My name is Yongmei Cha from Mayo Clinic and we are going to have a very interesting and exciting session here. It's the novel CRED technologies and novel CRED issues, how to do contemporary CRED troubleshooting. So we have a great four speakers here going to present. So we'll start with the first speaker and it's Dr. Harold Kawata from Oregon Cardiology Sacred Heart Medical Center. So he's going to present optimization of a left bundle branch pacing at implant and in follow-up. Thank you very much. Thank you for this great opportunity to talk about this important topic. So I did a fellowship at UC San Diego so I'm very glad to talk about these things and coming back to San Diego. Thank you for coming. So let's talk about, you know, let's begin asking the fundamental question, why do we need to perform left bundle branch pacing? So the RB pacing bypasses physiological pathway leading to myoside-to-myoside signal, slow transmission with single electrical signal coming from apex or septum. So with optical pacing, like, you know, you can see this EKG, QIS 190 ms, very wide, and with activity and delay and desynchronized manner, so leading to electromechanical desynchrony. So as you can see, this is activation mapping during the RB pacing, so the signal is coming from apex. So then, next slide, so then various echocardiographic markers of electromagnetic desynchrony, one of the most well-known is apical locking, as you can see. So in apical locking, the apexes move from side to side, so due to desynchronous contraction. So daily trial clearly showed that in patient with ICD, without pacing indications, excessive RB pacing lead to increasing death and heart failure. So incidence of pacing-induced cardiomyopathy varies across studies, but in general, it's said approximately 15% in three or four years. Recent studies showed left-bound branch pacing offers benefit when RB pacing more than 20%, so you can clearly see the difference if we see the pacing more than 20%. So this is, again, the three-day activation map during RB pacing and left-bound branch pacing. So left-bound branch pacing, ideally, there are until first school and post-first school activates simultaneously. This patient, some like delaying there until first school, however, still, the lateral is activated very quickly compared to RB pacing. So the left-bound branch pacing is no longer optional. I think this is essential at this point, so the EP must learn to perform how to do it. So I personally use mainly 3S3L lead and 315C. I don't personally use deflector with this very often. So before stepping into CAS lab, understand patient-specific anatomy is very important. Some patients CAT scan, so we can take advantage of CAT scan. In patients with right ventricular enlargement, sometimes 315C doesn't reach very well. It's hard to put the catheter into septum. So in that case, potentially more medial puncture might be useful. So this is an example of a CAT scan. So as you can see, this is a 90-year-old patient after surgical aortic valve replacement. So this is after the pacemaker implantation. You can see the angle of the lead is more like, you know, the tilted angle. Then you see the picture during the implantation. So it's not parallel to the ground. So in comparison, if you see most of the patients, 60-year-old, stethoscoptic one of pacemaker, you see the wire direction is more parallel to the ground. So it's very important to know, because sometimes I don't feel comfortable when the lead is going very upward. But some patients, the reason why it's going upward. So you need to understand anatomy. So let's start with the RAOB. That's how we start. So the advanced 3S is the lead to the chip of C315C, and manipulate them as a single unit. The C315C should be positioned perpendicular to septum. So perpendicular orientation, you can make sure by seeing the make the chip appear circular in RAOB. So this is contrast septography. I use contrast septography all the time. So as the lead is gradually deployed after contrast septography, so you start seeing RAOB, then gradually rising the unipolar pacing impedance. Also you need to know how deep you need to go. So chip to helix is 1.8 millimeter. From here to the ring is 9 millimeter. So basically from here to here, almost 10.8 millimeter. So then this is after the deployment. So that you can see the ring is also touching to the septum. So the balance and rotate the 3S is the lead. This is very important part. Press 3S is the lead firmly against the septum. Then ask your assistant to hold the C315C steady, rotate the lead clockwise. So personally I don't care about how many, because it can vary. Some patient need five times, some patient ten times. I don't care. So I want to make sure how much I can go. And like, you know, I usually continue until the other balancement, one centimeter. Because you know, the 10.8 millimeter, that's the distance. So the adequate septal penetration is very important. There's a study showing that. You compare left bundle branch pacing, RAOB septal pacing. So left bundle branch pacing goes more deeper. So you need to go deep. So then after the positioning, I check the unipolar pacing along the helix chip of distal chip, also electrode. So as you can see, you can start seeing the V1, RAOB, QR pattern. Then like, you know, I switch to the ring unipolar pacing. Now you start seeing the W pattern. That means even the ring touching the RAOB septum, then you can make sure you capture the septum by ring. So that means your depth is at least 10.8 millimeter. So common challenging during 3AC is the lead penetration to the septum. In this slide, I'll show a typical case where the lead forced