Fluoroless Mapping and Ablation with Integration of a Pentaspline Pulsed Field Catheter

Introduction: Fluoroless mapping and ablation using Pentaspline pulsed field ablation catheter has many advantages. This can be achieved using “tripolar configuration” which enables high-quality electroanatomical maps, improved ability to localize EGMs, minimize use of additional mapping catheter when compared to the standard bipole configuration. We aimed to evaluate the benefits of using tripolar configuration in fluoroless atrial fibrillation ablation when compared to the standard bipolar configuration. Methods: The study was approved by the local Institutional Review Board. This study aims to compare a standard method of pinning the pentaspline catheter to an alternative “tripolar pinning” technique. In the tripolar pinning configuration, visualization of not only the 3rd electrode but also the “interpolation of electrode 1, 2, & 4 on each spline is done. Procedures were performed under general anesthesia, EnsiteX system (Abbott, Abbott Park, IL) was used for mapping. Intracardiac echo and electroanatomical map was used to identify catheter location and identify local EGMs. Tripole and standard bipole signals were displayed on the same page to evaluate the signals pre and post each PFA application. Results: Ablation was performed in 59 cases (42 males, average age 65 (30 – 85); 17 females, average age 74 (59 – 83)) in which we configured the catheter in tripole for comparison with the standard bipole setup. Geometry and post voltage maps were created using the tripolar signals in 40 of the 59 patients. Average case duration was 85 minutes (53 – 198; PVI alone 70 minutes (53 – 97)). The average number of PFA applications was 48 (31 – 72). Standard bipole EGMs demonstrated a large far field component when compared to tripole configuration. Ectopic atrial foci, atrial flutters were successfully mapped and ablated in four and five patients respectively. We were able to demonstrate line of block across mitral isthmus and cavotricuspid isthmus ablation. In cases where mapping was performed, geometry creation with the tripoles allowed for field scaling on Ensite X. Conclusion: Integration of the pentaspline pulsed field ablation catheter with the tripolar configuration is feasible and facilitates fluoroless PVI. Title: Fluoroless Mapping and Ablation with Integration of a Pentaspline Pulsed Field Catheter Authors: Ayesha Shaik, MD 1 ; Tri Nguyen, RT(R), CEPS 2 ; Gregory Michaud MD 3 ; Alan Hanley, MBBCh, BAO 1 1. Demoulas Center for Cardiac Arrhythmias, Massachusetts General Hospital, Boston, Massachusetts, USA 2. Abbott Medical, St Paul, Minnesota, USA 3. Harvard-Thorndike Electrophysiology Institute and Arrhythmia Service, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA Short title: Fluoroless PFA AF ablation using tripolar pentaspline configuration. Disclosures: Ayesha Shaik – none Tri Nguyen – Abbott mapper Gregory Michaud – Boston Scientific, Abbott, consultant fees and honoraria for speaking Alan Hanley - none Financial support: no financial support/grant was required Word count: 2927 Acknowledgments: Design, analysis, drafting of article, interpretation of data: Ayesha Shaik, Tri Nguyen, Alan Hanley Critical revision: Alan Hanley, Tri Nguyen, Gregory Michaud Final approval: Alan Hanley, Gregory Michaud Corresponding author: Dr. Alan Hanley Demoulas Center for Cardiac Arrhythmias, Massachusetts General Hospital, Boston, Massachusetts, USA

Fluoroless mapping and ablation using Pentaspline pulsed field ablation catheter has many advantages. This can be achieved using “tripolar configuration” which enables high-quality electroanatomical maps, improved ability to localize EGMs, minimize use of additional mapping catheter when compared to the standard bipole configuration. We aimed to evaluate the benefits of using tripolar configuration in fluoroless atrial fibrillation ablation when compared to the standard bipolar configuration.

