title: Left atrial appendage ligation in patients with atrial fibrillation leads to a decrease in atrial dispersion.
abstract: BACKGROUND
  Left atrial appendage (LAA) exclusion has been performed in patients with atrial fibrillation (AF) to prevent thrombus formation and subsequent cardioembolic events. Left atrial electrical remodeling is a recognized factor in the recurrence of AF. The effects of LAA exclusion on P-wave characteristics and left atrial electrical remodeling have not been well described. The purpose of this study was to evaluate the effect of LAA ligation on P-wave morphology in patients with AF.
  
  
  RESULTS
  Fifteen patients who were in sinus rhythm during the LAA ligation procedure were included in the study. We evaluated the P-wave characteristics, including P-wave duration, P-wave amplitude, PQ interval, and P-wave dispersion, before and after ligation. Eleven patients had paroxysmal AF and 4 patients had persistent AF (12 male patients and 3 female patients). P-wave duration immediately after ligation was significantly shorter compared with baseline in all limb leads except lead aVR (P<0.05). P-wave amplitude immediately after ligation was significantly greater compared with baseline in inferior leads; however, P-wave amplitude after 1 to 3 months was significantly lower compared with immediately after ligation. PQ interval immediately after ligation was significantly shorter compared with baseline (P=0.01), and P-wave dispersion after 1 to 3 months was significantly shorter compared with baseline (P=0.02).
  
  
  CONCLUSIONS
  LAA exclusion produces consistent P-wave changes consistent with decreased atrial mass and decreased atrial dispersion that may represent reverse electrical atrial remodeling. This is a potential mechanism to explain the role of LAA ligation in maintaining sinus rhythm in patients with AF.
authors.affiliation: Section of Cardiac Electrophysiology, Division of Cardiology, University of California, San Francisco, San Francisco, CA (M.K., M.M.S., R.J.L., N.B.).
authors.forename: Mitsuharu
authors.initials: M
authors.lastname: Kawamura
authors.affiliation: Section of Cardiac Electrophysiology, Division of Cardiology, University of California, San Francisco, San Francisco, CA (M.K., M.M.S., R.J.L., N.B.).
authors.forename: Melvin M
authors.initials: MM
authors.lastname: Scheinman
authors.affiliation: Section of Cardiac Electrophysiology, Division of Cardiology, University of California, San Francisco, San Francisco, CA (M.K., M.M.S., R.J.L., N.B.).
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Lee
authors.affiliation: Section of Cardiac Electrophysiology, Division of Cardiology, University of California, San Francisco, San Francisco, CA (M.K., M.M.S., R.J.L., N.B.).
authors.forename: Nitish
authors.initials: N
authors.lastname: Badhwar
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020517:Atrial Appendage / Q000000981:diagnostic imaging / Q000601:surgery*; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D064752:Atrial Remodeling; D006348:Cardiac Surgical Procedures / Q000379:methods; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008026:Ligation / Q000379:methods; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional / Q000379:methods
keywords: P wave; atrial fibrillation; atrial remodeling; left atrial appendage; ligation