Electrophysiologists at Penn Medicine have introduced pulsed field ablation (PFA) for catheter ablation of atrial fibrillation (AF). Recently FDA-approved, PFA is a novel, cardiac catheter ablation therapy that uses high voltage, microsecond duration electrical pulses to bring about myocardial cell death through a non-thermal, tissue-selective process, irreversible electroporation.
The FARAPULSE PFA catheter is designed to treat the four pulmonary veins simultaneously in a large circular lesion.
What is Electroporation?
Irreversible electroporation is the process of creating pores in a cell membrane to destabilize the cell wall, culminating in apoptosis or necrosis. Among its benefits, irreversible electroporation is tissue-specific, and is thus less likely to harm surrounding organs during application (a drawback of both radiofrequency- and cryotherapy-based ablation).
The tissue specificity of PFA is a result of the myocardium’s susceptibility to irreversible electroporation relative to that of the esophagus, phrenic nerve and pulmonary veins, which are comparatively resistant to injury. A secondary advantage, rapid pulmonary vein isolation, has the benefit of reducing procedure time. The mechanisms of AF include rapidly firing foci in and around the pulmonary veins, and isolation of these foci is a principal focus of ablation therapy for AF.
Advantages of PFA
According to David Frankel, MD, tissue specificity is one of several key benefits for PFA. “From an operator’s perspective, the advantage of PFA is it’s shorter procedure time and similar effectiveness to radiofrequency and cryoablation, with better safety.” Director of the Cardiac Electrophysiology Laboratory, Dr. Frankel cautions that because PFA has a relatively narrow indication at this time, for the time being, it will not replace other forms of catheter ablation at Penn Medicine.
“Right now, pulse field ablation comprises approximately 40% of the atrial fibrillation ablations we’re doing,” he observes. “This is partly because radiofrequency ablation is currently preferred for repeat procedures and for patients who have a history of organized tachycardias.” Future clinical trials are expected to examine these applications in PFA, he notes.
A History of Innovation
PFA isn’t new at Penn Electrophysiology, which took part in the 2020 pre-approval ADVENT clinical trial of the FARAPULSE Pulsed Field Ablation System (Boston Scientific). The first randomized clinical trial to directly compare the efficacy and safety of PFA against standard-of-care ablation, ADVENT involved pulmonary vein isolation of adult subjects with drug refractory recurrent symptomatic atrial fibrillation (AF).
Led at Penn Medicine by Francis Marchlinski, MD, ADVENT found that therapy with FARAPULSE was as safe and effective as conventional thermal ablation, with significantly shorter ablation times and a rapid learning curve for physicians. Penn Medicine continues to participate in clinical trials to evaluate the efficacy of other innovations in PFA therapy.
Currently, PFA is being performed at Penn Medicine at the Hospital of the University of Pennsylvania, Penn Presbyterian Medical Center, Pennsylvania Hospital, and Lancaster General Hospital.
Additional Resources
Podcast | Update on Atrial Fibrillation with Drs. Kendall Williams and Benjamin D’Souza.
Faculty | Penn Cardiac Arrhythmia Team