 What do I say, this is the heart of fetal heart, these common abnormalities, this is very important to have this understanding. It's actually something like fetal heart has become a very big deal because there's so much stuff now with understanding of the anomalies. So now this is the, can you see my screen now? The anomalies about. Yes, we can go ahead. Right now, this is like a pretty important group of lesions, not that the four chamber view is important, but from a cardiologist perspective, these are important because many of these anomalies are critical, but they are also amenable to correction. So that is the two words critical, but amenable to correction. So a human effort can actually make a difference in a life of an individual. Pick them properly, counsel them properly, take the correct decisions you can potentially save a life. Now the second important thing is that like some of these lesions can be associated with genetic syndromes, particularly 22-Q deletion, also called the Dijord syndrome. So it is important that we are very holistic in our approach towards these lesions. So this is the algorithm which and in that four chamber view we covered quite a lot. Alpena is going to cover the site in the next lecture. So between the two of that most of the lesions are covered. So the ventricular arterial junction and the anomalies relating to that is what I'm covering. In fact, there is a very close connection between the three vessel and the outflow anomaly. So often there could be a little bit of repetition in the subsequent lecture. But here we are essentially going to focus on the lesion where the ventricular arterial junction and relation is varied. Now this is repetition, but worth repeating. The LVOT view, some people say that the fetal heart, if you do four chamber and three vessel, you get all the details, but that different because this is important. This particular image which you see of the LVOT is important because it is important to demonstrate the continuity between the ventricular septum, which is the dotted line and the aortic wall, which is the bold line. So this is called the septo-iotic continuity. So the lateral view, it is shown, septo-iotic continuity. Now this is an extremely important concept in the fetal heart. And if you do not have this, then you have an important group of conditions. So this is the normal heart. Also, there could be a similar kind of continuity between the iota and the mitral valve, which is called the iota or mitral continuity, which we don't talk so much so in the fetal heart compared to the septo-iotic continuity. Now this is the LVOT. And we saw the outflow tracks crossing. These are the three basic concepts in the outflow track views, which we won't see. Now let us look at the various anomalies and see how these things are different. The important four lesions, which we need to understand in the outflow anomaly group is the tautology of fallow spectrum, which itself is a massive group. Then the double outlet right ventricle spectrum, which is so complicated in its spectrum that, you know, you talk on DORB, you can keep talking. So nevertheless, I will summarize the basic concepts. Then you have the common arterial trunk, also called the trangus arteriosus. And then we have the transposition, which there was somebody was asking a question about TGH, CCTJ, etc. So this four group of lesions, very common and very large number of conditions. So first is tautology and this is often your first clue. So I'm going to go in a systematic manner. This is the first clue towards outflow. You see the two equal size ventricle. You see this gap in the septum and you see an overriding vessel. So everybody jumps and says tautology of fallow. And you see this just like when everybody sees a tricuspid valve regurgitation, it says epstein's anomaly. But this picture could mean a bit more than tautology of fallow. So we will come to that. So the first step in the outflow anomaly is when you see a picture like this, a VSD with an overriding vessel, you try to identify the overriding vessel first. So the overriding vessel could be either the iota or it could be the pulmonary artery. So here in the first picture, you see that the overriding vessel is not branching. It is a single vessel which is going and that is an overriding iota. And in the second, you see that overriding vessel, if you look carefully, it comes and you see the division here. It's a bifurcating this. So that is an overriding PA. So first, something new for you today is that all that overrides is not iota. And PA also can over. Okay. So then you are entering. If you look carefully at the second picture, you'll see that there is even a ventricular, you know, the inversion also. That ventricle seems to be on the right side here. So that will come to that a little later. So this is important to identify the overriding vessel. So the first and the most common lesion is this. You have a normal looking four chamber view. And, but when you look at the cardiac axis here, you find that there was a left toward shift of the cardiac axis, even though the first glance of the four chamber view looked normal. So this gave you a clue that, okay, this is not normal. Next, when you sweep towards the five chamber view of the LVOT view, the VSD becomes very obvious. And there is an overriding vessel, which in this case was traced as the iota. So we have a VSD with an overriding iota. That iota is now