What is Pulsed Field Ablation?

Pulsed Field Ablation is a relatively new modality for treatment of atrial fibrillation. In conventional ablation for atrial fibrillation, either heating of tissue is produced by radiofrequency application or freezing of tissues by cryoablation. Most popular method is pulmonary vein isolation using these energy sources as the pulmonary veins harbour the triggers for atrial fibrillation. Potentialy serious, though rare complications of ablation for atrial fibrillation are phrenic nerve injury resulting in diaphragmatic paralysis, pulmonary vein stenosis and esophagial injury resulting in catastrophic atrio-esophageal fistula. Pulsed field ablation in contrast uses high voltage electrical fields on microsecond scale to irreversibly electroporate tissue. Destabilization of cell membranes cause cellular necrosis without any significant heat generation. While myocardial tissue is preferentially ablated, effects on adjacent structures like esophagus, phrenic nerve and pulmonary vein tissue is limited with pulsed field ablation.

ADVENT trial published in the New England Journal of Medicine in 2023 compared pulsed field ablation with conventional radiofrequency or cryoballoon ablation for drug-refractory paroxysmal atrial fibrillation [1]. Pulsed field ablation group had 305 patients while thermal ablation group had 302 patients. Pulsed field ablation was shown to be noninferior to conventional thermal ablation with respect to freedom from a composite of initial procedure failure, documented atrial tachyarrhythmia after a three month blanking period, antiarrhythmic drug use, cardioversion or repeat ablation and procedure related serious adverse events, at one year. A recent just accepted article in the Journal of American College of Cardiology mentions that compared to thermal ablation, pulsed field ablation more often resulted in atrial arrhythmia burden less than the clinically-significant threshold of 0.1% burden. That was a new analysis of the ADVENT trial [2].

Reference

1. Reddy VY, Gerstenfeld EP, Natale A, Whang W, Cuoco FA, Patel C, Mountantonakis SE, Gibson DN, Harding JD, Ellis CR, Ellenbogen KA, DeLurgio DB, Osorio J, Achyutha AB, Schneider CW, Mugglin AS, Albrecht EM, Stein KM, Lehmann JW, Mansour M; ADVENT Investigators. Pulsed Field or Conventional Thermal Ablation for Paroxysmal Atrial Fibrillation. N Engl J Med. 2023 Nov 2;389(18):1660-1671. doi: 10.1056/NEJMoa2307291. Epub 2023 Aug 27. PMID: 37634148.
2. Vivek Y. Reddy, Moussa Mansour, Hugh Calkins, Andre d’Avila, Larry Chinitz, Christopher Woods, Sanjaya K. Gupta, Jamie Kim, Zayd A. Eldadah, Robert A. Pickett, Jeffrey Winterfield, Wilber W. Su, Jonathan W. Waks, Christopher W. Schneider, Elizabeth Richards, Elizabeth M. Albrecht, Brad S. Sutton, Edward P. Gerstenfeld, and on behalf of the ADVENT Investigators. Pulsed Field vs Conventional Thermal Ablation for Paroxysmal Atrial Fibrillation: Recurrent Atrial Arrhythmia Burden. J Am Coll Cardiol. May 18, 2024. Epublished DOI: 10.1016/j.jacc.2024.05.001.