Chapters Transcript Heart Rhythm Webinar Series: Challenging case discussion with Mayo Clinic experts on atrial flutter In this Heart Rhythm Webinar Series challenging case discussion, Mayo Clinic cardiology experts Samuel J. Asirvatham, M.D.,Abhishek J. Deshmukh, M.B.B.S., Siva K. Mulpuru, M.D., M.P.H., and Ammar M. Killu, M.B.B.S., discuss atrial flutter. welcome everyone to this challenging cases webinar my name is Samuel Peru from mayo clinic in Rochester. Today I am joined by my colleagues Dr Samuel Acibadem dr Abhishek Deshmukh and Dr amar killer today. Um Today the topic today is about atrial slaughter. Well received certain questions today and we will post them onto the chat box. So if you have questions along those lines we'll try to cover all those questions and the ones that we don't cover. Well we will try to post them as an as an add on video to this session wow. So to begin the session, dr axelrod um will give us a 10 minute introduction about atrial flutter. And based on the questions that come in we will take the discussion reviewing those questions thanks to. So um some of the some of the questions that you've sent in already uh are trying to cover a bit in this introductory overview. Mostly related to checking for block difficulties with flutter ablation and some are very specific. We'll have them written out here and we'll try to discuss as well and feel free to send in further questions. Two of you have also sent in an E. C. G. You'd like to discuss from one of your patients. Uh If uh I'll put them up and please do feel free to come up and present what aspect of the CG was of particular concern. So several issues about atrial flutter. I think I'll just try to go over the frequent concerns that come up especially for electro physiologists in training early in their career. This is the type of scG that today we call flutter or macro re entrant to protect cardio, it's completely unpredictable. What the P wave access, flutter wave access duration of the flutter wave will be. What is predictable. As many of these patients will have structural heart disease prior surgery and the vast majority will be in the context of a blading fibrillation or post even uh inflation flutters. This is really today the flutters that we deal with focus initially in this discussion and in our careers is with the flutter that's most studied and we know best how to oblate and we'll spend a little bit of time about that and why the difficulties we have in the cases of typical flutter. Help us when we have difficulties in today's flutters. Things that we have to think about is a simple atrial flutter. We produce is from the cable to the hospital business and it's not going away or it's recurring even after we've done an ablation. Some of the things have to do with local anatomy. We always have to think about wrong diagnosis. It looks like flutter that's typical, but it's not. And then issues with incomplete completion. And this will also address one of the questions that you had most important thing with any type of re entrant tachycardia. When we're trying to do an atomic ablation is to not only understand the un atomic obstacles that we're connecting with the flutter line, but what's in between. What I mean by that is if we take a simplistic picture in our mind, bicuspid valve ibc and it's a line literally a line through flat terrain. It causes a lot of difficulty when we're not quite getting rid of the flatter. It's important to have a realistic picture whichever place we are doing linear ablation of. What's the tissue that we believe is an obstacle. That means electrically inert like valve or abc. And what is the tissue in between? Is it flat or their excavations, ridges, things that I need to simply be able to manipulate my catheter through should also be aware of thickness of the tissue in that region. Does it vary if so the same type of ablation going from one to another will be difficult to do. And if there are crevices and we get our catheter are trapped between those two crevices. It may be difficult with thermal energy to be able to give an effective lesion. And we can look at specific examples of this as well. Mr case. This is one of my own from a while ago that illustrates approach for when it's not going young person, no structural disease but already on 1/4 ablation for typical flutter this is the index CCG. When patient was seen in the emergency room palpitation was the main symptom very active person and definitely looks like a ball trick hospital business. What do I mean by that? When our eye looks at this flutter wave the terminal portion. When we line up It looks positive and be one terminal positive and be one when we line up with what looks like a sawtooth or continuous flutter way. A lot of the early work with flutter ablation involved. Right atrial Matic. And we still rely on that to get us an idea when we're not sure what type of flattery it is. This usually involves multi electrode catheters and once we get experience with multi electrode catheters, using any kind of basket map, quick map of the atrium, we kind of relate back to what we learned from multi electrode catheters. One important area is the free wall of the right atrium. Is that activation counterclockwise or clockwise Down the free wall or up the free one. We rely on closely spaced catheters placed where we are going to do the ablation. So some electrodes on one side of the ablation