Clinical Electrophysiology -> Atrial Fibrillation & Atrial Flutter: -> Physiology D-PO03 - Poster Session III (ID 48) Poster

D-PO03-211 - Increased Left Atrial Volume Index Is Associated With Decreased Left Atrial Appendage Ejection Velocity (ID 364)

Abstract

Background: Left atrial enlargement is a marker of adverse remodeling and has been independently associated with atrial fibrillation and stroke, independent of atrial fibrillation. The majority of cardioembolic atrial fibrillation-related strokes are due to thrombi present in the left atrial appendage.
Objective: We aimed to determine if left atrial enlargement measured by left atrial volume index (LAVI) is associated with decreased left atrial appendage (LAA) velocities.
Methods: We identified 100 patients who underwent transesophageal echocardiography at an academic tertiary care center. The LAA ejection velocities of patients with and without a LAVI >35 cubic cm by BSA were then compared with Student’s t-test (assuming unequal variance) and Cohen’s d to determine the significance and size of any difference.
Results: Of the 100 patients identified, 78 had both a TEE and TTE within the past year and were not in permanent AF. Five patients were then excluded for an absent or omitted LAA data. In our final cohort, patients who had LAVI>35 (52%) and LAVI<35 (48%) had an average LAA ejection velocity of 41.6 cm/s and 49.5 cm/s, respectively. This difference was found to be statistically significant p = 0.032, with a small-medium effect size as measured by Cohen’s d = 0.43. In the subset of 17 patients who were in AF at the time of TEE, 35% of patients with LAVI>35 had an average LAA ejection velocity of 31.5 cm/s, while the 65% of patients with LAVI<35 had an average LAA ejection velocity of 49.5 cm/s. This difference was also found to be statistically significant p = 0.034, with a large effect size as measured by Cohen’s d = 1.01.
Conclusion: Increased LAVI is associated with decreased LAA ejection velocity. The effect size is increased in people with atrial fibrillation. Alongside other known prognostic markers of thromboembolic risk, this readily available non-invasive data point may facilitate decision making regarding the appropriateness of antithrombotic therapy in patients with uncertain risk-benefit balance.
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