very, very clear. In both the views, there is a VSD with an overriding iota, the five chamber view. So, normal heart, you have a septo-iotic continuity. Here, what is happening? There is a septo-iotic discontinuity. Same way in the lateral view, septo-iotic continuity. In this case, there is a septo-iotic discontinuity. So you find this gap. You see this gap between the septum and the iota? The gap between the septum and the iota, that is the VSD. So this VSD is referred to as the malaligned VSD caused by the malalignment of the septum and the iota. And this is a classical description of the VSD in tetrology. So it's a malaligned VSD. People also sometimes refer to this as sub-iotic VSD or perivembranous VSD. Sometimes it's called a conovendricular VSD. Conovendricular means between the conal septum of the iota and the vendicular septum. But a correct description is a malaligned VSD due to the malalignment of the septum and the iota. That is a classical description of the VSD. The conovendricular is also a very good description. So this is a classical VSD which you find in tetrology of fallow. And this you can only appreciate in the LVOT view. You cannot see this VSD in either the four chamber view or in the three vessel. When you put color, you find that both the ventricles are rejecting into that common single outflow. Like and often there will be some aliasing of the blood due to a larger amount of blood going into the iota. This is the little bit of aliasing. Both the ventricles are rejecting into the iota. Iota often will look very big also because it's receiving more blood than normal. And when it goes to the three vessel view, you see there is a forward flow here into the PA. But when you compare the size of the iota and the pulmonary artery, you find that the iota is actually quite big while the pulmonary artery is small. So in the three vessel view, what you find is that there is a discrepant size of the outflows with the larger pulmonary artery and the smaller iota. So these are the features of tetrology of fallow. Normal four chamber view, large mal-aligned conovendricular VSD in the LVOT view, smaller pulmonary artery vis-a-vis a larger iota in the three vessel view. With this you say, okay, this is a diagnosis of tetrology of fallow. So in this case, as Alpena said, it's both measuring some structures. Typically what I measure in tetrology of fallow is size of the iota and the three vessel view, size of the main pulmonary artery. I measure the same iota and the pulmonary artery in three vessel view. I also measure the pulmonary valve annulus and measure the right pulmonary artery and I measure the left pulmonary artery. Now I also calculate the Z score of all these structures. For the gestational age, we can get the Z score. And when I follow up this patient, I serially measure the same measurements. And if I find that the pulmonary artery is becoming smaller and smaller and smaller and the Z scores are becoming more and more minus as the gestation advances. I understand that the pulmonary stenosis is progressing in utero. And sometimes a mild form of stenosis in the beginning can end up with a more severe stenosis at the time of end of the pregnancy which means that the child may need an immediate neonatal intervention. So this is very, very important. So a normal heart, the PA to iota ratio is about 1.16. So PA is larger than the iota. Mild forms of tetrology typically have the PA to iota ratio of about 0.7 or more. And here as we see the PA Z score is minus 1.1. It is small but not very small. While in the very severe forms as we see here, the pulmonary artery is very diminutive. The pulmonary artery Z score is minus 3.76 here. And the PA to iota ratio in this case is less than 0.5. That is severe stenosis. And often the severe stenosis will be a very cyanotic patient at the time of birth. We also should look at the 3-vessel tracheal view and look at the pattern of flow. And we find a very funny kind of orientation of the 3-vessel tracheal view. You see here the pulmonary artery seems to be inserting much more proximally to the iota. The reason is that there is often a very, very unusual alignment of the ductus arteriosus and toff. A more vertical kind of a ductus. That's why the V becomes something like a Y. And the PA side, the smaller size, which we can appreciate, the iota is bigger, the smaller PA size. And there is all anti-grade flow. But later on, sometimes in the PA, you make it a retrograde flow, the red flow. That means the deletion has progressed towards a severe obstruction of the pulmonary artery, the form of pulmonary atresia. So, and also the last clue in TOF is that the aortic heart side can be seen. This is the first picture is a left heart. The second is a right heart. And third is a double heart. And when you have right heart or double heart with tetralogy or fallow, there is a higher likelihood of association with 22Q deletion syndrome. A garden variety of TOF with left heart is about 15% risk. But when you have a right heart, that risk can go up to 25 to 30%. So TOF with the right heart, map cause, et cetera, can be a reason for asking for an avenue and testing for 22Q deletion. So the findings of tetralogy or fallow, four chamber view, typically normal structures, axis could be shifted to left. The five chamber or LVOT view, septo-iotic discontinued. The three vessel view, normal relationships of great arteries, the pulmonary artery is smaller than