Good morning, everyone, and I think I have the honor of doing the only non-convergent talk for the day, so bear with me. So pulse field ablation, I'll spend some time talking about biophysics, what the most recent data is and what some of the limitations with pulse field are, including some case examples. So the current landscape, I borrowed this tweet with permission from Dr. Sanders, but when pulse field first came out, he put this case up and his comment was, well, this is getting a little too easy. You can see he's done the posterior wall, put the map up and somebody asked him, well, how long does it stay that way? And the answer is, we don't know. It does help, it does work. And why does it work? What is the evidence? Well, this is what we have right now. We have cryo, we have radio frequency, and now we have pulse field. What happens in pulse field, for people who have not used it or not heard much about it, essentially you deliver an electrical impulse. That impulse punches holes in the cell membrane, and when that happens, you can see that sort of the cells become permeable, and the hope and goal is to try to keep them irreversibly sort of impermeable. Pulse field has been used in agriculture. It's been used in gene modification. Reversible electroporation, meaning punching holes, introducing genetic material, and then having that reverse is commonly used in oncology and in, you know, gene modification for seeds. So this is not a new technique. It's been around for a while. The hope with cardiac is to have irreversible electroporation. But of course, you can't just dial up the ante, so to say. If you use really high voltage current to try to make the cells irreversible, there is a thermal or heating effect. So even though it's considered cardiac-specific and safe, it doesn't mean we can just keep doing it, keep doing it, because at some point, it does get thermal. If you look at tissue architecture, as expected, there is less hemorrhage, there is preservation of arteries, there is less necrosis with pulse field compared to radiofrequency. Same thing with the esophagus. This is an animal study where pulse field ablation was done from the aorta, right next to the esophagus. As you can see, with pulse field versus radiofrequency, there is really no significant effect to the esophageal architecture ablating right next to the esophagus. And the story goes on. This is a study looking at animal models ablating inside the pulmonary veins with radiofrequency versus pulse field ablation. No pulmonary vein stenosis was noted with pulse field, even if you ablated inside the pulmonary veins. Phrenic nerve. We ablated right on the phrenic nerve, and there is no damage to the phrenic nerve, one thing that we worry about with thermal technologies currently. So the story goes on, as you can see, that it's safe, it's cardiac-specific. But this is probably the most important slide, and I'm going to show this again when I do some cases, but this is where I think there is some limitation to pulse field. So if you focus in the center, I'm not sure if it's visible, but there's three tissue specimens with variable thickness lesions. And the bottom is about four millimeters away from tissue, the middle is about two millimeters away from tissue, and the top is right in contact with tissue. The issue is that even if you are about four to five millimeters away from the tissue, you are going to get a lesion with PFA, as long as you deploy the electrical current in the vicinity of the tissue. Once that's deployed, all electrograms go away, and you have no way of really knowing at this time if that is a deep lesion or not. In animal studies, it takes about an hour for that tissue to recover. If you look at unipolar signals, DBDT, ST-segment changes, and as you know, all EPs have a lot of patience to sit for an hour after finishing a case in 30 minutes. You know, it's really not a feasible answer. But that's the issue, is that you deploy one pulse, and you lose all electrograms. And when you do that, there is really no way of knowing how deep your lesion or how effective or how durable your lesion is going to be. If you look at esophageal studies, even though there was no effect on esophagus, there is some rise in temperature. In this study, about 23 percent of patients did have a rise of more than one degree Celsius in esophageal temperature, with a max rise of about, you know, four degrees. Even though there were no clinical outcomes, this just shows that it's not purely non-thermal. There is some increase in esophageal heat. You know, we have to be careful, because for cryoablation, it was also touted as being very safe for the esophagus. It took about 25,000 cryo cases before the first AE fissula was reported. So just because this is cardiac-specific, there is some thermal component to pulse field, and, you know, caution should be done. Looking at tissue depth, certainly there is less tissue heating. So if you look at surface, three millimeters versus seven millimeters radiofrequency compared to pulse field, you can see that the tissue heating really peters off. It's only about a degree at seven millimeters versus, you know, nine or ten degrees with radiofrequency. So there is thermal, but it's not as bad. So what is the current data now? What is the current data for pulse