Dr. Ellis describes the origins and prevalence of adult congenital heart disease and the impact of care at the local level.
Alexander Ellis, M.D., M Sc., FACC, FAAP
Thank you guys for being here for the second annual Kim starring memorial lecture. Uh Last year was on Eisen Minger Syndrome. Uh which is what, uh which is what Kim had this year. We're gonna be talking about single ventricle patients, half the heart, but twice the problems and a as you'll hear, it's probably more than twice the problems. Um uh but it is about half of the heart. Um Thank you for, for being here and thanks for those who are here physically in the room. I appreciate it. It, it's, uh it's nice to actually speak to, to, to people in the room. Uh And I wanted to, to thank um Mike starring, who's here, who's Kim's husband. Um Carl and Barbara Jensen. Kim's parents couldn't be here today. Uh But they as a group have endowed this uh congenital heart disease learning experience for uh for CHKD and Centa. So I appreciate it. Just, just AAA few words about Kim. Um uh I have many favorite patients, but Kim was certainly um w was certainly at the top of that list. Um Kim is seen here on the left. Uh There's, there's Mike with, with a mustache, not a full beard. Um uh And then, um at times that Mike took Kim to altitude, which is uh Kim and I would always joke he was trying to kill her. Um, because that's not what an Eisenman patient would want. Um But Kim was a wonderful person who lived life to its fullest even with her, uh very significant um limitations from congenital heart disease, um very briefly. Uh And I won't bore you with all of Kim's anatomy. But for those of you who remember, uh Kim was born with tetra technology of fallo with pulmonary atresia and had a Waterston shunt uh and a discontinuous left pulmonary artery leaving her with Eisenman or physiology. Um And even when her SATS were um uh we're in the sixties and seventies she still did. Uh she still worked in Chesapeake uh public school system and took great vacations with Mike. They brought me barbecue sauce back from uh from the Mississippi Delta and uh just really did live her life to the fullest. Um and uh a a and was a wonderful, wonderful patient and person. So, in that vein, for adult congenital heart disease, where have these patients come from? How many are there? And what are we seeing locally? So, just a very brief primer on the population um which I think will, will help us all to, to, to understand um the need for care for this population. So these grafts are uh Well, some of this is is us data and, and some of this is Canadian data. But uh what I want you to focus on on this slide is that there are now more than 1.5 million patients with congenital heart disease living in the United States. So that's essentially all of Hampton Roads. Um If everyone in Hampton Roads had congenital heart disease for the rest of the country. So it's a significant group of patients that has grown dramatically over the last 25 years. And importantly, there are now more adults living with congenital heart disease. So 21 and older uh was the definition here uh than there are Children. So, as much as we do in, in A at CHKD right next door, there are more adults that potentially could be in this building than in our building. It is the most common birth defect if you want to, to use that nomenclature. Um I don't love that nomenclature, but it affects 1% of all babies born. And as you'll see, our survival has, has increased significantly. So in these charts, the the first chart shows all congenital heart disease um with the black lines being adults and the gray lines, uh and bars being Children. Um And as you see, both populations are increasing, um but the number of adults has outpaced, the number of Children and the bottom is severe congenital heart disease. So not your simple V sds your pdas, your A sds, even your simple um uh partial A V canals or, or, or uh vein issues. Um, but rather things like what Kim was born with and like what we'll be talking about today, your single ventricle patients, you're involved tetra technology and trunks and transposition patients. The number of adults here even 24 years ago, uh was essentially the same as the number of Children. And as I've just told you that uh that um relationship that ratio has changed. So uh the survival has improved, but it is still relatively representative of what you see on this graph. So here, things like cotta A SD and T and VSD had even um 15 years ago, very high survival. Uh five years after intervention. Unfortunately, things like what Kim had cyanotic congenital heart disease. Um The graph is showing that five years after intervention, patients with, with involved cyanotic defects, like our single ventricle patients had a survival that was significantly lower than the rest of the uh of the congenital heart disease population. Um So unfortunately, a lot of what we have achieved with medical and surgical and transcatheter interventions have allowed our patients to survive and thrive um into adulthood. But most of these are palliative interventions. They are not curative and we still have a long way to go in terms of um improving their survival and they will all have ongoing medical management um and interventional needs. So, uh I show this because I think that this is an important uh pie chart to show how things have improved uh just in in 50 years. So, uh again, there are more than 1.5 million adults living with congenital heart disease that are mostly palliated in 19, in the 19 sixties. Very few. Excuse me. About a third of patients with congenital heart disease survived into uh what they defined as adulthood, which is after age 18, you need a body with an 18 year old in the room. I have a 16 year old in the room and a 18 year old. There's no chance that 18 is an adult. Um It it it is not so um fast forward 50 years and in 2010, now, 85% of patients of all comers with congenital heart disease were now surviving into adulthood. Thanks again to advances in medical, surgical and transcatheter and ep interventions. This is uh a as, as we talk about partnering with Sara Moore from an inpatient standpoint. Uh First, we're gonna show you some outpatient statistics from two big ach D programs in the country um or in North America, I should say one in Toronto at sick kids um and Toronto General and the other at Mayo Clinic in Rochester with Carol Warrens, who's one of the pioneers in adult congenital heart disease uh medicine there at Mayo Clinic um known by Dr Taraia. Well, this is their combined data. So the darker bars are Mayo Clinic and the lighter bars are Toronto. Um And this is about 10 year data that's about 10 years old and you can see that their, their patients