Scott Webb (Host): Welcome to Wise and Well, presented by Community Memorial Healthcare. I'm Scott Webb. There are a few forms of ablation that are used for heart rhythm disorders like AFib, but pulsed field ablation is fast becoming the gold standard. And my guest today, electrophysiologist, Dr. Jonathan Dukes, is here to tell us how it works and how patients are benefiting from this revolutionary technology.

Doctor, it's nice to have you back on the podcast. Today, we're going to talk more electrophysiology, of course. And let's just do that. Like, what exactly is that when I say electrophysiology? And why is it so crucial for addressing heart rhythm disorders?

Dr. Jonathan Dukes: Electrophysiology is, at least for me, a very interesting specialty. It's a subspecialty of cardiology, meaning that it's a subset of cardiac care within the cardiology field. And what we do is we deal just with heart rhythms: too fast, too slow, regular, irregular. We're the ones that are trying to make your heart beat more regularly at a normal rate. So, patients are sent to us that have heart rates that are going too fast, patients that are feeling palpitations, feeling lightheaded and dizziness, passing out. These are all symptoms that would prompt a visit to an electrophysiologist.

We also can deal with devices such as pacemakers and defibrillators. These are devices that are designed to help the heart not go so slow, or in cases of patients that have heart failure. These devices can both lengthen your life, prevent sudden cardiac death, and patients that pass out because of very fast heart rhythms, it can reset your heart to bring you back alive

Host: Yeah. And I've had other heart experts on, heart doctors on, and they've simplified it for people like me and listeners that, you know, some heart docs are plumbers, some are electricians, and you're more the electrician type. And I want to have you give listeners just a sense anyway of the patient's journey, like when they're referred for electrophysiological evaluation and treatment at Community Memorial Healthcare. Take us through that process, the journey, if you will.

Dr. Jonathan Dukes: Yeah. So generally, these symptoms and these conditions are discovered either by primary care doctors, or sometimes from emergency room doctors and hospitalists when you're admitted to the hospital. And what happens is patients come in with complaints of passing out or fatigue or rapid heart rates or palpitations, something feeling off. And often, there's an EKG that's done, either by the primary care doctor or the doctor you're first encountering that notices that the rhythm isn't quite right.

Sometimes these EKGs are still normal and involves more longer testing, such as wearing a heart monitor for anywhere from 24 hours to a month. And when the abnormal rhythms are discovered in these monitors, it prompts a referral, either first to cardiology or directly to electrophysiology. More often than not, you first see a general cardiologist that then digs a little bit deeper into the symptoms, does a little bit more testing, such as those long-term monitors like I suggested, that then results in a referral to an electrophysiologist.

Host: Right. Yeah. And then, from there, Dr. Dukes would take over, if you will. And one of the things you might do with some patients, Doctor, is pulsed field ablation. I like just saying that. It sounds cool, pulsed field ablation. And I've been hearing more about that. So, what is it, and how does it differ from traditional ablation techniques?

Dr. Jonathan Dukes: So, one of the ways that we treat the heart rhythms that are too fast, especially the ones that are irregular, is we do something called ablation. Historically, for years, we were doing something called radiofrequency ablation or sometimes cryoablation. The way to think about ablation is radiofrequency ablation is hot ablation. It's a long catheter, usually with a small metal tip about three millimeters wide that's at the tip, and that tip can emit very high frequency radio waves that's at a high power. And what essentially it does is it cooks the tissue that's nearby. Problem is t heats up the tissue to nearly 50 degrees centigrade. That heat can spread out from the heart tissue into the lungs, nerves, and surrounding nerves and vessels and other tissues and cause damage to those tissues as well. So, we had to work really hard not to damage those other tissues.

In the terms of cryoablation, there was a catheter or a balloon that got really cold full of nitroglycerin that would freeze the heart muscle. But again, that thermal energy, that really cold temperature of -20 degrees centigrade would then spread out from the tissue and damage the surrounding tissue.

We went an entirely different direction with pulsed field ablation. Pulsed field ablation is a catheter that emits about 2,000 volts of energy right from the tip of that catheter and from its electrodes into the muscle tissue. That energy is non-thermal. And so, it's very localized. That 2,000 volts of energy only affects the tissue about five millimeters deep within the muscle.

And beyond that, the energy is dissipated enough that the nerves surrounding the heart, all of the blood vessels, the lung tissue, the lining of the heart, the lining of the lungs, those are left entirely untouched and undamaged. So, you don't get collateral damage outside of that, that five-millimeter zone of heart muscle that you're ablating. And so, we're much more localized and have much less complications. Studies have shown that there's less damage to the phrenic nerve, so the nerve that goes to your diaphragm, which allows you to breathe. So, the chance of that getting damaged is nonexistent. There's less chance of causing ulcers in the esophagus that runs behind the heart, which was a big and very, very serious complication that we could have with a radiofrequency or cryoablation. Complications like these don't happen with this new type of ablation.

