Abstract 2549: Impact of Left Atrial Appendage Exclusion on Left Atrial Function
Objective: We sought to investigate the short- and mid-term effects of left atrial appendage (LAA) exclusion on left atrial (LA) function.
Background: LAA exclusion is considered a possible therapeutic option for stroke prevention in patients with atrial fibrillation. Favorable outcomes have encouraged widespread use of LAA exclusion in cardiac surgical patients, even for patients in sinus rhythm who have stroke risk factors. However, the chronic effects of LAA exclusion on LA function are unclear.
Methods: Nineteen mongrel dogs (29.7 ± 5.2 kg) in sinus rhythm were studied. The Doppler signals from the pulmonary vein (PV) flow, transmitral flow, and tissue Doppler imaging (TDI) of mitral annular motion were obtained before and after LAA exclusion. Dogs were evaluated at 7 days (n = 2), 30 days (n = 7), and 90 days (n = 10) following LAA exclusion in the same manner.
Results: Except for a significant increase in early diastolic transmitral flow velocity at post-LAA exclusion (P = 0.01), no significant differences were found in any parameters related to the transmitral flow and TDI measurements throughout follow-up. The systolic components of PV flow at follow-up revealed a significant reduction compared with baseline (the peak systolic velocity: P < 0.0001 and the systolic velocity-time integral: P < 0.0001) despite no significant changes in the LA pressure, left ventricular volume, and stroke volume.
Conclusion: LAA exclusion may cause no adverse effects on the hemodynamics in the clinical settings in mid-term phase, although LA reservoir function may be negatively affected.