to penetrate to the septum. When the septum is very hard or firm, the lead may bounce off and deflect in the wrong direction. If the lead advance to far upward or downward, it's better to stop and reposition. Also, if the C315C is not well stabilized, it will shift approximately due to the principle action, the reaction. It happens very frequent, as you can see there, C315C is almost coming out. This one, the lead is going upward. So the QR morphology by pacing location, as you can see, this patient, lead position antiofascial. Then you can see the lead 2,3 is positive, which means it's capturing antiofascial. But this patient, as like lower, capturing left posterior fascicle. Now you can see negative, negative in lead 2,3. So here's a challenging case. I attempted to capture the left antiofascial for this patient initially. This patient had a heart block, then I tried to capture the antiofascial, then I put the Cs in the anterior, then this is septum. Then at the end of the case, I thought I could capture the left bundle because I see the R wave in the V1. However, it happens occasionally after the case, you're disappointed. Now you can see QS, a wider QS pattern, then every activation time is very long. So I think it really came out. And actually, this patient, the dislodgement, it's rare, it can happen, dislodgement. Then fortunately, we can replace, reposition the lead. This time, I intentionally go to more posterior because I know now, anterior is very hard. Even you no matter how many tries, if it's hard, you can penetrate. So I just went to the lower posterior fascicle. Then now you can capture the posterior fascicle, QRS is shorter, then it'll be activation time is 76. I think better result. So when chips not advancing very well, it's better to check the myocardial tissue on the hex. It can happen, you can remove with YA or something, or sometimes you have to change the lead because it doesn't work. Contrast infiltration, this happens relatively well, often. Because the first time when I see, I really surprised, but it happens more than I think. Then it usually doesn't cause any serious complication. Also this is an example with a breach in coronary sinus vein. So if we use inject contrast, as you can see, the contrast going to coronary sinus vein. I had probably five or 10 cases, but so far, nothing serious happened, even this happens. Also the perforation to septal, so there's sometimes lead completely penetrated into every cavity, but you have to monitor the impedance. If you have low impedance, like less than 450, so that's suggesting your chip is out of the, go penetrate into every cavity. If that happened, it's better probably reposition, because now it's maybe loose, or the wire can move. So I usually change the location if I think the chip is completely, gets to every cavity. So as a technical consideration, during C315C's removal using a splitter, usually I do it very slowly, but integrated larval bulb may fail to separate completely, then catching on the 3SD lead, and leading to possible dislodgement. So if you think the larval bulb is stuck, you have to stop, and somebody has to cut using scissors. A complication, this is the result from more than 2,500 patients, much for European centers. So the acute perforation ratio is usually less than the 1%, it's 0.3 to 6%. Every lead dislodgement, usually I think at a 1 to 2%. So my experience, it happens very rare. Compared to even RBApex spacing, I think dislodgement is, I feel, much less frequent. So there's a learning curve for any procedure. So also, there's a study showing that if you do more than 100 cases, you get your success rate getting better. I agree with this result. So initially my success rate is much lower, but the more you do, you feel more confident. So follow-up, check unipolar and bipolar pacing morphology on threshold of three months, because EKG can change. I'll show you later. Following left bundle branch pacing, another capture may lead to QRS widening. So to avoid this, consider reducing pacing output early when appropriate. Follow-up echocardiogram for patient with high ventricular pacing is always important. So another capture, if you pace 3.5, 4.0, a higher output, as you can see, you capture the RBA septum. Then, like, you know, by lower the output, you start capturing the left bundle. So QRS morphology can change. Even like you're happy at the end of the case, but three months later, you may be disappointed. So like this, after implant, so you see the QRS, really wide RBA septum pacing, but three months later, you change bipolar to unipolar, now you capture left bundle. So this is, again, the example activation pattern, left bundle branch pacing. So the QRS is now 140, capturing RBA activation to 67. So partial perforation is relatively common. During echocardiogram, you see the partial perforation, but usually it doesn't cause serious problem, too. Pacing in this cardiomyopathy instance, after the left bundle branch pacing, I think, relatively low. But some patient need upgrade to CS. So there's the data. If you have a heart failure, wide QRS, big heart, you might need to end up doing upgrade to CS after left bundle pacing, because it's non-responder. So there's a study, like, showing that there's beneficial. So you might need to do regular CRT upgrade after left bundle pacing. So in summary, left bundle branch pacing should be actively considered in patient, expect to require frequent ventricular pacing, as it may prevent pacing in this cardiomyopathy. Proper technique requires solid understanding of both the electrophysiological and anatomical principle, and there's a learning curve. So the instance of serious