肥厚型梗阻性心肌病扩大室间隔切除术后左心房功能变化及意义

Left Atrial Function in Patients with Hypertrophic Obstructive Cardiomyopathy Before and After Septal Myectomy

目的应用二维斑点追踪应变显像技术(2DSTE)评估肥厚型梗阻性心肌病(HOCM)患者扩大室间隔切除术后左心房功能的变化特点,并探讨其临床意义。方法39例HOCM患者入选此研究。应用2DSTE技术测量房间隔,左房侧壁、前壁,下壁的基底段、中段,以及房顶部共12个节段各个时相的心房心肌应变率,取平均值,得出左心室收缩期左心房峰值应变率(mSRs)、左心室舒张早期左心房峰值应变率(mSRe)、左心室舒张晚期(心房收缩期)左心房峰值应变率(mSRa)。应用2DSTE自左房容积曲线获得左心房最大容积(LAVmax)、左心房收缩前容积(LAVp)、左心房最小容积(LAVmin),计算左心房容积指数(LAVI)、左心房主动排空分数(LAAEF)、左心房被动排空分数(LAPEF)、左心房扩张指数(LAEI)。比较术前、术后中期各参数的变化特点。结果与术前比较,39例HOCM患者扩大室间隔切除术后,左心房最大前后径(LAD)、室间隔厚度(IVS)、左心室后壁舒张末期厚度(LVPWd)、左心室射血分数(LVEF)、左心室流出道最大压差(LVOT-PG)、二尖瓣反流(MI)均明显减低(P均<0.05);左心室舒张末前后径(LVEDD)、左心室收缩末前后径(LVESD)均明显增大(P均<0.05);二尖瓣E峰减速时间(DT)缩短,舒张晚期二尖瓣环运动速度(a’)增加(P<0.05);左心室舒张晚期mSRa较术前明显增加(P<0.05);各个时相LAVmax、LAVp、LAVmin以及LAVI均明显减小(P<0.05),LAAEF增加(P<0.05);左心室舒张晚期mSRa与LAAEF在0.01水平上呈中等程度负相关(P<0.01)。结论HOCM患者扩大室间隔切除术后左心房辐泵功能较术前恢复。2DSTE能够敏感反映左心房功能的变化特点。

Objective To investigate the change of the left atrial function in patients with hypertrophic obstructive cardiomyopathy(HOCM)before and after myectomy by two-dimensional speckle tracking strain echocardiography(2 DSTE),and the clinical significance.Methods 39 patients with HOCM were enrolled in this study.Conventional echocardiographic and left atrial stress rate curve(including 12 segments)were obtained by 2 DSTE,from the left atrial stress rate curve,gained peak systolic strain rate(mSRs),peak early diastolic strain rate(mSRe),peak atrial systolic strain rate(mSRa),left atrial minimal volume(LAVmin),left atrial maximal volume(LAVmax),left atrial presystolic volume(LAVp),and then calculated left atrial volume index(LAVI),left atrial passive emptying fraction(LAPEF),left atrial active emptying fraction(LAAEF),and left atrial expansion index(LAEI).Then compared these parameters before and after myectomy.Results For patients with HOCM,the left atrial diameter(LAD),interventricular septal thickness(IVSD),left ventricular posterior wall thickness(LVPWd),1 eft ventricular ejection fraction(LVEF),left ventricular outflow tract peak gradient(LVOT-PG)and mitral insufficiency(MI)decreased significantly,left ventricular enddiastolic diameter(LVEDD)and left ventricular end-systolic diameter(LVESD)increased significantly after myectomy(P<0.05).Mitral valve deceleration time of E wave(DT)decreased,the velocity of mital valve annulus(a’)increased(P<0.05).Peak atrial systolic strain rate(mSRa)increased(P<0.05).Left atrial minimal volume(LAVmin),left atrial maximal volume(LAVmax),left atrial presystolic volume(LAVp),and left atrial volume index(LAVI)decreased significantly(P<0.05),left atrial active emptying fraction(LAAEF)increased(P<0.05).mSRa was related to LAAEF at 0.01 level(P<0.01).Conclusion In the patients with HOCM,left atrial pump function improved after setpal myectomy.2 DSTE can detect left atrial function sensitively.