the iota. And the three vessel tracheal view, same color flow and the side of the arch and also as a bonus, the timers can be seen. In fact, that will give close towards your probability of associated 22Q deletion. So this is the sonographic summary of the features of tetralogy or fallow. Let us quickly look at a couple of variants here. This is another case where you see a overriding iota, a large iota. And when you look carefully in the next picture, the branch pulmonary arteries are seen, the RP and NP are very small structures. And when you look at color, you see this picture, you see this picture. And what you find is that there is a forward flow into the iota and there is a lot of aliasing. And if you look carefully, there's even a bit of iotic regurgitation, but there is a retrograde flow into the pulmonary artery. So this means that there is a large iota with an overriding artery with anti-grade flow and retrograde flow into PA means the pulmonary atresia. No flow into the PA, but only through the retrograde flow through the ductus arteriosis and the branch PAs are very small. Another example of tough, there is overriding iota. And when you look at the pulmonary artery outflow, you find this very characteristic picture of a two-and-fro flow into the pulmonary artery. That is the two-and-fro flow, there is both the stenosis and the regurgitation. And what you find here is that the pulmonary arteries are enormously dilated. So there is overriding iota, there is a dysplastic valve, pulmonary valve with both stenosis and regurgitation and dilated pulmonary arteries. And when you put this Doppler of the pulmonary valve, you find there is a systolic flow as well as a diastolic flow. So this is systolic flow, this is a diastolic flow, there is pulmonary stenosis and regurgitation. So this is an example of tetrology of fallow with absent pulmonary valve, a variant of tetrology fallow. The characteristic feature of this is that the pulmonary arteries are dilated, which is a very unusual finding for tetrology of fallow. So postnatal presentation, you can have a highly varied spectrum and it is important to identify these features in utero itself. You could have pulmonary atresia in top or even critical stenosis or it could be a milder form of stenosis. The critical forms will need a neonatal intervention followed by corrective surgery while the milder forms can go for an elective surgery in a later date. So what are the features which could predict the critical forms? One is that generally the smaller the PA, you say that stenosis is more severe, especially if the PAs are becoming more and more small with the gestational age. Second is the color flow pattern. If you have no anti-grade flow but predominantly retrograde flow into the pulmonary artery, that clearly tells that it is a very critical circulation. The third is the pulmonary valve Doppler. One study showed that if the peak pulmonary valve gradient was very high, more than 0.9 at 20 weeks and more than 115 centimeter per second at 34 weeks, this would mean that the stenosis of the pulmonary valve would be severe, mandating or requiring an intervention. So I would rely more on the sizes of the pulmonary artery and the direction of the flow in the ductus, particularly the ductal flow patterns. This will give us a very valuable clue regarding the severity of the stenosis. So that much for tetralogy. Now let us go to the next question which is similar to tetralogy but somewhat slightly different. The four chamber view, which shows there is a defect in the septum, which becomes more obvious with the five chamber, there is an override also seen. But when we move further, we see that the iotic override is so much so that it seems that a lot of iota seems to be more from the RV rather than the LV. But as we can see from the arrows, the pathway from the LV to iota is also seen. So that's it. See, this is the degree of override is very, very significant that iota seems to be predominantly from the right ventricle, but we can see the pathway from the LV to the iota. This is actually a scan which I had done in Dr. Vijay Barway's unit when we had gone there for that workshop. We're doing a demo there and we could see very clearly that very degree of override and then we could see that the LV to iota that pathways rather elongated here. Very characteristic. And as we see the outflow tracks now here, the iota seems to be substantially overriding and mostly from the RV. And the pulmonary arteries from a more anterior view, we can see the pulmonary arteries also from the RV. Both the great arteries are arising from the RV. So this is an example of a double outlet right ventricle. The pulmonary artery is smaller than the iota, so there is pulmonary stenosis. Three vessel views showed the PA is smaller than the iota, just like what would you expect in tetralogy. So the findings in this case was a large maliline VST, iota overriding substantially that most of it is from the RV. And PA is also from the RV with a smaller PA suggesting pulmonary stenosis. So double outlet right ventricle is defined as a lesion where both the outflow tracks are predominantly supported by the morphological right ventricle. And in the fetal life, you can remember the more than 50% override rule. More than 50% of the iota is come from the RV. So how do you separate off from the RV is this 50% override rule. In tetralogy, typically the override will be in such a way that the