t spend time looking at those sort of structures. And so I think whatever you can do to ensure that it’s a complete study, probably not trying to get the sonographer to go take the pictures real quick on their way out the door, because they’re probably gonna rush things or, things of that nature. 

[00:32:16] Not utilized a whole lot in pediatrics, but definitely in older teenagers and into early adulthood, if there’s chest wall trauma or the body habitus is unfavorable, and it’s just difficult to see the images, the use of echocardiographic intervascular, echocardiographic contrast agents can be very helpful cause it could just highlight the borders and make image acquisition much easier.

[00:32:37] And then I know this is always a bear when I say this, but sometimes, particularly if there is chest wall trauma, they’re trying to look at everything from the subcostal from the belly up. Or if there’s things in the way that you can’t get on the chest to take pictures, a transesophageal echocardiogram can be very helpful. And that’s where we would obviously insert a camera or a echocardiographic probe into the mouth, down through the esophagus, and then esophagus travel right behind the heart. You don’t have any lung in the way. You don’t have any bones in the way, and it has its own limitations, but as far as ventricular performance, it would be an excellent way to assess ventricular performance. So I think I would say consider that if, in the appropriate setting. 

[00:33:18] I think that’s mostly what we were gonna talk about today. So I think we’re gonna go to some questions. There are a couple that were provided ahead of time. And again, just for transparency again, I’m not an intensivist, but I will do my best to answer questions.

[00:33:31] (Question #1) So one of the questions was, “Can you speak to the value of sequential imaging?” I think I highlighted that intentionally a couple times during the talk. And then would it, “for example, would be repeat images after, a beginning T3 or T4?” I think that could be very reasonable. I think definitely sequential imaging from that statement paper. They also agree with that. I think probably if you get the initial echo and the EF is like 70% and you’re way above that 50 threshold, and then were to start another agent for some reason probably the function you don’t need to see that it’s even better than 70%. You’re already in a good place. And I would be surprised if it been decreased, but if you’re in that setting where it’s 40 to 45, or it’s 50, when after you make changes at the bedside, whether that’s a T3, T4, or some sort of presser, I definitely think that is one that could be a viable one to repeat. 

[00:34:22] And I think also in the mix is we didn’t, I didn’t the mechanism of injury in the downtime, right? So that, unfortunately, is what led to often the mortality of the patient and the brain death of the patient that can adversely affect the heart as well. And so, if the first echo is just really rough with an EF of severely depressed, the EF of 25%. Probably, that’s not gonna be a viable graft. The data is pretty clear less than 40 is definitely a no go. And I would be surprised if you’re gonna get that, recovery from a pretty abysmal level to a transplantable level. But if things change anything’s possible. And I do think that kids are very resilient and our tissues, when we’re young, are resilient. And you think just how an injury sets an adult back versus an injury for a child, they just bounce back from things better. And I do think insults to the cardiac myositis, so if there is an anoxic injury, as long as it’s not prolonged, there can be definitely additional recovery in myositis in the cardiac function after an abrupt insult like that. 

[00:35:30] (Question #2) Another question was, “When a pediatric patient is requiring pressers to maintain a blood pressure, is there any preference as to which pressers should be used rather than others? For example, as a coordinator I’m often told to use neo before levo before epi. However, in reviewing literature regarding this, I see no evidence based evidence to support this. If there’s a preference, why?” I pulled some of my ICU friends about this a little bit. I didn’t do a deep dive into the literature, so I’ll have to take your word on that. Within the donor realm, different than in just a standard patient with brain death, there are changes in the autonomic nervous system and there some issues with the hypothalamus and that whole axis not functioning well, and that can be a role for T3 and T4. I think what you would want to put this on here. I think you just want get a friendly chart to look at the common pressures. Although admittedly, this does not have nerine but it’s gonna be pretty similar to epinephrine, to look at what you’re trying to gain from whatever the agent is. If it’s the blood pressure, then you probably, you wanna maybe aim for something that’s gonna increase your SVR. If the function is marginal and you want to increase it, then you would go over something that can increase your stroke volume of the ventricle, the left ventricle. I think I would just look to try and titrate medicines that you think are gonna give you the desired effect to keep your blood pressure where it should be for age, where the heart rate should be for age to help make the case that this organ is graphable organ.