line, other electrodes on the other side. And it becomes pretty straightforward in that approach. When we have ablation done facing from the coronary sinus, closely spaced electrodes activation goes as expected on one side of the line and exactly the opposite. On the other side of the night. Very easy. This is our picture we carry in our mind when we think about a certain block in any unusual situation, but it's important to remember that this should be closely spaced electrodes if we have electrodes that are widely spaced, it becomes very difficult to know whether there's slow conduction or there's actually blood. So also very important to remember that some electrodes have to be on one side of the line and the other on the other side. If we have electrodes further away or they're not closely spaced, then we get fused wave fronts even before we have blade. And once we started blading and there's delay on one wave front, it will look like we have block when we actually just have a different degree of fusion as a result of slow conduction from our ablation. Like should also remember that cable tray. Hospital isthmus flutter is not the same as perry trick. A spit valve fluttered. In other words, the posterior boundaries that keep a circuit near the trick has been well are not complete all along the trick to spit man. So we may have a try caspit is thomas dependent flutter, but parts of the circuit maybe away from the track hospital back. This is important to keep in mind because we may and train trick hospitals must depend and flutter at some unusual sights when we're not certain of the theology of the flutter and then focus our attention in that region. When we could have had a much simpler solution with our own usual cable trickle speed. Isthmus flutter. One of the questions that came up and I'll just address it, since it has to do with difficulties in flutter ablation is this concept of lower loop. And if the doctor who asked sent in this question wants to discuss it in more detail, please do. But the issue of this lower loop is there is my accordion behind the ibc and in front of the I. V. C. So it's possible to get a flutter that goes around like this. Now if you a blade, the cable trackers but dismiss this flatter also goes away. That's why we don't really make a distinction between this and cable trigger speed. Isthmus perry trick has been well flatter, but where this becomes an issue is the lower loop can be a limb for conduction to the free world and to the east thomas, even after we have started a plate. What I mean by that is if we have only catheters on the free world, even though we have a complete line of block on the cable trick, hospital isthmus conduction through this part of the lower law will cause activation upward on the free world from CS pacing, Making us think that we have conduction, so called pseudo conduction. No need for further ablation solution is just bring the electrodes down here and you'll see this part is showing a reversal of activation. Perhaps more important is the opposite phenomenon. And that is when we have very slow conduction and we paste the coronary sinus, We might shunt around through this lower loop and given appearance of reversal of activation on the distal side of block on this side of our ablation, making us think we have block. The clue will be flutter continues and we're confused whether we made a wrong diagnosis with some other flutter misinterpreted entrainment, etcetera solution is closely spaced catheters straggling where we have waited. However slow the conduction is there will be some activation that's going and showing us that there still is conduction if there is dense enough electrodes, closely spaced electrodes or an actual map that's done at that. Now this question came up in one of our early sessions about how to use double potentials as a way of knowing we have block, widely spaced double potential suggests that conduction from one side cannot get to the other. Now, if we have a complete line of block, the widely spaced double potentials will be uniform across that line. On the other hand, if it narrows, it suggests there's still conduction and at that point where there is conduction, the electra graham might be single or it will be fragmented. We can use the same principle also for free wall flutters, just taking a multi electrode catheter and sweeping it anterior to posterior Anterior. You have way one way front posterior to some scar. You have another way front at the site where there's a turnaround for the flutter, you can see this double potentials pointing to where the gap is. And if an electrode placed at that gap shows fragmented signals. Very good bet that ablation at that site will complete that line of blood. We discussed this last week, but very important to remember technique where wherever the flatter line is done, it's possible for us to check for block anywhere, As long as we can pace on one side and we can map on the other side. Dense points of mapping should show complete reversal if it doesn't and there's even a slight activation going through that suggests we only have slow conduction and not complete block. So just a quick recap, if we have trouble a blading flutter, we first think about issues that are making it difficult for us to know if we've blocked across the line. We remember this concept of lower law conduction, and the real difficulty is defining whether slow conduction or block