Redo Ablation After Failed Pulsed Field Ablation—Go for Hybrid, Stick With Pulses, or Switch to Thermal?

Discussion With Bradley Knight, MD, and Arian Sultan, MD

 © 2026 HMP Global. All Rights Reserved.

Any views and opinions expressed are those of the author(s) and/or participants and do not necessarily reflect the views, policy, or position of EP Lab Digest or HMP Global, their employees, and affiliates. 

Edited by Jodie Elrod

Bradley Knight, MD, talks with Arian Sultan, MD, about the roundtable session entitled "Redo Ablation After Failed Pulsed Field Ablation—Go for Hybrid, Stick With Pulses, or Switch to Thermal?" at Western AFib 2026.

Bradley Knight, MD: Hi, I’m Brad Knight, Editor-in-Chief of EP Lab Digest. We’re here at the annual Western Atrial Fibrillation (AFib) meeting in Salt Lake City. I'm joined by Professor Ari Sultan, who just finished a roundtable. The topic of discussion was what to do with redo ablation procedures. I’d be interested to hear your thoughts, but I’d also like to walk through a few specific scenarios. When you see a patient in the office, it’s important to plan ahead and make sure you have all the necessary equipment available. What was your take from the roundtable?

Arian Sultan, MD: Yes, it was an interesting discussion. The focus was on what happens when patients who previously underwent a PFA procedure return to the lab after a failed outcome. We discussed specific scenarios, particularly patients with recurrent paroxysmal AFib who present with fully isolated pulmonary veins (PVs), and explored how best to manage those cases. To be honest, the answer is that there isn't a clear answer. The vast majority of us would ensure that the PVs are isolated, try to exclude epicardial accesses to the PVs, and look for non-PV triggers to target. But there was discussion—obviously US-driven—that they would go for the posterior wall. Maybe we have a more European or German perspective on that. Since there was no incentive to go for the posterior wall, we're not going to do that necessarily in every patient. Instead, we would aim for a more antral isolation of the PVs, leaving the surrounding healthy tissue untouched. 

Bradley Knight, MD: Let's stick with that scenario, because it's a common one. Someone with paroxysmal AFib undergoes a pulmonary vein isolation (PVI) procedure with pulsed field ablation (PFA). Regardless of the system, you've done what you think is a good, durable antral isolation. The patient comes back to the lab, and it looks pretty similar to what you thought you did last time. You were the one who did the last procedure, so you try to make it antral. You can talk about triggers and scar, but what exactly do you do? Do you create an electrogram map of the whole atrium? What do you look for?

Arian Sultan, MD: For us, it's a little different than in the US, because in the first procedure we might not have used 3D mapping. We will for sure use 3D mapping in the second one, to make sure we have an idea of the extent of the lesions and of the previous PVI. If you see that it's a very distal isolation of the PVs, then we would instead aim for a more antral isolation of the PVs. But I can also tell you, we have cases where I would say everything looks quite nice. We try to find non-PV triggers and we can't find something. One discussion point in this session was whether to then forgo ganglionated plexi (GP) ablation, particularly since younger patients might especially benefit from that approach. There are some cases where we might do an ablation, but to be honest, we're uncertain about the best course of action for these patients. We focus on risk factors modification, but remain cautious about performing extensive ablation, as both the data and our experience suggest that doing more than necessary may cause harm.

Bradley Knight, MD: Yes. I couldn't join the whole roundtable, but I listened to Frank Cuoco talk about looking for GPs. How would you practically do that?

Arian Sultan, MD: That's not a common scenario in our center, but in those cases we typically use radiofrequency (RF) ablation to address it, followed by a conventional heart rate test.

Bradley Knight, MD: I know that every center doesn't have every mapping system or every tool available, but at your hospital, if you were to bring that patient to the lab, what would be your choice for ultra–high-density mapping to be sure that the veins are isolated?

Arian Sultan, MD: That's an excellent point. In redo cases, we use ultra–high-density mapping to ensure there are no gaps within or around the veins. We have seen with lower-density mapping catheters that the veins appear isolated. Once we use high-density mapping, we see gaps. 

Bradley Knight, MD: So you wouldn't use a Sphere-9 (Medtronic) or Farapulse (Boston Scientific) catheter for mapping in that case?

Arian Sultan, MD: Not yet—that was also a question in the discussion. We would typically use a conventional 3D mapping system (eg, Carto, Johnson & Johnson MedTech) with a high-density mapping catheter (eg, a pentaspline or Advisor HD Grid, Abbott) to confirm whether the veins are fully isolated. We also perform pacing maneuvers to ensure the veins are truly isolated at the ostium.

Bradley Knight, MD: In a first-time procedure, do you routinely assess for exit block? Do you perform pacing within the veins when using PFA?

Arian Sultan, MD: Yes, we try, but not in every patient.

Bradley Knight, MD: Do you take an empiric approach in patients who come back? Do you isolate the superior vena cava or other structures?

Arian Sultan, MD: After a prior PFA ablation, we often find a small residual isthmus on the roof or sometimes along the inferior aspect between the veins. In cases where we can't find anything, we may empirically close that gap, for example, by completing the roof line. If a wide WACA has already been created, then we would simply close any remaining gaps. However, based on our experience from the RF era, we’re cautious about doing too much empiric ablation. More extensive ablation can lead to adverse outcomes, such as atrial tachycardias in patients who did not previously have them.