were predominantly in their twenties and thirties. Now, uh they tell me because I have friends at Mayo Clinic that they're seeing more patients in their thirties to fifties. That that is their, their average. Um uh and and this cohort is by definition getting older but it's also getting um but we're also seeing more admissions and inpatient, those were the outpatients. These are the inpatient and you'll see that our local data at the end of this talk will mirror this um that Mayo Clinic is up top and uh Doctor o'leary um did uh a national survey down at the bottom Mayo Clinic. You can see this is older data only through 1997. Uh But the triangular or the diamond bars uh are showing the over 30 admissions and those are the uh are the population that are really increasing. So, so institutions like t should be paying attention to this. That this is a growing trend even that was seen 25 years ago. Same is, is shown uh in the rise of adult admissions down at the bottom that the darker bars over 18, you can see had a steady increase from 1998 where the top graph leaves off up through 2010. Whereas the pediatric admissions were relatively flat. There were a few more in the latter years but not a statistically significant increase. So this is what I call the iceberg effect of congenital heart disease. There are many patients with congenital heart disease. They will have ongoing cardiac and other medical issues. They are coming to your EP lab, to your adult IC U, to the labor and delivery units, to your offices, to the inpatient wards. And they will need both general cardiology and specialty cardiology care, especially cath ep and heart failure and they're not going away. So, what we're seeing now is just the, the uh so called tip of the iceberg. There are many of them out there. Um and they're going to be showing up. Ok. So now that we have a better understanding about the population as a whole, let's talk specifically about single ventricles and we'll speak about the anatomy and surgical history, their physiology. And then most importantly, the multi organ system effects of being a single ventricle. I'm not gonna belabor the single ventricle pathway per se and we're not gonna talk about the Norwood or, or the shunted um phase uh because that's just not what's gonna end up in this building. We're just not gonna have patients that are uh that are still a as a single ventricle in the Norwood or Shunted Series. But I did want to at least mention that um we will be speaking a little bit about uh patients that have a superior cop pulmonary nomos is a so called Glen shunt. And then speaking much more about the total copula connection TCP C also called the Fontan. Um uh I will mention one thing and, and this is relevant for Kim as well. Um uh I I'll mention the types of shunts because what we do see in this building from time to time are those who've had the classic Blaylock tasic shunt and hopefully those out in cyber world uh can see the, the arrow here. Uh I don't like this graph in that it shows the the left subclavian continuing. That is not true. A classic Blalock Taussig shunt um from either side, right or left turns down that subclavian artery. So we, we had an example here in the building where I had somebody who had bilateral classic bt shunts and they kept trying to get blood pressures and they kept being very concerned that her blood pressure was in the seventies systolic and she said I feel fine. Um And they took her to the, to the C IC U here and started her on pressers. Um And it wasn't until we kind of uh clarified the anatomy that people realized that they needed to take a leg blood pressure because both of her soans were, were had been uh surgically um sacrificed. So, uh I will mention this. What Kim had is a Waterston Shunt. Um But uh II, I mentioned this because the anatomy matters. Um even from prior surgical intervention. So even if they don't have AAA shunt any longer, uh what they had in the past can still be relevant to their current physiology. So there just a few, just a little background since we were just talking about Blalock Taussig shunts. Um Some of the pioneers that came before us, Helen Taussig called the grandmother of congenital heart disease was at Johns Hopkins for many years. Um and an incredible clinician, she convinced uh Alfred Blaylock and his uh research and lab manager, Vivian Thomas uh to try and help uh the blue babies, the, the tetra patients of, of Baltimore. Um and they came up with um uh really, it was Vivian Thomas who came up with the, well with the idea and, and how to implement, well, Helen Tausig had the idea but the way to implement a classic Blaylock Taussig shunt in the dog lab uh and subsequently in 1947 in a human um uh what we'll be talking about today. Um There's more of a pantheon of white men, um Bill Norwood, um uh a great surgeon, but uh by all accounts, uh a challenging individual to work with um uh William Glenn, uh and Francois Fontan, uh who really were the uh the, the, the instigators if you will of, of um surgery for single ventricle palliation. And their names are now eponymous with uh their procedures and you will hear um us talk about Glens and Fontan. So just to put a face to those names. So speaking of a Glen, um a Glen is a superior copula anastomosis. This is the second um of uh the three phases or stages of, of single ventricle palliation. So typically, we will perform a gland at 2 to 6 months of age and we may still uh ha patients in adulthood may still, well, they will all have their glands. Um because that's part of being um a total cop pulmonary anastomosis. Um So it's important to understand the anatomy and physiology of this stage, but sometimes we will stop here. So you may have an adult that is just a glen in terms of their physiology. So, what is their physiology? Well, their shunt is ligated and divided as you can see here. Uh and their SVC is anastomosed to their pulmonary arterial tree. So you have a superior cavo pulmonary anastomosis. There is no longer any SVC blood that connects to um the right atrium. So the only source of pulmonary blood flow as shown there in yellow is your superior vena cava. This is a much more stable form of pulmonary blood flow compared to a shunt. It's less thrombogenic, it will grow with the patient um and can vasodilate or veo dilate um depending on the physiology. Um but this is passive pulmonary blood flow. There is no, of course, there's no pump and there's no arterial pressure head like there is with the shunt driving blood flow to the lungs, this is completely passive. So if you have something that obstructs that uh either thrombus or uh you have uh a pulmonary hypertensive event, you have um you're a smoker and you end up getting lung