title: Impact of left atrial appendage exclusion on left atrial function.
abstract: OBJECTIVE
  We sought to investigate the short-term and midterm effects of left atrial appendage exclusion on left atrial function. Left atrial appendage exclusion is considered a possible therapeutic option for stroke prevention in patients with atrial fibrillation. Favorable outcomes have encouraged widespread use of left atrial appendage exclusion for cardiac surgical patients-even for patients in sinus rhythm who have stroke risk factors; however, the chronic effects on left atrial function of left atrial appendage exclusion are unclear.
  
  
  METHODS
  Nineteen mongrel dogs (29.7 +/- 5.2 kg) in sinus rhythm were studied. The Doppler signals from the pulmonary venous flow, transmitral flow, and tissue Doppler imaging of mitral annular motion were obtained before and after left atrial appendage exclusion. Dogs were evaluated in the same manner at 7 days (n = 2), 30 days (n = 7), or 90 days (n = 10) after left atrial appendage exclusion.
  
  
  RESULTS
  Except for a significant increase in early diastolic transmitral flow velocity after left atrial appendage exclusion (P = .01), no significant differences were found in any parameters related to the transmitral flow and tissue Doppler imaging measurements throughout follow-up. The systolic components of pulmonary venous flow at follow-up revealed a significant reduction relative to baseline (peak systolic velocity P < .0001, systolic velocity-time integral P < .0001), despite the lack of significant changes in left atrial pressure, left ventricular volume, and stroke volume.
  
  
  CONCLUSIONS
  Left atrial appendage exclusion may affect left atrial reservoir function in the short-term and midterm periods. Further long-term studies with more clinically relevant models are needed.
authors.affiliation: Department of Biomedical Engineering, Lerner Research Institute, The Cleveland Clinic, Cleveland Ohio 44195, USA.
authors.forename: Keiji
authors.initials: K
authors.lastname: Kamohara
authors.forename: Zoran B
authors.initials: ZB
authors.lastname: Popović
authors.forename: Masao
authors.initials: M
authors.lastname: Daimon
authors.forename: Maureen
authors.initials: M
authors.lastname: Martin
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Ootaki
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Akiyama
authors.forename: Firas
authors.initials: F
authors.lastname: Zahr
authors.forename: Faruk
authors.initials: F
authors.lastname: Cingoz
authors.forename: Chiyo
authors.initials: C
authors.lastname: Ootaki
authors.forename: Michael W
authors.initials: MW
authors.lastname: Kopcak
authors.forename: Raymond
authors.initials: R
authors.lastname: Dessoffy
authors.forename: Jenny
authors.initials: J
authors.lastname: Liu
authors.forename: James D
authors.initials: JD
authors.lastname: Thomas
authors.forename: A Marc
authors.initials: AM
authors.lastname: Gillinov
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Fukamachi
mesh_terms: D000818:Animals; D020517:Atrial Appendage / Q000502:physiology*; D016279:Atrial Function, Left; D001783:Blood Flow Velocity; D002302:Cardiac Output; D002320:Cardiovascular Physiological Phenomena; D004285:Dogs; D004452:Echocardiography