Pulsed Field Ablation to Treat Atrial Fibrillation: A Review of the Literature

Abstract

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and catheter ablation, which can be used in symptomatic patients refractory to antiarrhythmic therapy. Pulmonary vein isolation (PVI) remains the cornerstone of any ablation procedure. A major limitation of current catheter ablation procedures is important to recognize because even when the PVI is performed in highly experienced centers, PVI reconnection was documented in about 20% of patients. Therefore, better technology is needed to improve ablation lesions. One of the novelties in recent years is pulsed filed ablation (PFA), a non-thermal energy that uses trains of high-voltage, very-short-duration pulses to kill the cells. The mechanism of action of this energy consists of creating pores in the myocardiocyte cell membrane in a highly selective and tissue-specific way; this leads to death of the target cells reducing the risk of damage to surrounding non-cardiac tissues. In particular during the animal studies, PVI and atrial lines were performed effectively without PV stenosis. Using PFA directly on coronary arteries, there was no luminal narrowing, there has been no evidence of incidental phrenic nerve injury, and finally, PFA has been shown not to injure esophageal tissue when directly applied to the esophagus or indirectly through ablation in the left atrium. The aim of this review is to report all published animal and clinical studies regarding this new technology to treat paroxysmal and persistent AF.

Study of necrotic apoptosis by pulsed electric field ablation in rabbit left ventricular myocardium

“…The basic biomedical engineering principles of PEF ablation are to release high electric-field energy in a short period of time at the microsecond and nanosecond levels by forming a local high-voltage difference through electrodes and to precisely deliver the electric field energy to the target area of the heart from the anatomically conformal design of the ablation catheter electrodes. PEF ablation increases cell membrane permeability through membrane electroporation, causing cell death ( 6 ). PEF ablation of cardiac myocytes is based on tissue resistance specificity, which determines the tissue PEF threshold differentiation, with the lowest ablation threshold of 400 V for cardiac myocytes, therefore prioritizing myocardial ablation, with complete cell death in the ablation area and less damage or even intact preservation of adjacent tissues such as blood vessels, nerves, and the esophagus in and around the ablation area ( 7 ).…”

“…permeability through membrane electroporation, causing cell death (6). PEF ablation of cardiac myocytes is based on tissue FIGURE Morphology of cardiac vessels and nerves in the ablation area (Masson staining).…”

New Perspectives on Risk Stratification and Treatment in Patients with Atrial Fibrillation: An Analysis of Recent Contributions on the Journal of Cardiovascular Disease and Development

“…As previously mentioned, much attention has been paid to the ultrastructural alteration of the left atrium (LA) in AF patients following the intriguing issue of atrial cardiomyopathy [ 24 , 25 , 26 ]. Several basic-science studies have investigated the micro-structural LA reproductions and the applicability of the new modality of catheter ablation in respect of such LA alterations [ 27 , 28 , 29 , 30 ]. The fetal AF theory was highlighted in some valuable papers enforcing the concept of the influence in AF predisposition both from the ambient, behaviour and lifestyle [ 31 , 32 , 33 ] and from the embryogenesis [ 34 , 35 , 36 ]/genetic pabulum [ 37 ].…”

“…Catheter ablation is one of the most improving techniques to treat non-permanent AF. An increasing amount of evidence on radiofrequency catheter ablation (RFCA), cryoballoon ablation (CB), and pulse-field (PF) ablation has been recently reported both in animal and human models [ 30 , 45 , 46 ].…”

“…The PF-CA may be an additional resource in the future of AF ablation for its extreme specificity in inducing apoptosis in the myocardiocytes by electroporation. Although animal studies represented the most conspicuous part of the literature on this topic [ 30 ], some initial human experience found the procedure safe and relatively simple to learn [ 56 ].…”