field ablation? It started with, you know, all the stuff from Dr. Reddy and his, you know, sort of small series in Europe, and initially there was a lot of promise. You're looking at about 75, 80% outcomes for paroxysmal and persistent patients. Another European study looked at sort of real-world outcomes. So this is, you know, all across Europe. This is using the Boston Scientific System. And if you see, the results were quite good at six months on both sides, but they tend to sort of peter off at about a year. If you look at persistence on the right, it really comes down to like the 50s again. Same thing with paroxysmals. It's really good at six months, and then declines significantly at 12 months. And why is that? Why is that there is, you know, such a huge difference from six months to a year in real-world outcomes? Going on to randomized IDE studies, FDA IDE studies, I'll show it just too quickly. This was a study done by Medtronic, the first pulse field ablation study, looking at 150 paroxysmal and persistent patients. And both Dave and I were part of the study. And you saw that there was sort of modest, it was a lot of fanfare, a lot of expectations. Results were sort of modest. You were looking at about 65 percent for paroxysmals and about, you know, 56 to 58 percent for persistence. One of the criticisms was that there was a lot of monitoring done. There was weekly monitoring done in patients in this study. So you know, I guess the more you look, the more you find. The second study was the Boston Scientific, which is the other commercial system available, the FERA Pulse Study, which was randomized between thermal and pulse field, comparing cryo radiofrequency to pulse field. And that study showed no difference. There was really no difference, but there was similar efficacy, safety was quite good with pulse field. Interestingly, Medtronic then ran their study, the pivotal study, with the same type of monitoring that was less rigorous done for this study, and the results were better. So they were able to get the 65 percent up to 73, 74 percent. Again, the more you look, the more you find. What about posterior wall? These were all studies looking at pulmonary vein isolation. Another study that just recently came out, again, the sort of manifest cohort, sort of went back and looked at their persistent population and said, well, how many patients actually had posterior wall ablation as well? And there were quite a few, about 24 percent or 130 patients underwent posterior wall and PVI compared to a similar matching cohort of PVI only, and at one year there was no difference. So is it the posterior wall that is not involved with atrial fibrillation, or we still don't have an endocardial answer to posterior wall isolation? That question is still really out there, and we don't really know the answer based on the current data that we have with pulse field ablation. So I'm going to finish off with some cases of pulse field, and for people in the audience who have not seen pulse field at play, I'll show you sort of a case where it does sometimes help to have the option. So this is a case of a de novo patient who came in for their AF ablation. It was an atypical flutter. You can see there's a nice channel drawn where there's scar, there's slowing of conduction. Patients obviously have, you know, hasn't had a PVI, but is in a sort of a mitral flutter with the anterior scar tissue, and you can see here, as soon as the pulse field catheter is applied and a pulse is delivered, the flutter terminates. It really is beautiful. When you do use it and it works like this, it really is something really fascinating. You can see most of the cycle length on the catheter, and one lesion terminates the flutter. And so we went on and did PVI posterior wall. You can see that you're able to do even anterior lines with at least this catheter, and you can still preserve anterior wall voltage. So pulse field is useful. It does help in these tough cases. But why does it, so why is it, if it's really that great, and all you need to deliver is one little two-second pulse to get termination, isolation, why aren't the results better? So I'm going to go back to this slide I showed again earlier about contact. So just to sort of think about contact as being important. The problem with today's maps, out-of-box setting, when we do our electroanatomic mapping, we are assuming it's called the 7-7-7 rule. So if you are 7 millimeters away from the tissue, you get a voltage point. That's the out-of-box setting for Abbott mapping or most mapping systems, give or take a millimeter or two. So that's 7, and if you're 7 millimeters away from each lesion, you get a lesion. That's where you get that dot on the map. With pulse field, that may not be ideal, because at 7 millimeters away from the tissue, you will still get a good lesion, but it may not be deep enough. Now how do we mitigate that with radiofrequency? Well, even if the map is a 7-millimeter approximation, you know how much you are pushing, because you also have contact force. So you can see how much you're pushing against the tissue, how many grams of force you're doing, what the heating is happening, what the impedance is doing. You don't have any of those parameters with pulse field. All you know is you delivered an electrical impulse, and