BACKGROUND: Radiofrequency (RF) ablation of premature ventricular complexes (PVCs) originating from the left ventricular summit may be unsuccessful, highlighting the need for alternative approaches. We aimed to assess th...BACKGROUND: Radiofrequency (RF) ablation of premature ventricular complexes (PVCs) originating from the left ventricular summit may be unsuccessful, highlighting the need for alternative approaches. We aimed to assess the efficacy and safety of a novel dual-modality focal catheter in treating left ventricular summit PVCs in patients who had failed previous RF ablation. METHODS: Patients were prospectively enrolled and underwent a redo ablation procedure using an irrigated, contact-force sensing, dual-modality focal catheter (TactiFlex Duo, Abbott) under compassionate use indication. The ablation strategy, including the choice of energy modality (monopolar pulsed field [PF], RF, or both), was left to the operator's discretion. Safety assessments included serial biomarkers, renal function, and CMR within 36 hours. Efficacy was defined as ≥80% reduction in PVC burden with symptom resolution at 3-month follow-up. RESULTS: Six consecutive patients (4 men; mean age, 53.8±15 years) with symptomatic left ventricular summit PVCs and a prior failed RF ablation (range, 1-2) were prospectively enrolled. All PVCs had an inferior axis, with a left bundle V1 morphology observed in 4 of 6 cases (mean burden, 30.1±5.3%). Acute suppression of PVCs was achieved in all cases. Acute suppression with a single PF application in the great cardiac vein-anterior interventricular vein occurred in 2 patients, while 3 patients required additional RF, PF, or combined RF+PF applications at adjacent sites. One patient with an inaccessible great cardiac vein-anterior interventricular vein was successfully treated in the left ventricular outflow tract with RF+PF application. Transient, reversible left anterior descending vasospasm was observed during PF delivery in 2 of 5 cases that underwent PF application adjacent to a coronary artery, despite pretreatment with intracoronary nitroglycerin without ECG or hemodynamic sequelae. All patients had durable suppression of PVCs at follow-up. CONCLUSIONS: In its first human application, dual-modality ablation was feasible and effective for refractory left ventricular summit PVCs. Transient coronary vasospasm occurred, though it was reversible and without acute clinical consequences.
BACKGROUND: Combining radiofrequency (RF) and pulsed-field (PF) applications in various combinations, or repeating PF applications, has been reported to augment lesion size and depth. We compared lesion dimensions using...BACKGROUND: Combining radiofrequency (RF) and pulsed-field (PF) applications in various combinations, or repeating PF applications, has been reported to augment lesion size and depth. We compared lesion dimensions using single, double, and combined applications of PF and RF for the large-footprint lattice-tip catheter. METHODS: Sixteen swine underwent endocardial ablation using the lattice-tip catheter. Four-second PF and 5-second, saline-irrigated, temperature-controlled RF energy were delivered in the ventricles using 1 of 5 different settings: single applications of PF (PF-only), single RF (RF-only), and 3 sequential settings: PF-PF (2 consecutive PF applications at the same location), PF-RF (PF followed by RF), and RF-PF (RF followed by PF). RESULTS: A total of 102 lesions (69 left and 33 right ventricles) were analyzed. Mean lesion depths were 6.8±0.3 mm (PF-PF), 6.6±0.3 mm (RF-PF), 5.7±0.2 mm (PF-only), 5.0±0.3 mm (PF-RF), and 5.1±0.2 mm (RF-only). Mean lesion depths did not differ significantly between PF-PF and either PF-only or RF-PF (=0.114 and =0.986, respectively). However, the variability in depth was significantly smaller in the PF-PF group compared with both PF-only and RF-PF (=0.017 and =0.013, respectively). Only the PF-PF setting produced significantly deeper lesions compared with the RF-only and PF-RF settings (=0.015 and =0.012, respectively). RF lesions exhibited a prominent dark hemorrhagic core and a thin pale rim; PF lesions appeared uniformly pale; and combination lesions demonstrated a central dark zone surrounded by a pale rim of variable thickness. CONCLUSIONS: Repeating PF twice created the optimal combination of greatest depth and least variation compared with all other strategies. RF-PF resulted in similar depth, but required toggling between settings and risked thermal adverse events.
