Echocardiographic Assessment Of Left Ventricular Function Before And After Surgical Treatment Of Hypertrophic Cardiomyopathy

Abstract 1 Evaluation of left atrial function in patients with hypertrophic cardiomyopathy by real-time three-dimensional echocardiography[Objective]To investigate the application value of real-time 3D echocardiography(4D Auto LAQ)in the evaluation of left atrial volume and function in patients with hypertrophic cardiomyopathy(HCM).[Methods]A total of 70 patients diagnosed with HCM in our hospital from December 2019 to December 2020 were consecutively collected as the study group,and 50 healthy adults with matched age and gender during the corresponding period were selected as the control group.After the patients were examined by two-dimensional and real-time three-dimensional echocardiography,differences between traditional diastolic function indexes and three-dimensional left atrial function parameters between the two groups were evaluated,and correlation analysis was also conducted.[Results]There were no statistical differences in age,gender,body surface area,heart rate and blood pressure between the two groups(all p>0.05).The IVSD,LVPWD,MWT,LVEF,E/E ',GLS,and PSD in HCM group were all higher than those in control group,while the LVEDVI,LVESVI,E'Sep,E ' LAT were all smaller than those in control group,which shows a statistically significant difference(allp<0.05).Among the left atrial function parameters,three-dimensional LAV Max,LAV min,and LAV preA were all higher in HCM group than those in the control group,and LATEF,LAPEF,LAAEF,SR,SCD,SCT,SRc,SCDc,and SCTc were lower in HCM group than those in the control group(all p<0.05).According to the correlation analysis,SR has a stronger correlation with GLS(r=0.798,p<0.01).[Conclusion]Left atrial function in patients with HCM is obviously weakened,which is of great significance for left ventricular filling.As the real-time three-dimensional echocardiography can evaluate the left atrial function and strain in different periods with good feasibility and ideal repeatability,it has higher clinical value.Abstract 2 Left Atrial Function in Patients with Hypertrophic Obstructive Cardiomyopathy After Extended Septal Myectomy Procedure[Objectives]To evaluate changes of left atrial function for patients with hypertrophic obstructive cardiomyopathy(HOCM)after Extended Septal Myectomy procedure using two-dimensional speckle tracking echocardiography(2DSTE),and explore its clinical significance.[Methods]39 HOCM patients were selected in this study.Atrial myocardial strain rates in 12 segments(including interauricular septum,basal segment and middle segment of left atrial side wall,front wall and lower wall,top of the atria)in different temporal phases were measured by 2DSTE,and mean values were calculated to obtain peak systolic strain rate(mSRs),peak early diastolic strain rate(mSRe),and peak atrial systolic strain rate(mSRa)of the left atrium.2DSTE was also used to obtain left atrial maximal volume(LAVmax),left atrial presystolic volume(LAVp),left atrial minimal volume(LAVmin)from the left atrial volume curve,and calculate left atrial volume index(LAVI),left atrial active emptying fraction(LAAEF),left atrial passive emptying fraction(LAPEF),and left atrial expansion index(LAEI).Then the changes of these parameters before myectomy and in the middle period after myectomy were compared.[Results]Compared with parameters before myectomy,for patients with HOCM after Extended Septal Myectomy procedure,the left atrial diameter(LAD),interventricular septal thickness(IVS),left ventricular posterior wall thickness(LVPWD),left ventricular ejection fraction(LVEF),left ventricular outflow tract peak gradient(LVOT-PG)and mitral insufficiency(MI)decreased significantly(all p<0.05).Left ventricular end-diastolic diameter(LVEDD)and left ventricular end-systolic diameter(LVESD)increased significantly(p<0.05).Mitral valve deceleration time of E wave(DT)shortened,and the velocity of mital valve annulus(a')increased(p<0.05).Peak atrial systolic strain rate(mSRa)increased significantly compared with the value before myectomy(p<0.05).Left atrial volume in different time phases,including left atrial maximal volume(LAVmax),left atrial presystolic volume(LAVp),left atrial minimal volume(LAVmin),and left atrial volume index(LAVI)decreased significantly(p<0.05).Left atrial active emptying fraction(LAAEF)increased(p<0.05).mSRa shows moderate negative relation with LAAEF at 0.01 level(p<0.01).Abstract 3 Impact of Extended Septal Myectomy procedure on Postsystolic Shortening in Patients With Hypertrophic Obstructive Cardiomyopathy[Objectives]To analyze the change law of left ventricle myocardium postsystolic shortening(PSS)for patients with hypertrophic obstructive cardiomyopathy(HOCM)before and after Extended Septal Myectomy procedure,so as to investigate the improvement of left ventricle diastolic function for patients with HOCM.[Methods]39 patients diagnosed with HCM after septal myectomy in our hospital from 2012 to 2017 were collected as the study group.The strain curves of 18 segments of left ventricular wall(including front wall,lower wall,front chamber interval,posterior wall,back chamber interval,basal segment,middle segment and apex segment of side wall)were analyzed using two-dimensional speckle tracking echocardiography.Myocardium postsystolic strain index(PSI)were calculated to determined that,when PSI>20%,PSS happens in the segment.The distribution of PSS in basal segment,middle segment and apex segment before myectomy and the changes of PSS in all segments after myectomy were compared and analyzed.[Results]After myectomy,the left atrial diameter(LAD),interventricular septal thickness(IVSD),left ventricular posterior wall thickness(LVPWd),left ventricular ejection fraction(LVEF),left ventricular outflow tract peak gradient(LVOT-PG)and mitral insufficiency(MI)decreased significantly,and left ventricular end-diastolic diameter(LVEDD)and left ventricular end-systolic diameter(LVESD)increased significantly compared with the values before myectomy.All the differences have statistical significance(P<0.05).Mitral valve deceleration time of E wave(DT)shortened(P<0.05),and the velocity of late mitral valve diastole(a')increased(P<0.05).After myectomy,PSS happened in 19 segments,among which 10 in basal segment,6 in middle segment,and 3 in apex segment.Compared with the values before myectomy,the frequency of PPS(2.71%vs.6.27%)and the average PSI[(2.34±2.33)%vs.(3.68±2.79)%]decreased significantly(P<0.05),especially in basal segments.All the differences have statistical significance(P<0.05).[Conclusion]Among the patients with HOCM,the frequency of PSS and PSI significantly increased in basal segments.After the myectomy,the frequency of PPS and PSI decreased significantly,especially in basal segments,which suggests the improvement in the left ventricle diastolic function.