title: Impact of atrial remodeling on heart rhythm after radiofrequency ablation and mitral valve operations.
abstract: BACKGROUND
  This study was conducted to determine the effect of left atrial structural remodeling on heart rhythm after radiofrequency ablation concomitant to mitral valve operation.
  
  
  METHODS
  Sixty-six consecutive patients with of atrial fibrillation (AF) and mitral valve disease underwent radiofrequency ablation and mitral valve operation. Heart rhythm was evaluated before and at 3, 6, and 12 months postoperatively. Biopsy specimens of the posterior wall of the left atrium were evaluated for the extent of fibrosis, myocyte diameter, intensity of inflammatory infiltrates, degree of myocytolysis, and capillary density.
  
  
  RESULTS
  Ten patients died and 1 patient was lost to follow-up. Heart rhythm at 12 months was used to divide the remaining 55 patients into two groups: group I, 34 with sinus rhythm; group II, 21 with AF. Paroxysmal AF preoperatively was more frequent among group I patients, and persistent/long-standing persistent AF in group II (p=0.0006). Groups I and II differed significantly in myocyte diameter (17.9±3.5 vs 20.3±4.6 μm, p=0.04), fibrosis percentage (38.7%±11.2% vs 47.6%±12.3%, p=0.009), inflammatory infiltrates (p=0.02), and preoperative left atrial diameter (5.03±0.7 vs 5.5±0.8 cm, p=0.04). No differences were found in capillary density (797.9±500.6 vs 946.0±373.7/mm2, p=0.3) and myocytolysis (p=0.4). Multivariate analysis showed myocyte diameter (p=0.047) and fibrosis (p=0.014) were independent predictors for an AF persistence at 12 months.
  
  
  CONCLUSIONS
  Left atrial structural remodeling strongly affects heart rhythm after concomitant radiofrequency ablation and mitral valve operation.
authors.affiliation: I Department of Cardiology, Poznan University of Medical Sciences, Poznan, Poland. anna.olasinska@poczta.onet.pl
authors.forename: Anna
authors.initials: A
authors.lastname: Olasinska-Wisniewska
authors.forename: Tatiana
authors.initials: T
authors.lastname: Mularek-Kubzdela
authors.forename: Stefan
authors.initials: S
authors.lastname: Grajek
authors.forename: Andrzej
authors.initials: A
authors.lastname: Marszalek
authors.forename: Wojciech
authors.initials: W
authors.lastname: Sarnowski
authors.forename: Marek
authors.initials: M
authors.lastname: Jemielity
authors.forename: Wojciech
authors.initials: W
authors.lastname: Seniuk
authors.forename: Maciej
authors.initials: M
authors.lastname: Lesiak
authors.forename: Marek
authors.initials: M
authors.lastname: Prech
authors.forename: Tomasz
authors.initials: T
authors.lastname: Podzerek
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods* / Q000401:mortality; D015331:Cohort Studies; D003131:Combined Modality Therapy; D015150:Echocardiography, Doppler; D004562:Electrocardiography / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000473:pathology*; D006349:Heart Valve Diseases / Q000150:complications / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D019918:Heart Valve Prosthesis Implantation / Q000379:methods* / Q000401:mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000473:pathology* / Q000601:surgery; D015999:Multivariate Analysis; D011182:Postoperative Care / Q000379:methods; D011183:Postoperative Complications / Q000453:epidemiology / Q000503:physiopathology; D020127:Recovery of Function; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D016896:Treatment Outcome