Chapters Transcript Video Imaging in PH Click here to view presentation deck Dr. Edward Sawey describes how to identify pulmonary hypertension using echocardiography. Echo evaluation and pulmonary hypertension. I don't have any disclosures. Um So uh the the learning objectives for this is, you know, what does it look like? Now, we've seen a few images but um you know, I wanna really dive into what the imaging uh component is and how it can help you. Um How do we differentiate the different types of pulmonary hypertension on echocardiography? Now, it's, it's not possible to get as detailed data as a right heart catheterization nor should you be avoiding a right heart catheterization. But you can certainly get a general idea of what you're dealing with how severe and how likely it is to be pulmonary arterial hypertension and I'll show you a score. Um a echo derived score that will help you somewhat with this as well. Um Common difficulties with interpreting the echocardiographic images and the setting of pulmonary hypertension. So, just for uh basics, the right ventricle is shaped completely different than the left ventricle. Uh most of you know this um but it, it, it, it really, when you look at it, it's kind of a piggyback uh ventricle, uh it sits on the outside of the left ventricle and uh the septum uh if you um so the, the LV septum sits right here uh and it contributes uh about 40% of the stroke volume. Uh and that becomes important later on when we're talking about what's happening with the hemodynamics, the actual embryogenesis of the right ventricle. Uh You're coming from a completely different um mesenchymal field. Uh And uh yes, this is the part where you need more coffee, but um your primary and secondary heartfield, they develop into the right and left ventricle and the right and left ventricle, as you can see, here are the right ventricle comes from this different uh secondary heart field. Um What does that mean? The cells are fundamentally different? Um They orient in a different way, uh They responded in a different way, they have different signaling for hypertrophy. Um And we'll talk a little bit about RV hypertrophy. But um you know, sometimes you'll see RV hypertrophy and you'll notice that it's a phenomenon of somebody who's younger. Um you know, people who are developing this RV hypertrophy when they're um when they're having their pulmonary hypertension that is discovered when they are older, you'll frequently find that they do not have end up having RB hypertrophy because the epigenetic signaling pathways are really based on fetal uh uh the fetal embryogenesis. And as you get older, those epigenetic components go away. So this is left ventricle. This is probably the most we'll talk about the left ventricle for now, uh everybody else knows the left ventricle, the myofiber orientation, there's three different ways that the myo fibers are oriented. You have the longitudinal, OK. Again, the longitudinal fibers that are squeezing it circumferentially, you have um sorry circumferential, you have longitudinal fibers and then you have oblique fibers. So in a sense, what you're getting is a heart that is squeezing circumferentially, pulling up longitudinally and twisting like uh when you wring out a towel that has water in it, it moves in a completely different way and you cannot get an appreciation for that on echocardiography. Though I have a few cardiac MRI images, which you may actually be able to see a little bit of that the my fiber orientation in the RV. You only get two out of those three, you get circumferential and you have longitudinal fibers. Now, many of you are familiar with hearing about Tab C and Tab C. Um And those measurements only measure the edge of the tricuspid annulus. So what are you measuring? You're only measuring these longitudinal fiber as they are functioning? You're not measuring half of the myo fibers that are actually functioning in the right side of the heart. Um That for us in the pulmonary hypertension world is a significant problem. And uh we already spoke about this. The RV, uh the septum can contribute 50 more like 40% of the RV stroke work. So, imaging the RV, everybody understands that. Um Well, take a little poll how many people get the actual information that they need routinely on the right side of the heart on an echocardiogram? Raise your hand. No 111. So um there's, there's a few issues here. Uh I put this image up here because it's very instructive as to how wanna see if this. Yeah, this shows up, I'd rather use this. So when you're looking here, right, ventricle, left ventricle and chest wall. Now, what you see is when you're trying to image the right ventricle with an ultrasound beam, you have to go through the apex, the four chamber view and you have to have the beam catch this free wall. Now, what I'm going to kind of illustrate here is this is very close to the anterior portion of the chest wall. Uh If I had a different image, you would actually see that it's more like here. Um This uh any idea what that might be, that's a gas bubble in somebody's intestines. Well, and the enemy of ultrasound is air, right? So if you have the probe over here, you're missing the entire RV, free wall, your echoy are struggling to get the RV free wall. Um even if you don't have terrible pal lung disease, which uh you know, all your pulmonologists, your lungs get in my way when I'm trying to image the RV. Uh It's a real problem. Uh But we get around it somehow. So um the um so you're trying to come here, but then you look, you have this little window here and, and then what do you have here? You have some lung, you can't get ultrasound beams through there either. So you have this incredibly tiny window. And you're saying, OK. Um