 Welcome everyone! Today we are going to talk about transesophageal echo for aortic valve stenosis, albedo-tobstruction and hypertrophic cardiomyopathy. I'm Faco Moreno and we are doing this lecture for the 2019 preparation for the National Board of Ecocardiography for our fellows at the Toronto General Hospital. So let's just start with everything, these closures, there is no disclosures, there is no academic conflicts, there is no financial conflicts of interest and no compensation given for that talk. So objectives. We are going to divide the talk basically into themes. We are going to talk about aortic valve stenosis and we are going to define what hypertrophic cardiomyopathy and how can we use transesophageal echo to help us assess those two pathologies. So to start with aortic stenosis, the last recommendations from the American Society of Echo were from 2017. This article is actually very well-brightened and it's really recommended to understand better the lecture. So let's go there and let's just talk about what is expected from us when we are assessing an aortic stenosis patient in the OR. So to start with it's important to remember the aortic valve anatomy, that's why I love this image of the heart from the top of the heart removing the atriums. On the right side of the screen we can see the caspid valve, on the left side of the screen we can see the mitral valve, the anterior to both ventricles, you always will have the aorta and the pulmonic. So the aorta is actually going to help us to orient it ourselves with T, because it's always going to be anterior to the tricaspid and the mitral. Other structures that can actually help us to get better orientation is the coronary sinus and the left atrial appendix. So when we want to assess the anatomy of the aortic valve, the first plane that is going to come to our mind is going to be the midasophageal aortic valve suraxis. It's normally obtained at 45 degrees as we can see in the picture on the left part of the screen and then the important part here is to differentiate the leaflets. An important thing that is going to help us to differentiate which leaflets are we talking about from the aortic valve is going to be the intra-atrial septum between the left atrium and the right atrium as you can see in the picture. The leaflet that is associated with the intra-atrial septum is going to be the non-coronary casp, because there is no coronary artery here. So the right coronary casp is always going to be in relationship with the right ventricone and the left coronary casp where we can in fact see the origin of the left main in the picture. It's going to be closer to the right side of the screen. So if we increase our angle in TE and we achieve the midasophageal aortic valve suraxis at 120-130 degrees, then that's the image that we are going to obtain and that's the image that we are going to use to measure the annulus and measure the LBOT diameter on the aortic valve. Okay, so in this image the classical thing that we are going to find is the right coronary casp attached to the right ventricle and the one that is attached to the anterior LBOT leaflet is going to be the non or the left coronary casp. As you can see in the cat, the higher your angle, the higher the possibility that you're cutting through the left coronary casp, the lower your angle, the higher the possibility that you are cutting through the non-coronary casp. Okay, anatomy. Here we have three good examples. Again, we are talking about those two planes. Recommendations of the anatomy but the American Society of Eco-Guylands are the parasternal long axis and short axis view on trans-terrathic echocardiography. So in transasophageal, the parasternal long axis is going to be equivalent to your midasophageal aortic valve long axis. Okay, the recommendation is to use sub-mode to get a better impression of the valve and then here we are going to actually assess the numbers of casps in C-story because it's when they are open and if there is a raffi present or not, you want to assess the mobility and you want to assess the degree of calcification. So as we were saying for us in TE, our aortic valve long axis is going to be equivalent to the trans-terrathic. Again, remember the leaflet in the long axis view that is attached to the right ventricles is going to be the right coronary casp. The leaflet that is attached to the left end is going to be the non-coronary casp or the left coronary casp. Okay, and then here on the right side of the screen you are going to have the aortic valve short axis and we have the different structures that they are going to help us. The left coronary casp, the non-coronary casp in between the right and the left atrium and the right coronary casp over there. Okay, aortic stenosis etiology. So there is different etiologies that will cause aortic stenosis. One of the most common ones is the fact of having calcification of the aortic valve and congenital, which the most frequent type of congenital is going to be the bicaspid. There is some dramatic disease of the aortic valve, but it's not as frequent in North America the fact of finding a dramatic disease. So basically the acquired type is the one that is going to be divided in dramatic and calcified and then we are going to talk a little bit about those. So first of all, when you have a rheumatic aortic stenosis, you should look for a triangular systolic orifice in the opening