cancer, you end up getting a pneumonia, you end up getting COVID, which really hurt our single ventricle population. Anything that causes increased pulmonary vascular resistance is going to decrease pulmonary blood flow. Likewise, anything that increases your cerebral vascular resistance, um which certain ventilatory techniques as we'll talk about. If you increase. If our IC U colleagues or others increase your cerebral vascular resistance, you'll have less pulmonary blood flow because blood won't be getting to the brain to then come back from the brain. Um And the arms uh you may hear this called Hemi Fontan. It's a surgical variant. Um but a Hemi Fontan is the same physiology as a glen um They sat they will still be mixers. Remember um as we'll show you here on this graph, the inferior vena cava is still taking deoxygenated blood. Um uh A and, and, and that is mixing with all the pulmonary venous blood is shown here with the red arrow. So the purple is important you the these patients are still mixing, they are not uh they're, they're oxygenated and deoxygenated circuits are not segregated um in the same way that they will be as a Fontan. Um So again, some patients will stay at this stage. Um I think that, um uh I think Dr Robertson's here in the, in the audience. I think he and I share an Epstein's patient and the RV was just, is just not sufficient to handle uh the pulmonary or I'm sorry, all the systemic venous return. So, in some Epstein's patients, we will, we will do a superior cop pulmonary nostos to volume, unload the right and that's all they'll have. We'll call them a 1.5 type repair. Um So they still have an RV pumping out to the lungs, but it's only pumping the IVC blood, the SVC blood is going into the i into the pump into the I, in this case, generally the right pulmonary artery. Um or if you have a small RV. Uh But so you will see some patients that stay at this physiologic stage. Um The uh I, I will mention two variants of this because I think it's important to understand the anatomy. First is the bilateral bidirectional glen. And, and again, I don't like this diagram because they're showing in an nominate vein. And most patients who have a persistent, less superior vena cava don't have a bridging vein or an anominous vein. You can. Um but most patients do not. So we would do a bilateral bidirectional glen. Um if they had a, both a right and a persistent left superior vena cava, and we all started off with that. Um uh Even uh even Matt sitting in the back, um, started off with a, with an LSVC as well as an RSVC. And generally in um in fetal life, your persistent or your left superior vena cave is not persistent and it involutes and you just have um, a, a jugular vein going to your anominous vein. Uh but there are patients, um and it's a normal variant. We see it from time to time and you all must as well when you're putting in pick lines or I, if Dr Patel goes to the, the EP lab and, and puts a, put, puts a, uh a, a lead in and it somehow goes down the left side of the chest. Um He must see uh LSV CS from time to time. We certainly on our side, see him really quite frequently. Um And we try and make sure patients know to tell their doctors in the future that they still have normal variant. But again, it's called a bidirectional glen. Look at the arrows here. The reason it's bidirectional is because in this case, SVC flow goes to the RP A and the LP A, it's a bilateral bidirectional glen when you have both uh an LSVC and an RSVC. Conversely a classic Glenn. And this is also very important um because the O a lot of older patients in this area have a classic Glen here, it is not bidirectional. So here the SVC and this is what, what um what, what Glenn uh talked about initially and what Francois Fontan did initially you'll see in the next diagram the SVC is connected to the RP A. Not there's no flow to the L P A. Um from this so classic Glenn, you have SVC to RP A and then the classic Fontan, the old school Fontan is just IVC to LP A. Um None of that is done anymore, but we um we unfortunately can't just um update patient software, so to speak. Um And, and change their anatomy. Um So there are several patients in Hampton Roads at least um with, with this anatomy. So just uh w when you see the term classic Glen, that's SVC to the RP A, it is not bilateral or bidirectional. Um And then the bi bilateral bidirectional Glen is shown here. Um a few little pearls for their physiology. Uh Remember of course, that it's passive pulmonary blood flow um uh their cardiac output is very preload dependent. Um uh That is gonna be especially true for Fontanes, but it's, it, it is also true for Glen's. Um It is, as we've already said, dependent on both your pulmonary vascular resistance, your PV R and your cerebral vascular resistance. So therefore, we don't want to hyper ventilate these patients. So if they are in the IC U, you don't want to uh blow down their P CO2 because that will cause cerebral vasoconstriction you will get less blood flow coming back to their, their head. Um and then therefore to the lungs. So you'll have net decreased pulmonary blood flow. So they will be blue no matter what you do. Um You actually want to hyperventilate uh to cause a little permissive hypercapnia, which will improve both cerebral uh blood flow and to some degree, uh it won't impact pulmonary blood flow that much. So your systemic oxygenation will be improved. Ok. Now, to the meat of the physiology and to the talk, the so called Fontan patients. So this is in our single ventricle palliation. This is stage three uh again, eponymous named for Francois Fontan, also called a total cavo pulmonary connection or TCP C. Now, we will have redirected all or almost all of the systemic blood flow um back to the lungs. So this is diagrammatically what it is. And again, it's a Fontan, not a fountain or Fontaine. I've seen it written all sorts of ways. This is a fountain, this is a Fontan. So Francois Fontan described this uh before I was born in 1971 with uh with doctor Baudet um separately uh Doctor Kreutzer um from Argentina, who subsequently ended up at, at Pittsburgh. And his daughter, Jackie Kreutzer is a calf doc. She's head of the Cath lab now at uh children's Hospital of Pittsburgh. Um uh and her brother is also a, a cardiologist. So they've kept it in the family. Um uh But Kreutzer de described this as well, but just as they say, uh you've got a publisher Parish, he did not publish it um with the same expediency as Francois Fontan did. But they, they kind of separately arrived at the same physiologic conclusion. The, the, the two diagrams on the left are from his paper from 1971. Um And this was with Tricuspid Atresia as um as the primary um an atomic substrate. So, uh