The study was approved by the local Institutional Review Board. This study aims to compare a standard method of pinning the pentaspline catheter to an alternative “tripolar pinning” technique. In the tripolar pinning configuration, visualization of not only the 3rd electrode but also the “interpolation of electrode 1, 2, & 4 on each spline is done. Procedures were performed under general anesthesia, EnsiteX system (Abbott, Abbott Park, IL) was used for mapping. Intracardiac echo and electroanatomical map was used to identify catheter location and identify local EGMs. Tripole and standard bipole signals were displayed on the same page to evaluate the signals pre and post each PFA application.

Ablation was performed in 59 cases (42 males, average age 65 (30 – 85); 17 females, average age 74 (59 – 83)) in which we configured the catheter in tripole for comparison with the standard bipole setup. Geometry and post voltage maps were created using the tripolar signals in 40 of the 59 patients. Average case duration was 85 minutes (53 – 198; PVI alone 70 minutes (53 – 97)). The average number of PFA applications was 48 (31 – 72). Standard bipole EGMs demonstrated a large far field component when compared to tripole configuration. Ectopic atrial foci, atrial flutters were successfully mapped and ablated in four and five patients respectively. We were able to demonstrate line of block across mitral isthmus and cavotricuspid isthmus ablation. In cases where mapping was performed, geometry creation with the tripoles allowed for field scaling on Ensite X.

Integration of the pentaspline pulsed field ablation catheter with the tripolar configuration is feasible and facilitates fluoroless PVI.

PFA, atrial fibrillation ablation, fluoroless ablation, pentaspline PFA catheter, tripolar configuration.

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia and is associated with significant morbidity and increased healthcare costs 1 . Since the initial description of the procedure in 1998, ablation for AF (pulmonary vein isolation; PVI) has assumed a progressively greater role in the management of AF and is a cornerstone of therapy today 2 . PVI using radiofrequency energy and cryoablation were standard practice until the advent of pulsed field ablation (PFA). Thermal and cooling modalities introduce the risk of collateral damage to adjacent structures, including the esophagus and phrenic nerve. In contrast, PFA causes irreversible myocyte electroporation and spares adjacent structures, and has been shown in clinical trials to be effective for PVI 3,4 . Several manufacturers have developed PFA catheters of various design capable of delivering energy of different waveforms. The greatest experience in the US is with the Farapulse system (Boston Scientific, Marlborough, MA). Manipulation of the catheter in the left atrium is typically based on fluoroscopic, intra cardiac echo (ICE) and three-dimensional electro anatomical map (EAM) guidance. There are advantages to abandoning routine fluoroscopy as an imaging modality, including reduction in exposure to ionizing radiation and the ergonomic benefits of removing the need for protective lead. This approach appears to be safe and effective 5 . Good quality EAM assumes greater importance in this context. Electroanatomical guidance and catheter visualization is critical for optimal catheter placement, ensuring adequate tissue contact and minimizing the risk of hemolysis and inadequate lesion sets. However, PVI using PFA is costly; it would be advantageous to minimize the use of additional mapping catheters where possible 6 . It is also desirable to avoid multiple catheter exchanges. The current configuration for integrating the pentaspline PFA ablation catheter to the recording and most mapping systems in the electrophysiology lab allows visualization and sensing from the third electrode of each spline only (“standard bipole”) 7 . Zamponi et al described an alternative method of pinning the pentaspline catheter to allow visualization of not only the 3 rd electrode but also the “interpolation of electrode 1, 2, & 4 on each spline” 8 . This configuration (“tripole”) allows for recording of local signals on each spline instead of across the splines.

We aimed to evaluate the utility of the tripolar configuration during fluoroless PVI procedures with respect to creation of high-quality EAM maps, improved ability to localize EGMs and minimize farfield sensing. EGMs and maps were obtained simultaneously using both the standard bipole and tripole configurations.