BACKGROUND: Pulsed field ablation (PFA) can generate low-intensity catheter-tissue interface heating. Recently, a large-focal PFA catheter able to measure the tip-tissue interface temperature has become available. Accord...BACKGROUND: Pulsed field ablation (PFA) can generate low-intensity catheter-tissue interface heating. Recently, a large-focal PFA catheter able to measure the tip-tissue interface temperature has become available. Accordingly, we aimed to characterize the electrode tip-tissue interface temperature dynamics during PFA. METHODS: A retrospective single-center study evaluated PFA lesions in 41 consecutive patients undergoing atrial fibrillation ablation using the lattice-tip catheter. Lesions were grouped by anatomic location with interface temperatures measured via catheter tip thermocouples. The association of predictors with lesion temperatures was evaluated with a mixed-effects model. An analysis of lesion dimensions and interface temperatures was also performed in swine. RESULTS: Among 41 patients, 2779 pulse field lesions were analyzed. Mean peak temperature was 41.7±2.2 °C (range, 37.2 °C-52.8 °C) and average temperature was 39.5±1.4 °C (range, 36.4 °C-46.9 °C). Temperatures exceeded 50 °C in 10 of 2779 (0.4%) lesions, most often in the anterosuperior left superior pulmonary vein (5/10). Univariate analysis showed peak temperature was positively associated with previous lesion temperature (=0.65 [95% CI, 0.63-0.67]; <0.001) and had weak associations with time between lesions (=-0.15 [-0.19 to -0.11]; <0.001) and percentage impedance drop (=0.20 [95% CI, 0.16-0.23]; <0.001). Even after multivariable analysis, the peak temperature remained significantly lowest at the right carina (39.7 °C), anterosuperior right superior pulmonary vein (40.9 °C), and right superior pulmonary vein roof (40.5 °C) locations. Swine demonstrated a moderately strong association between lesion depth with peak temperature (=0.53 [95% CI, 0.20-0.75]; =0.003) and average temperature (=0.49 [95% CI, 0.16-0.73]; =0.007). CONCLUSIONS: Lattice-tip temperatures during PFA vary substantially, with right superior pulmonary vein sites often demonstrating a blunted temperature response compared with other sites. Peak and average temperatures correlated with lesion depth.
BACKGROUND: The subcutaneous implantable cardioverter defibrillator (S-ICD) offers protection from sudden cardiac death without transvenous leads. Although contemporary techniques and programming have reduced inappropria...BACKGROUND: The subcutaneous implantable cardioverter defibrillator (S-ICD) offers protection from sudden cardiac death without transvenous leads. Although contemporary techniques and programming have reduced inappropriate shocks, high rates persist in certain populations. The objective of this study was to evaluate the impact of a novel quantitative vector screening (QVS) protocol on the incidence of sensing-related complications and inappropriate shocks in patients undergoing S-ICD implantation. METHODS: We analyzed 223 consecutive patients who underwent S-ICD implantation at the Hospital of the University of Pennsylvania from December 2018 to July 2025. Traditional vector screening was used before 2023. In 2023, we implemented QVS, which incorporated quantitative sensing scores for each candidate and raised the threshold for S-ICD implantation. The primary end point was time to first inappropriate shock or under-sensed ventricular arrhythmia. Secondary outcomes included SMART Pass deactivation and need for device revision. Outcomes were reported as survival analyses. RESULTS: During preimplant screening, the QVS protocol reduced patient eligibility from 96% to 83%. The median follow-up after implant was 42 months (interquartile range, 48) in the traditional vector screening arm and 18 months (interquartile range, 15) in the QVS arm. The primary end point of time to first inappropriate shock or under-sensed ventricular arrhythmia was longer in the QVS arm (log-rank, =0.02). There were 23 primary end point events among 145 patients in the traditional vector screening arm (5.2 per 100 patient-years [95% CI, 3.1-7.4]) and 2 primary end point events among 78 patients in the QVS arm (1.8 per 100 patient-years [95% CI, 0.01-4.38]). CONCLUSIONS: Implementation of a novel S-ICD screening protocol with stricter eligibility thresholds reduced sensing-related complications, particularly inappropriate shocks.