which is shown here on the far left. Uh On the second, you see the classic glands, you see the SVC connected to uh the right pulmonary artery. What he initially did is he took, he incised into the right atrium, right atrial appendage really put a valve here. Uh But at the uh CAVO atrial junction by the IVC and then another going into the left pulmonary artery, they quickly found out those thrombosed really pretty quickly and they dispensed with the valves. They didn't need the valves, they were flow restrictors, they didn't help things. Um But this became the basis for the classic atrial Pulmonary Fontan where they ended up using uh the right atrial appendage, which is not shown here and flapped that over to the LP A. So you had IVC flow that came through what became a very dilated right atrium, right atrial appendage into the LP A. Um Other variants of uh of the Fontan, no one is doing a an atrial pulmonary Fontan anymore. Uh But uh but our ep colleagues will see them because they are an incredible mess of atrial arrhythmias. Um And it's almost impossible to, to ablate these um a a as, as doctor gentles will, will, will tell you because the Atria is so huge. Um It's bigger than most New York apartments and you could move into it and the re entrance circuits are just uh insurmountable uh in most cases by catheter based techniques. Um So you have to do a Fontan conversion. Um Newer ways of doing this are the so-called lateral tunnel. And we'll see another uh example of that. But I do want to point out what's shown in number two that is a fenestration. Um And we still do fenestration. So, a fenestration is an intentionally left connection which our ep colleagues love if it's still there between the, the, the atrium or the IVC uh right atrial junction. Um and the heart because otherwise, again, after this stage, red and blue bloods, uh the, the oxidated and deoxy blood are completely segregated one from the other. So, uh the there is no way to from a venous connection to get into the heart without going uh transept across a, a lot of thick um uh tissue. Um So it's undesirable for our EP or interventional colleagues. Um The uh So, so a fenestration is still used and we, we do that um more for post operative stability and some will do if we have high fontan pressures and some of the, the, the long term consequences uh which we'll speak about a little bit later. Uh And then the more modern approach, the extracardiac conduit, generally a gortex tube graft uh between 18 and 22 millimeters in diameter depending on the patient's size. OK. So, uh because I, I think a lot of our colleagues use uh angiography. Um I do CT and Mr as many of you know. Um So here are the same three forms of the fontana diagrammatically at the top and then angiography, uh their angiography or excuse me, ct down at the bottom. I'm not gonna spend a lot of time on the atrial pulmonary again, other than to show you that, that you could move into that right atrium. It is so large. Um And so uh arithmetic, um the pacemaker leads uh I will point point this out. Um Remember that all the veins lead to the lungs now. So I did have when, when I first came to this area 17 years ago, we set up the ACH D program 17 years ago. I had uh a, a physician who's not at this institution and never has been um call me for one of my single ventricle patients who had just gotten off a plane from a vacation in Hawaii. And she said, oh, I just felt terrible about halfway through the flight. I felt incredibly tired. Um and on her way home from, from the airport, she said, I just got to go to the emergency room. I feel awful. She got in and had a heart rate of 38. Um and was in complete heart block and saw an electrophysiologist who then called me and said, well, I'm gonna put, she needs a pacemaker. I'm gonna put a pace maker in her. And I said, are you a cardiac surgeon? He said, no, I'm an electrophysiologist. And I said, so, how's that gonna go? And he said, well, and then he explained it to me. I, I think the current term is mansplained. He mansplained to me how he was gonna put a lead in him uh in her. And, and then I had to say, well, do you know if you put something through the jugular vein? Do you know where you're gonna end up? And he said, yes, the right ventricle. I said, no, you're not, you're not. Um So, uh uh understanding the anatomy is key. Um These are epicardial leads, of course, and that is what our fontan patients will need. Um is epicardial leads. Um They're, they're really, there's some emerging techniques, but there's nothing right now uh for, for transvenous pacing that is widespread um in this population. Um I will highlight again, lateral tunnel where we're creating uh this area loves tunnels, right? So this is a, a uh baffle or it redirects the venous blood up to the superior vena cava again, uh cutting off any connection uh to the atrium. And you, you can see that in here, this little bulge is, is right where um the uh uh the, the patch starts. So if you're an electrophysiologist, you wanna poke in here to get over through the atrium, not up here. Um uh And then the extracardiac conduit uh is shown here. Uh And our structural heart disease team here has helped us with some uh extracardiac conduit stenosis in, in the past, with stenting these. Um And again, the diagram here shows uh that it is common to have some pacing needs in our Fontan population. But they are generally, as I said, uh epicardial leads. So at the risk of o of boring people with physiology, I do want to show this diagram and I think understanding this really helps you understand Fontan physiology. So um you have lost your subpulmonary ventricular pump, you have no pump, driving blood flow to the lungs. So in, in graph A, that is our normal two ventricular circulation where you have your LV that drives blood out into the AORTA, you have pressure loss down through the systemic circulation. Uh That then that now you have deoxygenated blood that returns to a right atrium. That is if you can see a little bit lower than where things started in your LV, you then have an RV that drives blood out to the lungs. So it's a pressure head in through the pulmonary circulation, then through the alveolar capillary network, uh you have uh yy, you have gas exchange that then depending on your pulmonary vascular resistance that drops you down to your L A pressure, which is higher, of course, generally than your right atrial pressure that then ejects out to the body. We all know that system in your Fontan things are a little bit different. So you now just have a V no LV. You just have a VA V ejects blood to the aorta. Same thing you have loss of pressure as you come through all the tissue muscle, et cetera um uh through the body. Now, you