on systole on the leaflets of the aortic valve. While when we are talking about the calcification valve, you should look for an estolate shape systolic orifice. When we are talking about congenital, the classical valve that we're going to find is the bicaspid. The most common calciopacaspid aortic valve is going to appear as a ruffy between the left and the non coronary casp and we are going to talk in a second of how we can differentiate that, but you can see in fact other kinds of congenital disease on the aortic valve that will cause aortic stenosis as unicospital aortic valve or quadricospital aortic valve and you can actually see the images of those here. So the congenital type when we talk about bicaspid aortic valve, as you can see per safer at all in 2008, the power is that the type one, which is the most frequent type, is the fusion of the right and the left coronary casp and in 60 percent of the cases of this type there is a ruffy in between them, but there is 20 that they don't present a ruffy. So like around almost like a 10 percent of the between a between a 10-20 percent you can see the fusion of the right and the non coronary casp and it's extremely rare to appreciate type three, which is the the left coronary casp and the non coronary casp. So in Europe and United States of America, so the aortic valve replacements perform for aortic stenosis, 50 percent of them are due to bicaspid aortic valves. So the anostic we have two casps seen in systole and we have the elliptical systolic orifice as we previously mentioned and here as you can see that's the anatomy that we expect to see and that's where we are going to see the ruffy in a type one or our right to left coronary casp fusion with ruffy in the middle and the blue area is the opening area of the aortic valve. Okay so here's an example of a bicaspid aortic valve on the left side of the screen by using a 3d technology called x-plane this is from phillips and there are like depending on the platform that you can use you have the multiplane from g and you can actually do the same in in Siemens okay so what it does is it cuts in the long axis v of the aortic valve you get a parallel plane that is going to be with a difference of 90 degrees okay and on the right side of the screen we can see the same bicaspid aortic valve in the short axis okay so using 3d you can see that with a much better appreciation and you can perfectly see in that picture the ruffy coming into the image between the right and the left coronary casp so as per the american society of eco ecocardiography it's the primary non-invasive imaging method for valve and stenosis it's the key tool for the diagnosis and evaluation and it's really important in clinical decision making we are going to assess aortic stenosis with te based on three levels of a standard clinical practice we are going to base this lecture on the level one and level two and we are not going to talk about the level three which is not recommended routinely the level one is the most used one and it's appropriate and recommended and the level two is when there is a reasonable uh in selected in very specific patients so starting with recommendations as level one you are going to need to remember that the way to assess an aortic stenosis is going to start always with the jet velocity on the aortic stenosis after that you want to calculate the mean transaortic gradient and we are talking about mean which will be different when you are assessing a hypertrophic heart and in a hypertrophic cardiomyopathy okay and the valve area by continuity equation and we will explain during this lecture how to obtain that as a level two which is an alternate way of doing things for specific patients you can simplify the continuity equation to calculate your valve area or you can use the velocity ratio or the aortic valve area by planimetry and as the experimental things that can be though to actually see is aortic stenosis they are they are here as you can see as lb percentage of stroke work laws or covered pressure gradient energy laws impedance resistance or projected aba but those are subjects for another lecture so let's just to start how do we quantify the severity of our aortic stenosis so the main criterium that the the guidelines recommend us is starting with a peak velocity because the peak velocity is the one that is going to give you the mean gradient and we are going to explain that in a moment and what do you need to remember is a peak velocity of more than four is considered severe and the normal values are going to be below 2.5 meters per second the mean gradients it's more than 40 when it's severe less than 20 when it's mild for aortic valve area in centimeters to the square it's minus the minus below 1 centimeter to the square you're considering that as severe aortic stenosis and mild is going to be when it's going to be more than 1.5 you can do the indexed aortic valve area when you have very small patients or very big patients and then they are talking about severe aortic stenosis when it's below 0.6 and the velocity ratio and we will explain that in a second when it's below 0.25 it's when it's considered severe aortic stenosis there are some interesting conclusions from the cake points and these just came straight from the from the guidelines and they talk about it's very important for the aortic stenosis peak jet velocity to be obtained in multiple views and