complication low, operators must be familiar with potential risks before performing implantation. Thank you very much. Thank you, Hiro. We are over time a little bit. We'll ask our speakers to stay afterwards for a little bit, in case anybody has individual questions. Moving on to our next speaker, we have Dr. El-Mazri from Mayo Clinic in Arizona, who will speak on optimization of the single-chamber leadless pacemaker at implant and in follow-up. And I hope all the presenters stay. All right. Perfect. Thank you so much. Thank you, Dr. Char and Dr. Morin for the invitation. What I'll be doing in the next 10 minutes or so is discuss single chamber leadless pacemaker optimization at implant and on follow-up. Really hard to put all this together in a short period of time, but as a matter of introduction, at this point, as you know, the current level of practice, the leadless pacemakers have been established as an alternative to traditional transvenous pacemakers. And essentially what we have, it's an answer to the Achilles heel of the transvenous technology and a reduction in the lead and pocket related complication. But most of you who do these leadless devices and follow them up, you know that the skill set there is a little bit nuanced compared to the transvenous devices. So at the current time, we have around 100,000 leadless pacemaker implant in the U.S. Two devices are approved by the FDA. 2016 is the micro on your left and Avere was in 2022. So this is a table that compared the two devices and beyond the looks, one is short and chubby, the other is slender, longer. There are some more changes or differences between the two devices. Most importantly, number one is the fixation mechanism. The Avere is a screw in device reminiscent to the active lead. The micro is more of a tine, essentially fixation to the tribulation of the RV. Other important differences is that accelerometer, how it works in these two devices. And also the Avere comes with this extraction sheets that it has. So moving forward, we'll do some cases highlighting some of the challenges that we have in managing these devices. So to start with, in implantation, I'll share with you, this is a recent case that we had, a typical story, 86-year-old recurrent episodes of heart failure exacerbation related to AFib and RVR, a bunch of medical problems and more comorbidities, end stage renal disease, COPD. So obviously she wasn't handling the rate control and failed rhythm control. So we said, okay, that's a perfect case. Let's do leadless and then AV node. Not a great success story, by the way, which is okay. So we brought her to the lab and this is the first deployment that we have. Pretty standard. This is an LAO projection, a little bit more septal. However, the threshold there was very high, more than three volt. And if you remember for the, whoever is implanting micro, you want to strive to get that threshold less than one volt at 0.24. You can accept a little bit higher, maybe up to 1.5 if your impedance is more than 600 ohms, meaning you have a good bite into the myocardial tissue, good contact. Weren't successful. We did many deployment, went a little bit more apical. Then after the fourth deployment, really, we were a little bit on the desperate side. We went more basal and that's when it went south, I would say. So we had a hypotension and this is a stat echo that you see. Pretty large pericardial effusion. So this lady had to have a pericardial synthesis and actually surgery to correct that RV perforation that we caused. Of course, not a success story. But what does that highlight is the perforation risk that remains a challenge for the leadless technology, although it improved with clinical practice and as we learn about it, there is still around 1 to 1.5% perforation risk, higher than transvenous. But most importantly, it does need intervention in a good bunch of these patients. You see here the micro IDE, then the essentially post-approval registry, the leadless two from the AVIR. And there is a good chunk of these patients that need either cardiac surgery or pericardial synthesis. So what does that tell you? If you're doing these devices, you have to be ready to rescue the patient, be ready to do a pericardial synthesis and even progress a little bit further. So we were discussing about the perforation risk and it is important also to know how to plan your procedure. So know your patient who's coming to the procedure and know what is the risk for perforation. This is a study from Puccini and they actually identified that high-risk patients are elderly females, thin, and stage renal disease on dialysis, COPD, and if they didn't have any sternotomy. Now beyond the patient-related factor, there are also some device or procedure-related factors, right? So if you do more deployments like they show here, if you have a high-risk patient and you do four or more deployments, then your perforation risk jumps significantly. So plan your procedure. Again, you need to define where the ideal location for these devices. For a micro, you want to target this mid-RV septum and the RAO view would be very helpful for you to define that area. But also remember, you need to be facing the LV. You want to go into that interventricular septum. So in LAO, look towards the left ventricle. Try to avoid these recesses in the anterior and posterior where the RV thins out and increases the risk of perforation for you. Now for the AVIR, this is a different story. You're going to go always towards the RV apex. But I guess the AVIR is a little bit more controlled deployment where you turn, essentially screw the device in, and assess as you go for the current