2020 AF Symposium

Pulsed Field Ablation—Emerging Tech for Atrial Fibrillation

by Steve S. Ryan, Updated June 15, 2021

This article on Pulsed Field Ablation (PFA) may be challenging to read. But it’s worth it. As an emerging technology, there are many concepts and treatment strategies that will be brand new to you (they were for me). I expect PFA will change the way catheter ablations are done and will become an innovative and most effective treatment option for A-Fib.

The video presentations at the AF Symposium are always well attended. Usually these cases are presented live via streaming video. But this time the case was a pre-recorded video.

This emerging technology, Pulsed Field Ablation, and how it works was presented on video by Dr. Vivek Reddy from Mount Sinai Medical Center in New York City and by Dr. Petr Neuzil from Homolka Hospital in Prague, Czech Republic.

Dr. Reddy provided live commentary from the podium while the recently recorded patient procedure played on the screen behind him.

Pulsed Field Ablation (PFA) and Electroporation

Pulsed Field Ablation (PFA) from Farapulse, Inc. creates an instantaneous electrical field to open tiny doors (nanopores) in nearby cells, a process called ‘electroporation’ (electro-POR-ation).

Shortly thereafter, the contents of the cell exit through these doors and the cell dies.

Unlike current methods of ablation (i.e., radiofrequency and cryo) which rely on cooking or freezing tissue, PFA retains the cell’s original structure even after death and does not rely on thermal effects.

More importantly, PFA works on the selected cell types while leaving others alone.

Video Presentation: Pulsed Field Ablation Case

On the video, we saw Dr. Reddy use fluoroscopy to move the Farapulse catheter (Farawave) to the opening of the Left Superior Vein, a position similar to where one would place a balloon catheter.

The configuration of the catheter looked like a flat five-petal flower. He was also able to change the configuration to a more spherical “basket” shape. Each of the five splines contained four separate electrodes which delivered the PFA energy. The fully deployed flower-shaped configuration had a diameter of 31 mm.

Those same electrodes that delivered the PFA energy also recorded signals from the heart to show that the ablation was effective. They could switch back and forth during the ablation procedure.

Direct Contact Not Necessary

We watched how they delivered one application of PFA, then 10 seconds later they rotated the five-spline catheter a few degrees and delivered another application to optimize coverage and proximity.

Dr. Reddy explained that they perform two paired deliveries with the basket configuration, then two more with the flower configuration with occasional rotation of the catheter. They didn’t seem to worry about achieving direct, hard contact with the Pulmonary Vein (PV) openings.

Someone from the audience asked, “How much contact do you need?” Dr. Reddy replied, “You definitely need proximity. Do you actually need  contact? No. But you need proximity, to be within a couple of millimeters of the targeted tissue.”… “We’re not going to cause PV stenosis with this.”

We saw how the electrograms of A-Fib signals disappeared as the PFA applications progressed. The application process seemed to move very fast. Dr. Reddy stated that he could vary the size and shape of the configurations to fit individual anatomies.

Affects Heart Tissue but Not the Esophagus

Dr. Reddy added (enthusiastically),“What is really exciting about it is tissue selectivity.” He talked about how each tissue seems to have a different threshold for necrosis (cell death) which makes PFA very tissue selective.

PFA can affect heart tissue (cardiomyocytes) while not affecting nerve fibers or the esophagus. We watched as he ablated the Right Superior PV which seemed very close to the Phrenic Nerve. Dr. Reddy described how in 120 cases to date, he has never seen Phrenic Nerve paralysis or even palsy.

Posterior Wall Ablation

Using the flower configuration, Dr. Reddy then ablated the posterior wall by simply making overlapping flower-shaped petal lesions, two sets of lesions in each location. This also seemed to go very fast.

Cavo-Tricuspid Isthmus Line

He also showed how he made a Cavo-Tricuspid Isthmus line (to ablate Flutter from the right atrium) by switching to a catheter with a small basket used as a focal catheter.

After the video ended, Dr. Reddy said they have already performed 126+ ablations using PFA. (Certainly seems ready for ‘prime time’.)

