Impact of left atrial appendage exclusion on left atrial function.
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.
Kamohara
Keiji
K
Department of Biomedical Engineering, Lerner Research Institute, The Cleveland Clinic, Cleveland Ohio 44195, USA.
Popović
Zoran B
ZB
Daimon
Masao
M
Martin
Maureen
M
Ootaki
Yoshio
Y
Akiyama
Masatoshi
M
Zahr
Firas
F
Cingoz
Faruk
F
Ootaki
Chiyo
C
Kopcak
Michael W
MW
Dessoffy
Raymond
R
Liu
Jenny
J
Thomas
James D
JD
Gillinov
A Marc
AM
Fukamachi
Kiyotaka
K
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