Left atrial appendage (LAA) flow profile of its different waves and its correlation with direct left atrial pressure measurement: Can LAA flow profile be a surrogate to estimate left atrial pressure

ABSTRACT

Background:Left Atril Appendage(LAA) is one of the most contractile structure of the heart. Elevated Left atrial pressure (LAP) can change the flow profile in and out of LAA. There is little data on the effect of LAP on LAA flow velocities for patients in sinus rhythm, and it’s not properly known that by evaluation of LAA flow spectra and its velocities, the LAP can be predicted. We tried to find the relationship between LAA flow velocities and LAP, with the premise that LAA flow velocities can be used as a surrogate for measuring LAP, by obtaining a regression equation in this prospective observational study. Methods: In forty patients with normal systolic and diastolic heart function undergoing elective off pump coronary artery bypass (OPCAB) under general anaesthesia, TEE based LAA flow velocities were measured and simultaneous direct measurements of LAP was done by the surgeon. We also studied the relation between the ratio of early mitral inflow velocity (E) and mitral lateral annular early diastolic velocity (E’), that is, (E/E’) in all patients. Results: We found significant correlation between E/E’ and LAP (r = 0.424, p = 0.024) however there was no significant correlation between LAA flow velocities and LAP. Conclusion: LAA flow profile can not be used under anaesthesia to evaluate LAP however E/E’ shows a strong correlation with directly measured LAP.