AIM To investigate the predictive value of left atrial function for left atrial appendage thrombosis in patients with isolated atrial fibrillation (AF).

METHODS One hundred and forty patients who were definitely diagnosed as isolated AF and left ventricular ejection fraction (LVEF) ≥50% were selected as disease group. The disease group were further divided into non-thrombus group and thrombus group, and 60 healthy subjects served as control group. Ultrasound examination was performed in all 3 groups. The left atrial longitudinal strain (LA-LS), the global strain (GLS) of LA and the standard deviation for the time to peak of LA (LA-TPSD) in each section were measured by two-dimensional speckle tracking imaging (2D-STI) and the data were compared between the three groups.

RESULTS The proportion of paroxysmal atrial fibrillation in the thrombotic group was significantly lower than that in the non thrombotic group (P<0.01); Compared with the non thrombotic group, the LA-T (P<0.05), LAEDV (P<0.01), and LAESV (P<0.01) in the thrombotic group were significantly higher than those in the non thrombotic group, while LAEF (P<0.01) and LAA-v (P<0.01) were lower than those in the non thrombotic group. Comparison of spot tracking parameters showed that the longitudinal strain and overall strain of the left atrium in the four chamber, three chamber, and two chamber heart sections were smaller in the thrombus group than in the non thrombus group. The standard deviation of the peak time of longitudinal strain in each segment of the left atrium was greater in the thrombus group than in the non thrombus group. There were statistical differences in all parameters between the two groups (all P<0.05).

CONCLUSION The left atrial appendage thrombosis in patients with isolated AF is closely related to the LA structure, function and systolic coordination. The left atrial related parameters have certain non-invasive predictive value for the formation of thrombosis.