that's the recommendation okay not not basing your study in a single measurement is extremely recommended to have a dedicated dual crest crystal of continuous with doctor transducer and again this is this is going to be done by the machine but the mean gradient should be calculated averaging the instantaneous gradients over the reaction period and not base it and not obtain it from the velocity okay from the mean velocity so as an important source of error the lbut diameter the recommendation is to measure in transducer athic echocardiography in the parasternal long axis so we should measure it in the mid-sophageal long axis view of the aortic valve we are using D and as per guidelines it should be between 0.3 centimeters to 1 centimeters away from the annulus and in mid-systole from inner edge to inner edge of the septal endocardium and that's really important the same thing will be applied for the aortic annulus okay so and exactly at this level is where you are going to position your pulse weight Doppler to obtain your lbut Doppler profile okay so those are really important things when we are assessing aortic a stenosis so the direct planimetry of the lbut to be more accurate and not assume any geometrical shape in the lbut can be done by 3DTE with multiplying reconstruction or can be done by a CT scan to try over the source the the source of error so let's just go a little bit more deep into that and let's talk about what we are going to be doing okay so Balvanatomy when we are quantifying aortic stenosis we have already talked about how to do it and then the important part that we are going to discuss next on the lecture is going to be the lbut diameter the lbut velocity and the as jet velocity and how are we going to be able to calculate and obtain those so let's just start with the lbut diameter as we were saying before it should be measured 0.3 to 1 centimeter away from the below the aortic valve or if it is okay and as you can see in the picture this is recommended to be done in the parasternal long axis so the equivalent to that in TE will be the aortic valve long axis should be from inner edge to inner edge in mid-size story okay and it's important it's recommended to use zoom mode to get a better a better definition of it and even adjust the gain to optimize the the blood tissue interface lbut diameter is a big source of error so it's extremely important to do it properly otherwise we are not going to be able to get the aortic valve area in an accurate manner so if we can go in another option that we can do to actually try to avoid the time to avoid those mistakes when we are measuring the lbut diameter is go straight and calculate the lbut area so first of all things that we can do to do that so if we measure an lbut diameter which in this example is 2.3 centimeters we are calculating an aortic valve area of 1.3 which it will make the aortic valve area it will make the aortic stenosis as moderate but the problem that we have with that is that we don't know if we are cutting the lbut where we should be cutting so one thing that we can do is we can take a 3d picture image from here we can align the planes and then we can after doing that we can measure the diameter being sure that you are cutting the lbut where it should be cut because you can have actually a proper alignment with multiplying reconstruction using 3d and then we realize that the real lbut diameter is 2.02 centimeters compared to the 2.3 centimeters that we were getting so our value in the aortic valve area is going to be different okay and even more you can actually use that to calculate the lbut area directly and not assuming that the lbut is going to be a perfect circle and doing it doing pi per values to the square in the question to be able to actually obtain your your lbut area so we have talked about how to detect how to calculate and how to do the lbut diameter now we are going to talk about how to obtain lbut velocities okay so for the lbut velocities the first recommended way of doing that is using instead of continuous weight Doppler pulse weight Doppler because it's more accurate than continuous weight Doppler and the Doppler sample should be should be done at the level of the lbut as as where we were measuring the diameter of the lbut so to get that the recommendation as per the guidelines is from the apical long axis view or the five chamber view which in Te is going to be equivalent to the Te deep transgastric or the transgastric long axis so the deep transgastric we have an example here you can see the morphology and that's the way it's very important to align the plane and for the transgastric long axis in Te is not so easy to align the plane and normally we are not going to get like such a good alignment as in the deep transgastric but it's another source of possibility to measure the lbut so what you're going to do is you put your pulse weight Doppler at the level of the lbut and you trace and then you trace the and then you trace the the Doppler shape that you are getting and automatically the machine is going to calculate your maximum velocity and your your mean and your max big gradient and the bti of the lbut okay which is the velocity timing integral which is the conjunction of the momentous that are inside of the of the area of the Doppler so it's recommended again to be done with a sweep speed of between 50 and 100 millimeters per second as you can see