of injury to know how much bite of that RV you're taking. All right. Moving on, follow-up. And we'll discuss two cases here of challenges during follow-up. This is a case of very nice 64-year-old, very active patient, hikes regularly. She had a pacemaker done more than 20 years ago, dual-chamber transvenous. Then in 22, she started having difficulty because of an atrial lead fracture and asynchrony. And she presented to her cardiologist and said, hey, you know, there's a much better, newer device. Why don't you get a Micra? And she had the Micra, but her symptoms did not go away. Finally, she came to our ER with palpitations and a near syncopal spout. She had a lot of also erratic pulse and fullness in the neck. And this is what we had. If you look at the ECG here, you see that the ventricular pacing is asynchronous compared to that P wave, right? Geographically, the device looks okay. So looked at the device in more detail. This is the interrogation. And it looks a little bit different than the transvenous, right? You have to make sure that you're looking at how much synchrony that Micra AV has. And if you calculate that AM, which is the atrial mechanical sensing, it comes at 83%. So 83% AV synchrony. If you have a 95-year-old patient with that, maybe they're going to do okay. But for somebody who's young, that's a problem. So reviewing very quickly with you how that AV synchrony algorithm and the device looks like. It is a 3D accelerometer that detects events that moves the device in the RV. So A1 is your time when the mitral and tricuspid valve close. A2, when the aortic and pulmonary valve close, that's the end of ventricular systole. Then comes A3 and A4, which are the atrial events diastole. And then the atrial kick, which results in that mechanical delivery of the blood, A4. And that's marked by the device as AM. So the threshold of detection is set for A3 and A4. So what can happen? Many things can happen to the device where it can lose AV synchrony. Like an A4 that is very small, and that will be below the detection. Or A3 and A4 be fused. Or maybe that A4 is falling in the A3 window or in the PVAP, right? For our patient, if you noticed, she had underlying sinus tachycardia. So if you remember from physiology, those two, A3 and A4, they are fused together. So what did we do? And these are general guidance for AV synchrony. You can try it on every patient. Deactivate the A3 auto-threshold. Keep that A3 very high so that the device doesn't see it. And for people with complete heart block, deactivate that AV conduction mode switch. And finally, run that manual atrial mechanical test, where you can see where the A3 and A4 are falling and what is the amplitude of the A4. So for us, we did all these. She improved, but not to the 100%. It's rare to have 100% with these micro-AV. And she's still looking at the transvenous options at this point. Last case for me, lifecycle management. Very common scenario, right? This is one of our patients, 87-year-old, history of persistent AFib, failed rhythm and rate control. And she had an AV node and micra. Looks pretty good. Comes back five years later. She's at ERI. Her AF has dropped a little bit to 45% almost, but she remained asymptomatic. Now, she doesn't have much vascular access. She had prior breast cancer and lumpectomy, radiation to the chest, pretty old story. So what would you do here? Would you take away the micra and replace with a new one? Add a new micra? Would you upgrade her to those CRT devices? So two questions here. And you know, most of the time when we look at the devices at ERI, you go ahead and add another device, right? For us, a lot of people who do extractions, you know there are some complications. And you always have to balance what we know versus what we don't know. Yes, these devices can be extracted, but there's a risk of perforation. There's an unknown risk of damage to the tricuspid valve. And the encapsulation remains a challenge, right? Some of the devices you cannot capture. So in general, just add a new device, right? And the animal data showed that you can put up to three micra in the RV without any alteration of the mechanical or contractile function. The second question, CRT, and I quote this long-term micro-VR study. They followed more than 1,800 patients there. And if you look at that for five years, 2% only risk of CRT, or the rate of CRT upgrade was only 2%. Why is that? There's a lot of theories about where the micra is sitting, whether this is close to the septum and less pacing-induced. But most importantly, if you see a small drop in the ejection fraction, patient is asymptomatic, leave them alone. They don't need any more intervention. And shout out to this technology. Look at this. The micro-VR complication versus the transvenous, this is a historical cohort, was almost half of that rate. So pretty good result at five years. So in conclusion, for these leadless devices, choose the appropriate patient. Make sure you plan your device correctly. Plan the target implantation site and be familiar with the two devices. You have to recognize and treat quickly any complications, keeping in mind that a lot of them need intervention if you have a perf. And you have to long-term follow for micro-AV, need to take a look at that AV synchrony. And I kept it open here. There's a lot of questions about tricuspid regurgitation for these devices. And thank you for having me. Thank you. So if our audience have questions, please individually communicate. So we're going to move forward to the next speaker, Dr. Camille Frezier-Mills. She's from Duke University, and is going to talk about how to optimize the dual-chamber leadless