Transseptal access with an electrified guidewire and large pulsed field ablation sheath

Insertion of a large-bore pulsed field ablation (PFA) sheath requires multiple over-the-wire exchanges following a transseptal puncture (TSP) using the Swartz left (SL) sheath and Brockenbrough (BRK) needle assembly. As an alternative, this study provides the first clinical description of performing an electrified guidewire transseptal puncture (ETSP) using electrocautery applied to a standard 0.035″ guidewire within a 17 Fr Faradrive sheath. This zero-exchange transseptal workflow allows for the direct advancement of the PFA sheath. This was a single-centre, retrospective non-randomized study including patients undergoing atrial fibrillation (AF) ablation from March 2024 to May 2025. Patients who underwent ETSP with a standard 0.035″ Rosen guidewire directly via a Faradrive sheath (‘ETSP Faradrive’) were compared to patients who underwent either traditional TSP with a SL sheath/BRK needle (‘non-ETSP Faradrive’) or ETSP with smaller, non-Faradrive sheaths (‘ETSP non-Faradrive‘). We compared TSP success rate and time to left atrial (LA) access, defined as the time from groin puncture to first LA electrogram, and complication rate. System preparation: The Faradrive sheath–dilator assembly was flushed with heparinized saline and the 0.035″ Rosen guidewire was inserted to protrude 1 mm beyond the distal tip of the dilator (Figure 1: Panel 1A). The proximal segment of the guidewire, visible just distal to the dilator entry port, was marked with a sterile permanent marker to ensure consistent exposure of only 1 mm of the guidewire tip (Figure 1: Panel 1B). Advancement to the fossa ovalis: The sheath-dilator assembly was advanced to the superior vena cava (SVC) under fluoroscopic and/or trans-oesophageal echocardiography (TOE) or intracardiac echocardiography (ICE) guidance. The guidewire was withdrawn into the dilator, and slight flexion was applied to the sheath. The system was gradually withdrawn in an approximately 5 o’clock orientation until engagement with the fossa ovalis. Septal puncture: Moderate septal tenting at a mid-to-anterior location was confirmed with TOE or ICE (Figure 1: Panel 1C). The guidewire was advanced to expose only 1 mm beyond the dilator tip. Electrocautery was applied to the proximal guidewire using a Valleylab FT10 generator in coagulation mode at 15W for up to 2 s (Figure 1D). Left atrial access: Successful TSP was indicated by loss of resistance and guidewire entry into the LA. The guidewire was advanced into a left pulmonary vein, after which the sheath-dilator assembly was advanced into the LA, aspirated, and flushed before introduction of the ablation catheter. Electrified guidewire transseptal puncture (ETSP) with a large pulsed field ablation sheath. Normality was assessed using the Shapiro-Wilk test. Continuous variables are reported as median (IQR) and compared using the Kruskal-Wallis test with Wilcoxon post hoc tests and Holm-Bonferroni adjustment. Categorical variables were compared using χ2 or Fisher’s exact tests. Two-sided P < 0.05 was considered statistically significant. Analyses were performed using SPSS v29 and GraphPad Prism v10. A total of 98 patients (baseline characteristics—Figure 1 Panel2) were included: 58 ETSP through Faradrive sheath, 29 non-ETSP through Faradrive sheath, and 11 ETSP through non-Faradrive sheath. ETSP through Faradrive sheath was successful in 54 (93%) and 58 (100%) of patients after the 1st and 2nd attempt, respectively. No equipment exchange was required with ETSP in contrast to three with non-ETSP (Figure 1: Panel 4). The median time to LA access was significantly shorter using ETSP (Faradrive + non-Faradrive) compared to non-ETSP (Faradrive) (16 min [15–18] vs. 18 min [16–20] P = 0.021). (Figure 1, Panel 3). There was no periprocedural stroke, cardiac tamponade, systemic embolism, or residual atrial septal defects at 1 month of follow up by transthoracic echocardiography. No macroscopic evidence of charring or thermal injury to the dilator tips or guidewires was observed in ETSP group. This study describes a simplified workflow using ETSP for LA access which has not been evaluated when performed through PFA sheath.1 ETSP achieved universal procedural success without requiring multiple equipment exchanges, was safe and required significantly less time than the SL/BRK needle approach. Theoretical advantages of ETSP are a reduction in risk of emboli caused by equipment changes and minimization of abrupt mechanical force, required when using the BRK needle.2 Additionally, the guidewire-based approach avoids needle–wire exchanges within the left atrium, allows the sheath-dilator assembly to be repositioned into the SVC for repeat attempts, and overcomes the theoretical limitation of guidewire instability during sheath advancement associated with the non-ETSP technique. Compared with dedicated RF transseptal systems, this strategy may also reduce procedural costs.3 The technique requires no additional specialized hardware, apart from a standard electrosurgical generator and a sterile marker pen, both routinely available in electrophysiology laboratories. Three technical factors were critical for consistent success: adequate septal tenting (>10 mm) visualized on intracardiac imaging (TOE/ICE), exposure of no more than 1 mm of guidewire tip, and application of 15 W electrocautery in coagulation mode. Bench experiments using an ex vivo ovine model supported these observations, demonstrating focused energy delivery, lower tissue temperatures, and reliable TSP success without tissue charring or equipment damage.4 Importantly, tactile feedback is inherently diminished when performing TSP with a large-bore sheath so ETSP should be performed under real-time imaging guidance (TOE/ICE), as inadvertent electrification on non-septal structures carries a theoretical risk of perforation. Also, guidewire electrification without sufficient septal tenting may result in ineffective puncture attempts, increased thermal injury, and potential embolic phenomena.4 This was a single centre, retrospective, non-randomized study, evaluating 0.035″ guidewire-facilitated ETSP using TOE/ICE guidance only. Routine MRI to detect silent cerebral emboli was not performed. The time to LA access could possibly be confounded by factors relating to the puncture of the other vessels, and use of long-exchange wires in some cases. Shunt assessment was limited to simple TTE; no contrast echo or TOE was done to assess for remnant communication, which are more sensitive for detecting small interatrial communications. The data underlying this article will be shared on reasonable request to the corresponding author.