in the white arrow here so we have done we have done the lbut diameter we have done the lbut bti now we need to calculate the arctic the arctic esthanosic jet velocity the problem with the arctic esthanosic jet velocity is that we are not going to be able to calculate that with pulse weight Doppler because we are going to have an ali icing effect so you need to use a continuous weight Doppler and it's recommended that they you see to actually have a dedicated transducer for that so in this example we are taking that from the D trans gastric view in te and then you put you continuous weight Doppler in the middle of the valve and then you choose pulse and then you trace the bti from the outer edge of the densile signal and then automatically the machine is going to calculate for you your bmax and your mean gradients and if you have actually placed before the lbut diameter and the lbut bti the arctic barbaria is going to be calculated as in this example the advantages of this technique are going to be the possibility of doing a direct measurement of the velocity and these jet velocities the strongest predictor clinical outcome so we are going to talk a little bit at the end of the lecture about this critical outcome but definitely anything about 5.5 is going to have severe implications for the patients the limitation of this jet velocity is i think the most important one is that it's flow dependent so if the velocity is flow dependent the gradients are going to be flow dependence because the gradients are calculated from the velocity and it's extremely important to do a correct measurements with a parallel alignment of the ultrason beam and as we were mentioning before in the long axis view of the transgastric plane for te this alignment is not really good so you can't get a deep transgastric view it's going to be complicated to get normal values so okay so we have the lbot diameter we have the lbot vti and we have the as jet velocity so how are those mean transaortic pressure gradients calculated we were talking the whole time that from velocities we can actually get the mean transaortic gradients so to actually be able to get those you are going to need the Bernoulli equation that's how the machine the software of the machine calculates it so the Bernoulli equation is going to compare a difference in pressure it's going to be equal to connect convective acceleration flow acceleration and viscous friction consider considering a constant the viscous friction of the blood and having in account the the same flow acceleration so you can simplify this equation as the maximum or big gradient being equal to four per v to the square so that's how the machine does it so the machine calculates the maximum velocity on the Doppler and four per this velocity to the square is going to give you the maximum or big gradient but there is a problem with this formula because in this formula we are simplifying the proximal and the distal velocity and we talk about the proximal velocity we are talking about the velocity in the lbot and the distal velocity is the velocity in the arctic path so the exception where we cannot use this simplify equation is when your lbot velocity is more than 1.5 meters per second or when the arctic velocity is less than three meters per second then you need to use the modify Bernoulli equation which is the maximum or big gradient is going to be equal to four per the b max to the square minus the b proximal to the square okay being the b max the maximum velocity in the arctic valve and the b proximal the maximum velocity in the lbot if you want to understand this better try to remember that whenever the lbot velocity is one meter per second or less and a square number like a number that is one below one which we as square is actually smaller so it's very minimal the effect that is going to have in the maximum or big gradient then that's the way of calculating the maximum gradient so how do we calculate the mean gradients so that's something that the machine is going to do with the software and the machine is going to do an average of the instantaneous mean gradients over the reaction period another way to calculate it is doing 2.4 per the b max to the square but that's actually not recommended as per the ASC what we should go is by the average of instantaneous mean gradients so now that we know where to measure and how to measure how do we get the arctic valve area so we will be able to get the velocity and the mean gradients which is a level one for assessment of arctic stenosis another level one is to calculate the arctic valve area based on the continuity equation so what's the continuity equation the continuous the continuity equation establish that the stroke volume in the lvot should be equal to the stroke volume in the arctic valve and the stroke volume volume can be calculated by the croc section area per the bti or velocity time integral remember the croc section area the units are going to be centimeters to the square the bti centimeters centimeters to the square per centimeters centimeters to the cube which equals milliliters and that's how you get your stroke volume so what we are going to do is very simple we are going to say the arctic valve area per the bti of the arctic valve area which is the stroke volume in the arctic valve should be equal to the croc section area of the lvot per the bti on the lvot assuming that the bti of the arctic