have deoxygenated blood that returned via a cable vein. Notice that this is higher um than the pressure in graph A. This then goes through uh into your pulmonary arteries. You have depending on your pulmonary vascular resistance. You'll have a pressure drop uh in the lungs down to a left atrium that then ejects blood out to the ventricle. So you have to, by definition, you have to have a higher central venous pressure in graph B than you do in graph A to be able to uh to drive blood into the lungs. Your SVC pressure, the so-called central venous pressure um has to be higher than your mean pulmonary artery pressure and of course, has to be higher than your L A or your single ventricle EDP. Now, with time, excuse me, your uh late Fontan circulation. We've superimposed that on the early and the the width of the bars matters here as well. The width of the bars represents your cardiac output. So now with your late Fontan physiology, your cardiac output is smaller. And unfortunately, with your higher pulmonary vascular resistance, you now have a, as you see here, a negative spiral, your pulmonary vascular resistance increases. So here the pressure drop um is uh is larger and so the cable vein pressure is higher than it was initially. And you can see that from being superimposed one on the other, you then have reduced pulmonary blood flow because of that cable because of the higher PV R leading to higher central venous pressure that leads to higher ventricular EDP and or I'm sorry to less ventricular filling, a lower ventricular end diastolic volume, but a higher EDP as we remember, all of that serves to lower your stroke volume. You just have less, of course, in the ventricle, less filling and your cardiac output decreases. So notice how the left atrial pressure is higher than it was before the width of the bar is decreased because your stroke volume is decreased. So this is this negative spiral that our single ventricle patients get in. And so what we really have to do is to try and keep their ends pressure as low as we can and their pulmonary vascular resistance as low as we can. So with that in mind with the physiology in mind. Let's talk a little bit about the multiorgan system effects. Um And I have this diagram but I have another that I like even more that we're gonna go through the next few organ systems. Um and we're not gonna do them all. Um But we are gonna talk about the cardiac effects, of course, because this is cardiology, grand rounds pulmonary effects. Um because doctor Hooper uh and our pulmonary colleagues uh do take care of these patients with us in the IC U, the hepatic effects because of course, the liver feels a lot of the central venous pressure elevation um and the hematologic effects because I'm married to a hematologist. Um So this diagram talks uh a little bit about um what uh what Dr Jet Lik and our ep colleagues love the arrhythmia issues. We've talked about heart failure, thromboembolic complications, increased pulmonary vascular resistance. We'll talk about uh excuse me, a little bit of the lymphatic problems like protein, losing neuropathy and plastic bronchitis. Um but we'll just touch on those a little bit. So this is the diagram that I like very much. Excuse me. So in the top left, it's gonna speak to the cardiac complications. We've already mentioned some of the diastolic or systolic dysfunction arrhythmias, which is the number one complication that our uh adults with congenital heart disease that are single ventricle patients will experience, which is why it's so important to partner. Uh with our ep colleagues in adult cardiology. Um you can get a lot of a V valve regurgitation that we'll talk about. Uh and then the uh pulmonary venous um uh pressures uh which really should go along with diastolic dysfunction. All of that begets um uh decrease cardiac output and higher pulmonary vascular resistance. Um and the lower cardiac output will increase your central venous pressure, which will cause a lot of these problems. The kidney issues and the liver issues, the pulmonary vascular resistance can also be affected as we'll see from things we do to the chest wall and to the lungs um that the lungs themselves have not developed normally and we'll, we'll speak about some of these other related issues. Excuse me. All right. So, the cardiac complications of the fontan. Well, the number, uh well, the the most obvious is ventricular dysfunction. You have a single ventricle. The morphology of that varies. So, some single ventricles are predominantly in RV morphology. Some like tricuspid atresia are in LV morphology. Those are the good single ventricles. Of course, then some have a mixed morphology. Even with advanced imaging by echo, sometimes you can't tell. But even with advanced imaging, sometimes you have a hard time telling how much of this is an RV versus how much is an LV. The ventricular dysfunction. Uh when you're, when you're a shunt, going all the way back to that first stage, you're volume loaded. So every time the heart contracts, it is pumping blood to both the lungs through a shunt and to the body. So you have a volume loaded ventricle depending on how long they stay a shunt that can really increase. That has been shown to uh increase histologically, the amount of uh myocardial fibrosis. You have, um the more times you're exposed to cardiopulmonary bypass. Uh, that is not, as I say to my patients, it's not health food to go back on pump is not good for anybody's myocardium. Um And our patients will have generally a minimum of three cardiopulmonary bypass exposures by the time they're adults if they're a single ventricle. In addition, some of the shunts like the, the soo shunt that we showed earlier, it requires a ventriculotomy. You have to cut into the myocardium, which we really try and avoid now, but was done much more commonly in the sixties, seventies and eighties. Um You try uh the they, even with the soo shunt, now they've cut into the ventricular myocardium, which is Anita for ventricular arrhythmias and of course, myocardial scarring and dysfunction. Um and we have lower preload uh as because of what we've just talked about from a physiology standpoint with time. Uh So their, their ventricular function is impaired by the lower preload as well. You superpose on that, the normal co comorbidities that, that uh that, that you in this room and those out there on cyber world uh will see much more than I do the hypertension, the coronary artery disease, the diabetes, the obesity. Um uh these are things that, uh, that, that are plaguing our adults and unfortunately, single ventricle patients, um, are Fontan adults are not immune from these uh, ad acquired uh heart disease issues either. So, ventricular dysfunction