pulsed field ablation

Atrial fibrillation frequently results from bursts of tachycardia that originate in muscle bundles extending from the atrium to the pulmonary veins.{{cite journal | vauthors=McGarry TJ, Narayan SM | title=The anatomical basis of pulmonary vein reconnection after ablation for atrial fibrillation: wounds that never felt a scar? | journal=Journal of the American College of Cardiology | volume=50 | issue=10| pages=939–941 | year=2012 | doi = 10.1016/j.jacc.2011.11.032 | pmc=3393092 | pmid=22381430 }} Pulmonary vein isolation ablation technology has used thermal methods (radiofrequency ablation or, less often, cryoablation) to destroy pulmonary vein cells.{{cite journal | vauthors=Matos CD, Hoyos C, Osorio J | title = Pulsed Field Ablation of Atrial Fibrillation: A Comprehensive Review | journal= Reviews in Cardiovascular Medicine | volume=24 | issue=11 | pages=337 | year=2023| doi = 10.31083/j.rcm2411337 | pmc=11272841 | pmid=39076426 }} As with thermal methods of ablation, in pulsed field ablation, a thin, flexible tube (catheter) is inserted into a blood vessel in the groin and threaded up into the heart to ablate the areas of the pulmonary vein causing excessively rapid electrical signals.{{cite journal | vauthors=Ames A, Stevenson WG | title =Catheter ablation of atrial fibrillation | journal=Circulation | volume=113 | issue=13 | pages=e666-8 | year=206 | doi = 10.1161/CIRCULATIONAHA.105.613083 | pmid=16585395 }}

A major reason for recurrence of atrial fibrillation after ablation has been the belief of electrical pulmonary vein reconnection, which has not been seen for PFA.{{cite journal | vauthors=Reddy VY, Neuzil P, Jais P | title=Pulsed Field Ablation for Pulmonary Vein Isolation in Atrial Fibrillation | journal= Journal of the American College of Cardiology | volume=74 | issue=3 | pages=15–326 | year=2019 | doi = 10.1016/j.jacc.2019.04.021 | pmid=31085321 | doi-access=free }} In one study, atrial fibrillation recurrence in the thermal ablation group was 39% compared to 11% in the PFA group.{{cite journal | vauthors=Iyengar SK, Iyengar S, Srivathsan K | title=The promise of pulsed field ablation and the challenges ahead| journal= Frontiers in Cardiovascular Medicine | volume=10 | pages=1235317 | year=2023 | doi = 10.3389/fcvm.2023.1235317 | doi-access=free| pmc=10627215 | pmid=37937293 }} PFA can achieve pulmonary vein isolation faster than other ablation methods. Compared to radiofrequency ablation, PFA produces lesions of greater uniformity.

Cell death following PFA is usually due to apoptosis, which is a far less damaging and inflammatory form of cell death than necrosis. In contrast to thermal methods of ablation, PFA specifically kills cardiomyocytes (cardiac muscle cells) without injuring surrounding tissues. Thermal ablation methods can damage the esophagus, phrenic nerve, and coronary vessels (as high as 5% ), which are spared by PFA. One study showed an overall complication rate of 0.7% for PFA and no occurrence of phrenic nerve, esophageal, or pulmonary vein injury.{{cite journal | vauthors=Verma A, Haines DE, DeLurgio DB | title=Pulsed Field Ablation for the Treatment of Atrial Fibrillation: PULSED AF Pivotal Trial | journal= Circulation | volume=147 | issue=19 | pages=422–1432 | year=2023 | doi = 10.1161/CIRCULATIONAHA.123.063988 | pmc=10158608 | pmid=36877118 }}

Because PFA is a relatively newer ablation technique, there is a lack of uniformity in the parameters for its delivery. Better standardization could help reduce instances of coronary artery spasm and pulmonary artery hemorrhage, which can occur. The equipment cost and lack of specialized training have limited the widespread use of PFA, making it unavailable to many patients.

Recent (2024) comparisons of PFA with thermal methods have shown reduced time spent in surgery, but no superiority in safety and no better reduction of atrial fibrillation.{{cite journal | vauthors = Deering TF, Bunch TJ, Smith AM | title = Pulsed field ablation: A promise with future broad-based applicability or a pause needing further analysis-Is catheter ablation at a crossroads? A critical appraisal of the new challenger-pulsed field ablation | journal = Heart Rhythm | volume = 21 | issue = 8 | pages = 1242–1244 | date = 2024 | doi = 10.1016/j.hrthm.2024.03.1763 | pmid = 38548125 }} When used in areas other than the pulmonary vein, injuries have been seen.

There are several commercial systems in use or pending release:

• FaraPulse by Boston Scientific [https://www.bostonscientific.com/en-US/products/catheters--ablation/farapulse.html]
• PulseSelect by Medtronic [https://www.medtronic.com/en-us/healthcare-professionals/products/surgical-energy/ablation/pulsed-field-ablation/systems/pulseselect-pulsed-field-ablation-system.html]
• Varipulse by Biosense Webster [https://www.jnj.com/media-center/press-releases/biosense-webster-announces-regulatory-approval-of-varipulse-pulsed-field-ablation-pfa-platform-in-japan]

{{reflist}}

• [https://www.youtube.com/watch?v=ENFlU3yuZd0 Cardiac Ablations for Atrial Fibrillation: What to Expect After Your Procedure] on [https://www.massgeneral.org/heart-center Massachusetts General Hospital]
• [https://www.youtube.com/watch?v=2KuhjOVlatI&ab_channel=AcutusMedical Focal Pulsed Field Ablation Guided by Contact & Noncontact Mapping] on AF Symposium 2022

Category:Cardiac electrophysiology

Category:Cardiac procedures