valve area can be calculated by continuous weight Doppler in the transgaster view the bti of the lvot can be calculated by pulse weight Doppler per the bti in the lvot and the croc section area of the lvot is going to be calculated assuming that the lvot is a circle by you want to know the area so it's the perimeter so it's going to be pi per radius to the square so if you know the diameter you divide the diameter by two and you get the radius and that's how you get the croc section area in the lvot a very important point here thank you to the 3d technology we know now that the lvot is actually not circular it's more ellipsoid so if you have the capacity of doing 3d and multiplying reconstruction and get an lvot area this measurement is going to be much more accurate that only the lvot diameter or at least getting the lvot diameter by 3d is going to help you and not do so so so much mistake that if you choose to be advantages of this arctic valve area calculated by continuous equation it's flow independent compared to the velocities and the main ingredients which are flow dependent is helpful when the flows are very low or very high because those can have like an implication in the main ingredients very high flows going to give you high velocities high gradients very low flows going to give you low velocity low gradients okay doppler velocity and pressure gradients are flow dependent for an orifice area so that's what you need to bring home okay so the limitations of this equation is normally it's been observed that the effective valve area is going to be a little bit smaller than the real anatomic valve area when you are when you measure it from the surgeons okay and the changes in flow rate are going to give you changes in the valve area so if you go brady or if you go if you go tachycardic that might change and affect your arctic valve area by continuous equation and remember in those patients that they have severe lb dysfunction or they have an lbad because the opening of the arctic valve is not constant or is very minimal so those are the ones that are going to to give you like significant changes on the valve area with every single bit because it's going to be different so the double and not envelope technique i wanted to comment on that because i say that some people prefer this technique some people prefer to measure lbot bti by put width dopper in lbot and then do continuous width dopper and measure the arctic valve bti by continuous width dopper there so the advantages of using this technique is that you can simultaneously obtain the left ventricular flow track and arctic valve velocities in a single bit in the same bit that's good but the problem is measuring the lbot bti which is the b1 represented in the picture here when you use continuous width dopper it's not as accurate as when you just put width dopper so it tends to overestimate the peak so you're going to overestimate the arctic valve area you can use it but remember that the values here are going to be a little bit higher that the values if you just put width dopper in the lbot and you measure the lbot bti by the put width dopper so now we are more conformal with the methods that we use to assess arctic stenosis by level level one so we are going to keep going and we are going to talk a little bit about the methods that we use in the level two so simplify continuity equation so basically it's the continuity equation as it is but instead of using the vti that you need to trace the whole area of of the Doppler signal you are going to convert that into velocity being v the maximum velocity so you choose to measure the maximum velocity in the lbot and the maximum velocity in the arctic valve and use the arctic valve area to calculate your arctic valve the advantage of that is that it's faster to do but it's less accurate especially when there is an atypical shape of the Doppler and on the curve so another thing is the dimension and another method that we can use which is a level two recommendation is the dimensionless index or also known as velocity ratio so it's an even more simplified equation sorry even more simplified continuity equation okay so what we do here is literally just compare the velocity in the lbot divided by the velocity in the arctic valve so the usual scenario is the velocity should be pretty close one to the other so when the velocity in the lbot is less than 25 percent of the velocity in the arctic valve that means that the arctic valve is severely esthetic so when the dimensionless index is below equal or below 0.25 that's an indicator of severe arctic stenosis and it's an effective arctic valve area expressed as a proportion of the lbot process in our area so the third and final level two method to assess arctic stenosis is the arctic valve area by planimetry so the the main problem that you are going to find when you use the planimetry here is specifically when you have such a calcified area so you're going to have a normal arctic valve area is going to be between 0.6 2.6 and 3.2 centimeters to the square and it's a good technique if you are not able to get an unreliable Doppler estimation of flow velocities you can get a deep transgastric there is contraindication to go with the t in the transgastric so you basically are not going to be able to get the Doppler so you're not going to be able to get velocities gradients and you're not going to be able to calculate