You know, Miss or Mr Echo, can you please image, can you do a better job of imaging the right ventricle? Can you actually try? They're trying, you know, a lot of them are trying, most of them are trying. It's just really hard to get the RV free wall. Also combine that with the fact anybody have any idea how big a normal, how thick a normal RV is in millimeters, somebody take a guess. Anybody 88 millimeters, anybody else? Yes. Three. Yes closer. Not too bad. You fall into the range of right ventricular hypertrophy 0.5 millimeters. You're dealing with something about 2 to 3 millimeters in thickness. Um So you're looking to get an ultrasound beam through here. This is about a centimeter. You're trying to get a picture of something that's two millimeters. You're trying to get it through this limited window. And then if this guy wakes up with some gas that morning, you're not gonna get proper images. Um And if the lungs are in the way you're not gonna get proper images. So we're gonna continue to move on. Um These are some beautiful pictures by our sonographer of um what an RV can look like on perfect imaging. And what we're gonna talk about is a way to measure not only the longitudinal fibers but the circumferential function as well called the RV fractional area change. So what you take is the four chamber view and you take the diastolic and systolic and you take the diastolic volume and the systolic, well, sorry area, diastolic area, systolic area, you s uh subtract the systolic from the diastolic to get the amount the stroke volume there or the difference in area. And then you divide it and you get a percentage, uh anything less than 35% is going to be diminished. Now, this is useful more in tracking. Um There are no necessary hard cut offs that everybody agrees on as mild, moderate to severe like they do in left ventricular function. Um There can be as I measure these, sometimes myself, they can be um kind of inner observer variation in the ability to measure this. Sometimes you're maybe a little bit more here. Sometimes you're a little bit more outside when you measure and it does actually make a significant difference in your measurements. So, tricuspid annular plane excursion, exactly what we were talking about before it does only measure the longitudinal fibers. And here what you're seeing is you put a uh Doppler through the annulus, lateral annulus and you get the distance that we're looking at the travel. Um you get a TSI of less than 1.7. And it is highly suggestive of RB dysfunction. This is um problematic in some ways for us. Um, in pulmonary hypertension, I can't tell you the amount of times where I've seen somebody with a fractional area change of 10 and a topsy of 2.5. It doesn't correlate in any way, shape or form and I'll show you how that can happen. Um And the other part is you may have had people who are referred to you who have had cardiac surgery. What people don't necessarily realize in cardiac surgery is then you have adhesions to the chest wall of the RV. So your tabs is gonna be diminished, but it may not actually be reflective of that portion. Uh Really how this came to mind is as being uh you know, uh on the heart transplant side of things, transplant patients almost never have a normal topsy. We, I mean, we, we completely disregard it. We do visual uh estimations. Generally, here's your echocardiogram with the topsy again, uh measuring uh from uh diastole to uh cysto and the tricuspid annular peak systolic velocity. Uh again, a separate uh measurement, this is the speed at which or the acceleration at which the annulus moves. It has not necessarily very much to do with how far it moves. Uh But again, it is another longitudinal measurement of the motion of the annulus and longitudinal fibers anything less than 9.5 again, is suggestive of RV, systolic dysfunction. We're still gonna take a little bit of that with a grain of salt though. What I will say is when you have decreases in your tabs C and tabs B along with your decreases in fractional area change. I do believe that is significantly worse than somebody who has um preserved longitudinal fiber function and there's what your echo normally looks like. Um I'll have a better uh better picture next year. Um So assessment of the RV cavity size, this is something that's missing in many echoes. Normal size. I can't how many consults you're actually looking at it and you get referred for a RVSP of 40 right, or 45. And it says normal size and normal function, you still kind of wanna know because people say normal size and normal function, but they haven't measured it and it's actually big or they say enlarged and it's actually normal. So our general main approach to this is to measure the basal diameter. There are a lot of diameters that you can certainly measure. Uh for me, the most important is the basal diameter. Um and the upper normal value is 4.1 some will say 4.3. Um But in the absence of anything else, if you have normal fractional area change and you have dilation, we still look at it. If you have normal size and normal function, then you really don't have to be quite so worried about where you are with your pulmonary hypertension qualitative assessment. Now, I I think some people may disagree with me on this. I think it is helpful because there are uh not everybody is going to be able to make particularly the fractional area change measurements accurately. Having a visual assessment can be helpful. Now, I'm gonna tell you one of my kind of gripes about the, the where we are with software is even in the software, at least the software that we have, there's only two choices, normal or reduced function. That's it. The drop down only has normal or reduced. So you see reduced and it's not that