[00:36:54] We have some questions, I believe? 

[00:36:56] Laura Carroll: Yeah, I think we do. And please keep batting questions if there’s more questions, because we’re gonna keep them going for a little while. (Question #3) This one’s for Maggie Tarpley she asked, “In the adult world, if the EF comes back marginal, we will sometimes do a multi one challenge for 12 hours and repeat the echo. Is there anything similar in the Ped’s world? 

[00:37:16] Dr. Scott Simpson: What kind of challenge? I’m sorry.

[00:37:18] Laura Carroll: I’m sorry. She just corrected it. It was a typo. For the record everybody, I’m not clinical so I can’t say these words as well as everybody. Milrinone? 

[00:37:25] Dr. Scott Simpson: Milrinone, yeah. We love in the sort of living world or the pre-transplant world, we love, we call it vitamin M. So the ICU uses it with reckless abandon. They love it a lot. And I believe that was on that chart here. Yeah. So the issue could be, it can definitely help ventricular performance. The cost is sometimes it drops your SVR. So if you’re having blood pressure issues, it could drop your blood pressure. But definitely if your blood pressure’s fine and the function’s marginal, everyone loves Milrinone. From my standpoint, I think that would be a great trial. 

[00:37:58] Laura Carroll: Right. (Question #4) And then, Kimberly asks, “In the pediatric population, is there a preference between the use of”, I think you have it on the chart here too- “the dobutamine and the levo?” So, we’ll make sure to post this for everybody. I think it’s very helpful. So another question along those lines. 

[00:38:15] Dr. Simpson, I actually had a question and believe it, or not, as much as I’ve worked with you through the years, something rang out really big to me. And I think to some of the under CompuMed folks. The deep dive into the difference of the importance, not the difference, the very importance of using a pediatric cardiologist for these clinical assessments and reviews versus the adults. And think that’s something that we’ll spend a little bit more time on and maybe have you talk more in the future, but that was really helpful, and I think hopefully the audience on here knows that we do have the availability for that and the expertise for that at this point in time. 

[00:38:55] Dr. Scott Simpson: Yeah, I think I maybe referenced it, but I probably should have spent a little bit more time. So, because of the difference in size of patients and the evolution of the cardiac myocytes as we age. So the cardiac myocytes in a one month old are different; they are literally very different from even a one year old, and then definitely different than a 20 year old. And so to account for that, we have tables of sort of normative values and normal values at whatever age or size with regard to a lot of the different aspects of cardiac physiology. And I think no one is better prepared for that than a pediatric cardiologist to know what our normal values and what are not. And that’s not a knock against the adults. It’s just, their patients are a little bit more uniform overall size than in a dramatic difference between a small baby and a adult sized patient.

[00:39:49] Laura Carroll: And any other questions out there for Dr. Simpson? Some more are coming in, hang on one second. (Question #5) Oh, interesting. “If our images are submitted to CompuMed, will they automatically be sent to a PED specific cardiologist to read or do we need to specify when sending the images?” So I can preview this a little bit and then you can jump in how’s that, Dr. Simpson? So, this is from Sage Bailey. So, Sage, we actually have a way when you request it, it identifies the age on there and then our team will go ahead and they can determine which doctor it should be sent to. We’re actually building that out a little bit better so we can follow up on that with you.

[00:40:28] Some of our adult cardiologists, if you will, they can read to a certain age and it’s been an agreement that we’ve worked on with Dr. Simpson. But at certain age and below only at this point, Dr. Simpson reads them and we have other pediatric cardiologists, but he’s our primary at this point in time. So they are directly always assigned to him. And we actually look at it when they come in. I can say Dr. Simpson’s gotten off of an airplane, plugged his laptop in and has read these. So I remember that one. So Sage, they wrap them to the appropriate doctor.

[00:41:03] Dr. Scott Simpson: Yeah. Yeah. The, timing is sometimes I’m uncanny; my wife can attest to that, because know, heading out on a family trip and then a call will come in, but it’s the job we have. 

[00:41:12] Laura Carroll: (Question #6) Jason has a question, Jason Turner. “Do you explicitly read pedi echoes or do you do adult as well?” I think that’s directed at you Dr. Simpson, first. 