AF ablation was performed at a high-volume center. The study was approved by the local Institutional Review Board. All procedures were done under general anesthesia with uninterrupted anticoagulation prior to ablation. Bilateral groin access was obtained; a single right femoral venous access for transseptal access and ablation, and left femoral venous access for ICE, a decapolar coronary sinus catheter and a quadripolar right ventricular catheter was used. Heparin was administered and redosed throughout the case to maintain an ACT > 300s. Pacing and recording catheters were advanced to the heart using the EnsiteX system (Abbott, Abbott Park, IL) in impedance mode. EGMs were recorded using Cardiolab (GE Healthcare, Chicago, IL) with a 30Hz high pass filter, 500Hz low pass filter and notch filter on, at a gain of 2500. Transeptal access was obtained under ICE guidance alone using the VersaCross Connect system with the Faradrive sheath (Boston Scientific, Marlborough, MA). The dilator was removed and the Farawave pentaspline catheter was advanced over a wire through the sheath. The catheter was placed at the ostium of the superior and inferior veins using a combination of ICE and EAM guidance. As the catheter was manipulated in the chamber and between ablation applications, geometry was collected. Additional pulmonary vein anatomy was obtained from the wire as it cannulated each vein. ICE was used to evaluate catheter contact, while the EAM was used to mark the location of delivered lesions. Each vein had the recommended PFA applications in both “flower” and “basket” configuration. Tripole and standard bipole signals were displayed on the same page to evaluate the signals pre and post each PFA application. The tripole signals were labeled FW 1 to 5, which represented equatorial electrode 3 on each spline pinned to the combined electrodes 1,2 and 4 on the same spline. Following the completion of the lesion set, if the patient was in atrial fibrillation, a cardioversion was performed. A post ablation map was obtained using the Farapulse catheter and additional mapping and ablation was performed as needed.

Ablation was performed in 59 cases (42 males, average age 65 (30 – 85); 17 females, average age 74 (59 – 83)) in which we configured the catheter in tripole for comparison with the standard bipole setup. 30 patients underwent PVI alone. Twenty-five patients underwent additional left atrial ablation including posterior wall isolation and ablation of ectopic foci. Six patients underwent mitral isthmus ablation. Geometry and post voltage maps were created using the tripolar signals in 40 of the 59 patients. Average case duration was 85 minutes (53 – 198; PVI alone 70 minutes (53 – 97)). The average number of PFA applications was 48 (31 – 72). No fluoroscopy was used. Standard bipole EGMs demonstrated a large far field component; tripole EGMs displayed smaller or absent far field components across a range of baseline rhythms (Fig 1). The effect of ablation on local signals was more clearly discernable on tripole EGMs (Fig 1). Ectopic atrial foci were successfully mapped and ablated in four patients (Fig 2). Five patients developed atypical atrial flutters intraprocedurally, which were mapped and ablated using the Farapulse catheter (Fig 3). Lines of block were demonstrated at the site of mitral isthmus and cavotricuspid isthmus ablation (Fig 3). In cases where mapping was performed, geometry creation with the tripoles allowed for field scaling on Ensite X (Fig 4). Post voltage mapping using the tripole configuration showed clear demarcation of the level of isolation, comparable to that attainable with a dedicated multielectrode mapping catheter (Fig 4). PVI was achieved in all cases. There were no procedural complications.