the sonographer purposely chose to be vague. It's the only choice they have to type in mild, moderate or severe. So if you see it, at least in the synapse software, they've actually taken the time to type it in or the cardiologist has actually taken the time to type it in. Um And you do know with how productivity goes, people will click the boxes as they can see and then you get that enlarged with reduced function because those are the choices that were given to them. I do believe that at least visually classifying it is better than nothing as mild, moderate or severe. I usually classify it myself. I use visual um on top of all my RV parameters as kind of a gestalt. Again, there's no particular uh cut off for these, there certainly is going to be a great degree of inter observer variation and some people are gonna call an RV normal when the fractional area changes eight because it's moving along and you know, they see the lateral side of the heart moving, but they fail to notice that the septum is being severely flattened at the same time again, uh duplicate slide, sorry uh assessment of RV cavity size. There's multiple areas where you can uh assess this and the parasternal long axis or short axis views. Um And they have upper limits of normal. Again, you can use these to look at dilation. I think um the RBOT and then particularly if you don't have chest imaging, I don't wanna use that one. If you don't have chest imaging, you do sometimes get a reasonable view of the main pulmonary artery. Now, that view is nice though it can be foreshortened. Um uh if it's big and it's caught and it's measured as big, you can usually trust that, but I would say that this misses the mark uh in a lower way frequently than actually catching a dilated pulmonary artery. So what is happening in our progression to RV failure? Well, you have a pulmonary vessel narrowing that leads to increased vascular load on the right ventricle. We know this, we've talked about this. I think every presenter before me has spoken about this. The RV adapts increasing muscle contractility and coupling. Now, you see RVH in this picture uh right in the, oh I need to go back. You see RV hypertrophy here though. You're going to find frequently that you do not have that adaptation um that the people who have RVH are going to do significantly better than the people who do not have RVH. Um they're just able to generate more pressure finally to maintain cardiac output. You have uncoupling, um you have an increase in wall stress and leftward Boeing of the septum. This is a picture that we frequently see. And then we have end stage where there's complete uncoupling with high metabolic demand and reduced cardiac output. A little bit to talk about. Uh how much time do I have? 30? Uh oh I have plenty of time. 20 a little bit to talk about the elevated metabolic needs of the RV, free wall. Um When you have all of this pressure here, um the, the, the filling pattern for the RV, and the RC A is completely different than the filling pattern for the, the left system. And the left system, you're filling in diastole in the right system. You're filling in diastole and cysto here. When you're over pressured and you're getting close to the systolic pressures, you're starting to feel more like the left coronary system, you're filling, uh you're actually perfusing the RV only in diastole and you start to have relative ischemia. Um And certainly as you approach your systemic pressures, so we've already kind of talked about all the different types of pulmonary hypertension. I don't think we need to go through group 12345. You guys, you guys are all pros now. So here's a normal echocardiogram and I think, I think we need to just kind of look at it so we can set the stage for what, what it is that we're looking at. Uh this is a parasternal long axis. What you're seeing is a normal L A diameter. Here's the aorta. If you were wondering about that, that's, it's the sending aorta uh ascending aorta. And this is the RV outflow tract. You're not seeing any flattening here, you're seeing a normal, um You're seeing a normal uh diastolic diameter uh here, here to here. Um You're not seeing flattening and, and, and this looks wonderfully normal. So, uh and this is the equivalent on cardiac MRI of the picture that we're looking at. Uh we're looking at the uh parasternal long axis. Here's the RVOT aorta L A and left ventricle. So I need to go forward again. Uh There, this is mostly normal echocardiogram. You may see a little bit of septal flattening here though, not, not really so much. Uh If, if I called it, I would call it mild here. You're seeing, you're not seeing any of the septal flattening. This is the same exact patient. Um what you're seeing, maybe even a little LV dilation, uh normal size L A and R A normal functioning RV. And you're seeing that motion of the tricuspid annulus and your fractional area change would add up to somewhere around 40 ish, something like this. So, again, back to difficulty with imaging the RV. Um we were talking about where the echo probe needs to actually sit. The op probe for the parasternal views has to sit on the anterior chest, right, right by the left side of the sternum, you need the apex and then the subcostal views are right underneath your rib cage by your zippy process, super sternal. Um Up top, you're not really, this isn't gonna be anything that's particularly helpful and pulmonary arterial hypertension. Um Sometimes you catch uh aortic aneurysms, but that's not really a German into our talk here. So we had this discussion last night about diastolic dysfunction in the setting of ad shaped septum. And it's worth mentioning briefly. Uh It's uh our personal practice and our, our, our experience by um