Irreversible electroporation ablation for atrial fibrillation

Abstract

Atrial fibrillation (AF) is one of the most important problems in modern cardiology. Thermal ablation therapies, especially radiofrequency ablation (RF), are currently "gold standard" to treat symptomatic AF by localized tissue necrosis. Despite the improvements in reestablishing sinus rhythm using available methods, both success rate and safety are limited by the thermal nature of procedures. Thus, while keeping the technique in clinical practice, safer and more versatile methods of removing abnormal tissue are being investigated. This review focuses on irreversible electroporation (IRE), a nonthermal ablation method, which is based on the unrecoverable permeabilization of cell membranes caused by short pulses of high voltage/current. While still in its preclinical steps for what concerns interventional cardiac electrophysiology, multiple studies have shown the efficacy of this method on animal models. The observed remodeling process shows this technique as tissue specific, triggering apoptosis rather than necrosis, and safer for the structures adjacent the myocardium. So far, proposed IRE methodologies are heterogeneous. The number of devices (both generators and applicators), techniques, and therapeutic goals impair the comparability of performed studies. More questions regarding systemic safety and optimal processes for AF treatment remain to be answered. This work provides an overview of the electroporation process, and presents different results obtained by cardiology-oriented research groups that employ IRE ablation, with focus of AF-related targets. This contribution on the topic aspires to be a practical guide to approach IRE ablation for cardiac arrhythmias, and to highlight controversial features and existing knowledge, to provide background for future improved experimentation with IRE in arrhythmology.

Intracardiac pulsed field ablation: Proof of feasibility in a chronic porcine model

“…RF energy delivered via the circular array catheter has been shown to efficiently create contiguous, transmural lesions capable of PV isolation with documented clinical efficacy and safety. [20][21][22][23] Based on previous surgical findings delivering PFA 16 and reports on catheter deliveries of DC shocks, we hypothesized that pulsed electric field delivery through the circular array catheter could create contiguous transmural myocardial lesions akin to RF energy. The PFA research pulse generator was a novel, customdesigned generator that was originally designed to create linear atrial cardiac lesions with bipolar tissue clamp ablation devices.…”

Cardiac electroporation: The promise of the unknown

“…As discussed by Wojtaszczyk et al., varied tissue placed in the same electrical field may have vastly varied effects. With certain electroporation delivery algorithms, it appears the neural tissue is spared, and further, there is promise where not only an epicardial coronary artery may be spared, but beneficial modification of the endothelial layer may also occur without aneurysm or thrombus formation …”

“…Wojtaszczyk et al . make a unique contribution to “Techniques, Technology, and Innovation” where they simultaneously introduce a potentially groundbreaking method for cardiac ablation and describe the viable techniques presently available to implement this technology.…”

Feasibility of selective cardiac ventricular electroporation

“…One animal experienced an idioventricular rhythm of fascicular origin, this dissipated spontaneously and did not recur. Considering all published preclinical [8,10,[47][48][49] and the recent first in human clinical data [50], it is reasonable to deduce that that direct cardiac IRE delivery within the ventricle or atrium (epicardial or endocardium) is reasonably safe (when timed with R wave).…”