Doctors & patients are saying about 'A-Fib.com'...
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Dr. Douglas L. Packer, MD, FHRS, Mayo Clinic, Rochester, MN
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“I really appreciate all the information on your website as it allows me to be a better informed patient and to know what questions to ask my EP.
Faye Spencer, Boise, ID, April 2017
“I think your site has helped a lot of patients.”Dr. Hugh G. Calkins, MD Johns Hopkins,
Baltimore, MD
2026 AF Symposium
Pulsed Field Ablation Safety Session 1—Complications Associated with Pulsed Field vs Radiofrequency Ablation for AF
The 2026 AF Symposium had two full sessions with several speakers on the safety of Pulsed Field Ablation (PFA) for treating Atrial Fibrillation, reflecting the increased scrutiny and challenges that have arisen with the rapid, widespread adoption of Pulsed Field Ablation.
Some of the topics addressed in the presentations were:
· Complications
· Collateral Injury, Hemolysis
· Coronary Artery Spasm
· Real World Safety in 40,000 PFA patients
· Setting up a PFA Registry through the Heart Rhythm Society
· Air Embolism with Large PFA Sheaths
· Phrenic Nerve Stunting
· Conscious Sedation, Minimizing Muscle Stimulation
· Predicting PFA Lesion Efficacy
· Integrating PFA Workflow with AI (Artificial Intelligence)
Session 1 Safety of PFA: Complications Associated with Pulsed Field vs Radiofrequency Ablation for AF
The Early Days of PVI
Dr. Hugh Calkins
Dr. Hugh Calkins (Johns Hopkins Hospital, Baltimore, MD) described how 28 years ago Pulmonary Vein Isolation/Ablation (PVI) with Radio Frequency (RF), i.e., thermal energy, became the cornerstone of treating A-Fib.
In the early days of PVI, the major complication rate was 6% with 0.5% dying in the hospital. He mentioned stenosis (discovered in 1998), atrial esophageal fistula (2004), phrenic nerve damage (2005), cerebral embolism (2006), and gastric paralysis (2008).
He suggested that like RF developing a set of complications or discovering them over time, the same may happen with PFA. Time may reveal more complications with PFA than we are aware of currently.
Pulsed Field Ablation (PFA) Improves Complication Rate—But Has Its Own Problems
The good news is that over time the complication rate for catheter ablation, i.e., Pulmonary Vein Isolation/Ablation, has decreased remarkedly down to less than 1% (from a high of 6%).
Pulsed Field Ablation (PFA) has a low complication rate and is recognized as a major safety improvement over RF ablation. It avoids much of the damage seen with RF (thermal energy) ablation. Furthermore, it doesn’t harm adjacent tissue.
PFA Complication Treatments & Precautions: Nitroglycerin is used for coronary spasm, supplements and medications are prescribed for hemolysis, and the use of improved ablating and mapping techniques for better lesion formation.
But according to Dr. Calkins, “sadly we are still discovering new complications.”
PFA Complications
Reported PFA complications include coronary spasm (discovered in 2021), renal failure due to hemolysis (destruction of red blood cells) (2024), coronary narrowing (2025), problems with lesion formation (2026) and life-threatening ischemia/delayed sudden cardiac death (2026).
For current research on complications, Dr. Calkins referred attendees to the MANIFEST-17K study ”Safety of pulsed field ablation in more than 17,000 patients with atrial fibrillation in the Manifest-17k study.”
Two Recent Sudden Deaths!
In addition, Dr. Calkins reported the disturbing news of two sudden cardiac deaths as reported in the publication, Circulation (December 2025 issue).
Editor’s Comments
Editor’s CommentsPFA is Here To Stay: Pulsed Field Ablation (PFA) safety is a major improvement over PVIs with RF (using thermal energy) which is now used primarily for specialized needs.
PFA Set of Complications: As Dr. Calkins pointed out, PFA has developed its own set of complications which for the most part are dealt with, e.g., nitro for coronary spasm, supplements and medications for hemolysis, improved ablation and mapping for better lesion formation.
PFA Complication Rates: A large July 2024 study reported a 1% major complication rate. Other studies have shown rates between 0.5% and 2.3%.
Sudden Deaths are Obviously a Major Concern! The recent cases of sudden cardiac death are obviously a major problem that needs serious investigation.
Dr. Calkins postulated that these sudden deaths could be like when RF was causing damage to the esophagus before researchers knew about atrial esophageal fistula. I will be looking for the findings on what caused these deaths and will report them on A-Fib.com.