is present. Normal conduction versus block. Usually easy to tell. But slow conduction needs closely spaced electrodes that are straddling the line of block. If we're unable to put an electrode there, we can do a dense map in that location. Just a few words about wrong diagnosis. Remember a pattern of activation does not define a circular. We can have just by standard patterns of activation. This is a patient of mine where I had already attempted cable truck has been dismiss ablation because the pattern of activation suggested it. Patient did not have structural disease. Patient did not have a true fibrillation, but the real flutter was related to a scar in the left atrium for unknown reason. Small circuit that was the cause. But it just activated the cable trackers, christmas region and triggers. But well, like that was a flutter. So it's this region of activation, whether it's actually the circuit or whether it's wrong, diagnosis, something else stimulating it, we can usually sort out by seeing where we have the cycle length of the flutter and by employing and training. If any of you have specific questions on entrainment, we can use an opportunity to describe some of the difficulties when we have these multiple arrhythmias for multiple circuits. How we would employ entrainment. Just finishing up with this particular patient for abrasions, flutter clue. Was that flattered lines that were done at each procedure did appear to be complete. Why does a young person get multiple flutters in this patient? The issue was a trigger, much like we think about paroxysmal atrial fibrillation. This patient when mapping a variety of activation sequences have very high frequency activation in the right upper pulmonary vein. So patient just like paroxysmal a fib but presents as stable flutters. What really needed ablation. And what was done in this patient was isolation of the pulmonary vein and that takes care of these flutters. Now we'll come back later after we look through some of the questions about how we transfer our understanding of cable trickle speed, isthmus flutter difficulties and use that knowledge when we're dealing with other obstacles and other portions of the atrium especially post ablation flutters uh seva anything you'd like to add here or questions that you've come across that you would like to address now. Otherwise we can go through some of the questions that were already sent in. Yeah thank you. Sam I think there are a couple of questions they're talking about epic karniol connections in difficult to a blade putter. So the CG looks like typical flatter and we do an ablation but we're still not able to terminate the flutter dr lao says is it possible that there are these epic are ideal connections that were not really getting too during the tribulation. Okay fair enough. So maybe we'll use that as a segue for left atrial flutter as well. But here's the issue when we have harry trick hospital. Well I. V. C. And we're blading flutter here. No the epic cardio fibers and a cardio fibers in the vestibule after right atrium. You're not we're not seeing your marker. Well on the screen. Okay let me try another one. How about this 1? No no. Okay let me do it this way. So when we think about the perry trick hospitable this region where we are blamed the vestibule has fibers that are all parallel to each other. Now there's really not much of separation in the vestibule between endo Cardell and Picardy. However when we start going out laterally we sort of get this separation Because we start getting packed in 8s that farm like a layer or claim that's more in the cardio. And then the fibers of the vestibule that are on the floor become like their epic cardio. So they're usually the solution is trying to a blade more immediately. This is very different from the left atrium where we truly can have at the cardinal connections but in the case of the right atrium and let me share an image that might be able to address this. Can you see my slides? Yes. Not now. Okay. Okay. Again able to see them. Yes. Okay. So here's like an example of a cut section that might be that might help to illustrate this. So if we look here this is a vestibule and you notice how there's really just parallel fibers and the thickness there is not that different from like the floor of the coronary sinus. But as we go out more laterally, then we get these pectin. It's that are encroaching. So we get one layer like this at the plane of the pectin. It's and we get another layer that is the plane of the vestibule and gives this kind of impression of like endo kardian versus at Picardy in fiber orientation of the vestibule is different from the fiber orientation of the pectin. It so if we do a high density map, it looks like conduction from one side is coming to another. Also giving this appearance like we have some kind of connection. But in reality uh in the region of the cable trick has been dismissed. That's not an issue. Now, contrast that with a couple of other scenarios when we have free world flutters and we're trying to anchor to the trick hospital world. We do have an epic cardio layer and this epic Ardian layer can actually be seem to be continuous with the plane of the CS and the vestibule. So that becomes a pick cardio. And then we have take muscle that you can trace into the appendage and you have the pectin. It's that have come out of the appendage here. So this layer, this area for trying