Accurate Assessment Of Left Ventricular Systolic Function In Patients With Aortic Regurgitation By Quantitative Layer-specific Myocardial Strain

Objective:To explore the value of quantitative layer-specific myocardial strain technique in evaluating the subclinical changes of left ventricular systolic function in patients with different degrees of aortic regurgitation.Methods According to the standardized research program of American Society of Echocardiography（ASE）^[13],collected LVEF≥50%of AR patients and divided them into severe group（n=20）,moderate group（n=20）and mild group（n=20）.At the same time,20normal volunteers were selected as normal group（n=20）.Collection index include:conventional two-dimensional ultrasound index,width of systolic flow path,Global Longitudinal Strain（GLS）of left ventricular myocardium（epicardium,middle layer,endocardium）,Global Circumferential Strain（GCS）and Global Radial Strain（GRS）.Comparing and analyzing the changes of left ventricular systolic function in patients with different degrees of AR and normal population and the changes of left ventricular systolic function before and after surgery in patients with severe AR,myocardial strain parameters with good correlation with conventional ultrasound indicators were screened.Results:1、Comparison results of general data in mild group,moderate group,severe group and normal group:The diastolic blood pressure（DBP）and pulse pressure（PP）difference were statistically significant in the four groups（P<0.05）.The severe group had higher DBP and PP than the other three groups,and the systolic blood pressure（SBP）was less than the other three groups（P<0.05）.2、Comparison results of conventional ultrasound parameters in mild group,moderate group,severe group and normal group:The difference in LVEDD（mm）among the four groups was statistically significant（P<0.05）.The comparison between the severe group and the moderate group was higher than the normal group and the mild group（P<0.05）,and the severe group was higher than the moderate Group（P<0.05）;The difference in IVSD（mm）among the four groups was statistically significant（P<0.05）,and the severe group was higher than the normal group（P<0.05）;The difference between AAO and AOS in the four groups was statistically significant（P<0.05）.Compared between the groups,the severe group was higher than the other three groups;The difference in LVEF among the four groups was statistically significant（P<0.05）.Compared with the normal group,although the LVEF in the severe group was within the normal range but lower than the normal group（P<0.05）,there was no significant difference between the other two groups（P>0.05）;GLSendo,GLSmid,GLSepi,GCSendo,GCSmid,GCSepi,and GRS were statistically significant in the four groups（P<0.05）,and the severe and moderate groups were lower than the normal and mild groups（P<0.05）and the severe group is lower than the moderate group（P<0.05）;3、Preoperative and postoperative comparison results in the severe group:Compared with the normal group,the GLSendo,GLSmid,GLSepi,GCSendo,GCSmid,and GCSepi in the postoperative severe group were all reduced（P<0.05）;compared with the preoperative severe group,the GLSendo GLSmid,GLSepi,GCSendo,GCSmid and GCSepi were all increased（P<0.05）.4、Correlation between overall layered strain and LVEF:There was a positive correlation between Glsendo and LVEF（r=0.520,P<0.05）,Glsmid and LVEF（r=0.596,P<0.05）,Glsepi and LVEF（r=0.685,P<0.05）,Gcsendo and LVEF（r=0.560,P<0.05）,Gcsmid and LVEF（r=0.601,P<0.05）,Gcsepi and LVEF（r=0.611,P<0.05）,GRS and LVEF（r=-0.531,P<0.05）.Correlation between overall layered strain and LVEDD:There was a negative correlation between Glsendo and LVEDD（r=-0.899,P<0.05）,Glsmid and LVEDD（r=-0.897,P<0.05）,Glsepi and LVEDD（r=-0.852,P<0.05）,Gcsendo and LVEDD（r=-0.891,P<0.05）,Gcsmid andLVEDD（r=-0.891,P<0.05）,Gcsepi and LVEDD（r=-0.890,P<0.05）,GRS and LVEDD（r=-0.872,P<0.05）.Correlation between overall layered strain and AR/LVOT:There was a negative correlation between GLSendo and AR/LVOT（r=-0.921,P<0.05）,GLSmid and AR/LVOT（r=-0.918,P<0.05）,GLSepi and AR/LVOT（r=-0.900,P<0.05）,GCSendo and AR/LVOT（r=-0.928,P<0.05）,GCSmid and AR/LVOT（r=-0.919,P<0.05）,GCSepi and AR/LVOT（r=-0.920,P<0.05）,GRS and AR/LVOT（r=0.866,P<0.05）.Conclusion1、For patients with aortic regurgitation patients whose LVEF is normal,the quantitative layer-specific myocardial strain technique can be used to detect left ventricular myocardial subclinical systolic dysfunction;2、Quantitative layer-specific myocardial strain technique can be used as a new method of follow-up after aortic valve replacement（AVR）;3、The overall layer-specific myocardial strain values of the endocardial layer,middle layer and epicardial layer were correlated with LVEDD,JW/LVOT and LVEF.The correlation between the overall longitudinal strain of the endocardial layer and LVEDD,JW/LVOT and LVEF was the most significant,and the overall longitudinal strain of the endocardial layer was more sensitive in evaluating the changes in left ventricular myocardial systolic function of AR patients.