Edgar R, Scholte NTB, Ebrahimkheil K
… +13 more, Jansen CE, Beukema RJ, Brouwer MA, Yap SC, Mafi-Rad M, Knops RE, Ronner E, Cetinyurek-Yavuz A, Vernooy K, Boersma E, Stas PC, van Royen N, Bonnes JL
Circ Arrhythm Electrophysiol
· 2026 May · PMID 41979465
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Miyazaki Y, Nakajima H, Rimmer M
… +5 more, Hanna P, Hayase JH, Do DH, Shivkumar K, Mori S
Circ Arrhythm Electrophysiol
· 2026 Apr · PMID 41953997
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BACKGROUND: The mechanisms behind endocardial entanglement and resultant delamination during left bundle branch area pacing, as well as potential solutions, have not been fully demonstrated in the human heart. METHODS: A...BACKGROUND: The mechanisms behind endocardial entanglement and resultant delamination during left bundle branch area pacing, as well as potential solutions, have not been fully demonstrated in the human heart. METHODS: Active fixation of a lumenless screw-in lead into the right ventricular septum was attempted with or without delivery system support using donor human hearts rejected for transplant. Delivery sheath support was ensured through firm catheter support maintained by a fixed clip. Endocardial entanglement, endocardial delamination after unscrewing, and lead penetration were evaluated using both macroscopic and microscopic analyses. RESULTS: Each of 10 lead deployments with or without support was attempted using 4 donor human hearts. There was a higher incidence of endocardial entanglement and resultant helix-only penetration in the nonsupport group than the support group (70% versus 0%). Unscrewing after the endocardial entanglement consistently revealed extensively delaminated endocardium entwined around the helix. The median endocardial delamination area was larger in the entanglement group than in the nonentanglement group (25.0 mm versus 0.9 mm, <0.001). In the regions with endocardial entanglement, histological analysis confirmed extensive endocardial delamination with minimal myocardial injury. On the other hand, localized endocardial delamination and deep intramural penetration were observed in the regions without entanglement. Screw-in procedures reattempted into the regions with extensive endocardial delamination following entanglement achieved deep penetration even without delivery system support. CONCLUSIONS: Endocardial entanglement and delamination were confirmed in donor human hearts. Adequate delivery system support, particularly its coaxiality and counterforce effect, is likely to prevent endocardial entanglement and facilitate effective penetration of a lumenless screw-in lead into the human ventricular septum.
Wong CX, Lee XW, Badhwar N
… +7 more, Alvarez CK, Lee AM, Woods CE, Dewland TA, Gerstenfeld EP, Beygui RE, Lee RJ
Circ Arrhythm Electrophysiol
· 2026 Apr · PMID 41930410
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BACKGROUND: Although emerging evidence supports 3-dimensional myocardial activation during atrial fibrillation (AF), human studies remain limited. We thus characterized the endocardial and epicardial left atrial posterio...BACKGROUND: Although emerging evidence supports 3-dimensional myocardial activation during atrial fibrillation (AF), human studies remain limited. We thus characterized the endocardial and epicardial left atrial posterior wall (LAPW) in humans to assess the prevalence of asynchronous endocardial-epicardial LAPW conduction during AF. METHODS: Patients with symptomatic nonparoxysmal AF who had unsuccessful antiarrhythmic or catheter ablation therapy referred for hybrid epicardial-endocardial AF ablation and left atrial appendage ligation underwent high-density mapping of LAPW with Grid catheters, including simultaneous endocardial-epicardial mapping. RESULTS: Twenty-seven patients (19 men, median 69 years, 55% long-standing persistent AF) were included. There was significantly greater epicardial compared with endocardial LAPW bipolar voltages during AF. In areas of low endocardial bipolar voltage, normal endocardial unipolar voltage corresponded to normal epicardial bipolar voltage. Asynchronous endocardial-epicardial LAPW AF activation during simultaneous endocardial-epicardial mapping was universal. Furthermore, more rapid epicardial compared with endocardial LAPW AF activity was observed during simultaneous endocardial-epicardial mapping in AF. Conduction block between the endocardial and epicardial LAPW surfaces was also common during organized AF, with instances of isolated or multiple blocked beats, Wenckebach conduction, and sustained endocardial LAPW entrance block with ongoing epicardial AF observed. Epicardial-to-endocardial entrance block was also infrequently observed during sinus rhythm. At 12-month follow-up, freedom from atrial arrhythmias was 68%. CONCLUSIONS: Endocardial-epicardial LAPW asynchrony may be observed during human persistent AF and is characterized by: (1) greater epicardial compared with endocardial bipolar voltages, (2) more frequent epicardial-to-endocardial activation gradients during AF, and (3) conduction block commonly seen between the epicardial and endocardial surfaces during AF. Although the study was predominantly descriptive in nature, the observations suggest a dynamic 3-dimensional arrhythmogenicity of the LAPW and the potential importance of the epicardial layer, with implications for ablation therapies. Future prospective studies are required to determine the significance of these findings to clinical ablation outcomes.