pacemaker. Thank you to the speakers and organizers. I appreciate the ability to talk in front of you. I tried to start this early. Can you hear me? All right, great. So thank you for giving me the opportunity to speak in front of you about dual-chamber leadless pacemaking and the follow-up. So my disclosures are listed here. I'm going to start with the case. I'll go over the data related to leadless pacemaking, and then talk about some implant considerations, and then finish with the case as well. So a 76-year-old female, she had PAF. She came in with symptomatic bradycardia. I'll not go in great detail, but she had prior cancer, and so we talked to her about different devices. Her EKG is demonstrated here. She had bradycardia down into the 20s, and had syncope with that. She was on the EP service, or admitted in the hospital, and the cardiology service consulted EP, and we talked about a pacemaker. Because of her prior radiation and reports that she had with her cancer, we discussed transvenous versus leadless pacing. She had sinus bradycardia, so we talked about the AVIR-DR system looking at atrial pacing specifically for her. She consented to the procedure. The procedure went well. The philosophy time in these devices tends to be a lot longer than you were with the traditional ventricular devices, so 16 minutes of fluoro. Her RV sensing was 15.8. Her impedance was 1,400. Her threshold was 0.75. The RA thresholds tend to be high at these, so 3.5 volts at 0.4. The impedance was 320. That tends to be low, and the sensing is usually around 0.5 to 1 millivolt. The total case length was 97 minutes, so the procedure length was 76 minutes. Her post-procedure EKG is demonstrated here. It shows nice atrial pacing with capture. So she did well following the procedure. She did have more of her atrial fibrillation. She had known AFib that was proxismal, but hadn't been as bothered by it, but after the procedure, she did have a definite uptick in atrial fibrillation. She had previously on dronetarone, which had to be stopped because of her bradycardia before she got her device, and so that was restarted, and that did help her overall AFib burden. The rate response factor related to this device is temperature-mediated, and so out of the box it comes in, you can have it set at, I think it was at a level four, which is really aggressive, and so we had to make some changes in that. I cut it down initially to a level two because she was having lots of palpitations that weren't correlating with her atrial fibrillation, and I felt it was because it was overpacing her at times because of the rate response feature. We brought it down to a two that made some fatigue, and so ultimately we increased it to a level three. So what is the data for dual-chamber leadless pacing? The original article was published in the New England Journal, and it was on 300 patients and looking at the technology. It had a 98.3% success rate of implanting, and the complication rate, or freedom from complication rate, was 90.3%. For those patients, it had the endpoint of capturing was met in 90.2%, and then the atrial capture threshold tended to be a little bit high, again, in these patients at implant. To achieve at least 70% AV synchrony, that occurred in 97.3% of the patients. When we think about these devices and thinking about the complications, being able to implant the device is one thing, but the complication rate, particularly with this device, seemed a little bit higher, and us trying to figure out, well, what was going on and what do they qualify as a complication? So first, it's talking about, one, the duration of the procedure, so it's definitely longer than you would for a typical transvenous device, and definitely for at least the micro, for ventricular implanting. So thinking about the duration of the procedure is important for your patients. We have a number of repositionings, also, and making sure you have adequate fixation was another component here. So you had to move the device around about 25% of the time in the atrium and in the ventricle about 12% of the time in order to be happy with your location and your thresholds. As you walk into the procedure, you need to think about what is your approach and where are you going to implant the device. And so pre-procedure visualization is important, so doing your contrast injections in order to see what the atrium looks like and what the ventricle looks like and where you're ultimately going to place your device. It's important that when you place your RV device that it's sitting somewhere in the mid to low septal location. And then when you're going to implant your atrial device, that it's within two breaths of, or two device lengths total from the knob to the knob. And so you really pay attention to where this knob is. You want the second one to be so that the full thing is no more than two leadless devices. And that's important to allow the eye-to-eye communication, which allows the devices to speak to each other in order to maximize the functionality of the dual-chamber device. Another consideration is location. And so in the initial trial, they were placing them very apical. The perforation rate was a little bit higher, and so I think sticking it, making sure you're placing it on the septum and sticking with the septum is always good in, sorry, the device location. So either in the one, Zone 1 or Zone 2 compared to the septum, compared to Zone 3 at the apex. So if you look at 51% of the time, the device was placed in the apical septum. And in the mid-septum, it was about 38 or 40% of the time. And you really wanted to avoid true apical placement of it. For the atrial device, you