Effective reduction of fluoroscopy duration by using an advanced electroanatomic-mapping system and a standardized procedural protocol for ablation of atrial fibrillation: ‘the unleaded study'

Aims It is recommended to keep exposure to ionizing radiation as low as reasonably achievable. The aim of this study was to determine whether fluoroscopy-free mapping and ablation using a standardized procedural protocol is feasible in patients undergoing pulmonary vein isolation (PVI). Methods and results Sixty consecutive patients were analysed: Thirty consecutive patients undergoing PVI using Carto3 were treated using a standardized procedural fluoroscopy protocol with X-ray being disabled after transseptal puncture (Group 1) and compared with a set of previous 30 consecutive patients undergoing PVI without a specific recommendation regarding the use of fluoroscopy (Group 2). The main outcome measures were the feasibility of fluoroscopy-free mapping and ablation, total fluoroscopy time, total dose area product (DAP), and procedure time. Sixty patients (age 60 ± 10 years, 73% male, ejection fraction 0.55 ± 0.09, left atrium 42 ± 8 mm) were included. In Group 1, total fluoroscopy time was 4.2 (2.6-5.6) min and mapping and ablation during PVI without using fluoroscopy was feasible in 29 of 30 patients (97%). In Group 2, total fluoroscopy time was 9.3 (6.4-13.9) min (P < 0.001). Total DAP was 13.2 (6.2-22.2) Gy*cm2 in Group 1 compared with 17.5 (11.7-29.7) Gy*cm2 in Group 2 (P = 0.036). Total procedure time did not differ between Groups 1 (133 ± 37 min) and 2 (134 ± 37 min, P = 0.884). Conclusion Performing mapping and ablation guided by an electroanatomic-mapping system during PVI without using fluoroscopy after transseptal puncture using a standardized procedural protocol is feasible in almost all patients and is associated with markedly decreased total fluoroscopy duration and DA

Pulsed-field ablation for the treatment of left atrial reentry tachycardia.

BACKGROUND We describe our initial experience using a multipolar pulsed-field ablation catheter for the treatment of left atrial (LA) reentry tachycardia. METHODS We included all patients with LA reentry tachycardia treated with PFA at our institution between September 2021 and March 2022. The tachycardia mechanism was identified using 3D electro-anatomical mapping (3D-EAM). Subsequently, a roof line, anterior line, or mitral isthmus line was ablated as appropriate. Roof line ablation was always combined with LA posterior wall (LAPW) ablation. Positioning of the PFA catheter was guided by a 3D-EAM system and by fluoroscopy. Bidirectional block across lines was verified using standard criteria. Additional radiofrequency ablation (RFA) was used to achieve bidirectional block as necessary. RESULTS Among 22 patients (median age 70 (59-75) years; 9 females), we identified 27 LA reentry tachycardia: seven roof dependent macro-reentries, one posterior-wall micro-reentry, twelve peri-mitral macro-reentries, and seven anterior-wall micro-reentries. We ablated a total of 20 roof lines, 13 anterior lines, and 6 mitral isthmus lines. Additional RFA was necessary for two anterior lines (15%) and three mitral isthmus lines (50%). Bidirectional block was achieved across all roof lines, 92% of anterior lines, and 83% of mitral isthmus lines. We observed no acute procedural complications. CONCLUSION Ablation of a roof line and of the LAPW is feasible, effective, and safe using this multipolar PFA catheter. However, the catheter is less suited for ablation of the mitral isthmus and the anterior line. A focal pulsed-field ablation catheter may be more effective for ablation of these lines. This study shows the feasibility to ablate linear lesions with a multipolar pulsed-field ablation catheter. 27 left atrial reentry tachycardia were treated in 22 patients

Sex-Specific Aspects of Cardiac Electrophysiology and Arrhythmias

This article provides a condensed but comprehensive summary of the latest knowledge of sex-specific aspects of arrhythmias. Starting with sex-based differences in electrophysiological properties of the heart, it further covers sex- and gender-differences in supraventricular tachycardia, atrial fibrillation, ventricular tachycardia and selected inherited cardiac arrhythmias. Keywords: Arrhythmia; sex difference; gende

Validation of the accuracy of contact force measurement by contemporary force-sensing ablation catheters.

