Objective To investigate the relationship between the left atrial volume index(LAVI)and left atrial anteroposterior diameter(LAAP)and their consistency in evaluating left ventricular diastolic function.Methods The study enrolled 315 patients who underwent echocardiography in our hospital between July 2018 and December 2019,including 68 healthy patients(21.6% ),98 patients with hyper-tension(31.1% ),97 patients with atherosclerotic heart disease(30.8% ),32 patients with dilated cardiomyopathy(10.2% ),11 patients with pulmonary heart disease(3.5% ),and nine patients with congenital heart disease(2.9% ).General clinical data were collected,and echo-cardiography was performed to detect various cardiac indicators,including LAAP,left atrial volume(LAV),mitral inflow-early diastolic(MV E),mitral inflow-late diastolic,septal early diastolic mitral annulus peak velocity(Septal e'),lateral early diastolic mitral annulus peak velocity(Lateral e'),tricuspid regurgitation peak velocity,and left ventricular ejection fraction(LVEF).Patients were divided into a normal LVEF group(LVEF≥53%,n=264)and a reduced LVEF group(LVEF<53%,n=51).An independent samplettest was used to compare the parameters of left ventricular diastolic function between the two groups.The correlation between LAVI and LAAP was analyzed using Pearson or Spearman correlation analysis.The kappa test was used to analyze the consistency of LAAP and LAVI in eval-uating left ventricular diastolic function.Results LAAP,LAV,LAVI,MV E/e',and TR were significantly higher in the reduced LVEF group than in the normal LVEF group(all P<0.001),while Septal and Lateral e'were significantly decreased(all P<0.001).LAAP and LAVI were positively correlated(r=0.74,P<0.001).The results of the LAAP and LAVI evaluations of left ventricular diastolic function in all patients and groups showed that LAAP and LAVI were consistent in evaluating whether left ventricular diastolic function was reduced and graded(P<0.001 for all).Conclusion LAAP and LAVI measured by echocardiography were positively correlated and showed strong consistency in evaluating whether left ventricular diastolic function was reduced and graded.The correlation between LAAP and LAVI was higher when the LVEF was reduced,and the consistency of LAAP and LAVI in evaluating left ventricular diastolic function was stronger.Therefore,in patients with a reduced LVEF,LAAP can be used instead of LAVI for evaluation when LAVI indicators cannot be obtained.