want to hit really the base of the anterior base or the posterior base of the right atrial appendage. So looking in that Zones 4 and 6 as demonstrated on this slide, that gives you a better fixation and it gives you better communication for the eye-to-eye communication. So another thing to consider as you're, when you're placing your device. When we think about fixation for the device, it's important to look for changes in your impedance and also the degree of contact. If you put too much force, then you're going to have a higher rate of perforation. If you don't have enough force, then you're going to have dislodgement. And in this device, they had 10 acute dislodgements in the early trial. And then in follow-up, that gets better if you have more experience with it. But the dislodgement rate, particularly for the atrial device, is, it's higher than what we've seen in other devices, and definitely in the transvenous. And so being able to make sure you have adequate fixation, paying attention to those impedance changes, and then assessing your threshold. So pearls related to implant. The implant location, again, is key. Maintaining positive forward pressure is important. Watching your impedances closely. When you do your deflection test to make sure that you have good contact, do a thorough one, and make sure you align your tethers to make sure you're able to really test it to make sure you have adequate fixation. Because again, the fixation, particularly for the atrial device, tends to be a bit higher. You're going to look for this RSJ complex also with your contact. And if you see excessive movement of the device, then you know that you don't have adequate fixation, and you need to reposition it before you release the tether. It gets better as you learn. And so this study looks at people who have done one to four implants versus greater than nine implants of the DR system. And as you gain more experience, your overall procedural time will decrease from that 70-ish minutes down to 59 minutes. Your fluoroscopy exposure also will decrease from that initial 18 minutes down to 14 minutes. And your freedom from complication increases. And so you have less complications with more experience. And so I think that, again, repetition, understanding where you're placing, how to do the device in a safe way, and gaining experience overall will decrease those complications. I think I covered that. When you're seeing these patients in clinic, there is an algorithm and you can get it from your reps or look online. And you can have this in order to optimize your DR programming. So the biggest question is, do you need to have both the atrium functioning, communicating with the ventricle in order to maintain AV synchrony, or do you need it more for atrial pacemaker? If you do need it for both AV synchrony, then you need to optimize your eye-to-eye communication settings. If you don't need it as much and you can have it as a VVIR backup with AIR pacing, then you're able to extend that battery longevity in this image right here. So you want to optimize your safety margins whenever it's possible. Consider switching over to AIR with VVI backup if appropriate. That will extend your battery. And then make some adjustments to your eye-to-eye communication settings. Lastly, I'll end with just a quick case. There was a 26-year-old patient who had congenital heart disease, had prior ICD. They ended up having an infection. It got extracted and they needed a device. The ICD was found placed initially for syncope. The patient had never had any arrhythmias over multiple lifetimes of device, so they opted to place a leadless pacing system in the patient. She had heart block initially, and with that they put a micro AV in the V and put a VIR AR in the A, and it worked really well. And it was nice to see the ability for the atrium and ventricle to work in sync. So in conclusion, dual-chamber leadless pacing represents an advancement in technology. Placement is key. You want to consider programming changes in order to maximize your battery longevity. And lastly, consider novel approaches in combining various technologies potentially. Thank you very much. Thank you, Dr. Frazier-Mills. Lastly, we have Omar Aldas from the University of California, San Diego, who will discuss optimization of the EVICD at implant and at follow-up. OK. Good afternoon, everyone. I'm Omar Aldus. I'm one of the electrophysiology fellows at UCSD. I'm going to be talking about optimization of the extravascular ICD at implantation and follow-up. And I think one of the cases I did with Dr. Green was a great demonstration of some of the problems you can run into with the EBICD and how to kind of circumvent them. So I'm going to try to go quickly due to time, but we have a 62-year-old male with a history of non-ischemic cardiomyopathy. He had an EF of 35 to 40 percent. He had a prior V-TAC and V-Fib with secondary prevention ICD. He was presenting to us to establish care. He had an ICD implanted initially in 1994 after a V-Fib cardiac arrest while driving. He had a new ICD in RV lead place for kind of unclear reasons at an outside hospital and then had a generator change, a pocket revision due to an erosion several years later, and then again had an atrial lead replacement for kind of unclear reasons, and then unfortunately, following this, had multiple pocket erosions. And by the fifth one, he was starting antibiotics, had a repeat echocardiogram showing a perforation of the tricuspid valve leaflet, and then a couple months later, had an attempted lead extraction that was unsuccessful, so had the leads abandoned, generator extracted, and unfortunately, that procedure was