Rodriguez-Riascos JF, Navale D, Somappa A
… +4 more, Estrada-Mendizabal RJ, Scott LR, Shen WK, Srivathsan K
Circ Arrhythm Electrophysiol
· 2026 Apr · PMID 41930400
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BACKGROUND: Catheter ablation for atrial fibrillation is a widely used rhythm-control strategy, yet its role in reducing thromboembolic risk and enabling oral anticoagulation (OAC) discontinuation remains uncertain. This...BACKGROUND: Catheter ablation for atrial fibrillation is a widely used rhythm-control strategy, yet its role in reducing thromboembolic risk and enabling oral anticoagulation (OAC) discontinuation remains uncertain. This meta-analysis aims to comprehensively synthesize and evaluate randomized controlled trial evidence supporting long-term antithrombotic strategies in patients with atrial fibrillation undergoing catheter ablation. METHODS: A systematic literature search was performed in MEDLINE/PubMed, Embase, and the Cochrane Central Register of Controlled Trials to identify randomized controlled trials evaluating antithrombotic strategies after catheter ablation for atrial fibrillation. The primary outcome was ischemic stroke. A frequentist network meta-analysis comparing reported treatment arms, along with a pooled incidence meta-analysis for outcomes of interest, was conducted. RESULTS: Four randomized controlled trials, including 3924 patients, met the inclusion criteria. Three trials compared long-term OAC continuation versus OAC discontinuation, and 1 compared OAC continuation with left atrial appendage occlusion after catheter ablation. No significant differences in stroke incidence were observed when comparing OAC or left atrial appendage occlusion with no antithrombotic therapy (incidence rate ratio, 0.90 [95% CI, 0.02-33.85]; =0.95; incidence rate ratio, 0.79 [95% CI, 0.00-241.01]; =0.94, respectively). Among patients who discontinued antithrombotic therapy without undergoing left atrial appendage occlusion (n=1161), with 2864 cumulative person-years of follow-up, the pooled incidence of stroke was 0.23 events per 100 person-years (95% CI, 0.02-2.43; I=0%). CONCLUSIONS: This analysis reinforces that, across randomized data, the incidence of thromboembolic events in patients who discontinued OAC after successful ablation remained low. However, the evaluation of net clinical benefit is limited by the low number of events across all treatment arms, underscoring the need for larger studies with prolonged follow-up to further validate the safety of this strategy, particularly in higher-risk populations.
Reddy VY, Petru J, Funasako M
… +8 more, Canepa S, Metzdorff C, Okeson B, Mikos E, Oesterlein T, Gutbrod SR, Koop BE, Neuzil P
Circ Arrhythm Electrophysiol
· 2026 Apr · PMID 41919393
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BACKGROUND: Remapping studies have evaluated chronic lesion durability of the first-generation pentaspline pulsed field ablation (PFA) catheter that did not have integrated electroanatomical mapping. By invasive remappin...BACKGROUND: Remapping studies have evaluated chronic lesion durability of the first-generation pentaspline pulsed field ablation (PFA) catheter that did not have integrated electroanatomical mapping. By invasive remapping, this first-in-human study evaluated the durability of lesions facilitated by the integration of the navigation-enabled pentaspline PFA catheter and mapping system in patients with atrial fibrillation. METHODS: The trial evaluated the second-generation, mapping-integrated pentaspline PFA catheter. Lesion durability was assessed by invasive remapping 60 days post index procedure. RESULTS: After index ablation in 20 patients with the pentaspline PFA catheter, remaps were performed 60 days later in 17 patients, demonstrating a high rate of lesion durability in the pulmonary veins (95%) and posterior wall (86%). CONCLUSIONS: By facilitating real-time visualization of catheter positioning and acute lesion estimation through tags, the second-generation map-and-ablate pentaspline PFA catheter and integrated mapping system may enhance procedural success. REGISTRATION:URL: https://www.clinicaltrials.gov; Unique identifier: NCT06175234.
