Background

Pulsed field ablation (PFA) is a non-termal technology to perform pulmonary vein isolation (PVI) for atrial fibrillation (AF). A novel PFA generator allows pulsed electric field (PEF) applications via established contact force-sensing ablation catheters and implementation in 3D mapping systems. So far, data are sparse.

Methods

Patients scheduled for first PVI were prospectively enrolled. The CENTAURI PFA generator (Galvanize Therapeutics) and a single-tip ablation catheter (Biosense Webster Thermocool Smarttouch) were used to perform wide antral circumferential PVI guided by 3D mapping system (Biosense Webster CARTO 3D). Map was acquired using the PENTARAY catheter. Contact force of >7g was intended for each PEF application. PEF dosing was 25 Ampere (A) (anterior) and 22 A (posterior), respectively. Atropine was not routinely administered. At operator’s discretion, energy could be switched to radiofrequency (RF) to treat extra-PV tachycardias. Prior to PFA of the cavotricuspid isthmus, 1 mg nitroglycerin was administered i.v. to prevent coronary spasm. PVI was the primary efficacy endpoint and was demonstrated by re-map, PV entrance and exit block. Block of lines was documented by differential pacing. The secondary endpoint comprised procedural safety.

Results

Seventeen patients with symptomatic AF (65% female, 71±2 years, CHA₂DS₂-VASc Score 2 [1-3], history of AF 19 [4-47] months) underwent point-by-point PFA-PVI under conscious sedation. Acute PVI was achieved in 100%. First pass isolation was 88% (56/64 PV) and further ablation was necessary in the left-sided carina (n=6), the left inferior PV (n=1) and the right-sided carina (n=1). Three patients were additionally ablated for typical right atrial flutter (PFA in 2 and RF in 1 case, respectively) and 1 left atrial tachycardia was treated by creation of an anterior line using PFA. Total procedure time, fluoroscopy time, and dose area product were 165±45 minutes, 6±2 minutes, and 4.7±4.1 Gy*cm², respectively. Procedure time was prolonged in several cases to due integration errors of the CARTO 3D system and the PFA generator. No severe bradycardia, phrenic nerve palsy or coronary artery spasm was noted. Two peri-procedural complications occurred. One pericardial tamponade requiring drainage resulted from coughing during PFA delivery at the roof of the left superior PV whilst no real-time visualization of catheter position and no contact-force information were available. One aneurysm spurium was treated conservatively.

Conclusions

Point-by-point PFA-PVI in combination with a 3D mapping system is acutely effective, considered safe, and allows toggling to RF energy, if necessary. Non-availability of real-time catheter visualization and contact-force information during, and several seconds after PEF delivery, is a current technical limitation that could be associated with complications. Further improvements regarding the interplay of the PFA- and mapping system are necessary to optimize workflow. Further studies are awaited to determine fields of application aside from PVI, as successfully performed in a limited number of patients of our cohort.