is a major problem in our Fontan patients but not uh uh to the uh, it, it's a problem but we can manage that medically pretty well. Valvular dysfunction. Unfortunately, we can't manage as well medically as you guys all know. And this is generally not amenable to transcatheter, um MitraClip or Tricuspid clip type techniques. Um Most of these patients they've had, as we've already said, volume loaded hearts, they have unusual geometry, both of the m uh uh of the ventricle themselves and often of the A V valves with their attachments. So it is common to have AAA fair amount, a moderate amount or more of a V valve regurgitation and we do go back in and try and make this better surgically. Um We do that at CHKD a couple of times a year with our Fontan patients. Um Generally, uh sometimes we'll do it before the Fontan stage sometimes after. Um but it is, it's tricky um to, to do this and the surgeons um uh only do it if they really think they're gonna make a big difference. Um because it, you, you can often times make things worse, unfortunately, uh A V valve station is very common with our A V canal variants, whether you, you have um an unbalanced a V canal. So you have a RV, dominant A V canal. And so you have a common A V valve, there is no separate, uh you know, your mitral valve is not really small. Your tricho valve is not dominant. You just have a single A V valve, often with a cleft or zone of a position that is missing in the anterior leaflet or the anterior bridging leaflet. Or uh if you have a something like hypoplastic left heart syndrome, you really just have a tricuspid valve and that has had to function as a mitral valve for, for a long time and it was just not bioengineered to do that. So the third complication is, is, as I said, probably, unfortunately, the number one complication uh arrhythmias and sinus node dysfunction. Let's talk very briefly about the functional assessment. Um So, looking at uh single ventricle patients and their function, um what is good is what we all do is echo. It is relatively subjective whether it's transesophageal or transthoracic. We can use an ejection fraction. Uh We can use a myocardial performance index. We use D PDT from a V valve regurgitation. We will use strain imaging. Although um uh you guys are much better at strain imaging that we are than we are in congenital heart disease and we don't have normal values for that. So we have to extrapolate based on uh a two ventricle uh set of patients for, for normal values. Uh And I'm not convinced that those are the same. So an a, a normal strain for uh for, you know, a 50 year old um man's LV is probably not the same as for a 30 year old fontanes uh single ventricle. It's probably not, but we don't know what normal is for them. What is better and quasi objective is cardiac Mr. Um But that can be very limited by devices or other intracardiac metal, whether we have, you know, put plats or devices in or coils or other things. Um And as you'll see from this diagram, this is one of our MRS. Um you can trace this ventricular myocardial endocardial border pretty easily. But then, you know, do you include the little nugget of an RV here? Um This is the Fontan here. There, there is no uh there is no fenestration in this. Um And so it depends different institutions will do it different ways you have to. So it becomes difficult to interpret biometric analysis from say the mayo clinic versus here. Um So we try and standardize it but it doesn't always happen. Cardiac CT is a good way of doing things. But as you guys will see, this is somebody who uh the, the, the big problem is that the er will scan everybody, right? If you walk in and you say, you know, you have a cough, you're gonna get a chest CT, um, and what they'll do is they'll inject from the arm and that op pacifies blood coming through the glen circuit very well, but none of the blood flow coming from the legs or the abdomen. So, what you'll see here, this, this Fontan has a stent in their Fontan and you can see that this is unified blood, of course, coming back from the abdomen and from the legs uh compared to what's in the heart. So every Fontan, they're gonna come back if they do it this way, they're gonna say, oh, can exclude a pulmonary embolism um or may have a pulmonary embolism. They may call that. So we at CHKD have some techniques uh where, where we try and um uh have different contrast injection protocols to try and minimize that. But uh but ct in a Fontan population is not easy. Um But it can be done. Um systolic function. Um It generally uh we, we can quantify it pretty well by either of the good or better methods. Um But it is harder again because the of the unusual geometry and the lack of normal values, diastolic function. Um I'll go right out on a limb and Doctor Robertson's here, he can correct me, but I don't think we're very good at estimating diastolic function noninvasively anyway, um by echo or by any other means. Um Really it's, it's a calf diagnosis. Um And I'll tell you, we're even worse in the congenital heart disease population. We're just gonna assume that they all have some degree of diastolic dysfunction given their history. Um, we are not good at uh, noninvasively assessing diastolic function in single ventricle patients. What is something that's important is a functional assessment? I say I can see what your heart looks like when you're laying on an echo table or in an MRI, but I really want to see what you can do and so putting them on the treadmill or on the bike uh and getting a functional assessment of their exercise capacity um with some spirometry is important. Uh just, just again to, to show you there, there are various um when, when we look at single ventricles, it can be very challenging to, to how much do you include, how much of the myocardium is? Um II I is, is really blood pool, how much uh you know, some people will exclude papillary muscles in their assessment. Some people will, will exclude any vestigial septum. Um So, uh unfortunately, the uh the the numbers are not always comparable between institutions or programs. Ok. So what are the arrhythmic complications of being a Fontan? Um A lot of atrial arrhythmias as, as Doctor Gent Lisk and, and others will, will tell you um there's a lot of sutra line scar that begets intraatrial reentrant, tachycardia or I A RT A variant of atrial flutter, but unfortunately, less responsive to medications generally, um, is quite responsive to cardioversion. Um, uh, but uh a and can be mapped and abated in the cath lab but is not always controllable by medication. Um, and there are some uh molecular regulation or dysregulation problems. The hand one and the Wnt genes that, that seem to be uh upregulated in congenital heart disease