SAN DIEGO–Recurrence of symptoms is common for many patients treated for atrial fibrillation, at least partly because the source of the arrhythmia is unknown. New research seeks to remedy that situation.
Reporting earlier this year in Journal of the American College of Cardiology, researchers involved in the Conventional Ablation for Atrial Fibrillation With or Without Focal Impulse and Rotor Modulation (CONFIRM) trial found that atrial fibrillation is caused by small electrical sources within the heart, in the form of electrical spinning tops (“rotors”) or focal beats. They also pinpointed a way to detect the sources so that therapy can be more effective.1
“Localized electrical rotors and focal impulse sources are prevalent sustaining mechanisms for human AF. [Focal Impulse and Rotor Modulation] ablation at patient-specific sources acutely terminated or slowed AF, and improved outcome. These results offer a novel mechanistic framework and treatment paradigm for AF,” the authors write.
The CONFIRM study, led by Sanjiv Narayan, MD, PhD, director of electrophysiology at the San Diego VAMC and a University of California professor, examined 107 patients with atrial fibrillation referred for a nonsurgical catheter ablation procedure. The new FIRM technique to help perform precise burns was used in one group of patients, while the other group received conventional catheter procedures.
Researchers found that FIRM shut down or significantly reduced atrial fibrillation in 86% of patients in an average of only 2.5 minutes.
“During a median 273 days (interquartile range: 132 to 681 days) after a single procedure, FIRM-guided cases had higher freedom from AF (82.4% vs. 44.9%; p <0.001) after a single procedure than FIRM-blinded cases with rigorous, often implanted, electrocardiography monitoring,” according to the report. Overall, the new method demonstrated an 86% improvement over conventional treatment, according to the authors.
“We are very excited by this trial, which for the first time shows that atrial fibrillation is maintained by small electrical hotspots, where brief FIRM guided ablation can shut down the arrhythmia and bring the heart back to a normal rhythm after only minutes of ablation,” Narayan said.
1. Narayan SM, Krummen DE, Shivkumar K, et.al. Treatment of Atrial Fibrillation by the Ablation of Localized Sources: CONFIRM (Conventional Ablation for Atrial Fibrillation With or Without Focal Impulse and Rotor Modulation) Trial. J Am Coll Cardiol. 2012 Aug 14;60(7):628-36. Epub 2012 Jul 18. PubMed PMID: 22818076; PubMed Central PMCID: PMC3416917.