Objective To evaluate the clinical value of left atrial（LA）and left atrial appendicular（LAA）strain in stroke prediction of patients with nonvalvular atrial fibrillation (NVAF) by using two-dimensional speckle tracking technique(2D-STE). Methods Collecting 80 patients with nonvalvular atrial fibrillation

TTE and TEE was performed in all patients. Through routine measurement and software analysis. LAD

LAVI

LAEF

LAAEV.LAAFV

LAAEF were obtained. The LASr

LAScd and LAAS were measured by 2D-STE.The TTE images of LA and the TEE images of LAA were acquired for data analysis;Comparing the difference between the two sets of the above parameters. Multivariate Logistic regression was used to analyze the influencing factors of stroke in patients with NVAF. Receiver operating characteristic (ROC) curve was drawn to analyze the predictive efficacy of left atrial and left atrial auricular strain in stroke. Results Left atrial ejection fraction(LAEF)

Left atrial strain reservoir function(LASr)

left atrial ejection fraction(LAEF)

Left atrial appendage emptying velocity(LAAEV) and Left atrial appendage filling velocity(LAAFV) and The left atrial appendage strain（LAAS）in the stroke group were significantly lower than those in the non-stroke group(P＜0.05);The logistic regression analysis

LAAS[OR=0.790(95

%CI:0.678~0.90)]

LASr[OR=0.727(95%CI:0.575~0.919)]

LAAS and LASr were independent predictors of stroke in patients with NVAF(P＜0.05);LASr:cut-off value≤16.96%

sensitivity 72.5%

specificity 75%

AUC 0.766;LAAS ;cut-off value≤-6.88%

sensitivity 52.5%

specificity 90.0%

AUC 0.753; Conclusion LASr and LAAS reduction are independent predictors of stroke in patients with NVAF

which can predict the occurrence of stroke early and effectively.