iota is sort of equally committed to both the RV and the RV. However, in the RV, when you have the iota will be more committed to the right ventricle than to the left ventricle. So that's more than 50% override. The other methods are there, like you look at this here, the iotic valve and the mitral valve are continuous. While in this case, iotic valve and the mitral valve are discontinuous. You see this where my arrow is pointing there is a white fibrous bundle which is separating the mitral and iotic valve that is called iota mitral discontinuity in the RV. So if you truly want to define the RV, it is iota mitral discontinuity and more than 50% override. The other type of the RV, we saw the classical TOF type and here you see balanced ventricle. And here you see that both the outflows are arising from the right ventricle here, as we can see in this picture. And when we put color, you see again that flow showing the VST and both the iota and PA are arising from the right ventricle. And in this, we can very clearly see the double outlet origin of the right ventricle. What do you find is that the more anterior outflow is not dividing while the more posterior outflow is bifurcating here. So the anterior outflow is the iota while the posterior outflow is the PA, which means that the great arteries are transposed here. So this is what we call the TGA type of DO RV, where the iota is completely from the RV. PA is also mostly from the RV, but the first and the more posterior outflow is the PA. And the iota will be continuing as the iotic parts here in this case, without any obstruction. So this is an example of a DO RV, which is a TGA type. So when you look at DO RV, you have the two common types, the TOF type where the VST is sub-iotic, great arteries are normally related and often there is some amount of pulmonary stenosis. And secondly, the TGA type of DO RV, where the VST is typically below the pulmonary valve or sub-pulmonary, the great arteries are transposed. The iota is more anterior and the PA is posterior. Now from here, you can have multiple variations with co-optation and arch hyperplasty and so many. And so I won't be discussing and do those types. Now I am demonstrating here a simple technique called tomographic ultrasound imaging, in which you can see a multiple planes of the feet to heart just like one would you would see in a CT or an MRI data search. So in the most caudal frame, you can see the BSD here and the ventricles. In the middle frame, you see that the both the great arteries are arising from the right ventricle. And the topmost cranial, you see the great arteries, how the three vessels became. So this tells us the DO RV TGA type with unobspected outflow tracks and iota cars and all in one single, you know, CINY loop in the TOI mode of demonstration. Okay, so that much about the double outlet right ventricle. So I'm not covering the more complex forms of DO RV in this lecture obviously because we can't finish this session if you continue to do that. Then we have this next entity where you see that the ventricles are equal and you see there is a large vessel here. There's a very large vessel coming off from the right ventricle and that vessel is giving rise to the iota as well as the pulmonary artery. So this is the big one is iota and you see this vessel and which is dividing into two. So that is the pulmonary artery where the arrow that is the pulmonary artery. So this is an example of a common arterial trunk. The common arterial trunk is characterized by presence of a VSD and there is a single trunk which arises from the heart which gives rise to both the iota and the pulmonary artery. There are three different types of common arterial trunk on whether the PA arises as a common trunk and then divides which is a type one, whether the pulmonary, the two branches arise separately from the iota with this type two and type three where they arise separately and in a very distal manner. So those are more complex what need to just understand the concept of a common arterial trunk. Now, there are two lesions where you have a VSD with an overriding vessel with a single outflow. One is a common arterial trunk and the second is a TOF with pulmonary arteries. So this is like two lesions which need to be separated and how do you separate this? Now you need to look at the color flow and you see how the flow into the pulmonary artery is. In a TOF with the pulmonary arteries here, there will be a forward flow into the iota but there will be a retrograde flow into the pulmonary artery. You see because the pulmonary artery is fed to the ductus arteriasis. However, in the common arterial trunk or truncus, there will be a forward flow into the iota and also there will be a forward flow into the pulmonary artery as well because these are actually arising as one branch which one continues as iota and the other is the PA. So in common arterial trunk, the direction of flow of PA and iota are same. While in a pulmonary artery here, iota is an anti-grade flow while in the PA, it is a retrograde flow through the ductus arteriasis. Now this is an important differentiating point and whenever I talk about this, I remember our very, very close friend and all of you know him. He is no more with us, Chandrasegarh Kenjale. He is one of the most, one was such a gifted speaker and a gifted radiologist and I heard him talk about this in one of the meetings in Nashik and I was so moved by his description. So