to draw a line, for example, some electro physiologists, If you have a right free wall flatter well, a blade that flutter and anchor it to the trick hospital. Well, with the idea that simultaneously I'll get blood that will prevent cable trick hospice, MS flood. And it's true if it's done and it's perfect. That's true. But it's much harder than if you were drawing the line here so many times in recurrence of those cases, that will be the problem. And rather than over going over it again, we might be better off to just do it here. Like we would with a normal flutter. Does that answer the questions? Yes, I think so. In the same line dr Marto is asking as a question, how about we use just the electrodes from an ablation catheter to check for block instead of using a multi electrode catheter. Okay so maybe I'll kind of draw a picture here for that as well. And if any of you have a case you'd like to share it illustrates that that'll be fine too. So here's the problem is if this is where we've drawn the line whatever this is. My truest mystery. Hospitalist mus roof and we want to know does conduction go from here to here? The problem is if there is very slow conduction that we're trying to look to see, does it come out there? So if we just put two electrodes here and there's slow conduction and say we go around I. V. C. Or pulmonary vein in the case of the left atrium through another scar. In the right atrial free world we will very readily see that this could look like it's blocked. The proximal electrode will be earlier than the distal electrode. If this is how we kept the catheter. Now we get a little better when we have a multi electrode catheter we get even better if we span that multi electrode catheter. Moving it from all sides of that business to see any place to recede distal is earlier than proximal activation. Still can be difficult. In some cases multiple ablation longitudinal lines. Then we do have to do a high density map to try and clarify if activation is going through. Now I know we had uh some question about the left side flatter uh ablation difficulties. Um Should we try to answer some of those are there's some others that any of you have come across from the audience today. So we have a question about while doing a C. T. I flutter. And we're using a electron atomic mapping system and we're using a high density mapping catheter. Are there any specific pitfalls that we have to consider if you're not using a multipolar catheter, you want to take a shot at that? Siva? Sure definitely. So if it is it difficult to a blade atrial typical atrial slaughter. So using a high density mapping catheter like a grid or a panta rei it gives you an idea. The problem with most electron atomic mapping systems is automatic annotation. You'll have to go back clearly look at how the system is annotating the signals and try to make sense of all the points you have created. And one of the things that I find difficult is um if it is endo cardio, you have these projections or if you have like a prominent you station ridge, you may not annotate it. Well, if you just rely on a high density map. Having an understanding of the anatomy using intra cardiac echo sometimes helps you, you know helps you localize those points better. So maybe I'll just add to that uh that uh when we do Kind of a Quick Map 1st Map, multiple electrodes map and if we're pacing from this side while we're doing that man with whatever we're using. If some of the electrodes picked up a signal on this side of the line, then the whole map becomes very difficult to interpret because then you'll have something here that will get interpreted to being something earlier than this side and it will look like it's conduction when it may not be. So it's a tough thing. I think if we wanted to we could do a multi electrode math grid pantry, any of those, even a non contact map on one side of the line. But then when we get close to the line, it's probably better to do point to point mapping. So we don't have those crossover type points now. So we had we have several very specific questions about ablation difficulties along the mitral is miss. And I think we can address, we can address those. Maybe I'll just do a quick overview of what the source of those difficulties might be. The three big points at least from my experience. Maybe add some anything that any of you would like to. And then we can take a look at some of the specific questions. Now, I think this slide and the next one kind of illustrate. Be able to see this. Yes. So unlike the right atrium, the veins of the left atrium all have muscles. So the biggest difference is when we draw a line to a vein, it's just like half the east mrs of late. So we have to create a boundary by going around the vein. So that's why We have two pair. A typical flutter ablation in the left atrium with pulmonary vein isolation. So it turns out that many times it's a transgenic flutters after an ablation that we've done in the left atrium. So we have to or have already isolated me. But that's a very important concept, especially for those who are new to ep to understand that a line has to be anchored and that anchor is an artificial anchor in the case of the left a tree. Second thing to remember about this mitral isthmus region is unlike the cable trick, hospitals mus, the mitral isthmus, the mitral isthmus region has a definite epic karniol surface and that epic are ideal surface is the