Assessment Of Left Ventricular Systolic Function After Aortic Valve Replacement In Patients With Aortic Stenosis By STE

ObjectiveThe aim of this study is to analyze the left ventricular systolic function and assess the strain and strain rate in pre and post-Aortic Valve Replacement(AVR) for Aortic Stenosis(AS) by 3D-STE and 2D-STE. This study also helps to provide the comparison of two kinds of technology and accurate information for clinical treatment options, and evaluates the effect and prognosis of AVR.MethodsThirty patients with aortic stenosis and preserved EF were analyzed before the aortic valve replacement. The same patients were examined two weeks and six months after aortic valve replacement. Biplane Simpson’s method was applied to measure the conventional indicators in the apical two-chamber view and four-chamber view. Important parameters such as Left Ventricular End of the Diastolic Volume(LVEDV), Left Ventricular End of the Systolic Volume(LVESV), and Left Ventricular Diastolic Diameter(LVDD) was measured by two-dimensional and 3D-STE. Left Ventricular Systolic Diameter(LVDS), and Left Ventricular Ejection Fraction(LVEF) were also included in the study. Two-dimensional and three-dimensional gray-scale images of six consecutive dynamic heartbeat cycle of stable rhythm were obtained from apical section. The Left Ventricular wall was divided automatically by the system into 17 various segments. The Left Ventricular wall was spontaneously categorized into segments of anterior wall, ventricular septal segment near anterior wall, ventricular septal segment near lower wall and adjacent wall near anterior and apical segments etc. The results of peak systolic strain, strain curve and the overall peak strain of all the segments were acquired and investigated. Furthermore, the results were assessed to evaluate the relationship of the global peak strain with LVEF, to scrutinize the difference between the two results and the local and overall left ventricular function. Comparative analysis of the study was conducted with the help of control group and patient group.Results1、Comparison of conventional ultrasound measurement results:Compared to control group:LVEDV,LVDD and LVDS had not changed significantly. The parameters have no significant difference statistically(P>0.05).LVESV were higher before and after AVR, LVEF were proved lower than the control group(P<0.05).Compared to patients before AVR:LVEDV,LVDD and LVDS had not changed significantly at two weeks after AVR. The parameters have no significant difference statistically(P>0.05),the parameters such as LVEDV,LVDD and LVDS at 6 months after AVR were found to be lower when compared to the level before the AVR. LVESV at two weeks after AVR were improved and lower at 6 months after surgery. LVEF at two weeks after AVR were lower,however, at 6 months after AVR, LVEF was improved when compared to the level before the surgery.The parameters have significant statistical difference(P<0.05).Compared to patients at two weeks after AVR:the parameters such as LVEDV,LVESV,LVDD and LVDS at 6 months after AVR were found to be lower when compared to the level two weeks before the AVR.Additionally, LVEF were improved at 6 months after AVR.The parameters have significant statistical difference(P<0.05).2、STE measure left ventricular total systolic function:(1) GLSpeak measured by 2D-STE and GLSpeak、GASpeak measured by 3D-STE:Compared to the control group:GLSpeak、GASpeak were both reduced before and after AVR;Compared to the patients before AVR: GLSpeak、GASpeak at two weeks after AVR were found to be lower,and these parameters demonstrated improvement at 6 months after AVR,the parameters have statistical significant difference(P<0.05);Compared to the patients at two weeks after AVR: GLSpeak 、 GASpeak at 6 months after AVR were confirmed improvement.The parameters have significant difference(P<0.05).(2) GRSpeak and GCSpeak measured by STE:Compared to the control group:GRSpeak and GCSpeak had not changed significantly before and at 6 months after AVR. The parameters have no significant difference(P>0.05).GRSpeak and GCSpeak were observed to be lower at two weeks after the surgery.The parameters have significant difference(P<0.05).Compared to the patients before AVR:At two weeks after AVR, GRSpeak and GCSpeak were observed to be lower.The parameters have significant difference(P<0.05). GRSpeak and GCSpeak had not changed significantly at 6 months after AVR. The parameters have no significant difference(P>0.05).Compared to the patients at two weeks after AVR: At 6 months after AVR, the measurements confirmed improvement when compared to before the surgery. The parameters have significant difference(P<0.05).3、The left ventricle global strain parameters of 3D-STE and 2D-STE were both positively correlated with LVEF. The left ventricle global strain parameters of 3D-STE have higher correlation than 2D-STE.GASpeak was proven to have the more higher correlation with LVEF.Conclusion1、The left ventricular systolic function in patients with aortic stenosis may be underestimated by conventional ultrasound. It also established that the 3D-STE parameters seemed to be more accurate than conventional ultrasound and it also detected subtle improvements in myocardial function after AVR.2、The left ventricle global longitudinal peak strain and global area peak strain were more sensitive than the global radial peak strain and global circumferential peak strain for AS patients, both before and after the operation.3、Area strain is the most sensitive, among other strain parameters by 3D-STE.4、The left ventricle global strain parameters of 3D-STE have higher correlation than 2D-STE.