whenever I present this slide, I remember him and God bless him always. Okay, now with that we move to the final end in this outflow anomaly and this will hopefully answer some of the questions which were asked in the chat box. So we have covered tetralogy of fallow, we have covered the DORV common types and we have covered common arterial trunk. We also learn how to separate common arterial trunk from the top with the pulmonary artery. Now we move on to a very, very important group of patients in the fetus which is a TGA. So the transposition, the common feature of TGA is that the outflow tracks are abnormally related. The important thing is that the aorta comes from the right vent and the pulmonary artery comes from the left vent. So there are two types of TGA. The first type is where the atria-vendicular relationship is normal or congordant. That is called the complete TGA or what we call the DTGA. DTGA means the right ventricle is the D or right side. The second type is the AV discordance where the atria-vendicular relationship is discordant. So which means the tricuspid valve has come to the left side. So the right ventricle is on the left side here. That is called the LTGA or the L loop of the right ventricle or also called congenitally corrected transposition. Most of you call this CCTGA. Either way this correct doesn't matter what is your terminal. So you have DTGA or LTGA or corrected TGA, CCTGA is empty. So let us study this case which is the normal looking four chamber view here. But the second view which is the LBOT view you pick up the first clue. You look at this vessel here and I will come back to this in great detail. There is something odd about this LBOT. The way it is going, it is not going in the normal this way. Normally you would expect the aorta to go from the left ventricle towards the right. Here this vessel is going like this. It is dipping posteriorly. See towards the spine. So normally the LBOT direction is this way that is towards the right. While in the TGA you see this is towards this. And you also know an important difference here. You look at this LBOT you can clearly see it bifurcating. See one branch and the second branch. So not only is that first outflow bifurcating but the direction in which the first outflow is running is also posteriorly towards the left rather than anteriorly and towards the right. So this is the difference. The first clue. Then when we come to the plane of both the outflows normally you would expect the outflows to cross. Iota is a red line and the PA is the blue line. You expect them to cross. Here what do you see? The pulmonary artery is going posteriorly. Iota is an anterior outflow is running parallel. You don't see the crossing. You see the two outflows are parallel to each other. And by the time that is the parallel outflows seen here very nicely in color. And if you look at this color picture you see that the first outflow is bifurcating as well. Normally you expect the outflow to cross like this but here you see parallel outflows. And by that and then what do you see? Normally the ductus arteriosus will continue as a ductal arch to the more anterior arch here. Here what do you see? The iota with the anterior and that is the continuing as the arch here. A more curved arch here. The more anterior arch. Three clues. And the most important is this. Normally you find the three vessel view like this but in this relation you only find two vessels in the three vessel view. Only the iota and the SVC. The reason is because the PA has already come as a posterior vessel and it is not visualized in the three vessel view. So this particular view which you are seeing in your screen now is actually the view you get in TGA during the screening. So whenever you get this picture one of the important conditions. TGA is not the only condition. One of the important conditions you should suspect is the TGA and you should go back to the outflow and the other views to confirm how the great arteries are related. Now let us study this particular case. So this is an example what we saw now was a complete TGA. Now let us look at this picture. The full chamber view itself gives you a very useful clue here. You see this ventricle is perhaps a little smallish but it is also maybe due to the cut. The right is marked here but you find a rather smooth ventricle on the right side. And a more trabeculated ventricle here. You see that the right side, this valve is at a higher level. The right-sided valve while the left-sided valve is at a lower level. You find that the pulmonary veins are in fact bringing normally into the left-sided atrium here. So the atrium level it is all good but the valve it seems to be abnormal. That's exactly what we confirm. The tricuspid valve is in fact in the left side and the mitral valve is on the right side. The pulmonary veins are draining into the left-sided atrium. But there is an atrium ventricular discordance. So this is a normal greater AV relationship but this is what you find in CCTV. What you find is that the tricuspid valve is left-sided and the mitral valve is right-sided. So normally the right ventricle is right-sided and here the right ventricle is left-sided. So normally the pulmonary veins are draining normally and here also it's draining normally. So the atrium level everything is normal but the level of the AV connection things are abnormal. So normally you find the offsetting like this with the tricuspid