Pulsed Field Ablation—Groundbreaking Innovation in Atrial Fibrillation!

3D mapping images of heart during Pulsed Field Ablation

One of the most important, groundbreaking innovations in Atrial Fibrillation (A-Fib) treatment is Pulsed Field Ablation. PFA is widely approved and used in Europe beginning in 2021 when Boston Scientific first secured a CE mark for its Farapulse Pulsed Field Ablation system.

In the U.S., the Boston Scientific Farapulse PFA first received U.S. Food and Drug Administration (FDA) Breakthrough Device designation in 2019, a path designed to expedite development of technology for life-threatening or irreversibly debilitating diseases. Then, the Farapulse PFA was FDA approved in January 2024.

The market now includes five FDA-approved Pulsed Field Ablation systems: Boston Scientific’s Farapulse, Medtronic’s Affera, Medtronic’s Pulse Select, Johnson & Johnson’s Varipulse, and Abbott’s Volt.

Challenging Reading: Pulsed Field Ablation is an emerging technology with many new concepts and treatment strategies.

What Makes Pulsed Field Ablation Different

Preceding Pulsed Field Ablation, the two main energy systems for catheter ablation were thermal, i.e., radiofrequency (RF) (heat) and Cryo (freezing).

Pulsed Field Ablation instead uses a fundamentally different process called “Irreversible Electroporation”.

Illustration of damaged esophagus during catheter ablation: Left, RF ablation; Center, CryoBalloon ablation; Right, Normal Esophagus with Pulsed Field Ablation.

During Irreversible Electroporation, an instantaneous electrical field is applied to targeted cells which open up tiny doors (nanopores). Shortly thereafter, the contents of the cell exit through these doors, and the cell dies. The cell is rendered electrically inactive.

Unlike ablated tissue using RF and Cryo thermal energy, PFA retains the cell’s original structure even after cell death. Because it doesn’t rely on thermal effects, there is no charring or crust formation.

This electroporation process is tissue selective. Heart tissue (cardiomyocytes) has a particularly discriminating threshold to those specific electrical pulses, meaning the signal doesn’t affect other surrounding non-heart tissue such as the esophagus or phrenic nerve.

Video still: Boston Scientific FARAPULSE™ PFA System Workflow Animation.

Most importantly, in practical terms, this means that PFA is much safer than other ablation energy sources.

PFA Fast, Precise and Versatile

Pulsed Field Ablation, using irreversible electroporation energy, delivers a series of ultra-short electrical pulses to ablate heart tissue. This series of pulses, or “waveform,” makes a long-lasting lesion in a matter of seconds.

By comparison, ablation lesions using thermal technologies, i.e., radiofrequency (RF) and Cryo (freezing) can take much longer (60 seconds–150 seconds per lesion).

This translates into shorter catheter ablation procedural times, i.e., usually 1–3 hours for PFA versus 3–5 hours for RF and Cryo Catheter Ablations.

Pulsed Field Ablation is also very precise and versatile. PFA can be programmed to deliver ablation therapy through the many different styles of today’s ablation catheters.

[For purposes of discussion, we will describe use of the Boston Scientific FARAPULSE™ PFA Systemom ]

FARAPULSE Catheter: Two Configurations

Farapulse catheter Open-Basket configuration

Farapulse catheter Flower configuration

One configuration of the FARAPULSE catheter looks like a flat five-petal flower. This can be changed to a more spherical “basket” shape.

Each of the five splines contains four separate electrodes which deliver the PFA energy. The fully deployed flower-shape configuration has a current diameter of 31mm.

Pulsed Field Ablation: Pulmonary Veins and Other Areas

A typical Pulsed Field Ablation using the FARAPULSE™ PFA System involves two paired energy deliveries, first with the basket configuration, then with the flower configuration.

Illustration: Basket configuration

Illustration: Flower configuration

The catheter is first deployed to basket configuration in the left atrium and positioned in the opening of a Pulmonary Vein. Two paired Pulse Field applications are performed each 2.5 seconds in duration rotating the catheter between paired applications.

The catheter is then deployed to flower configuration, and 10-seconds later two final paired applications with rotation are performed for a total of eight applications per vein to complete and ensure electric field penetration. The procedure is repeated as needed for the remaining Pulmonary Vein openings.

The same technique can be used in other areas of the heart, i.e., ablating the Posterior Wall of the Left Atrium. Or, in the right atrium, for example, making a Cavo-Tricuspid Isthmus line to ablate Flutter.

These same electrodes that delivered the PFA energy can also record signals from the heart to show that an ablation is effective.

Pulsed Field Ablation is typically performed under general anesthesia. For many patients, recovery is resting for a few hours before going home the same day or the next morning.

Low Complication Rate

The main advantage of PFA is that it limits the risk of injury to the organs surrounding the heart. Research shows that PFA lowers the risk when it comes to:

▪ Esophagus damage
▪ Phenic nerve damage
▪ Pulmonary vein stenosis

A large July 2024 study reported a 1% major complication rate (similar to RF/Cyro ablation compilation rates). Other studies have shown rates between 0.5% and 2.3%.

In addition to these reduced risks, PFA is also generally more efficient than traditional ablation. This means less time under general anesthesia.

For a more detailed report of a Farapulse ablation, see 2021 AF Symposium: Pulsed Field Ablation—Emerging Tech for Atrial Fibrillation

Pulsed Field Ablation: A True Game Changer!

PFA catheters: variety of shapes and sizes from Boston Scientific, Medtronic, Johnson & Johnson and Abbott.

I’ve watched Pulsed Field Ablation technology evolve over the past five–six years at the various AF Symposium conferences I attend each year.

It was amazing to see how fast, easy and effective PFA appear for treating Atrial Fibrillation. And the data show that PFA, in general, is safe and effective.

Rapid Adoption of PFA: We’re seeing rapid, widespread adoption of PFA first in Europe and now in the US and worldwide. I predict that Pulsed Field Ablation will supersede all other types of ablation for Atrial Fibrillation.

But Don’t Postpone Your Ablation to Wait for PFA. If PFA isn’t available to you, remember that A-Fib is a progressive disease that can alter and damage your heart over time. If you are considering a catheter ablation, know that RF and Cryo are very good and effective, so don’t postpone having your ablation.

Related Posts