Contemporary Trends in Pulsed Field Ablation for Cardiac Arrhythmias

Abstract

Pulsed field ablation (PFA) is a catheter-based procedure that utilizes short high voltage and short-duration electrical field pulses to induce tissue injury. The last decade has yielded significant scientific progress and quickened interest in PFA as an energy modality leading to the emergence of the clinical use of PFA technologies for the treatment of atrial fibrillation. It is generally agreed that more research is needed to improve our biophysical understanding of PFA for clinical cardiac applications as well as its potential as a potential alternative energy source to thermal ablation modalities for the treatment of other arrhythmias. In this review, we discuss the available preclinical and clinical evidence for PFA for atrial fibrillation, developments for ventricular arrhythmia (VA) ablation, and future perspectives.

Keywords: atrial fibrillation; cryoablation; pulsed field ablation; radiofrequency; ventricular tachycardia.

Figure 1

Conceptual figures showing an association between proximity of the electrode and relationship between strength of the electric field which may result in irreversible and reversible cellular electroporation. Theoretical differences between unipolar and bipolar configurations on biophysics of pulsed electric field delivery.

Figure 2

Clinical and investigation catheter technologies for pulsed field ablation.

Figure 3

(A) In four swine, direct ablation with PFA and RFA within the lumen of the esophagus were performed to assess the effect of PFA on esophagus tissue. Left, 3D anatomical map of the esophagus and RA. Red dots represent RFA while green dots, PFA. Middle, gross pathology demonstrates direct ablation to the esophageal lumen, interchangeably with PFA and RFA. Right, histological slides of PF and RF lesions show mild edema and focal superficial necrosis in PFA lesions, while RFA shows severe edema, necrosis, and hemorrhage spanning to the deep muscularis layers. (B) In six swine, 5.5 (1–8) PFA applications were placed on the endocardial RA, opposing the phrenic nerve. These did not result in phrenic nerve paralysis. Comparison RF ablation. Left, anatomical map with the course of the right phrenic nerve identified by pacing the lateral RA marked in light-blue tags. Green tags represent PFA and red represent RFA. Middle, gross pathology of the phrenic nerve with clear lesions at RFA sites opposed to the healthy-looking tissue at the PFA sites. Right, histological analysis at PFA application sites demonstrating PFA selectively affected cardiomyocytes but spared blood vessels and nervous tissue.

Figure 4

(A) First pulsed field ablation (PFA) application from left atrium near right superior pulmonary vein induces a profound vagal response. (B) The red spherical tags show radiofrequency lesions given nearby the PFA lesion where acute vagal response was obtained which are indicated with blue and green spherical tags (from superior view). Although radiofrequency (RF) lesions did not induce further vagal response after PFA application, RF applications were performed to ensure long-term parasympathetic denervation. Image reproduced with permission from Sikiric et al. J. Interv. Card Electrophysiol. (2024).

Figure 5

(A) shows penta-spline pulsed field ablation (PFA) catheter positioned at the right superior ganglionic plexus. (B) shows penta-spline PFA catheter position at the left superior and right inferior ganglionic plexuses.