Host: Amazing. Are there some patients that maybe are a better candidate for this type of procedure?

Dr. Jonathan Dukes: Yeah. This type of procedure, we've been doing for about two years now. And it's pretty much taken over the ablation for a disease called atrial fibrillation, which is a disease that we ablate mostly in the left atria by ablating around the pulmonary veins to make them electrically silent.

Smart French physicians in the 1990s discovered that a lot of atrial fibrillation starts within these veins that bring blood back from the lungs into the left atria. And there's signals of electricity sparking from these veins that are abnormal, that shouldn't be coming from these veins, and these are what's triggering and starting the atrial fibrillation.

And if we could electrically silence the veins, we can make the AFib stop. Pulsed field ablation works really well for this because these veins are near important structures that we don't want to damage, and it isolates them both safely and quickly. By doing a pulsed field ablation, we can get the ablation done in half the time, usually well less than an hour, which used to take an hour and a half to two hours to do a procedure. Now, we can do it in about 45 minutes with more safety, which has been a very, very amazing and incredible change in our field.

Patients that have other arrhythmias such as SVTs, supraventricular tachycardias, atrial flutters, those are still best served for the moment by standard RF ablation. So, we still do those ablations with our radiofrequency ablation generally. But the field has changed and new catheters are coming out and new catheter types that can better approach other arrhythmias. We're going to start doing ablations of a condition called ventricular tachycardia, which is in the lower chambers with pulsed field ablation. We did our first case as part of a trial last December. But now, the catheter just got FDA approval, so we'll start be using this catheter more regularly in the lab and being able to use it on these other more higher-risk ablations that we call ventricular tachycardia ablations.

Host: Yeah. And you mentioned the trials there, and I wanted to have you sort of toot your own horn a little bit just to what you folks have been doing there, how it's benefiting patients, other medical providers, doctors and such. Just tell us what you guys have been up to.

Dr. Jonathan Dukes: So, the EP space, the electrophysiology space is pretty amazing because the field is changing very quickly and very rapidly. The radiofrequency and cryoablation catheters we were using were relatively unchanged besides some changes, some basic features for really 25 years.

And then, about two and a half years ago, we ended up starting to use these pulsed field ablation catheters. And it's caused a wealth of both new ways of using these catheters, approaching the diseases, but also it's required us to do testing, one, to make sure that they are as safe as advertised; and two, to understand how we can best use them.

And so, this has resulted in a number of trials that are both sponsored by different institutions as well as by different companies to really get a handle on how's the best way we can use these catheters, and really, what is their true safety profile and how effective are they?

Community Memorial Hospital has been very active in this space, and I've had the opportunity to act as the principal investigator for a number of different trials in the EP space that we've been participating in. Most recently, we just published our most recent research in the New England Journal of Medicine in a trial called the AVANT GUARD Trial.

This trial was done in association with Boston Scientific, which is the study sponsor, and it was looking at the FARAWAVE catheter in its use in persistent AF patients. Persistent AF patients are patients that have the most severe form of atrial fibrillation. This atrial fibrillation is constant, doesn't stop, doesn't come and go.

And this trial was looking to see if we could use pulsed field ablation catheters as a first-line therapy, meaning that we could go straight towards ablation and not have to try medicines first or other therapy options. And what it found is that there was a much higher rate of conversion in normal sinus rhythm and staying in normal sinus rhythm if you use the FARAWAVE catheter compared to medicines in a traditional cardioversion, which is a very exciting finding. We also found that we were able to treat these patients in well less than an hour with a simple procedure, and most patients went home the same day. The safety profile was good. There were some small findings of complications, but the complications were very rare and were about similar to what was seen with cardioversions and medicines.

Host: Right. Yeah. And just trying to, you know, relate this for patients, you know, like having all of this tech, right, in the hands of experts right there at Community Memorial Hospital is so amazing. And maybe you can just discuss that a little bit. Like, how does this all translate to them? How does this benefit the patients?

Dr. Jonathan Dukes: Well, it is really exciting, because it means that we're often the first hospital in the area to get some of these advanced technologies. So, the pulsed field ablation, we started doing the AVANT GUARD trial before it was FDA-approved, meaning that the only way you could get pulsed field ablation really in, in Southern California was only at a couple centers, and ours was included in that. Two centers were doing pulsed field ablation in Southern California when we started it. It also means that we have the most experience with pulsed field ablation, since we were one of the first centers to start using it.