Characteristics of Pulsed Field Ablation (PFA)

Tissue Selective and Safer

The underlying process of Pulsed Field Ablation called “Irreversible Electroporation” is tissue selective. Cardiomyocytes (heart tissue) happen to have a particularly low threshold to these electrical fields which don’t affect other surrounding non-heart tissue such as the esophagus or phrenic nerve. In practical terms, this means that PFA is much safer than current ablation energy sources.

Very Fast and Precise

Pulsed Field Ablation is a non-thermal energy system that uses a series of ultra-short electrical pulses to ablate heart tissue. This series of pulses, or the “waveform”, makes a long-lasting lesion in a manner of seconds. PFA can be  delivered in seconds or minutes compared with hours for radiofrequency.

PFA is not only very fast but very precise as well. The Farapulse generator, which creates the waveform, can be programmed to deliver therapy through different PFA catheters.

Doesn’t Require Direct Contact

Unlike standard ablation energy sources such as RF (heat) and Cryo (freezing), the PFA catheter does not require actual physical contact but only needs proximity to the tissue to be ablated. And it doesn’t cause scarring or char formation.

Doesn’t Produce Stenosis

Clinical trials have shown that direct application of PFA to pulmonary veins does not seem to result in PV stenosis (swelling) which can occur from heating (RF) or cooling (cryo).

FDA ‘Breakthrough Device’ Designation for PFA

The FDA gave PFA (Farapulse, Inc.) their Breakthrough Device designation May 8, 2019. This FDA Program is designed to “help patients receive more timely access to breakthrough technology which has the potential to provide more effective treatment and diagnosis for life-threatening or irreversibly debilitating diseases and  conditions.”

Translation: The FDA recognized how PFA can potentially change the nature of catheter ablation and become a major innovative improvement in the treatment of patients with A-Fib.

PFA Ablation: A Few Years Away for A-Fib Patients

As Dr. Jais and others commented at the end of the presentation, it will probably take 3-5 years for PFA to be available for A-Fib patients worldwide.

Assuming eventual FDA approval (very likely), the small start-up company Farapulse, Inc. will probably have to be bought by a major device manufacturer with a world-wide manufacturing, marketing and distribution network. That’s probably the only way to produce and distribute the Farapulse Pulsed Electrical Field generators in quantities sufficient to treat large numbers of A-Fib patients.

Disclosure: Dr. Vivek Reddy of Mount Sinai Medical Center in New York city has invested in and owns stock in Farapulse, Inc. This is an indication of the confidence he has in PFA technology.

Editor’s Comments

Note: All forward-looking statements and claims regarding safety and effectiveness are those of the author alone.

PFA Ablation: A True Game Changer: Everyone at the AF Symposium was in awe at how fast, easy and effective PFA ablation seemed to be.

I predict that Pulsed Field Ablation will supersede all other types of catheter ablation for A-Fib. But it will probably take 3-5 years for PFA ablation to become standard and available for most A-Fib  patients.

Update: June 2021: This estimate was way too conservative. Farapulse has already received CE Mark approval and can market in the Europeans Union and other CE Mark countries. In the U.S.. the ADVENT Trial, is underway with the first patients treated at New York’s Mount Sinai Hospital by Vivek Reddy, M.D.

But Don’t Wait for PFA: If you are asking yourself if you should wait 3-5 years for PFA ablation to be available, the answer is no. Today’s ablation techniques are very good and effective, though not apparently as good as PFA. And waiting 3-5 years for an ablation could do serious harm to your heart.

In fact, read about my second Ablation in 2019, 20 years after the first.

Thanks to Farapulse, Inc who provided technical content and images for this report. For anyone interested in investing in PFA and Farapulse, Inc., it’s a privately held company with no stock currently available.

Read More About Pulsed Field Ablations (PFA)

See my summaries of five abstracts (one-page descriptions of A-Fib research) distributed at the Symposium as a printed digest.

• Lesion Durability and Safety Outcomes of Pulsed Field Ablation

• Pulsed Field Ablation with CTI Lesions Terminates Flutter in a Small Study

• Durability of Pulsed Field Ablation Isolation Over Time: Preliminary Study

• Pulsed Field Ablation vs RF Ablation: A Study in Swine 

• Using MRI to Check Pulsed Field Ablations (PFA)

If you find any errors on this page, email us. Y Last updated: Tuesday, June 15, 2021

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