valve at the lower level on the right side. Here you see what is the reverse offsetting. The right-sided valve is at a higher level. The left-sided valve is at a lower level. The reason is because the atria are normal here. LA receives pulmonary veins but the AV valves have become reversed. So tricuspid valve is on the left side, mitral valve is on the right side. That's why the mitral valve is at a higher level and the ventricles are also reversed. The right ventricle is on the left side and the left ventricle is on the right side. So this is atrio ventricular discordance which you find in CCTV. And then the outflows. The first outflow as we can very clearly see is bifurcating and that is coming from the right-sided NV. That is what you see here. You see the right-sided NV. If you look very carefully here, you may even argue with me that the pulmonary artery seems to be sort of overriding also. You are right because there is also a VSD here in this case. And then the final outflow is the iota which is arising from the right ventricle just like what you would find in the TG. iota from the right ventricle. So here is an example of CCTV. The difference between the previous one and this one is that there is, in addition to the transposition relationship, there is also an atrio ventricular discordance. So if you do not play here to this four chamber view, the findings of atrio ventricular discordance and straight away go to the outflow track, you will mislabel this entity as a TGA and miss the corrected transposition altogether. Altogether. You understand that's why it is so important to go in a systematic manner. So we conclude our study of the outflow tracks with this algorithm. Now I like these algorithms and from a cardiology perspective because it helps you to move in a very systematic manner. So whenever you talk about outflow tracks, the first step in our algorithm is to see how many outflows are there. Whether there are two outflows or whether there is only a single outflow. So if there are two outflows, you see whether they are related normally or they are transposed. In the normal related rate artery, then you can look at the degree of override more than 50% or less than 50% or the iotomytal continuity. If there is an iotomytal continuity, degree of override is 50% or less you are talking in terms of tough. If it is not, if there is an iotomytal discontinuity and if the degree of override is more than 50%, it's a DORV type tough. TGA, you can have same TGA or TGA VSD and we have DORV or TGA. That is the algorithm for the two outflows. On the other hand, if there is a single outflow, you can look at the direction of blood flow into the PA. And if it is the same, it is a common arterial front. And if it is a reverse flow into PA, that is a tough with the pulmonary atresia. So this is a kind of an algorithm which you can actually use for a patient for VSD with an overriding outflow tract based on the number of outflows and the greater relationships and the direction of flow. Often useful. One lesion which is not covered in this is a CCTGA where the clue will come from the atria vendicula discordance in the four chamber. So I will stop this lecture here and go back and see the questions. Too fast to understand. No, this is fine. Any questions can come from the audience please go ahead. Too fast because what happens is when you get into a little more difficult territories, we really need to actually spend a lot of time and keep interacting also. Because the four chamber view anomalies are obviously more easy to understand. Once you get into the level of the outflow tracts, the difference between the normal and the abnormal becomes a little bit more subtle. And when it comes to three vessel view, it becomes even more subtle. That is the issue here. So obviously the key things which you read to understand from this is I hope the tetrology of fallow part is sort of clear. That is an important lesion. Do you already and talk is something which is often very difficult and very, very confusing. Single outflow is important and the two lesions are common trunk and the pulmonary atresia needs to be differentiated and of course transposition. I think TG is extremely important and it is important to differentiate the TGA and the CCTG. I think one question which was coming is the significance of more than 50% override. I think it is sometimes difficult in the prenatal part when we're talking about 50% and this. Yes, I think a lot of people ask what is DORV? DORV is actually a Normans land. It's basically a very simple English double outlet right ventricle means the right ventricle is giving rise to both the outflows. So how do you actually decide that? One of the outflows will be obviously from the right ventricle and if it is a normal related data tree, the pulmonary artery is completely from the right ventricle. If it's a TGA type of BORV, the iota is completely from the right ventricle. Now the second outflow is the important thing. One outflow is anyway coming to the right ventricle and the second outflow you decide. In the top, the override is such that so if I can go back to that one slide which I showed, I'll just come back to that one single slide outflow anomalies. Just a second. Here. Just give me a second. Yes, this is the one. Okay, this slide. Can you see that. So here, like, Oh, sorry, sorry, let me share the screen. Let's read this. Yes. So with this, I think you can understand.