title: Left atrial appendage anatomy and function: short term response to sustained atrial fibrillation.
abstract: OBJECTIVE
  To determine whether there is significant atrial or atrial appendage enlargement or functional remodelling as a result of one to two months of sustained atrial fibrillation, a duration similar to that experienced by patients undergoing warfarin anticoagulation before elective cardioversion.
  
  
  METHODS
  To test the hypothesis that left atrial and left atrial appendage enlargement develop as a result of short term atrial fibrillation, serial anatomical and functional indices were measured using transoesophageal echocardiography (TOE) in 20 patients with recent onset atrial fibrillation (14 men, six women; mean (SEM) age 67 (2) years). Serial TOE was performed 2.5 months apart in patients with sustained atrial fibrillation.
  
  
  RESULTS
  There was no significant change in left atrial area (23.7 cm(2) to 24.1 cm(2), p = 0.98); length (5.7 cm to 5.7 cm, p = 0.48); width (5.2 cm to 5.2 cm, p = 0. 65); volume (83 cm(3) to 87 cm(3), p = 0.51) or left atrial appendage area (7.9 cm(2) to 8.1 cm(2), p = 0.89); length (4.6 cm to 4.5 cm, p = 0.8); or width (2.5 to 2.4 cm, p = 0.87). Peak left atrial appendage velocity ejection (0.2 m/s to 0.2 m/s, p = 0.57), and presence of severe spontaneous echo contrast in the left atrial appendage (n = 15 (75%) to n = 13 (72%)) were also not significantly different. There was no correlation between changes in left atrial or left atrial appendage dimensions.
  
  
  CONCLUSIONS
  In the setting of sustained atrial fibrillation, significant left atrial and left atrial appendage functional and anatomical remodelling do not occur with atrial fibrillation of a duration similar to that used for conservative anticoagulation in preparation for cardioversion.
authors.affiliation: Department of Medicine (Cardiovascular Division) and the Harvard-Thorndike Laboratory of Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Weigner
authors.forename: S E
authors.initials: SE
authors.lastname: Katz
authors.forename: P S
authors.initials: PS
authors.lastname: Douglas
authors.forename: W J
authors.initials: WJ
authors.lastname: Manning
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D020517:Atrial Appendage / Q000000981:diagnostic imaging / Q000473:pathology*; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000473:pathology*; D004452:Echocardiography; D017548:Echocardiography, Transesophageal; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013997:Time Factors