also complicated by right upper extremity DVT. So this was his chest X-ray shortly before his attempted lead extraction. We had talked to the patient in clinic about potential open surgical extraction, but he did not want to have any surgery, and unfortunately, he had failed the subcutaneous ICD screening. So really, at this point, his only option was to get an extravascular ICD. And at UCSD, for all our extravascular ICD procedures, we do get pre-procedural chest imaging just because it's been very helpful for procedural planning and also to identify potential roadblocks that you might have during the procedure. So I'm going to play a video of his pre-procedure chest CT, and it's going to play caudally from the liver, and then scroll up cranially towards the carina, and then after it plays, I'll point out some notable findings. So, one of the first notable things is that he does have a bifid xiphoid process. This is helpful to know, especially when you're palpating your landmarks. You don't want to be surprised when he comes into the EP lab. The other thing you can see here is that the retrosternal space where you're going to be putting the extravascular ICD lead is very, very small in this patient. And just anecdotally, what we've noticed is that the vast majority of these patients will have pleuritic chest pain post-procedure that responds to colchicine. So we've been discharging these patients on two weeks of colchicine, similar to our RF ablation procedures because of this. Another notable finding is that you can see his right atrial appendage is very close to the retrosternal space where the ICD lead will be. The reason that's important is because, unlike with the subcutaneous ICD, where you can run into issues with T-wave over-sensing, with the extravascular ICD, you can actually run into issues with P-wave over-sensing, especially with the right atrial appendage so close to the retrosternal space, like in this patient. Typically, you're aiming for an R to P-wave ratio of over 10 to 1, so in this case, you're definitely concerned about this, and going into the procedure, you're already thinking you might have to pull the lead a little more caudal away from the right atrial appendage to avoid running into issues of P-wave over-sensing. Another finding here, we like to think of the lungs as being compartmentalized, so left and the right, but very often, you'll see, as in this patient, that they cross the midline, and so when you're trying to advance the tunneling tool, it's not uncommon for you to run into the lung and the pleura and feel resistance. Unlike when you're running into bone with the lung, you'll actually feel a little bit of give to it, not a complete, hard stop, and what we've done is we've actually asked anesthesia to just make the patient apneic briefly, similar to how we do with the Watchman procedures, and that helps deflate the lungs a little bit and allows you to pass the tunneling tool past the lungs, and then you can reinflate them, and so this is an example where on fluoroscopy, the lead looks like it's in an appropriate position, everything looks great, but then if you ask anesthesia to make the patient apneic, all of a sudden, you can see that the right lungs are pulling the lead to the right, and that's kind of a way to find out that you were actually in the pleura and you weren't aware of it, so the apnea is not only helpful for passing the tunneling tool, but it can also be as a way to double-check to make sure you're not actually in one of the pleura on the left or the right before you use that lead location, so in this case, you'd have to pull out the lead and retunnel. So once you've reviewed the pre-procedural imaging, kind of got a sense of what potential roadblocks you'll encounter, it's really important to identify and draw your landmarks. This is typically how we do it. We have the sternal midline we draw here, the left sternal border, you've got a tunnel kind of in between those two, you have the xiphoid process here, and then the costal rib margin. Where that costal rib margin and the xiphoid process meet, you'll draw your sub-xiphoid incision. Typically, this is, you know, a few millimeters, centimeters below that triangle there is where you draw it. In very obese patients, you can draw a little bit lower to give you some runway to reach the diaphragm. In a very thin patient, sometimes this costal margin is very vertical, and so this horizontal incision won't work. You have to draw a diagonal or vertical incision, again, to give you enough runway to reach the diaphragm. And then, obviously, you're going to draw the device pocket incision location, which is not shown in this picture. So to kind of summarize some of the tips and tricks for optimizing the EVICD at implant, really review the pre-procedural chest imaging. Even if you don't order CTs or MRIs, often these patients will have some for other reasons. Try to identify the xiphoid process in the sternum. Evaluate the proximity of the right atrial appendage to the retrosternal space so you know if you're going to have to pull more caudally than usual, and then evaluate the distance between the right and left lung from the xiphoid process up to the carina. Apnea is a very helpful tool to pass the tunneling tool, but also to check to make sure you're not in the pleura, and then really spend time palpating and using fluoroscopy to accurately identify line works. So even if you've taken all these steps, you had a perfect implant procedure, you still will potentially have some issues at follow-up, and so I'm going to kind of show some common examples of problems you will see at follow-up and how to troubleshoot