Dense SEC connection with Left Atrial Appendage Asynchrony and Mechanical Function in patients with Non-Valvular Atrial Fibrillation

Left atrial appendage thrombi (LAAT) or dense spontaneous echo contrast (SEC) is relatively common observed on transesophageal echocardiograph (TEE) in patients with non-valvular atrial fibrillation (NVAF), who need strengthen anticoagulation therapy before cardioversion or radiofrequency ablation. Nevertheless, little is known about the meaning of left atrial appendage (LAA) asynchrony and its possible associations with the formation of dense left atrial appendage spontaneous echo contrast (LAASEC). We aimed to analyze LAA global longitudinal strain (LAAGLS) and LAA mechanical function, namely mean peak atrial longitudinal strain (mPALS) and synchrony; we also sought to examine their possible relationship with LAASEC development. Methods: A retrospective study of 360 patients with NVAF was conducted. Two-dimensional speckle-tracking echocardiography provides the following metrics of LAA strain: LAA strain divided the LAA wall longitudinally into six segments. Moreover, we measured the mean of peaks derived from segmental strain curves (mPALS). The LAA asynchrony was evaluated using the standard deviation of the time to positive peak longitudinal systolic strain for each of the left atrial appendage segments that were normalized to the R-R interval. Results: Patients with dense LAASEC had older age (66.43 ± 8.23 vs 62.28 ± 10.82, P = 0.002), more females (53.1% vs 36.2%, P = 0.009), more per-AF (87.2% vs 44.3%, P < 0.001), more diabetes and heart failure (26% vs 10.3%,25% vs 4.6%, both P < 0.05). The presentation on compliance dysfunction in dense LAASEC group was significant (5.40 ± 2.82 vs 12.40 ± 7.30), and higher PSD LAA (4Segments) (93.44(47.41 ~ 153.35) vs 59.00(13.71 ~ 115.25)) in dense SEC group, especially the peak time of longitudinal strain is obviously prolonged in the middle and apex segments of the left atrial appendage ( 102.50 (20.00 ~ 200.75) vs 23.00 (0.00 ~ 153.00), 19.00 (0.00 ~ 76.25) vs 0.00 (0.00 ~ 19.00), P < 0.001, P = 0.001, respectively). Conclusion: NVAF patients with LAA Asynchrony have an increased dense LAASEC. Especially the peak time of longitudinal strain is obviously prolonged in the middle of LAA.