Di Biase L, Marazzato J, Schiavone M
… +21 more, Zou F, Spangler T, Bhardwaj R, Hsu J, Govari A, Altman A, Okarski K, Sharma T, Parikh P, Beeckler C, Troutman T, Chen Q, Nakagawa H, Maddox W, Nair D, Mohanty S, La Fazia VM, Ynoa D, Lin A, Natale A, Zhang X
Circ Arrhythm Electrophysiol
· 2026 Apr · PMID 41919387
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BACKGROUND: Integration of catheter-tissue contact force with pulsed field ablation (PFA) dosing is essential for achieving safe and durable lesion formation with contact force sensing catheters in ventricular models. Ho...BACKGROUND: Integration of catheter-tissue contact force with pulsed field ablation (PFA) dosing is essential for achieving safe and durable lesion formation with contact force sensing catheters in ventricular models. However, data on the use of these catheters for atrial ablation remain limited. This study evaluated the procedural safety and 30-day lesion characteristics of atrial PFA delivered with the OMNYPULSE ablation catheter in a porcine model. METHODS: Twelve pigs were randomized to receive either 6 (×6 or Group A) or 12 (×12 or group B) PFA applications per ablation. Following 3-dimensional electroanatomic mapping, PFA was delivered to the right superior and inferior pulmonary veins, cavotricuspid isthmus, right atrial posterior wall, left atrial roof, and mitral annulus. Procedural safety was assessed acutely, and lesion characteristics were evaluated on 30-day histology. Maximum transmurality extent (MTE) was defined as >80% of the lesion span exhibiting continuous endocardial-to-epicardial fibrosis within representative histological sections. RESULTS: Adequate catheter-tissue contact was achieved during PFA delivery (contact force, 28±15 g). No acute procedural complications were observed. At 30 days, PVs and right atrial sites (ie, cavotricuspid isthmus and right atrial posterior wall) demonstrated near-complete MTE regardless of PFA dosing. In contrast, MTE was significantly lower at the mitral annulus and LA roof compared with other sites (44±30% and 21±26%, respectively; <0.001). Increasing the number of PFA applications (×12) resulted in a remarkable improvement in MTE at these locations, with MTE increases of up to 68% compared with ×6 dosing at these sites. CONCLUSIONS: Atrial PFA using the OMNYPULSE catheter was feasible and safe in a porcine model. However, lesion transmurality varied by atrial location and was dose-dependent at select sites, underscoring the need for site-specific PFA dosing strategies. Further studies are warranted to define optimal PFA parameters for consistent atrial lesion formation.
Sakamoto D, Sunaga A, Matsuoka Y
… +24 more, Hasegawa H, Kida H, Dohi T, Nakatani D, Okada K, Kitamura T, Masuda M, Tanaka N, Watanabe T, Minamiguchi H, Egami Y, Oka T, Minamisaka T, Kanda T, Okada M, Kawasaki M, Matsuda Y, Tanaka K, Makino N, Hikoso S, Inoue K, Sotomi Y, Sakata Y, OCVC-SUPPRESS-AF Investigators
Circ Arrhythm Electrophysiol
· 2026 Apr · PMID 41919382
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BACKGROUND: Catheter ablation has been shown to improve prognosis in patients with heart failure (HF) and atrial fibrillation (AF); however, the optimal ablation strategy remains undefined. METHODS: In this multicenter,...BACKGROUND: Catheter ablation has been shown to improve prognosis in patients with heart failure (HF) and atrial fibrillation (AF); however, the optimal ablation strategy remains undefined. METHODS: In this multicenter, randomized controlled trial, 300 patients with persistent AF and HF, including both HF with reduced ejection fraction (ejection fraction ≤40%) and HF with preserved ejection fraction (ejection fraction >40%, including mid-range ejection fraction [ejection fraction 41% to 50%]), were enrolled and randomized equally to the anatomic-guided ablation, electrogram-guided ablation, and extensive electrogram-anatomic-guided ablation groups, with 100 patients in each group. The coprimary end points were: (1) the composite of cardiovascular death or HF-related hospitalization/urgent visit within 36 months; and (2) maintenance of sinus rhythm at 36 months. Secondary end points included AF burden <1%, New York Heart Association class improvement (≥1 grade), 6-minute walk test change, NT-proBNP (N-terminal pro-B-type natriuretic peptide) reduction, and procedure-related complications. Subgroup analyses were performed for HF with reduced ejection fraction and HF with preserved ejection fraction. RESULTS: At 36 months, the extensive electro-anatomic-guided ablation group demonstrated the lowest incidence of the composite end point (17.0%) compared with the electrogram-guided ablation (29.0%) and anatomic-guided ablation (36.0%; overall =0.010) groups, and the highest rate of sinus rhythm maintenance (62.0%) compared with the electrogram-guided ablation (53.0%) and anatomic-guided ablation (44.0%; =0.039) groups. Consistent improvements were observed for AF burden <1%, New York Heart Association class, 6-minute walk test, and NT-proBNP. Major complications were low and similar across all groups. These trends were consistent in both the HF with reduced ejection fraction and HF with preserved ejection fraction subgroups. CONCLUSIONS: Electrogram-anatomic ablation provides superior long-term rhythm control, reduces cardiovascular events, and improves symptoms in patients with persistent AF and HF, regardless of ejection fraction. REGISTRATION:URL: https://www.clinicaltrials.gov; Unique identifier: NCT07153718.