them. So here is an interval plot showing the classic train track that you'll see with over-sensing, and whenever you see this, obviously you have to look at the EGMs to see what the device is over-sensing. And so in this case, the ring one to ring two is your sensing polarity, and this bottom strip here is your far field, and you can see that the device is appropriately sensing these R-waves, but then it's also sensing these sharp deflections, and on the far field you can see that these correspond to the P-waves. So this is classic P-wave over-sensing that we see with this. And then in this interval plot, it's showing fast irregular episodes here, and again, you have to review the EGMs to see what the device is seeing, and immediately when you look at the EGM here, you can see that it's sensing these high-frequency potentials that are classic for myo-potentials. In this case, they were very short, and they don't really have an indication for reprogramming, but if they sustain, you will have to program around this to avoid inappropriate shocks. So this is the lead, and then this is the CAN, so you have two coils, two rings, and you have the CAN. You can program a sensing polarity from ring one to ring two, ring one to CAN, or ring two to CAN. Ring one to CAN is where you often will have the most issues with P-wave over-sensing, and you can see that's because this ring one is the most distal. Ring two to CAN and ring one to ring two is where you'll have more issues with myo-potentials typically. On the left here are kind of the nominal settings, and on the right are the ranges you can program, so sensitivity and sense polarity are just like any other device. For these other parameters, the blink after sense, the sensing threshold decay delay, the drop time, and the over-sensing prevention, I think they're better illustrated with a figure in the next slide here. So blink after sense, we're all kind of familiar with this concept where after you sense an R-wave, it won't sense anything for this duration. After the blink after sense, you have this first plateau shown here in the red line called a decay delay. You can program the duration of that decay delay, but you can't program the height. It's fixed at 53% of the R-wave, and the point of this first plateau is to avoid sensing the T-waves here. After this first decay delay, it will drop to the second plateau, which is known as the drop time, and again, you can program the duration of this drop time, but in this case, you can also program the height, which is called the over-sensing prevention. Nominally, that's set at 25% of the R-wave, and the point of this over-sensing prevention is to not sense the P-waves, myo-potentials, and noise over here, and then after that designated duration for the drop time, it will drop to your sensitivity, and the point of this area is to detect a coarse or fine VF that wouldn't have been sensed in these other regions. So if you have issues with over-sensing, and you're having NSVT episodes over six seconds, or you're having a number of intervals to detect over 50%, there's usually three issues you need to troubleshoot. One of the more common ones are P-waves, so if you don't have an R-to-P-wave ratio of 10 to 1, you'll often run into this. The first thing, typically, to try is to increase the over-sensing prevention, increase that fence so that you don't see those P-waves. If that doesn't work, other things you can try, if the P-waves are falling into this sensitivity area at the very end, and that's what's being over-sensed, you can increase the sensitivity. You do run the risk, though, of not detecting VF, so you have to be careful with that. And then you can use alternate sensing vectors, like I mentioned earlier, ring one to the CAN, which is the nominal one, and often has the worst P-wave over-sensing. Very rarely you can get T-wave over-sensing, I haven't seen this clinically, but if you did get that, often increasing the sensing threshold decay will be enough. You can also try alternate sensing vectors. And then if you're getting noise, obviously you want to identify the source of the noise and see if you can avoid it, but assuming you can't, the first thing is to adjust this over-sensing prevention, increase the fence so you don't see it. If that doesn't work, and it's falling in this area here where the FIB is, you can increase the sensitivity, but again, you have to be very careful that you're not doing it too much so that you're not going to see the VF. And then you can try alternate sensing vectors, again, ring two to CAN, and ring one to ring two have worse mild potentials. And then we had a patient that had all four of these did not work, and so we had to go to step five, which was just to increase the number of intervals to detect, and that actually has worked well for him. He hasn't had any VF where he's syncopized from and has not had any inappropriate shocks, so that can be kind of a last-ditch effort if the other stuff is not working. Okay, thank you. Thank you. I would say it's a super fellow presentation, wonderful. So I apologize for not having too much time. If there's any one question we can answer, other questions, I think presenters have replied by text. Probably not. Thank you all for coming. I hope you have an excellent meeting.

Heart Rhythm 2025

cardiac resynchronization therapy

left bundle branch pacing

leadless pacemakers

single chamber pacemaker

dual chamber pacemaker

extravascular ICDs

implantation challenges

pacing-induced cardiomyopathy

procedural planning

CRT technology

dual-chamber pacing

extravascular ICD

anatomy understanding

technique refinement

device complications