Do Pulsed Electric Fields Present a New Era of AFib Ablation?

Pulsed electric field ablation is a paradigm-shifting energy source that may have the potential to transform the field of atrial fibrillation (AFib) ablation, according to a study presented May 11 during the Heart Rhythm Society's 39th Annual Scientific Sessions and simultaneously published in JACC: Clinical Electrophysiology.

Vivek Y. Reddy, MD, et al., sought to report the first acute clinical experience of AFib ablation with pulsed electric fields in both catheter-based pulmonary vein isolation and epicardial box lesions during cardiac surgery. Using a custom over-the-wire endocardial catheter for percutaneous transseptal pulmonary vein isolation and a linear catheter for encircling the pulmonary veins and posterior left atrium during concomitant cardiac surgery, pulsed electric field ablation was performed in 22 AFib patients who underwent ablation under general anesthesia.

Of the 22 AFib patients, 15 underwent endocardial pulsed electric field ablation of their pulmonary veins and seven underwent surgical epicardial pulsed electric field ablation of their left atrial posterior wall and pulmonary veins. Endocardial voltage maps were created pre- and post-ablation.

Results showed that catheter pulmonary vein isolation was successful in all 57 pulmonary veins in the 15 patients with a procedure time ranging from 52 to 84 minutes, catheter time 16 to 23 minutes and total pulsed electric field energy delivery time less than 60 seconds per patient. Surgical box lesions were successful in six out of the seven patients with the catheter time for epicardial ablation ranging from 30 to 75 minutes.

Furthermore, the authors found no pulsed electric field catheter-related complications such as deployment failure, cardiac perforation or catheter entrapment within the pulmonary veins or valvular apparatus. There was also no evidence of charring or thrombus formation upon catheter removal from the left atrium.

The authors explain that the most unique aspect to a pulsed electric field is its tissue selectivity, as tissues have specific characteristic threshold field strengths that induce necrosis. They add that pulsed electric fields may be uniquely suited for AFib ablation because cardiomyocytes have among the lowest threshold values of any tissue, the absence of coagulative necrosis obviates the risk of pulmonary vein stenosis and the speed of pulsed electric fields has advantages for both lab workflow and safety of left-sided procedures.

"Unlike thermally-based energy technologies, pulsed electric field ablation was distinguished by its ability to achieve ultra-rapid pulmonary vein isolation or posterior box isolation with total ablation times of less than 60 seconds," the authors conclude. "[It] is both feasible and safe and associated with excellent acute efficacy."

Clinical Topics: Arrhythmias and Clinical EP, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Pulmonary Veins, Atrial Fibrillation, Myocytes, Cardiac, Workflow, Heart Atria, Catheter Ablation, Endocardium, Thrombosis, Anesthesia, General, Electrophysiology

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