populations and will lead to more atrial arrhythmias. Um, but in general, catheter based ablation techniques are less um successful in our single ventricle patients than they are in general, irregular acquired heart disease. Adults, um atrial pacing uh may be beneficial in these patients to try and maintain cardiac output. Cardiac output is heart rate times stroke volume, times hemoglobin. We really care about the hemoglobin. There's not a lot we can always do about the car about the stroke volume. So the heart rate does help, but a lower heart rate is better for our Fontan patients. We don't want a heart, an average heart rate of 90 or 100 but we also don't want it of 40. So um there is a, there is a happy medium um and uh a prolonged CRS and V and a lot of ventricular pacing we know are bad, but we really don't understand the role of cardiac resynchronization in this population very well. There are patients uh or places that are doing this. Um and, and some early work says that they think that there's they're offsetting some harmful effects but we really don't know, exercise does seem to decrease the arrhythmia risk. VT, of course, is the even more worrisome uh complication. Uh And I do want to highlight that my, my fontan patients that, that have sustained VT that is a really bad prognostic sign. Of course, it is for everybody but even more so, excuse me, for our font ends. So about 11% of, of single ventricle patients ended up having uh sustained VT and this was highly associated with needing transplant or death um uh in five years. So sustain VT, we try and become very aggressive with the treatment uh both from an anti rhythmic standpoint, an ablation standpoint, but also doing everything we can to optimize their, their hemodynamics, their pulmonary vasculature um getting into a Fontan circuit is challenging and I think Dr Lui has has has done this for one of my patients. Um and it John Reed, I think may have come over although it may have been with, with, with Doctor Gramas or Doctor Gentles, it's challenging to get into these. Um because uh a as you can see um and as you saw before this is an extra cardiac conduit to IVC, um you really don't wanna be perforating through a thick gortex tube that's been in there for 20 some years. Um It's just gonna be very challenging and a surgical rescue or bailout is gonna be difficult as well. Uh So, trying to figure out where the connection between native tissue and the extra cardiac conduit to be able to, to perforate across there is, is not entirely easy. Um And uh and it can be challenging. Um So, uh and, and of course, as you can see the treatments at the bottom, antihyp medications, ablation, um and access to the heart are are options, the devices pacemakers, as we said, and you can see in the diagrams there on the right um that they need to be epicardial leads or patches. The anti tachycardia pacing can be very helpful. But again, getting a device in there is, is often requires a repeat sternotomy. Um and finding enough real estate on the heart to put leads or patches. Um If you have an I CD um and Fontan conversion, that is a very specialized procedure where they will take an old style atrial pulmonary Fontan and make it into an extra cardiac conduit and do a lot of um cox mazes type work in the in the atrium. Um that is really only done in a couple of institutions around the country. Um And the the the mortality unfortunately is around 15%. So it is it is a nontrivial procedure to go into. Ok. So we've talked a little bit about the cardiac uh issues. Now, we're gonna talk there on the bottom left about um pulmonary problems, things that can lead to increased pulmonary vascular resistance. So some of the pulmonary effects are uh Well, of course, as we've talked about, there's complete redirection of all of the venous blood passively to the lungs. So, it depends on your preload. So if you drive these patients out, they will not have adequate preload or if you have increased systemic vascular resistance, um or pulmonary vascular resistance, they will not get blood back to their lungs passively. The SATS are not entirely normal, but they're more normal than in any other stage. And the reason that they're not normal is because of course, your coronary sinus blood, the most deoxygenated blood in the body still returns to the heart. So there is no Fontan palliation where the coronary sinus goes to the lungs. So coronary sinus blood will always go back to the heart still. And so that will leave our Fontan patients somewhat desaturated. So if you're getting assad of 99 or 100% in a Fontan, the number is not right. It generally a good Fontan is 96 to 98%. And then there can be Venus collaterals that we'll talk about. But um uh but that is a typical 94 to 97 is a typical Fontan set, um two pearls and we talk about this for those who are doing procedures as well as for those who are taking care of patients in an IC U positive pressure is bad for Fontan. They hate it, it decreases pulmonary blood flow. And if you have passive pulmonary blood flow with no pump, driving blood out there. You can really get into trouble with prolonged positive pressure, ventilation in a Fontan, especially if you increase the, the peep. So we try and keep the peep as low as possible but not to beget atelectasis and our tidal volume 6 to 8 MLS per kg. Um A and we try and limit, of course, the time that they're on a ventilator as much as possible, noninvasive ventilatory techniques or if we had an iron lung here, those would all be better ways of ventilating. Um Are Fontan patients. So the goal is to have the lowest mean a airway pressure as possible. So you want to avoid hyperinflation, but you also don't want adalacis, it's like goldilocks, you don't want too much, you want too little, you want it just right. So you, you want to do things to decrease your pulmonary vascular resistance. You'd rather have them a little alkalic. You'd rather give them some oxygen. Nitric oxide is fine. Um And again, some hyperventilation which will make you have a reso alkalosis, but a metabolic alkalosis is a good thing as well. Um So, uh I, I'll skip ahead a little bit just in the interest of time. Um And just say that we, we do see some chest wall geometry issues like pectus or repeated sternotomies that lead to restrictive lung disease. That is very common in our single ventricle patients to have restrictive lung disease. And to have some respiratory muscle weakness because they may have had a frantic nerve injury, uh, or diaphragmatic injury. Earlier, the last thing I wanted to talk about is Fontan associated liver disease. And this is really important. Uh, not because you're a gastroenterologist, you're not. But because we all give medications