the arctic valve area based on that so if you can do that and you can you don't know how to use 3d then this is a good alternative so it's inaccurate specifically when the calcifications give you shadows and reverberations and what is a limitation because and the limitation of actually identifying the the orifice so you want to perfectly see insistently the three leaflets you can use color Doppler to narrow to narrow to to get the narrowest office and you can reduce the gain to avoid the blooming to avoid the blooming from from the calcium another way is you're going to press the long axis or in our case we go to the long axis of the arctic valve so you do you do like a end mold closing closing through the through the annulus of the arctic valve and you can see the separation insistently of the casps and what we know is anything below eight millimeters is associated with an arctic valve area of minus one centimeters to the square those two techniques are very well described in the book of pereno and colleagues and remember when we are doing a planimetry of the arctic valve changes in the cardiac output doesn't mean changes in the panometric or arctic valve area so it's not affected by flow as as the gradients and the velocities are so we have a couple of discrepancies when we are measuring arctic stenosis and there are three scenarios that is worthy to mention the first one is when you have low flow and low gradient arctic stenosis and we will explain what's that and you have preserve or decrease ef which is going to change how do we assess this as and then a third and interesting scenario is the one where you have a normal flow but you have low gradient and you have an arctic valve area that is less than one centimeter to the square with preserve ef which makes no sense so we will talk about the three of them and what can be happening when we go to those scenarios so the new guidelines from the american heart association divided arctic stenosis in four clinical stage abc and the the important part here for us is the symptomatic severe arctic stenosis is the one that we are going to see in dor and the main different changes that we are going to do is between the d2 and d3 so d2 is the low flow low gradient as with imper levendicons historic function and the d3 is the low flow low gradient as with normal preserve lbf which is considered more than 50 percent so based on those new classifications for the american heart association the recommendation from the american society of echo to assess those types of arctic stenosis are as followed so we have a case of low flow that means that your stroke volume indexed for the body surface area of the patient should be less than 35 millimeters per meter to the square you have a low gradient and to get a low gradient means that your b max is less than four which is the which is the cutoff to consider an arctic stenosis severe or you mean gradient is less than 40 which is the same cutoff to be considered as severe and you have a normal reaction fraction from the ventricle which is 50 percent or more so in that situation if you get an arctic valve area of less than one centimeter to the square so why are we getting those uh what how is possible to get a severe arctic valve stenosis when your velocity and your main gradients are not matching the criterion for severe arctic stenosis so the first thing that you need to remember is that the velocity and the gradients are flow dependent and the arctic valve area even by plan imagery or even by continue the question they are not flow dependent okay so some of the key points that we got when we are doing that is the possibility of when we are doing the measurements the patient being like severely hypertensive during the examination or being a patient with leventical severe leventical hypertrophy due to chronic hypertension and that's what is actually going to explain why the flows were low and why the gradients were low because the flows were actually low okay so it should be a situation where your flows are decreased but not because the heart can actually eject properly it's because there is something that is not allowing the flows to actually be bigger than the specter and those situations are normally as we mentioned severe hypertension with severe increase in the afterload or it can be especially like after after like a cardiopulmonary bypass in those patients when you have a patient extremely dry and you increase okay so the other thing that is important to actually exclude when you are getting this kind of situation is that you didn't make like a measure error and the most important part is going to be in the LBOT area and the LBOT diameter okay so as you can see in table five this is the criteria that increase the likelihood of severe AS in patients with low flow low gradient AS and preserve EF so and the recommendations that they do is assess the leventical hypertrophy assess the severity of the of the calcium in in the CT to see if it's actually high and this is more consistent with AI so when we have that situation okay so we are talking about low flow low gradient severe overtake stenosis and normally F so the recommendation from the guidelines is to go to an integrate approach and this integrated approach is is the one that we were that we were just mentioning before okay so recommendation to be sure that you don't mess up with the calculation of the LBOT diameter