Cardiologists at the Mayo Clinic Heart Rhythm Clinic in the United States have used a new and innovative energy source to safely and successfully treat atrial fibrillation. The treatment, called pulsed-field ablation, has received FDA approval, marking a major breakthrough that culminated years of research and is superior in several respects to traditional ablation.
atrial fibrillation
Atrial fibrillation is a heart rhythm disorder that causes the heart to beat irregularly, which can cause blood clots to form in the heart and thus increase the risk of stroke.
It is estimated that by 2030, 12.1 million people in the United States will be diagnosed with atrial fibrillation, more than double the number in 2010. Globally, the number of patients diagnosed with atrial fibrillation is increasing.
Sometimes atrial fibrillation causes no symptoms, and the person has no idea that their heartbeat is irregular. The condition is discovered during a routine examination. Symptoms may include heart palpitations, where the patient feels as if their heart is fluttering or beating irregularly, and this usually lasts a few seconds, or perhaps minutes, and irregular heartbeats, where the heart may beat very quickly.
Doctors can use medications and treatments to help the heart return to normal rhythm, but some patients have persistent atrial fibrillation that gets worse over time. Ablation therapy has been used to treat these patients for two decades, but pulsed-field ablation uses a different approach.
Conventional ablation versus pulsed ablation
Ablation has traditionally been used as a secondary treatment for people with atrial fibrillation who have debilitating symptoms and whose condition has not been controlled by medications.
When performing the ablation, the doctor guides a thin, flexible catheter tube through a large vein to the heart. A device attached to the tip of the catheter tube emits energy that destroys small spots of heart tissue that are causing an electrical disturbance in the heart.
Instead of applying heat or cold as in traditional ablation, pulsed field ablation uses short bursts of high-energy energy called irreversible electroporation to affect the heart tissue that causes atrial fibrillation. Pulsed field therapy was successfully performed on patients at Mayo Clinic in Rochester in February 2024. Since then, cardiologists have used pulsed field therapy to treat more than 200 patients with atrial fibrillation.
Obstacles were the inspiration for this innovation.
“The traditional approach to treating atrial fibrillation using thermal energy sources, radiofrequency, laser, cold energy…all carry the risk of injury to nearby structures such as the esophagus and phrenic nerve,” says Dr. Siraj Kaba, a cardiac electrophysiologist at Mayo Clinic in Rochester, Minnesota.
Pulsed field ablation technology has been in development for more than 18 years. Pioneering research at Mayo Clinic began with ablation therapy under the direction of another cardiac electrophysiologist, innovative inventor Samuel J. Asirvatham, M.D., who had a growing interest in developing new energy sources that would allow selective action on heart tissue.
“The principle behind pulsed-field ablation is that, depending on the composition of cell membranes of different tissue types, some tissues may have different energy thresholds that can be necrotic or ablated while other tissue types are preserved,” says Kaba. “It has been suggested through hundreds of preclinical experiments that pulsed-field ablation of cardiac tissue could allow a targeted approach to cardiac tissue ablation while avoiding collateral injury to structures such as the esophagus or phrenic nerve.”
Benefits of pulsed field ablation
Pulsed field ablation can reduce procedure time, reduce anesthesia time, and eliminate some of the risks associated with traditional atrial fibrillation ablation.
“Reducing risks and making effective treatments more widely available is crucial to delivering treatment to as many patients as possible,” Dr. Kaba said, according to EurekAlert.
“There is a growing body of evidence supporting more aggressive rhythm control using ablation, both early in AF diagnosis for better long-term outcomes and in the context of other comorbidities such as heart failure, where ablation has been shown to reduce mortality,” Kaba adds.
Next steps
Early data from preclinical trials suggest that pulsed field ablation may be superior to current thermal energy-based approaches in this area. Looking ahead, Dr. Kaba anticipates rapid growth and development of pulsed field therapy.
“Within the next year, we expect to introduce at least a half-dozen catheters and systems that use pulsed field therapy, providing new research opportunities and the potential to deliver transformative care to patients with heart rhythm disorders,” he explains.