reading echoes and correlating them with the right heart catheterization that the diastolic pressures in a flattened septum do not correlate with metro inflow measurements or the ede primes. Um So we do not call diastolic dysfunction. When there are septal flattening. The loading conditions are completely different. You're having over pressuring of the RV that is over pressuring the septum that is uh moving into the LV. Um And you have diminished flow from right to left and I'm not really sure that anybody knows exactly how to interpret that. To be honest, the calls on diastolic dysfunction are difficult in normal hearts. There's a lot of different parameters and, um, it's, it's, it's very difficult to actually call it. And what does 12 and three diastolic dysfunction mean? Anyways, um, people will argue about that. Uh, when I was training, um, about 10 years ago I was in an Echo LA where they did not call diastolic dysfunction because they did not know that it was particularly helpful for management. I disagree with that uh to some degree, but there is a lot of variability in the community. So what are we seeing here? This parasternal long axis? Um I guess this is a fellow question, huh, Mike. Um So uh sorry to put you all all on the spot. What do you, what are you guys seeing with this echocardiogram that is now Clark fellows? It is time I am going to go. What do you think? So, I'll orient you RVLVL A aorta dot So we're looking at the RB outflow tract, I'll give you I'll give you a few multiple choice normal big or small big, right? You already see you get a hint. These are the first images that you're getting and it's big. What about this LV cavity? Let me slow this down just a little bit. If it, if it, if it'll let me make them stay with that view though because I think that's worth seeing. Yeah. So what do you, what do you see this vi cavity doing right here? Normal size, big or small? Yeah, the opposite. Right. So you're looking, even the RB outflow tract is bigger than the middle of the LV cavity is something that you're gonna be very worried about straight away. How about here? Why is it not like? Oh, there we go. So, now what are we looking at here? Speak? Mhm Yep. Big R A big RV septal flattening. What about that left atrium? Now, this is a little bit more of a can you, can you put it in motion doctor? So, oh yeah, sure. What about that? Left atrium? There you go. Yeah. Left atrium is relatively small compared to the right atrium. And what, what is it doing here? It's bowing into the left side, right. So not only is the right bowing in there, but the left is bowing. Uh And it's really due to the amount of flow you're getting from the right into the left, the left atrium is just not filling, it's just not filling enough. This one's gonna be pretty straightforward for you guys. I would call this severe septal flattening. And what do you notice here? I think you, you, you should always take away more than a few things from each image. What are you seeing on, on this if it's going to play? What are you noticing on the RV side? Again, it's humongous, right? I mean, you don't, you, you have multiple views, every single view that, that you get the RV is humongous and that's a doctor term. So um so sorry, I went backwards instead of forwards because I'm trying to use two different clickers. So, so the that, that is a picture that you need to be worried about. That is a picture that may be somebody that needs to be in the hospital. Um And I need to wrap it up a little bit. Um So how do we measure the pressure for the RV? We use the simplified Bernoulli equation. It's pressure four times the velocity squared. This assumes that there is a, the same aortic, uh the same orifice area on or all echoes. Um And it assumes the same Doppler angle for every jet. So if I can get your eyes up here, if the jet is moving up this way and you get the Doppler this way, you're getting the full velocity. But if you're getting the jet going up, but you get the Doppler coming like this, right? You're getting a vector of it, you're only getting partial amount of the velocity this way because you're, you're coming in at this angle. So what's that going to do? That's going to underestimate your pressures. Now, I know there's one paper that says, yes, it can over estimate uh you, but it really, if it does, it doesn't really overestimate all that much. And what you're gonna find in overestimation is that there are bubbles in there. Somebody put definity in there and you're catching accelerated parts of uh of what's going on. And if it overestimates it, it overestimates it in a very small degree, it underestimates it frequently to a much larger degree. So here are some good envelopes uh and you'll get calls for RBS P all the time and some of them don't make sense. Uh This one will make sense because you're getting a good envelope and they're, they're measuring it relatively appropriately here as well. Look at this, where am I supposed to be measuring here? This is an envelope that should be going like this. So if I covered up, if I was able to cover up this side here, where should I be putting this? Should it belong there? Should it belong there? Is it gonna peak out somewhere here? Remember, this is a, a squared variable here. So this is a huge change. This could be 20 or 30 millimeters of mercury. And frequently people will call this and will tell you what it is. And it's underestimating it's saying 34 when it could be 5464. And then you need to add in a uh R A pressure estimate. So uh you have the valve gradient in the R A pressure estimate. It's kind of crude. Uh All of this assumes there's no pulmonic stenosis. Luckily, that's pretty rare. Um Here's the IVC, this is dilated and here is a