muscle of the coronary science. So the coronary sinus is something that we don't have an equivalent in the cave Potrykus christmas. So it brings in a whole new vantage point for ablation. It brings in a whole new source of difficulties. So you can be perfect with cable trackers to dismiss ablation, know every trick in the book to a blade. It, but you have a few new things with left atrial ablation one is the posterior boundary isolation of the vein. The second is the issues with the coronary science. So if we look closely at this, you notice we have the vestibular fibers from the mitral isthmus. Plus we have muscle potentially in the coronary sinus depending on where this lesion is done. So because of that the muscle here and here might be related to each other. And if it is, if they connect with each other it's possible to shunt around ablation lines. That's one source of difficulty. The second source is probably more common is we have competitive cooling. So we're trying to a blade on the end a cardio surface but we're cooling because of the blood flow in the coronary sinus. And if that happens we'll have a rim of tissue that were not able to get adequate temperature increase and complete that night. This is probably the most common reason why we wind up at blading in the coronary sinus in some patients. It's not so much the muscle acting as a shunt. Although that is possible it's more likely that that's the place where it's cooling. So that's where we have the gap, that's where we need to put the catheter in and play. There are other ways to get around that issue and that is like including the coronary sinus for example can temporarily cause cessation of that flow and we're able to a blade in that location. Now the last point of difficulty I'll just share in general and then let's look at some of the specifics is we have to appreciate just like with the cable trick hospital harry try caspit well, flutter is not the same as cable trikus christmas, flutter. Perry mitral flutter is not the same as mitral Islamist dependent flutter. When we say mitral is miss dependent. All we mean is part of that circuit is using the strip of tissue between the parliamentary veins, usually the left lower pulmonary vein and the mitral valve. When does that this joint come to play is if we imagine a circuit that's only hugging the mitral graph and then we entrained at this yellow spot here. We should eliminate the flutter with this ablation. But that circuit instead of going only hugging around the mitral valve, maybe going in and out of the pulmonary vein and then completing the circuit. Now, even if we isolate the pulmonary vein, it's still possible through gaps in our isolation sequence or even going through slow areas of conduction in the posterior world, in the roof between a roof line, we can complete the complex circuit of flutter even though we can train near the mitral valve in one location, That's why we have to pare entrainment with the map of the flood. Are we able to also in train at other sites along the mitral business of mitral valve? If not, it could be one site that's using near the mitral valve. Others are complex going through gaps in a roof line, posterior line are in the pulmonary vein circles in a way, even though this is a complex flutter, it does give us multiple ways to solve the problem. For example we can train here but in training here is way up that should suggest some posterior part of the circular. And a simple solution could be completing and isolation of the right upper vein in some patients depending on what the rest of the map is, what you're going to have to a blade and isolate anyway. And what the entrainment at multiple sites is conversely we may have a complete isolation of the vein but in plain of flutter here and find either the sinus node artery or esophagus is nearby, making it difficult to complete. But part of the circuit is the mitral isthmus and perhaps a line there will solve the problem even though we don't have to give taking away the need to a blade near a difficult structure. So that's just kind of a setting the table for issues related two difficulties. When we transfer our knowledge from cable trick, hospice, Miss Ablation over to the left a train. Now some of these specific questions here are with difficulties with this line but maybe Alaska each of you as we tackle those questions um are anything that you'd like to add or solutions that you found in difficult cases or cases to share. Sure, thank you. So for micro flatter I think you mentioned the main points in terms of difficulty blocking it sometimes if we're bleeding and accordingly and sometimes epic Ardley via the C. S. Sometimes you have to resort to um using you know other techniques such as alcohol which someone specifically asked about. Um And I know that's gaining increasing traction and popularity in the literature and if you'd like we can show an example of that why don't you show that? Okay so what do you want to show you are my trophy or shall I show my just my alcohol? Sure. Yeah. Why don't you go ahead and more. So I'm just going to show an example of alcohol ablation and then we can show it relative to peri metro flutter. All right. Can you see the Flora Skopje? Yes we can. Perfect. So this was somewhat unique case. It wasn't perry mitra flatter but it was a case where they had undergone pulmonary vein isolation on two separate occasions elsewhere and they