The use of electro anatomical mapping has been a critical component of PVI, utilized for creating geometry, catheter visualization, delivering lesions and assessing levels of block. In the era of PFA, the role of EAM in PVI has major challenges, as it requires the use of dedicated mapping catheters and additional catheter exchanges and adds to the procedural cost. Should we forego the use of EAM? Gunawardene et al. studied use of high-density mapping with PFA; early vein reconnection was seen in 5 out of 20 patients, connection gaps were noted along the anterior superior aspect of the PV ostium and these were reablated 9 . In another nonrandomized study comparing PFA with mapping (127 patients) and without mapping (70 patients), the procedure, LA dwell time and fluoroscopic time were significantly lower in the non-mapping group. However, in 9 out of 127 patients at least 1 PV was connected and required reisolation. There was one stroke and coronary artery air embolism in the mapping group. Arrhythmia-free survival was higher in the mapping group although this was not statistically significant 10 . Hence, it was concluded that benefit from mapping should be balanced against the safety of having shorter LA dwell time and fewer catheter exchanges. By expanding the use of Zamponi et al’s configuration and incorporating it into our fluoroless workflow, we can achieve the benefit of mapping, eliminate catheter exchange and attendant risk of air embolism/stroke and simultaneously reduce LA dwell time. Use of the tripolar configuration has not only helped with catheter visualization but also allowed for effective creation of high-quality 3D shell and voltage maps with cost benefits over using a separate mapping catheter. The tripolar pinning strategy can reduce ambiguity by showing high quality local signals and markedly reducing the far field component. This can help localize low amplitude fractionated signals in the LA and obtain high fidelity timing data. As a result, we have found the method useful for mapping and ablation of focal and re-entrant arrhythmias in addition to pulmonary vein and posterior wall isolation. We were also able to identify lines of block following linear lesions sets at the mitral isthmus and cavotricuspid regions. Pacing from one of the tripolar configured electrodes allows recording of data from the other four electrodes. In contrast, information from the adjacent electrode is lost when pacing in the standard configuration, due to the presence of a saturating large amplitude pacing spike (figure 1D). An additional advantage of the technique relates to field scaling. Impedance based EAMs have an issue with non-linearity that can be corrected by using a scaling algorithm that incorporates electrode spacing of the mapping catheter 11 . The scaling algorithm will only incorporate electrode spacing of less than 11mm into the scaling. The standard bipole pentaspline configuration has the electrode spaced roughly 17mm apart, a hindrance that can be overcome with the tripolar configuration (Fig 4c, 4d). New technologies allowing visualization and magnetic tracking of the ablation catheter will undoubtedly be forthcoming. These will likely require additional investment in hardware and mapping systems. In a resource constrained environment, it would be advantageous to improve the use of existing systems and catheters, particularly those with which a significant degree of familiarity has developed, such as with the integration of tripolar mapping as we have described.

Integration of the pentaspline pulsed field ablation catheter with the tripolar configuration is feasible and facilitates fluoroless PVI.

With tripolar pinning, the catheter will be visualized as pentaspline and not in basket or flower configuration. Jumping pins allow the combination of visualizing the flower & basket form as well as the 5 bipolar sticks. This is a small single center experience with new pinning configuration.