Bradley Knight, MD: When posterior wall isolation was the goal, we used to create a roof line and a floor line. However, due to concerns about the durability of those lines, we stopped relying on that approach and instead began ablating the entire posterior wall. With your PFA tools, how do you approach posterior wall ablation?

Arian Sultan, MD: We no longer call it isolation—we refer to it as ablation, and we aim to ablate it fully. With current catheters, we create broader lines, which often cover much of the area between them. We still perform a roof line and an inferior line, extending the inferior line slightly toward the coronary sinus (CS) to ensure that region is adequately covered. In the end, we may be left with 2 or 3 flowers in the center of the posterior wall, so we proceed with complete ablation of the entire area.

Bradley Knight, MD: What about a different scenario—a patient with recurrent persistent AFib who presented in AFib at their initial procedure and you opted to do a more extensive ablation. They return to clinic still in persistent AFib. We can discuss what to do once you’re in the lab, but planning ahead is key. For us, that means deciding which mapping system to use, which PFA or RF system we want to have available, and having reps present. How do you plan ahead for that scenario of redo persistent?

Arian Sultan, MD: For redo cases of persistent AFib, we are fortunate to have access to a wide range of tools, allowing us to choose from a broader armamentarium. With the availability of newer PFA systems, including those with toggling capabilities, we tend to use those platforms in these patients.

Bradley Knight, MD: Toggling meaning dual energy?

Arian Sultan, MD: Yes, dual energy in terms of PFA and RF. For us, there is still a role for conventional RF in these patients. Much more important for me, however, is the choice of mapping system. I want to ensure I obtain a reliable, high-density map of the atria to truly understand what to target. Where is the substrate? Is there a functional disorder in the left atrium that I should address, rather than simply relying on a powerful ablation tool? Today, we’re fortunate to have both high-density mapping and effective ablation technologies. But for me, mapping is the key—it guides what therapy to deliver. I don’t rely solely on an anatomic approach; instead, I aim to target the true substrate. As we discussed earlier, posterior wall ablation or isolation may not be the right target for every patient. For example, in older women who often have substrate on the anterior wall, focusing on the posterior wall may offer little benefit, and they may return with persistent AFib.

Bradley Knight, MD: I suspect you have most of these PFA tools available to you. At this meeting, I've seen a lot of people talk about which tool they use and in which scenario. At our institution, we've moved toward a Farapulse single-shot procedure for first-time PVIs and if we're going to do the posterior wall. We tend to use the Sphere-9 catheter for redo procedures, if we think there's going to be a flutter line, if we think we're going to make linear lesions, or if we want dual energy. Let's give you a scenario of a patient with persistent AFib who has had an ablation and they present in atypical flutter. What do you anticipate is the catheter and system you'll use?

Arian Sultan, MD: I wouldn’t necessarily choose a larger-footprint catheter, such as a pentaspline or a balloon catheter, because I'm aiming or expecting to create a line due to the atypical flutter. For that, I prefer a catheter that is somewhat larger than a traditional single-tip catheter, but still well suited for line creation. For example, the Sphere-9 would be an option, as it allows me to create lines relatively quickly. Combined with high-density mapping, this gives me the familiar advantages of RF while leveraging a potentially more powerful tool. That said, I have also used pentaspline catheters for similar approaches. However, these tend to create broader lines. If you try to manipulate them into a more linear configuration, you may risk hemolysis due to incomplete spline contact. We also have experience with PFA balloon technology, which allows for the option of selectively choosing splines and can be used to create linear lesions. However, this catheter is not specifically designed for that purpose. While it is feasible—and we plan to publish on it—it is not our go-to tool for patients presenting with atypical flutter.

Bradley Knight, MD: Right. There are situations where these arrhythmias arise during the procedure and you already have a catheter in place that you can use. More often, though, we’re planning ahead based on what we anticipate needing in the lab. The term “hybrid” is in the title of the roundtable—does that refer to hybrid surgical approaches, such as convergent procedures?

Arian Sultan, MD: I think the discussion was more focused on toggling between RF and dual energy approaches. That said, hybrid strategies are also a very important topic right now. We recently completed a questionnaire assessing physicians’ and centers’ capabilities and perceptions of hybrid approaches, and the results were quite interesting. At the same time, PFA has also begun to shift the landscape. There are patients we might previously have referred to our surgical colleagues, but now we’re more inclined to manage them ourselves on the first attempt.

Bradley Knight, MD: Right. We believe we’re creating durable, transmural lesions similar to those achieved previously, but I’ve seen cases where patients go to the operating room and still have epicardial signals. So it remains to be seen how effective we truly are.

Arian Sultan, MD: Yes, but the implementation of PFA has enabled us, at least in those larger atria, to give it a shot with those systems. 

Bradley Knight, MD: I would tend to agree with that. Anything else that came up that we didn't talk about?

Arian Sultan, MD: One topic discussed was the use of AI to better understand persistent AFib and tailor treatment approaches. A key takeaway was that relying solely on an anatomical approach may not be the most effective way to treat patients with persistent AFib. Also, if you look at the data, the only positive studies were those that really had a tailored approach to tackle persistent AFib. So, everybody was quite positive that these tools might help us under foreseeable. 

Bradley Knight, MD: Right—I’m concerned we may end up with many patients who have undergone extensive anatomic ablation yet continue to have AFib, highlighting the need for more electrogram-guided approaches.

Arian Sultan, MD: Exactly.

Bradley Knight, MD: Well, thank you very much. It was interesting and I appreciate all your comments. Enjoy the meeting.

Arian Sultan, MD: Thanks for having me. 

The transcripts were edited for clarity and length.