We also have early access to catheters from a wide variety of the companies that are offering pulsed field ablation at this time, as well as traditional RF ablation. New advances usually come first to our center because of the studies that we're doing. We're still involved in other studies with radiofrequency ablation. We're involved in studies looking at ablation of ventricular tachycardia. We're also involved in studies looking at new types of ways of managing the strokes in atrial fibrillation, such as the conformal trial, which is a new type of left atrial appendage closure device, as well as the newest form of the Watchman device, which is the most common device used to close the left atrial appendage. And these are to reduce stroke risk in atrial fibrillation.

So to get the most advanced care, often people think they need to go down into Los Angeles to a large university hospital. This actually can be done locally here in Ventura County at Community Memorial Hospital, and you can get the most advanced care and the newest care using the newest technology right here at home.

Host: Right. Just down the street. Talk about pulsed field ablation, and do you see it, like, really sort of shaping the future of electrophysiology? Like, is this going to be the gold standard, and it's just already in your hands?

Dr. Jonathan Dukes: It really does seem that way. I mean, whenever a new technology comes out, you always have to be a little skeptical to make sure that there isn't untoward problems or just not going to work quite as well as advertised. In the last two years, especially in the atrial fibrillation space, it really seems like it's been working as advertised. The safety profile has been very robust, meaning that we're not seeing a lot of complications with this catheter, not like we saw with the old catheter. We can ablate without having to be scared that something bad is going to happen one to two weeks down the line, that there's going to be an ulcer that develops and suddenly there's going to be bleeding or that patient's going to have problems breathing because they got some nerve damage. We also are able to treat more patients because the cases aren't taking as long.

The other thing to think about is that now as we're starting to move in new spaces such as ventricular tachycardia, more research is needed because, yes, we have this brand-new catheter that can treat our VT patients or ventricular tachycardia patients better, we think. We really need to prove it; hence, the reasons that we're still doing more studies. But the data profile was so positive, it appears to be so beneficial in the AFib space that we feel that it will likely be the same in the VT space. And so, we're very happy to offer these trials to our patients because our feeling is that based on what we saw in atrial fibrillation, it's going to be just as good or better in ventricular tachycardia.

Part of the reason why I think better is because we can ablate deeper. The lower chamber of the heart muscle is thicker. So, the problem with the radiofrequency ablation is we couldn't get as deep as we needed. We were only getting about a couple millimeters. Here, with the newer VT-focused ablation catheters, we can get a centimeter deep, unheard of in the RF era. And so, we can really get these deep areas of disease and target them and get rid of them

Host: it's amazing and it's always educational and inspiring to have you on. I always feel good about the future of things related to what you do, of course, and other things at Community Memorial. I'll just give you a chance here at the end, maybe if you could just pick one, I'm sure there are thousands, but a memorable case or story that really illustrates the impact of electrophysiology on a patient's life.

Dr. Jonathan Dukes: I feel honored to be part of this specialty, because many parts of medicine, what we're doing is managing disease and we're not getting rid of disease. And I think the thing that's really amazing about electrophysiology and attracted it to me in the first place is that we have this opportunity to actually get rid of disease, that we can stop and cure as opposed to just manage.

And I can think of a patient that we were dealing with back in December. There was an amazing patient that had come in that had had ventricular tachycardia, that was this lower chamber arrhythmia that was affecting their life. They had a defibrillator, which is a special type of pacemaker that is designed to bring someone to life if they were to collapse at home, and they were getting shocks over and over and over again from their defibrillator.

So, we brought them in, and we were using this new PFA technology under a trial to be able to ablate their ventricular scar, where this VT, this ventricular tachycardia arrhythmia was coming from. And they'd been ablated other areas and the traditional ablation had not been successful. And we were able to go in and use this new type of ablation catheter, the one that we're going to start using commercially, which means with FDA approval and we were able to use it in their case. And we were able to find the source of the arrhythmia, which was in a very difficult, very deep place, and we were able to ablate it with this new catheter.

And then, as we've watched him, as the months have been going forward, the ventricular tachycardia has gone away. We no longer see any more of these arrhythmias. The shocks aren't occurring. And we're thrilled that we were able to do this. We've been able to help other patients with this catheter as part of the trial as well. But this gentleman, I think of very clearly because his quality of life had been so affected by getting repeated shocks from his defibrillator that were causing significant pain and discomfort, and we were able to make them go all away using this new technology, PFA, when the old radiofrequency ablation technology had failed.

Host: Right. Yeah. I'm sure you could go through a long list of patients that have benefited patients' families. We'll leave it at that today. As I said, great stuff, educational, just really inspiring. Thank you so much.

Dr. Jonathan Dukes: No, my pleasure. Thanks, Scott.

Host: And to learn more, visit mycmh.org/heart And if you found this podcast helpful, please share it on your social channels and check out the entire podcast library for additional topics of interest. I'm Scott Webb. Thanks for listening. This is Wise and Well, presented by Community Memorial Healthcare.