[00:41:19] Dr. Scott Simpson: Yeah, I’m comfortable with reading and trained to read into the twenties. But the bulk of my, I guess time when I’m not working with CompuMed is gonna be in the pediatric realm. But definitely, when you’re getting past your second decade, I probably would triage it up to the adults because there could be new problems that can evolve and develop and they would have that expertise that I probably wouldn’t have on my radar as much. So I would triage somebody older up to the adult cardiologist. 

[00:41:46] Laura Carroll: Yeah. And, Jason, along those lines that’s where we have a whole team of a cardiologists. And again, I think it ties back to the study Dr. Simpson put up earlier, which is we have a really compact group because we have very specific standards and it’s very focused on donor and transplant interpretations of the echo. And they work very close together on the standards. 

[00:42:13] (Question #7) Maggie Tarpley says, “How long should we wait post brain death to obtain an echo?” 

[00:42:18] Dr. Scott Simpson: That’s a good question. Because obviously time is of the essence. I think that’s the million dollar question, I guess. So it’s, that’s gonna be a tough one. I think you have to assess the the mechanism of death. How the downtime, how much support you’re needing, the patient is requiring. Are they requiring a lot of pressors that maybe you could peel some stuff back with time? I think if you feel like things are going reasonably well and getting an initial look, quickly would be helpful. Cause then you can maybe be surprised that things actually look better than you expected, or maybe it’ll just reassure you that yeah, we are pretty borderline, maybe have an interval of time to see if this heart can recover further. So, I wouldn’t say there’s a one size fits all answer for that one.

[00:43:02] Laura Carroll: (Question #8) Sarah Angle asks us, “We often have the donor patient on high peep. Even if they are peds, we are often up to 10 on a peep. For adults, we try to turn the peep down to 5 to give a better read for the sonographer. Would you say this would be helpful for peds too?” 

[00:43:18] Dr. Scott Simpson: Yes, absolutely. 

[00:43:21] Laura Carroll: (Question #9) And then we’ve got question from Christina Lutsko. She said, “I’m sure there are many variables that affect this, but in general, is there a guideline for how long to wait between serial echoes?” 

[00:43:34] Dr. Scott Simpson: Again, I don’t know if I don’t think there’s any data driven information. I think it’s gonna be very case by case, but depending on all the variables at play, and I would think you would kind have to look at the bedside, if the physiology seems like it’s improving. And then again, that number, the sweet spot is 50 or greater. So if you are a long way from that, you may want more time, one to two days versus if you’re pretty close and within 12 hours, things are significantly better. I think that could be a reasonable timeframe.

[00:44:02] Laura Carroll: (Question #10) And Sarah Engel has another question. She would like to know, “We often do T4 if we have a low EF. Do you prefer Milronone or T4 for better results?” Thanks. 

[00:44:13] Dr. Scott Simpson: I don’t have a strong preference. I think either T3 or T4 utilize, we don’t typically use that outside of this area, at least in pediatrics. I think, probably, the T4 will just help create stability when you have a brain death situation, and the Milronone could then augment the cardiac output a little bit better. I would probably think in this setting, probably having the T3 or T4 on board and then adding additional things after that, from my standpoint.

[00:44:43] Laura Carroll: Right now that seems to be all the questions that we have coming through. Dr. Simpson, on behalf of everybody who’s on this and everybody that you’ve worked with at CompuMed, we can’t thank you enough for this and the time and the information, and those 2:00 AM, 3:00 AM calls that you do with the coordinators to help. I think as a group, everybody on this call, we’re all trying to help others. So, we’re absolutely honored and humbled to have you on this. Thank you so much for your time and if there’s anything else you wanted say, or, we’re just so happy. Thank you. 

[00:45:13] Dr. Scott Simpson: Thank you for the opportunity to talk to everybody and showcase what we do. And, it’s a little bit of a a niche that’s not really well known and I appreciate the opportunity. 

[00:45:23] Laura Carroll: Great. So, for everybody else on, we’ll be there’ll be a rewatch of this soon. We’ll send it out and you can keep the questions coming in; we’ll get them to Dr. Simpson and follow up as best we can. If you aren’t working with us yet and you have additional questions just reach out and you can even do it through this group here on here. And then we will have another series coming up where we’ll have a couple radiology series, a couple pathology series, so just stay tuned. We plan to keep doing these every single month and we appreciate everybody’s time. Thanks.