title: Focal impulse and rotor modulation as a stand-alone procedure for the treatment of paroxysmal atrial fibrillation: A within-patient controlled study with implanted cardiac monitoring.
abstract: Focal impulse and rotor modulation (FIRM) has been proposed as a novel approach for the treatment of atrial fibrillation (AF).
  
  
  
  This study aimed to investigate the efficacy of FIRM as a stand-alone procedure for the treatment of paroxysmal AF.
  
  
  
  A total of 27 patients with paroxysmal AF underwent sequential biatrial computational mapping. Sites with repetitive centrifugal or spiral reentry-like activity were considered to be AF-sustaining sources and targeted by irrigated radiofrequency (RF) ablation. All patients were seen in the outpatient clinic after 1, 3, and 6 months and thereafter every 6 months. Cardiac monitors were implanted 3 months before ablation in 17 patients (63%).
  
  
  
  Repetitive activity interpreted as sustained AF sources was found in all patients, with an average of 3.0 ± 1.1 sources located in the left atrium and 0.6 ± 0.6 sources in the right atrium. The majority of sources were rotors (95%). The total source-ablation radiofrequency time was 20.0 ± 9.0 minutes. At 15.2 ± 3.9 months of follow-up, the prespecified end point of <1% AF burden (outside a 3-month blanking period) was achieved in 2 of the 17 continuously monitored patients (12%). Of all the 27 patients who underwent FIRM, AF episodes of ≥30 minutes were recorded in 23 (85%), while AF episodes ≥60 minutes were recorded in 21 patients (78%).
  
  
  
  This study suggest that biatrial ablation of localized patient-specific sources alone, as detected by this method, is not sufficient to reduce paroxysmal AF burden in the majority of patients.
authors.affiliation: Arrhythmia Section, Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway. Electronic address: rfb123@hotmail.com.
authors.forename: Rolf Franck
authors.initials: RF
authors.lastname: Berntsen
authors.affiliation: Arrhythmia Section, Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Trine Fink
authors.initials: TF
authors.lastname: Håland
authors.affiliation: Arrhythmia Section, Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Rita
authors.initials: R
authors.lastname: Skårdal
authors.affiliation: Arrhythmia Section, Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Torbjørn
authors.initials: T
authors.lastname: Holm
mesh_terms: D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D018780:Body Surface Potential Mapping; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography; D004567:Electrodes, Implanted; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D019990:Perioperative Care
keywords: Atrial fibrillation; Catheter ablation; Mapping; Radiofrequency; Rotors