and the medications, uh, are just not conjugated in the same way in a Fontan patient. So if you're in an EP lab, a Cath lab, if you're doing a procedure and you give some fentaNYL or some versed, it's not gonna be metabolized in the same way as it would be if you didn't have uh Fontan associated liver disease. So why do you have f uh, they're, they're cirrhotic and why are they cirrhotic for the same reason that our alcoholics are, you have decreased cardiac output, which leads to, uh, increased in, in diastolic pressure and less tissue, uh, perfusion and increased central venous pressure because of the nonpulsatile flow. So, the increased central venous pressure and the de decreased cardiac output will lead to a cirrhotic like state. So, what do we do about this? Well, we try and optimize their hemodynamics as much as we can. Um, we try and keep them in sinus rhythm. We try and keep their central venous pressures as low as possible. Any Fontan pathway obstruction in the Fontan, the gland, the pulmonary arteries, we try and alleviate that. Um, but most, almost all have some degree of fibrosis. And we, as a, we as a congenital heart disease community don't know what to do with this yet. We will tell you that we don't know what to do with this. Um, other than we know to look for the complications, synthetic and conjugated uh problems, their albumin is low, their platelets are low. They end up, as I said, not conjugating medications as normally. Um, they have bleeding problems because again, they, they, they factor um their, their clotting factors are not being synthesized normally in the liver. Um And they're at risk for developing hepatocellular carcinoma. I've had, as you can see in that bottom, um right in the room. Um uh I've had two patients who have uh unfortunately developed a pato cellular carcinoma. We don't even agree with how to screen for that. As you can see on this, this, this is a paper that, that, that came out relatively recently. Um uh in circulation on Fontan associated liver disease, they talk about Mr elastography. We don't even have that at Norfolk General. You can't get Mr elastography here very easily. Um So most of what we're doing um is either abdominal MRI or uh or ultrasound. Um And the, the sensitivity and specificity for ultrasound of course, are not as good. Uh but it is much more readily available and uh easier for patients to do, especially if you have a device um or a lot of metal. Um But all of this is, is not important for you to remember other than to say, we don't know what to do with it even. Um Yeah, even in terms of screening, other than say, it's time to go to transplant for both heart and liver and those don't unfortunately go well in most cases. Um And everyone that I have sent from here to various institutions has been turned down. So I've not had anyone who has been successfully um had heart liver transplant. There was one at M CV last year and he died unfortunately, about two weeks afterwards. So, um you have to for Fontano liver disease. Our mandate is to optimize hemodynamics, avoid hepatotoxic medications, try and get them to stop drinking and screen for, for hepatocellular carcinoma. So I think uh I'm going to end on this slide because I think our time is up. If, if I could have you remember these things, I think this would be uh a worthwhile hour. These are the single ventricle pearls. If you're managing a single ventricle or a Fontan patient, please try and optimize the preload. Um You want them euvolemic to slightly dry. Um If you're too dry, your blood pressures are gonna be low, you're gonna develop a metabolic acidosis. If you're too wet, you're gonna have more ascites, you're gonna have more pulmonary edema. Um And your liver is going to be big. Um And you're gonna have more arrhythmias. You want to minimize afterload, please things like, like um leva fed are not going to be beneficial for our single ventricle population. It would be much better to have them on a little debut amine or EPI um which will uh if you can tolerate the higher heart rates. Um You don't want to have afterload against the valves or the ventricle. Uh the ventricle, you wanna keep your SVR as low as you can, you want to also keep your pulmonary vascular resistance as low as you can keep your lungs dry and optimized in terms of their mechanics as much as possible. Um maintain sinus rhythm or get it back as soon as possible. Please, please don't leave Fontan in an atrial tac for a week. It's, it's one thing to do it overnight uh until we can get anesthesia arranged or whatnot for cardioversion, but please don't leave them in an atrial arrhythmia if we can avoid it. Um Sinus rhythm is really important for them and lower heart rates generally are better for ventricular filling. But again, a Fontan with a heart rate of 40 is probably too low. Um But uh but you know, sixties, seventies much better for our Fontan. We'd rather have them have that than a heart rate of 90 to 120. Um We've already talked about limiting positive pressure, ventilation, air filters. I'll come back to that from the, from the fenestration. Remember we talked about us leaving a fenestration for post-operative stability and when our central venous pressures or fontan pressures get high, that can act as a pop off. So you can actually maintain, you're blue but you have a cardiac output. You have the ability to, to, to load your ventricle. Please make sure that they have air filters. These are the 0.2 micron air filters. They're available in Hemon wards. They're available in the, er, they're available. If, if you, uh, if the nurses know what to use for amiodarone, for the filters, for amiodarone, it's the same thing. Please make sure that every IV has an air filter. Paradoxical embolization definitely happens with this po leading to strokes. Um And what happens is people are like, oh, it's hard to flush through these. Let me just take the filter off. No, that's the whole point of having the filter. Please put air filters on all IV lines. We did that for Kim all the time. Uh Please make sure uh that we don't, we've knock on wood, had not had a stroke related to this and I'd like to keep it that way. Uh Lastly, there's a risk for thrombosis. All of these patients are at least on aspirin. Uh But many, if they've had arrhythmias or ventricular dysfunction, um they will also be on Coumadin. Uh There's growing uh evidence uh for, for no ax or do ax. Um But in the hospital they should be on sub cu heparin sc DS and early ambulation. All right. Well, I think we're out of time. We didn't actually get to discuss the, the, uh, local statistics. We can do that at a different time. Um, but I'll open the floor to questions both virtually from Amy or somebody in the room.