couldn't isolate the left pulmonary veins. And so coming into the case we were thinking could this be something unusual such as an Epic, are your connection vein of martial? Something like that. Now we were able to isolate the vein just with catheter ablation um on the left wacker, both on the vain side of the left lateral ridge, the Coumadin rich as well as from the appendage side. But given that this was what was her third ablation procedure. We wanted to be as thorough as possible. And with the dentist in testing we continue to have dormant conduction into the vein. And we noticed what we thought was, you know a very thick left lateral ridge as well as potentially a vessel through it. So we did an angiogram in the coronary sinus. And we could actually see that there was this structure going right through that ridge. So you can see both the oreo and the elio Dabas vessel which is the vein of marshall. And so after we included that and injected alcohol into it, we were able to eliminate dormant conduction in that day. And sometimes this kind of technique is used for peri metro flutter. Thanks thanks so much. Now maybe I'll just show a quick anatomy section of that same that same site. So this is the region that um are is mentioning this ridge here. And if you notice this ridge. Unlike the christa term analysis, it's not really a thick tissue ridge, but it's an in vaginal nation. And this in vaginal nation is from the left superior vena cable. So sometimes if we have a significantly large vein of marshall or there's good flow through that pain. The same issue as mitral isthmus and CS we get problems with competitive cooling and this epic are ideal fibers different from the fibers that are on the ridge itself. So if you do a cross section here at the ridge, your fibers on the appended side fibers on the vein side, longitudinal fibers of the ridge itself and then deep to this would be fibers left behind by the leftist we see. So if we want to oblate that epic arterial tissue either because there's a trigger there or we need isolation of the vein. Or we have a flutter that could go through there. Then that becomes a vantage point for us to use. Now be shake you have you do some careful uh inter cardiac echo when doing your a defibrillation, flatter relations any thoughts to share on how you estimate this relationship or any examples to share of the relationship between the CS and the micro business in real time? Yes, absolutely. Let me share and ice image here shortly. Can everybody see this? Yes. Okay, so this is the left atrium trans septal puncture. Now we are doing a mitral is thomas line connecting the left inferior pulmonary vein to the Mitel analysts. And we at least in this case we went over it a couple of times and still it was not blocking but looking at. So we wanted to make sure we are in good contact. Our signal is changing and whether we are making a good legion based on intra cardiac echo as we're looking at it behind this, you will see there is this a vessel which is the coronary sinus and that sometimes acts as a heat sink area. Now the unique thing about this case is whenever you're a plating here, one could see like a fire field atrial signal. In addition to the near field left atrial signal. So that was a clue that while a plating, we were just not changing that far field signal. So at least in these cases it's sometimes worth while going into the coronary sinus and adjacent uploading it adjacent to the site from the CS. A couple of things to remember here, you know, we can certainly endure a lot of things in the coronary sinus, coronary arteries become the major rule. But as long as your catheter in aerial view is looking more eight really and you have a big atrial electra graham, I think that could be uh somewhat of uh safety net. But if any, there is any concern, we should certainly do a coronary angiogram. If you're looking to atrial again, the chance of damaging the forensic is going to be low. But again, if you, if you are seeing more and more ventricular electra graham, which is much bigger, then we should not a plate. And if that's the only way we are able to a blade, this then check for forensic becomes important. Some of the other challenges would be impedance, how to try trade the power based on that. Certainly the catheter sometimes can get wedged in that location and then some of the, you know, the tricks you can think we lost. You there be chic, but thanks thanks for sharing that you don't mind while operating from the left atrium. Thanks thanks a lot of the ship. But now uh now the uh there's a comment from believe dr Strauss about accessing the Epic Ardian. uh the we actually covered this in uh at the end of one session a few few weeks ago. That should be available on Youtube as an addendum. And if after that, there's still some questions about Epic Cardinal access will cover it in one of our VT sessions. For sure. Now we have some we have two questions relating to post mais flutter. So maybe we can spend about 10 minutes on that and then we can tackle a few other questions. Um maybe we'll start with uh a case and then we'll get comments from everybody about this. I think I'm going to share the screen now. So kind of a typical scenario patient. The key things about Postmates flutters. Is there so many kinds of mazes? So you have to understand which means it is. So, the best way I think about it is there's the curtain soulmates. And then