INTRODUCTION Contact force-sensing catheters are widely used for ablation of cardiac arrhythmias. They allow quantification of catheter-to-tissue contact, which is an important determinant for lesion formation and may reduce the risk of complications. The accuracy of these sensors may vary across the measurement range, catheter-to-tissue angle, and amongst manufacturers and we aim to compare the accuracy and reproducibility of four different force sensing ablation catheters. METHODS A measurement setup containing a heated saline water bath with an integrated force measurement unit was constructed and validated. Subsequently, we investigated four different catheter models, each equipped with a unique measurement technology: Tacticath Quartz (Abbott), AcQBlate Force (Biotronik/Acutus), Stablepoint (Boston Scientific), and Smarttouch SF (Biosense Webster). For each model, the accuracy of three different catheters was measured within the range of 0-60 grams and at contact angles of 0°, 30°, 45°, 60°, and 90°. RESULTS In total, 6685 measurements were performed using 4x3 catheters (median of 568, IQR 511-606 measurements per catheter). Over the entire measurement-range, the force measured by the catheters deviated from the real force by the following absolute mean values: Tacticath 1.29g ±0.99g, AcQBlate Force 2.87g ±2.37g, Stablepoint 1.38g ±1.29g, and Smarttouch 2.26g ±2.70g. For some models, significant under- and overestimation of >10g were observed at higher forces. Mean absolute errors of all models across the range of 10-40g were <3g. CONCLUSION Contact measured by force-sensing catheters is accurate with 1-3g deviation within the range of 10g to 40g. Significant errors can occur at higher forces with potential clinical consequences. This article is protected by copyright. All rights reserved

Fluoroscopy-Free Pulmonary Vein Isolation in Patients with Atrial Fibrillation and a Patent Foramen Ovale Using Solely an Electroanatomic Mapping System

INTRODUCTION: The advent of electroanatomical mapping (EAM) systems for pulmonary vein isolation (PVI) has dramatically decreased radiation exposure. However, the need for some fluoroscopy remains for obtaining left atrial (LA) access. The aim was to test the feasibility of fluoroscopy-free PVI in patients with atrial fibrillation (AF) and a patent foramen ovale (PFO) guided solely by an EAM system. METHODS: Consecutive patients with AF undergoing PVI and documented PFO were studied. An EAM-guided approach without fluoroscopy and ultrasound was used. After completing the map of the right atrium, the superior vena cava and the coronary sinus, a catheter pull-down to the PFO was performed allowing LA access. The map of the LA and subsequent PVI was also performed without fluoroscopy. RESULTS: 30 patients [age 61+/-12 years, 73% male, ejection fraction 0.64 (0.53-0.65), LA size in parasternal long axis 38+/-7 mm] undergoing PVI were included. The time required for right atrial mapping including transseptal crossing was 9+/-4 minutes. Total procedure time was 127+/-37 minutes. Fluoroscopy-free PVI was feasible in 26/30 (87%) patients. In four patients, fluoroscopy was needed to access (n = 3) or to re-access (n = 1) the LA. In these four patients, total fluoroscopy time was 5+/-3 min and the DAP was 14.9+/-13.4 Gy*cm2. Single-procedure success rate was 80% (24/30) after a median follow-up of 12 months. CONCLUSION: In patients with a documented PFO, completely fluoroscopy-free PVI is feasible in the vast majority of cases

First clinical experience of a dedicated irrigated-tip radiofrequency ablation catheter for the ablation of cavotricuspid isthmus-dependent atrial flutter.

BACKGROUND Different types of irrigated-tip ablation catheters are available for ablation of atrial flutter (AFL). The aim of this study was to compare an established with a novel dedicated Gold irrigated-tip catheter for ablation of AFL. METHODS AND RESULTS We compared consecutive patients undergoing ablation of AFL using a standard 3.5 mm irrigated-tip platinum-iridium (Pt-Ir) catheter (Thermocool, TC-group) and a 3.5 mm irrigated gold-tip catheter (Gold-group) specifically designed for cavotricuspid isthmus ablation (CTI). The primary endpoint was acute efficacy (net RF time) to achieve block across the CTI. Secondary endpoints included procedure time, fluoroscopy duration, complications, and recurrence of AFL.153 patients (age 68 ± 11 years, 74% male) were included. Net RF time to achieve CTI block was not different between the TC-group (793 ± 503 s) and the Gold-group (706 ± 422 s; p = 0.406). Total procedure time was not significantly different between the TC-group (70 ± 26 min) and the Gold-group (70 ± 27 min; p = 0.769). A significant difference between the groups was identified for the fluoroscopy duration (TC-group: 934 ± 537 s, Gold-group: 596 ± 362 s, p < 0.001). There were no major complications observed in the groups. Recurrence of AFL occurred in 3 of 66 (5%) in the TC-group and in 2 of 87 (2%) in the Gold-group (p = 0.652). CONCLUSIONS In conclusion, acute and chronic efficacy of the irrigated Pt-Ir and gold-tip catheters were comparable. However, the dedicated catheter design was associated with decreased fluoroscopy duration

Eliminating transseptal sheath exchange for pulsed field ablation procedures using a direct over-the-needle transseptal access with the Faradrive sheath.

AIMS Pulsed field ablation (PFA) for pulmonary vein isolation (PVI) combines the benefits of high procedural efficacy and safety. Transseptal puncture (TSP) to obtain left atrial (LA) access during PVI remains an important source of complications during LA procedures. For PFA procedures, TSP is generally performed using a standard transseptal sheath that is then exchanged over the wire for a dedicated PFA sheath, which might be a potential source for air embolism. We aimed to prospectively evaluate the feasibility and safety of a simplified workflow using the PFA sheath (Faradrive, Boston Scientific) directly for TSP. METHODS AND RESULTS We prospectively enrolled 100 patients undergoing PVI using PFA at two centres. TSP was performed using the PFA sheath and a standard 98 cm transseptal needle under fluoroscopic guidance. TSP via the PFA sheath was successfully performed in all patients and no complications occurred. The median time from the first groin puncture to the completed LA access was 12 min (IQR 8-16 min). CONCLUSION An over-the-needle TSP directly with the PFA sheath proved feasible and safe in our study. This simplified workflow has the potential to reduce the risk of air embolism, to shorten procedure time, and to reduce cost

Validation of a multipolar pulsed-field ablation catheter for endpoint assessment in pulmonary vein isolation procedures.

AIMS To validate the performance of a multipolar pulsed-field ablation (PFA) catheter compared to a standard pentaspline 3D-mapping catheter for endpoint assessment of pulmonary vein isolation (PVI). PFA for PVI using single-shot devices combines the benefits of high procedural efficacy and safety. A newly available multipolar PFA catheter allows real-time recording of pulmonary vein (PV) signals during PVI. METHODS AND RESULTS Patients undergoing first PVI using PFA with the standard ablation protocol (eight applications per PV) were studied. Entrance and exit block (10 V/2 ms) were assessed using the PFA catheter. Subsequently, a high-density 3D electroanatomical bipolar voltage map (3D-EAM) was constructed using a standard pentaspline 3D-mapping catheter. Additional PFA applications were delivered only after confirmation of residual PV connection by 3D-EAM. In 56 patients, 213 PVs were targeted for ablation. Acute PVI was achieved in 100% of PVs: in 199/213 (93%) PVs with the standard ablation protocol alone and in the remaining 14 PVs after additional PFA applications. The accuracy of PV assessment with the PFA catheter after the standard ablation protocol was 91% (194/213 veins). In 5/213 (2.3%) PVs, the PFA catheter incorrectly indicated PV-isolation. In 14/213 (6.6%), the PFA catheter incorrectly indicated residual PV-conduction due to high-output pace-capture. Lowering the output to 5 V/1 ms reduced this observation to 0.9% (2/213) and increased the overall accuracy to 97% (206/213). CONCLUSION A novel multipolar PFA catheter allows reliable endpoint assessment for PVI. Due to its design, far-field sensing and high-output pace-capture can occur. Lowering the pacing output increases the accuracy from 91 to 97%

Technical and procedural comparison of two different cryoballoon ablation systems in patients with atrial fibrillation.

PURPOSE The aim was to report procedural and technical differences of a novel cryoballoon (NCB) ablation catheter for pulmonary vein isolation (PVI) compared to the standard cryoballoon (SCB) catheter. METHODS Consecutive patients with atrial fibrillation (AF) undergoing PVI using the NCB and the SCB were included. Procedural parameters, technical differences, acute efficacy, and safety are reported. RESULTS Eighty patients (age 66 ± 10 years, ejection fraction 57 ± 10%, left atrial volume index 40 ± 6 ml/m2) were studied. With the NCB, 156 of 158 PVs (99%) were isolated compared to isolation of 159 of 159 PVs (100%) with the SCB. The median number of freezes in the NCB and the SCB group was 6 (IQR 5-8) and 5 (IQR 4-7), respectively (p = 0.051), with 73% and 71% of the PVs isolated with a single freeze, respectively. Nadir temperature and temperature at isolation were - 59 ± 6 °C and - 45 ± 17 °C in the NCB group and - 46 ± 7 °C and - 32 ± 23 °C in the SCB group, respectively (both p < 0.001) with no difference in time to isolation (TTI). Procedural differences were observed for the total procedure time (84 ± 29 min in the NCB group and 65 ± 17 min in the SCB group, p = 0.003). There was a peri-procedural stroke in one patient in the NCB group. Differences in catheter design were observed that may account for the differences in temperature recordings and ice cap formation. CONCLUSIONS Acute efficacy and TTI were similar with the NCB compared to the SCB. Measured temperatures were lower with the NCB, most likely due to differences in catheter design