the electrograms went away. So this is a patient of mine who had a two-year redo, and we remapped her. So we are doing remapping of all these cases that are coming back, and we are reducing that proximity indicator to 2 millimeters. So unless you are within 2 millimeters of the tissue, that would not be called as good contact. You can do that with this system, with the Ferropulse system, which is the more commonly used system, it is right now impossible to get beyond 6 millimeters. So the only approximation they can give you is that you're within 6 millimeters of the cardiac tissue. With Medtronic, you can get down to about 2, you know, with reasonable sort of efficacy. So this is a patient that had PBI posterior wall, and you can see on the remap there's sort of significant tissue or less contact on the left side. Same thing on the anterior side of the left veins, really there's, you can see the shadows, but there's no real contact. And sure enough, in the redo case, you can see that there is reconnection of the left veins, both in the carina, inferiorly, and all around anteriorly, where even though you had great maps, you didn't really have durable isolation. And you can see the pulmonary vein potential in that area. How about GP modification? There's always increase in sinus rate when you ablate with cryo or radiofrequency. And in this patient, again, these patients are staying bradycardic. They are still having pauses, still getting pacemakers. This is a patient, the same patient where a right upper freeze was done, and there was a significant increase in heart rate by about 15 beats a minute. So it's showing that pulse field ablation does not affect the GPs, which are now considered an important part of AF ablation protocol. This is a five-month redo. You can see that all those lesions done on the right bottom, you know, there's no, nothing was spared. It was a fairly aggressive lesion set. You can see the map on the left bottom that shows very nice posterior wall isolation. And this case sort of taught us a lot. This is very early on redo. And if you redid this map with how close you really were, and we are using eyes, we are using everything, we are using x-ray, pushing against the tissue. But you can see that even though we thought we were in contact, the catheter really is not really at the cardiac tissue. And you look at the remap. Just at five months, there's reconnection of three out of four veins, and half of the posterior wall is also reconnected. So again, shows just because you have great-looking maps, you know, like this, it doesn't always correlate to durable isolation of the veins or the posterior wall. I'll finish with the last case. This is a 1.5-year redo. It was a very straightforward case. And I want to show you the electrograms and the lesion set. This was the index procedure. You can see, again, nothing was spared in trying to ablate the veins and the posterior wall. If you looked at the post map on the right bottom, you can see, as Dave showed, there is nothing there. There are no electrograms. It's just all dead tissue. And we had a 20-minute wait time, mandatory wait time, for each vein in the study. So you're looking at at least 30 minutes out from when we started ablating, if not more. This guy was also remapped with the proximity map. And again, very poor true proximity to cardiac tissue with the catheters. And this is his post map, or sort of map at 1.5 years. You can see that there is reconnection of all four veins and complete reconnection of the posterior wall. And you can see delayed potentials in all four veins in this patient and recovery of entire posterior wall conduction. So we reablated him. And I'll finish with the last slide, which is the cost basis, something that we cannot ignore in today's day and age. And this is sort of obviously average cost basis. If you look on the left side for radiofrequency and cryo, the current cost with the best system, the best mapping, or what sort of standard approach, is about $7,000. That can go up to between $10,000 to $13,000 once you start using pulse field ablation. This is actually the Medtronic system that I've shown, which is the cheaper sort of version of pulse field. It's the cheapest one out there. If you take the Boston Scientific one, you add about $1,500 to $2,000 more. So for AFib ablation, where your average delta right now is about $8,000 to $10,000, depending on where you are, what your insurances are. If you take away almost 40%, 45% of that delta by adding a tool that is cool, maybe a little bit faster, but we don't really know what the durability is, it really sort of behooves the question, is it really worth switching? Is pulse field ablation really going to replace all thermal modalities, all surgical modalities, and are we really there yet? So just to conclude, it is a safe, non-thermal way of ablating cardiac tissue. Currently, there is no real evidence that posterior wall isolation with pulse field is either durable or effective based on clinical evidence. Contact with PFA is very important based on animal studies, but we don't really have the technology yet to figure out how close we are to the tissue and how deep our lesion set is. And there is significant cost to the current PFA systems. Thank you. 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