Impact of a standardized pacing protocol on end point verification and first pass isolation using a multipolar pulsed-field ablation catheter for pulmonary vein isolation

Pulsed-field ablation (PFA) has emerged as a novel treatment strategy for patients with atrial fibrillation (AF) ( 1 Badertscher P, Weidlich S, Serban T, et al. Pulsed-field ablation versus single catheter high-power short-duration radiofrequency ablation for atrial fibrillation: procedural characteristics, myocardial injury and midterm outcomes. Heart Rhythm 2023. Google Scholar , 2 Reddy VY, Dukkipati SR, Neuzil P, al. Pulsed Field Ablation of Paroxysmal Atrial Fibrillation: 1-Year Outcomes of IMPULSE, PEFCAT, and PEFCAT II. JACC Clin Electrophysiol 2021; 7(5):614–627. Google Scholar ). In general, acute pulmonary vein isolation (PVI) may be confirmed by entrance and exit block ( 3 Duytschaever M. Meyer G de Acena M. et al. Lessons from dissociated pulmonary vein potentials: entry block implies exit block. Europace. 2013; 15: 805-812 Crossref PubMed Scopus (25) Google Scholar ). The penta-spline PFA catheter only provides larger electrodes and wider inter-electrode distance making such an assessment less reliable. Little is known about the required number of applications when using PFA as systematically assessed via exit block testing. Likewise, since close proximity of the PFA catheter to the PV ostium seems to be of importance ( 2 Reddy VY, Dukkipati SR, Neuzil P, al. Pulsed Field Ablation of Paroxysmal Atrial Fibrillation: 1-Year Outcomes of IMPULSE, PEFCAT, and PEFCAT II. JACC Clin Electrophysiol 2021; 7(5):614–627. Google Scholar ), catheter positioning might be optimized by pacing before the first PFA application and adjusting contact depending on the ability to capture atrial myocardium. Thus, our aim was to assess the number of PFA applications per PV until acute PVI was observed and to assess the impact of a standardized pacing protocol on first pass isolation (FPI) confirmed via electroanatomical mapping (EAM). We prospectively enrolled consecutive patients undergoing their first PVI. In brief, the PFA 31 mm Farawave© catheter (Boston Scientific, Marlborough, MA) was inserted into the left atrium via a single transseptal puncture. PVI was performed as described previously ( 2 Reddy VY, Dukkipati SR, Neuzil P, al. Pulsed Field Ablation of Paroxysmal Atrial Fibrillation: 1-Year Outcomes of IMPULSE, PEFCAT, and PEFCAT II. JACC Clin Electrophysiol 2021; 7(5):614–627. Google Scholar ). In group 1 no standardized pacing protocol was applied prior or after PVI. In group 2, pacing was performed prior to the first application across all five bipoles to assess proximity of the PFA catheter to the PV ostium. Entrance and exit block were then assessed after each PFA application per PV separately. PVI was subsequently confirmed via EAM. The study was approved by the local ethics committees and adhered to the Helsinki Declaration.