1. Joglar JA, Chung MK, Armbruster AL, et al.: 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation 2024; 149:e1–e156. 2. Chung MK, Refaat M, Shen W-K, et al.: Atrial Fibrillation: JACC Council Perspectives. J Am Coll Cardiol 2020; 75:1689–1713. 3. Verma A, Haines DE, Boersma LV, et al.: Pulsed Field Ablation for the Treatment of Atrial Fibrillation: PULSED AF Pivotal Trial. Circulation 2023; 147:1422–1432. 4. Reddy VY, Gerstenfeld EP, Natale A, et al.: Pulsed Field or Conventional Thermal Ablation for Paroxysmal Atrial Fibrillation. N Engl J Med 2023; 389:1660–1671. 5. Lurie A, Amit G, Divakaramenon S, Acosta JG, Healey JS, Wong JA: Outcomes and Safety of Fluoroless Catheter Ablation for Atrial Fibrillation. CJC Open 2021; 3:303–310. 6. Calvert P, Mills MT, Xydis P, et al.: Cost, efficiency, and outcomes of pulsed field ablation vs thermal ablation for atrial fibrillation: A real-world study. Heart Rhythm Elsevier, 2024; 21:1537–1544. 7. FARAPULSE TM Pulsed Field Ablation (PFA) System [Internet]. www.bostonscientific.com. [cited 2025 Feb 10],. Available from: https://www.bostonscientific.com/en-US/products/catheters–ablation/farapulse.html8. Falasca Zamponi A, Olson J, Scheel S, Englund A, Scorza R, Tabrizi F: Procedural efficiency is enhanced combining the pentaspline pulsed field ablation catheter with three-dimensional electroanatomical mapping system for pulmonary vein isolation. J Interv Card Electrophysiol [Internet] 2024 [cited 2024 Nov 19]; . Available from: https://doi.org/10.1007/s10840-024-01846-39. Gunawardene MA, Schaeffer BN, Jularic M, et al.: Pulsed-field ablation combined with ultrahigh-density mapping in patients undergoing catheter ablation for atrial fibrillation: Practical and electrophysiological considerations. J Cardiovasc Electrophysiol 2022; 33:345–356. 10. Badertscher P, Serban T, Isenegger C, et al.: Role of 3D electro-anatomical mapping on procedural characteristics and outcomes in pulsed-field ablation for atrial fibrillation. Eur Eur Pacing Arrhythm Card Electrophysiol J Work Groups Card Pacing Arrhythm Card Cell Electrophysiol Eur Soc Cardiol 2024; 26:euae075. 11. Brooks AG, Wilson L, Kuklik P, et al.: Image integration using NavX fusion: Initial experience and validation. Heart Rhythm Elsevier, 2008; 5:526–535. Figure 1. Tripole signals compared to standard bipoles Depicted are the electrograms recorded from tripoles and standard bipoles across a range of circumstances. Panel A and B show tripolar (green arrow) and standard (red arrow) EGMs pre-and post-ablation in an atrial paced rhythm and normal sinus rhythm respectively. Panel C shows EMGs recorded in atrial fibrillation. Discrete EGMs can be seen on the tripolar recording with easily discernable timing (green box) whereas adjacent electrodes appear to have the same timing on the standard recording (red box). Farfield components with the standard setup (red arrows) are absent on the tripoles. Panel D shows pacing from FW5 with local capture and exit block. Information is lost with the standard configuration due to large pacing artifact on the adjacent channel (red arrow) which is absent with the tripolar arrangement (green arrow). Figure 2. Recording and mapping focal activity Depicted are recordings and mapping of focal activity. Panel A shows automatic firing from the right superior pulmonary vein (RSPV). The site of earliest activity is FW2 (green arrow). EGMs from adjacent channels with the standard set up are on time with each other (red arrow). Similar findings were observed in the left superior pulmonary vein with spontaneous firing after isolation (panel B, 200mm/s sweep). Panel C shows mapping of an ectopic atrial focus identified post PVI on the anterior left atrial wall. The site of earliest activation is show (green arrow). 3D electroanatomical mapping of a left atrial focal tachycardia with successful ablation is shown in panel D. Figure 3. Atrial flutter mapping and demonstration of lines of block Depicted are mapping of a mitral isthmus dependent flutter (panel A), which terminates with ablation. Following ablation, widely split EGMs are seen (panel B, green arrows) with the catheter placed on the ablation line. Panel C shows EGMs recorded from the catheter at the cavotriscupid isthmus, at the site of a prior radiofrequency ablation for typical flutter. The timing from the septal side of the line (FW2) to the lateral side (FW1) indicates that persistent block is present. 3D electroanatomical mapping of a mitral isthmus dependent flutter is shown in panel D, along with pulmonary vein and posterior wall isolation. Figure 4. Electroanatomical maps displaying field scaling and level of isolation Depicted are electroanatomical maps and the tripolar vs standard pinning. The ability to field scale with data from the tripolar configuration is shown in panel A. Post ablation voltage mapping comparing standard configuration (red arrows) to the tripole setup (green arrows) is shown in panel B, with improved visualization of the level of isolation with the tripolar configuration. Panel C shows how the electrodes are configured. Panel D illustrates which electrodes data is recorded from Fara 1,2 with the standard setup, the interelectrode distance, and electrodes from which data is recorded with the tripole setup (three integrated electrodes; yellow circles, to the third electrode; black circle). Information & Authors Information Version history Peer review timeline Published Journal of Cardiovascular Electrophysiology Version of Record9 Sep 2025Published Copyright This work is licensed under a Non Exclusive No Reuse License. Collection

Authors Metrics & Citations Metrics Article Usage 456views 213downloads Citations Download citation Ayesha Shaik, Tri Nguyen, Gregory F. Michaud, et al. Fluoroless Mapping and Ablation with Integration of a Pentaspline Pulsed Field Catheter. Authorea. 17 April 2025. DOI: https://doi.org/10.22541/au.174490068.83544159/v1 DOI: https://doi.org/10.22541/au.174490068.83544159/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu.