Evaluation Of Left Atrial Function In Hypertrophic Cardiomyopathy With Four-Dimensional Ultrasound Quantitative Analysis Technique

Objective(s):This study aims to use noninvasive four-dimensional ultrasound quantitative analysis technology(4D Auto LAQ)to evaluate the left atrial function of patients with hypertrophic cardiomyopathy(HCM).And to analyze the application value of left atrial strain based on 4D Auto LAQ in the evaluation of left ventricular diastolic function in patients with hypertrophic cardiomyopathy.Methods:We studied 24 HCM patients and 24 healthy volunteers whose age and gender roughly matched the HCM group.All participants in the study had obtained informed consent.According to the transthoracic echocardiographic operation guidelines recommended by the American Society of Echocardiography,the GEvividE95 color Doppler ultrasound system is equipped with a transthoracic two-dimensional ultrasound probe M5Sc(frequency 1.4-4.6 MHz)and a 4D volume probe(frequency 1.5-4.0 MHz),collected the relevant echocardiographic views and four-dimensional volume images of the left atrium,measured conventional ultrasound measurements(LAD,IVSd,LVPWd,LVIDd,LVOTPG.in the four-chamber at the tip,Two-chamber incision,tracing the left ventricular end-diastolic and end-systolic endometrium,calculate LVEF according to the Simpson formula and the indicators recommended by the measurement guide to identify left ventricular diastolic dysfunction(E/e’,e’,TR,LAVI),and import the four-dimensional volume image into EchoPAC-PC workstation,Start the 4D Auto LAQ analysis software to obtain the parameter set(LAVmin,LAVmax,LAVpreA,LAEV,LAEF,LASr,LAScd,LASct,LASr-c,LAScd-c,LASct-c)for evaluating left atrial function.in the control group and The HCM group was compared,and the correlation analysis between the strain parameters of HCM and the ejection fraction,volume parameters,chamber size,left ventricular outflow tract peak pressure difference,and left ventricular diastolic dysfunction were analyzed.Results:Compared with the normal control group,in the HCM group,LAD,LAVmin,LAVmax,LAVpreA,LAVImax,LAVImin were higher than it in the normal control group,and the HCM group’s LAEF decreased,and its LASr,LAScd,LASct,LASr-c,LAScd-c,LASct-c were lower than the normal control group(P<0.05).In HCM patients,LASr decreased with the increase of the peak left ventricular outflow tract pressure,but there was no significant correlation between LVOTPG and LAScd,LASct,LASr-c,LAScd-c,and LASct-c.In HCM patients,LAEF has a good correlation with strains in the left atrial reservoir phase,conduit phase,and contraction phase,respectively.LASr,LASr-c,LASct-c all have good correlation with LAVImax(r:-0.6198,-0.7181,0.4297),LASr,LASr-c,and LAScd all have good correlation with the peak flow velocity of tricuspid regurgitation(r:-0.6658,-0.6186,0.4144),there is no significant correlation between left atrial strain and E/e’,e’.Conclusion(s):In this study,we found that the functions of the left atrial reservoir phase,conduit phase,and contraction phase of HCM patients were all impaired through the 4D Auto LAQ assessment.In HCM patients,the longitudinal strain of the left atrial reservoir decreases with the increase in the peak pressure difference of the left ventricular outflow tract.The left atrial strain based on 4D Auto LAQ has certain clinical application value in the assessment of left ventricular diastolic function of HCM patients.Increasing left atrial strain to evaluate left ventricular diastolic function is beneficial for early clinical identification of diastolic dysfunction in patients with hypertrophic cardiomyopathy.