sniff with the IVC. If you notice the I BC is not collapsing with sniff, which means um that this would be estimated at 15 dilated though we all know this could be 2025. You know, there's really no way to exactly say that. Um let's keep going. What about group two pulmonary hypertension? The majority of the tr jets are above 35 and that's what generates referrals. Uh pulmonary venous hypertension is much more prevalent than pulmonary arterial hypertension. How do you use the echo to gather evidence? So, there is an echocardiographic score based on ED prime left atrial dimensions and it's has two cutoffs and the RVOT pulse wave Doppler at the pulmonic valve. What you're getting here is this is going to be diastolic dysfunction. This is a big L A that's a small L A. This will be more pulmonary hypertension. Here you have group three, or uh group three diastolic dysfunction at the ed primes are going to be um higher and then lower. And here this classic mid systolic notch that you see on the Doppler of the outflow tract uh or the pulmonic uh pulmonary artery. So going through this kind of somewhat busy slide, what you're going to see is when you have a score of negative two, which was all the way on the left, you're going to have a wedge that's somewhere in the twenties. So you can kind of predict that when you go all the way to the right side, you're gonna have a wedge somewhere around 10 or lower. And you can use this, not that you should be using this as your noninvasive right heart C but this is a good way to predict this. And here's the, you know, scatter plot for plot where the plus twos are all all following. Um This is the pulmonary arterial hypertension looking echoes and they're all fall falling within this quarter of the high PV RS. And then uh on the other side, you're getting high wedge pressures. So what about this? This is, this is another hopefully fairly obvious. And for her in the interest of time, what you see here is very thick LV walls, you see an enlarged left atrium again, same thing, very thick, enlarged. You see a very large this left atrium though it looks small. This uh volume index is 53 which again is humongous. So now what if you can't see the RV? We talked about uh not being able to see the RV. And this, this is something that does happen. Uh Cardiac MRI can be used to collect this data without contrast and it can give you pulmonary arterial size. Um The downside is it cannot calculate the RVSP A and that is a big downside for where we are. So just for um everyone to see the uh cardiac MRI images are very pretty to me. What you're seeing is um Pernal lung disease. That's why we could not get those RV images. You see the septal flattening, you see an enlarged RV uh very clearly. Next, you see the septal flattening and you see that it's primarily in cysto, this is not in diastole. So the fluid volume is well managed in this patient and you're able to get a sense of and I always measure septal flattening in the mid cavity. Now, what we do is we go through all of these and we do about four millimeter cuts through all of these and to get RV, ejection fractions, we draw them out, draw out the RVS and the LVS and then eventually, what you're able to get is that cysto and that's diastole and it'll give you, oh, here's your pulmonary artery. Very nice, beautiful picture of the pulmonary artery. That's a 3.8 centimeter pulmonary artery. And you get that on all the cardiac MRI S anyways. And then after that, you get this wonderful output of stroke volume and RVEF as well as and diastolic volume and, and diastolic index. You get a wealth of data here except for the RVSP. Um So in your patients, this is about the only problems with this is it's about an hour long study and they have to lay flat and they have to hold their breath uh a bunch of times. So this is going to be fairly difficult to obtain, but when you are able to get it if you need it, they give you very beautiful images. So Pearl's technical difficulties, um echo assessment in the heart of the right heart and PH can be technically difficult for the reasons that I told you diastolic dysfunction should not be graded in ad shaped septum. The uh qualitative assessment can be helpful particularly when you do not have an institution that's going to give you some of the parameters, particularly fractional area change. Tr Jet Doppler frequently underestimates the RBS P because of hashtag physics uh and consider a bubble study for intracardiac shunting evaluation. We do bubble studies on all of our patients uh very early on. Um And I think I've run over time. Any questions? Yes. Cause like I was working at a free SCT for the fall like it has to be applied for any of this because don't forget it. You're gonna get a people like your dia like you should be able to the problem with CT. It is rate dependent. So they give all of your patients 5 mg of IV Lopressor. If you have somebody who has RV failure, that's a really good way to send them into the hospital. Um So we try to avoid that. Um It's going to involve contrast. So if you have anybody with renal dysfunction, the CT can't be done without contrast. Cardiac MRI can be done without contrast. Both of them are gated studies. Um You can get uh you know, LBEF and RBEAF off of both of them. Um But uh we, I like to stay away from those particularly for that high dose bol uh bolus because they need a heart rate of 60 or less, which is not gonna be achievable in our sicker patients. Thank you very much, Doctor soy. We're gonna need to move on. Thank you. Thank you very much. Published November 28, 2023 Created by Related Presenters Edward J. Sawey, M.D. Sentara Advanced Heart Failure Center View full profile
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