there's everything else. Everything else is more like scar related flutters. How do you tackle that? The thing that's unique about the surgical mazes is that you really do have armory vein isolation. In most cases you have a very clean set of lines in most cases. And then we really start thinking of large circuit flutters. Most other mazes, limited mazes, torque Aske opic mais combined. Hybrid maze have to treat them more like scar related flutters in my last amount to comment after just looking through this case quickly. Most of the time the pulmonary veins will be isolated. So it's a patient with the flutter. But you can see here, I believe this was one of the veins maybe ah right sided vein that clearly there's exit block coming through this vein. Look at another vein, you'll see like it's still fibrillating after all this time, but can't get out to the rest of the atrium many times with the curtain. So mais, especially for large circle around all veins was done, you'll see that the posterior wall is also isolated, so really solid line of black posterior. So some things to keep in mind is it's not usually going to be an issue where there is some porosity of your posterior anchor point in flutters that our post curtain soulmates. What are some of the things to think about is here, we're putting a multi electrode catheter across the cable trickles, christmas, I'm sorry, across the metro business, at the level of the left lower pulmonary name and you get the sense that there is a reversal of activation. So, kind of block. Now, the thing to remember here is this is a situation where endo cardio and epic are ideal separation is real. So second principle of post mais flutters first is in curtain, so mais posterior part is usually really an anchor. The second is you cannot trust into cardio activation to be the same as a pericardial activation and vice versa. In other words the CS seizes to be a surrogate for indoor cardio activation and an indo Cardell man does not tell you whether there is the same activation at the courage. In an extreme case you could have had the surgeon using a pry open or a incision and accordingly that gives you a nice block but didn't do anything in the coronary science. So this is an important unique feature of Postmates fred what you'll notice and usually will be an easy early clue is despite this weird activation and accordingly you can train and get good evidence that you are in the circuit with approximation of the post basing in trouble with attack, cardio cycle length from the C. S. And usually you need only little output. You don't need big output from that pacing to do it because all you need to do is capture the CS muscle, the activation sequence and entrainment and post entrainment mapping and Postmates flutter can be very confusing. What do I mean by this? When you look at the map it will actually look like you can trace most of the circuit visually and accordingly. But the cycle length will be not even close what you meant and that's because the slow areas and complete circuit can be far more complex. Why is it? That entrainment mapping can be confusing as it will look to you like there's just too many things in the circuit, you do the cable trackers we dismiss it looks like it's in a circuit. You look at the CS, it looks like it's in a circuit. You do the roof, it looks like circuit septum looks like in a circuit. These are truly very large circuits and they could have been involved right atrium and left atrial my accordion. What these circuits to complete let's say the classic inter atrial flutter right atrium and left atrium. You connect from right atrium to left atrium through Bachmann's bundle. But how if you have block and accordingly can you connect back to the right atrium? There we have connections. Epic Ardebili to the coronary sinus and the coronary sinus is used to bring you back here and that's why if the cable trackers but business hasn't been a pleated. You might and train it from the cable trackers partisans but a blading there alone will take this limb out of the circuit but you could still usually not always, but you could still usually use the septal my accordion to finish the circuit. The key is finding a common limp and that could be the roof by Baartman's bundled but could be the muscle of the coronary sinus and if the ablation report doesn't mention cryo in the CS muscle. That's a good bet to think about where you could have played. So that's the one that we took as an approach in this case a blading within the coronary sinus and ah that terminated the flooding. This is just an adjunct toward the marshall vein of marshall. This is a human heart autopsy and flip it around. Sorry. And when we flip it around and we do a section through here, that's exactly the ridge between the pulmonary veins and the appendage. So just some points that distinguish mais flatters post mais flatters, assuming this is a curtain soulmates for other mazes. My own personal approach is to think of it like scar related flutters. Try to understand what procedure was done. Don't anticipate very thin lines like you do with the curtain soap and then map out the scars using treatment and mapping and try to figure out what that flutter might be. Um Are any additional comments to go along with that? No, I think um that was very helpful. One thing I like to do and I'd be interested to hear what the others think is is for post maze or post