is to go and try to get it in 3d if you don't know how to do 3d or the 3d images were not taken you can actually go and assess it by CT or MRI and then get a customer score by the by the CT and they say that if immense the customer score is more than 3000 there is a very likely possibility of being severe AI okay so the other situation is when you get low flow low gradient AS and decrease the ejection fraction in that situation the problem is you still have low flow so your stroke volume index is less than 35 milliliters per meter to the second you have your B max which is less than four meters per second and your mean gradient less than 40 millimeters of mercury because the mean gradients are are are being given by the B max but you have an EF that is less than 50 percent or abnormal you still have like a severe Arctic stenosis there's the Arctic but various less than one centimeters so when we have this as an area you need to know if this is a true severe AS or this is due to LB dysfunction so to do that the recommendation is to do a WDM stress echo and we will talk a little bit about how do we do that so when you do the WDM stress echo what you want to know if there is a flow reserve or not we understand flow reserve the increase in the stroke volume up by 20 percent if you are able to achieve it with the WDM stress echo and you're out in Bulgaria still less than one centimeter to the square this is known as true severe Arctic stenosis and the severe Arctic stenosis means that it's real and it causes the LB LB systolic and the cause of that is the LB systolic dysfunction the low flow okay but when you increase your stroke volume by a 20 percent with the WDM stress test and the Arctic valveria it's more than one centimeter to the square so that means that it's a severe severe Arctic stenosis and the low flows are the ones that causes the velocity and the gradients to underestimate the severity of the Arctic valveria due to LB dysfunction okay when there is a no flow reserve you do the WDM stress echo you are not able to increase your stroke volume by 20 percent so we cannot say it so the recommendation is to go to the customer score by city and if there is high enough we are going to consider that a real Arctic stenosis so here is the protocol and for the WDM stress echo they recommend to start like 2.5 to 5 mics per kilo per minute and to increase the doses between 2.5 to 5 mics every three three to five minutes up to a maximum of 20 mics per kilo per minute and then again you are able to increase your stroke volume per 20 percent and you are able to get a final valveria which is more than 1.0 centimeters that is suggestive of not being a true Arctic stenosis okay so we already know the parameters for that and those are the the absence of contractile reserve which means failure to increase the stroke volume more than 20 percent has a high surgical mortality and poor lanter outcome despite the the bad replacement may improve the LB function and outcome even in this subgroup which is really interesting for the patient prognosis okay so the third scenario is is probably the more weird one is when you have like normal flow but with normal flow you you have low gradients you have an article variant is less than 1 centimeters to the square and you have a normal adex on fraction so how having a normal adex on fraction with a normal flow you are getting a severe or the stenosis on your area but your gradients doesn't they don't match the the Arctic valveria so in this case the most possible scenario is that you are making a mistake and you are making an underestimation of the LBOT area or again the same situations that we were mentioning before you are doing the study with severe hypertension and this is what is going to give you like an inconsistency in the in the inconsistency in the values that's why in those cases when you have like low gradient AS which preserve EF you need to to assess your stroke volume and if it's normal you most likely are doing an error of measurement of the LBOT area so prognostic markers there are several predictors of certain development but I think what we really need to know and the implications for us is like in clinical practice the guidelines that actually impact the decision for surgery in asymptomatic AS is going to be a peak velocity of more than 5.5 and increase in the peak transvabular velocity of more than 0.3 meters per second per year and then increase in the mean pressure gradient with exercise by 20 millimeters of mercury so with all the information surgical approach on the left side a hand of the screen we can see why we need to operate and as you can see the survival rate goes really low once you have when you start to have severe symptoms and that's why the American Heart Association is recommended any severe AS by echocardiography parameters which is symptomatic is a class one indication for point for surgery and the other thing that you might have in account is that when you have an asymptomatic patient but you have a low EF or a maximum velocity of more than five is is actually or you have another indication for cardiac surgery is another another good reason for for actually considering valve replacement okay so here's the first part of the talk I think we need to do a little break now take a breath and just relax a little bit and chill a little bit out and then we will start with the hypertrophic cardiomyopathy