Evaluation Of Left Atrial Strain Function In Patients With Primary Nephrotic Syndrome By Speckle Tracking Imaging

Objective:The purpose of this study was to evaluate the myocardial strain function of the left atrium in patients with primary nephrotic syndrome by two-dimensional speckle tracking imaging(2D-STI),to explore whether the strain parameters of the left atrium are more sensitive to the assessment of early cardiac function changes in patients with primary nephrotic syndrome,and to analyze the correlation between the functional parameters of the left atrium and renal function in such patients.Methods:Seventy-one patients with primary nephrotic syndrome admitted to our hospital from 2021 to 2022 were selected as case group and 32 healthy subjects in the same period were selected as control group.The case group was divided into normal renal function group(eGFR≥90 ml/(min·1.73m~2)according to the estimated glomerular filtration rate(eGFR).37 cases]and renal dysfunction group[eGFR<90ml/(min·1.73m~2)group,34 cases].General clinical data,including age,gender,blood pressure,C-reactive protein,serum total cholesterol,uric acid,creatinine,etc.,were collected.Routine two-dimensional echocardiogram images,tissue Doppler images and two-dimensional spot tracking images of the subjects were collected.Conventional two-dimensional echocardiogram parameters obtained include:Left atrial diameter before and after end-systole(LADs),left ventricular ejection fraction(LVEF),end-diastolic left ventricular diameter(LVEDd),end-diastolic posterior left ventricular wall thickness(LVPWd),end-diastolic ventricular septal thickness(IVSd),early peak diastolic flow velocity(peak E)and late peak diastolic flow velocity(peak A),mitral valve The early diastolic peak(e’)and late diastolic peak(a’)of the ring ventricular septal myocardium movement velocity were calculated,and the ratios of E/A and E/e’were calculated.Left atrial strain during reservoir phase(LASr)and peak left strain rate during reservoir phase(pLASRr),left atrial strain during conduit phase(LAScd)and peak left strain rate during conduit phase(pLASRcd),and left atrial strain during contraction phase(LASct)and peak left strain rate during contraction phase(pLASRct)were measured by off-line analysis software.The differences of conventional two-dimensional ultrasound parameters,left atrial strain and strain rate among the three groups were analyzed and compared,and the correlation between left atrial functional parameters and renal function was discussed.Results:1.Comparison of general clinical data:there were no significant differences in age,gender,height,weight and BSA between the case group and the control group(P>0.05);Compared with the control group,the C-reactive protein,uric acid and total cholesterol in the case group were significantly increased,while the hemoglobin was significantly decreased,with statistical significance(P<0.001).2.Comparison of routine two-dimensional echocardiographic parameters:Compared with the control group,LADs,LVMI,A and E/e’in the normal and abnormal renal function groups were increased,and the differences were statistically significant(P<0.05),while e’and E/A were decreased,and the differences were statistically significant(P<0.05).Compared with the control group,the peak E of patients with normal renal function group had no statistical significance(P>0.05),but the peak E of patients with abnormal renal function group was lower than that of the first two groups,and the difference was statistically significant(P<0.05).LADs,LVMI,A,E/e’,e’peak,E/A showed no significant differences between groups with normal and abnormal renal function(P>0.05).There were no significant differences in LVEF and a’among the three groups(P<0.05).3.Comparison of left atrial 2D-STI parameters:Compared with control group,LASr,LASct,pLASRr and pLASRct in normal renal function group were decreased,with statistical significance(P<0.05),while there was no statistical significance in LAScd and pLASRcd in normal renal function group compared with control group(P>0.05).The levels of LASr,LAScd,LASct,pLASRr,pLASRcd and pLASRct in renal dysfunction group were lower than those in control group and renal dysfunction group,and the difference was statistically significant(P<0.05).4.Correlation analysis:eGFR was negatively correlated with LADs,LADd,LVMI and E/e’,and positively correlated with e’and E/A.Hemoglobin was negatively correlated with LADs,LADd,LVMI,A,E/e’.C-reactive protein was positively correlated with LADs,LADd,LVMI,A,E/e’,and negatively correlated with E,e’,E/A.Uric acid is negatively correlated with e’and positively correlated with E/e’.Total cholesterol was positively correlated with LADs and LADd,but negatively correlated with E,e’and E/A.5.Multiple linear regression analysis:Gender,LVMI,systolic blood pressure,diastolic blood pressure,C-reactive protein,eGFR and other factors were included in the multiple linear regression analysis,and the results showed that the left atrial strain function parameters were no longer correlated with gender,LVMI and C-reactive protein(P>0.05).However,after adjusting for gender,blood pressure,LVMI,C-reactive protein and other factors,the left atrial strain parameters were still positively correlated with eGFR.eGFR was associated with LASr(β=0.808,P<0.001),LASct(β=0.608,P<0.001),pLASRct(β=0.445,P<0.001)showed an independent correlation;The left atrial conduit function parameters(LAScd,pLASRcd)were positively correlated with eGFR and negatively correlated with diastolic blood pressure(β=-0.231,P=0.031;β=-0.291,P=0.011).6.ROC result:In the case of primary nephrotic syndrome,the AUC of LASr was0.884,sensitivity 0.969,specificity 0.690,and that of LASct was 0.877,sensitivity0.969,specificity 0.746.The AUC of LASr was 0.937,sensitivity was 0.884,specificity was 0.882,and the AUC of LASct was 0.886,sensitivity was 0.841,specificity was 0.824.Conclusion:1.E,e’,E/A decreased and E/e’increased in patients with primary nephropathy,indicating that these patients have a tendency of early left ventricular diastolic dysfunction compared with normal people.Conventional two-dimensional echocardiographic parameters can have a certain diagnostic efficacy.However,in patients with normal renal function in the early stage of the disease,conventional two-dimensional ultrasound parameters lack a certain sensitivity to detect subtle functional changes in the left atrium.2.Speckle tracking imaging technology was applied to evaluate the left atrial strain function in patients with primary nephrotic syndrome.It was found that the longitudinal myocardial strain and strain rate of the left atrial in these patients were reduced at various stages,indicating that the left atrial function of these patients was impaired,and with the continuous decline of renal function,the left atrial injury became more obvious.3.Serum C-reactive protein level in patients with primary nephrotic syndrome was significantly higher than that in the normal group,and correlation analysis results showed that left ventricular diastolic function parameters were significantly correlated with C-reactive protein,indicating that persistent inflammatory response is associated with cardiac insufficiency,and C-reactive protein level can be used as one of the predictors of cardiovascular adverse events outcome.4.After adjusting for gender,blood pressure,C-reactive protein and other related factors,LASr,LASct and pLASRct were independently correlated with eGFR,indicating that the storage function and systolic function of the left atrium were independently correlated with renal function.The left atrial storage longitudinal strain(LASr)has higher sensitivity and specificity for myocardial injury of the left atrium after renal function decline in patients with primary nephrotic syndrome.