surgical a vibration. I think it helps to try and consolidate everything that was done by the surgeon if it's not intact as well. Sometimes that simplifies the approach I think because even though it may not be necessarily key for the Flatterer hand there and then it maybe in the future, especially if you can induce it. So that's something that I try and do in these cases. Great. And ah I see a I see a question from dr Marto here about effective anterior mitral lines, collateral damage. So just a quick thing about what we mean. And I'll ask um are too comment on this as well. What do we mean by an interior micro line? So mitral valve? See us vertebral bodies coming in the backs of posterior part of the analyst, anterior part of the annual list. Usually what's meant by mike anterior land is a line that's connecting the pulmonary vein circles to the mitral valve. So it's kind of going anterior lee from the pulmonary veins to this may be true but you'll hear the same term also for lines that are parallel to Bachmann's bundle on the roof but placed relatively interior lee. For example if the appendage has been isolated connecting to the appendage. So specific question here is about collateral damage, collateral damage to the mitral. Well ah I mean for an anterior micro nine Um are do you want to tackle that? We have about four or 5 minutes left and then maybe we can handle other questions offline. Sure. So I think that's a great question some people uh I think like to do an anterior line rather than the true maestro isthmus line. The thought is that it may be easier to get block. It's maybe thinner tissue. I think in the literature the risk of perforation maybe a bit higher for that reason. But the other thing is you can actually delay trans atrial conduction time. So you may get issues that way. Sometimes I think you have to be careful as well if you're going to do that is to really try and analyze the ct scan as well and see if you can determine um the anatomy based on the sino atrial nodal artery as well because there are some cases where it may come off from the left sided system and the way it traverses, it may actually get inadvertently injured. And so, um I'm not sure if that's one of the main points you wanted to bring out dr as far as um But I think that's that's yes. So it's uh, you know, just going back to this figure, ah mm hmm. It's really kind of bored structures. If you're bleeding here. Do you need to worry about? So this is the crevice where the high arctic valves, it's soon on coronary sinus of al silva will be right here. That's why perry Metrotech courteous. Sometimes we a blade from the non coronary science that's not so much collateral damage, but a collateral structure we have to just think about and remind ourselves is located in that region. The sinus node artery when it comes from the circum flex will traverse right over here. And as you pointed out, 845% of patients it exists and maybe an important supplier for the sinus known. So if we do a line there and we don't realize that arteries there, we might block a blade, that artery and get sinus node dysfunction, the best ways to avoid it is just avoid the line. If you can solve the problem somewhere else. If not look at imaging and see if you can see there's a major artery there at the very least don't a blade during flutter. So you're in sinus while of waiting, maybe you'll be able to pick up that something is happening to the sinus node and you can stop mm blading in that location. Sometimes folks will ask the worst place to a blade. It's like the you have in the middle the non coronary sinus. You have anterior lee, the mitral ground that little triangle between these two here. That's the thinnest part of the roof. My according behind you get thicker with thicker portions of Bachmann's bundled in front, you get the valve to the side, you get the non coronary sinus thinner there, that's the part where you're most likely to perforate. It's not a common sight for perforation because we don't do much ablation there. But simple thing is to remind yourself if there's no electro graham there or very little electro graham there. You don't need much ablation. Maybe I'll just take a minute to ask one question that dr Majumdar is asking if the veins are silent. Do you still need to encircle the veins to create a posterior boundary. The answer is no but veins if they're silent, it usually means that isolated in most adult human hearts, there will be some myocardial um that's viable going into the pound remains not true in young Children but most adult hearts. That's true. Yeah. I think we're coming to the end of the session today and thank you all for attending and sending your questions. We have a couple of questions that are answered about the alcohol injections into the vein of Marshall will try to answer those questions and post onto the Youtube video. Following this session, you will get any email about evaluation of these seminars and how best to improve these sessions. Please try to send in your replies so we can improve these webinars. Thank you everyone for attending today. Published March 31, 2021 Created by Related Presenters Samuel Asirvatham, MD Cardiac Electrophysiologist View full profile Abhishek Deshmukh, MBBS Cardiac ElectrophysiologistCardiologist View full profile Siva Mulpuru, MD Cardiac ElectrophysiologistCardiologist View full profile Ammar Killu, MBBS Cardiologist View full profile
