二维斑点追踪成像评价心尖肥厚型心肌病左心室局部功能

Two-dimensional Speckle Tracking Imaging in Evaluating Regional Function of Left Ventricle in Apical Hypertrophic Cardiomyopathy

目的探讨二维斑点追踪成像评估最大心肌厚度对心尖肥厚型心肌病(AHCM)患者左心室旋转和扭转的影响,为临床治疗提供依据。资料与方法19例AHCM患者依据左心室乳头肌水平以下心肌最大厚度分为重度肥厚组9例和轻度肥厚组10例,并选择15例正常人作对照。采用二维及M型超声心动图测量左心房大小(LAD)、左心室心肌最大舒张末期厚度(LVMTmax)、左心室收缩末期容积(ESV)、舒张末期容积(EDV)、左心室射血分数(LVEF),采用二维斑点追踪成像测量左心室基底部和心尖部心肌收缩期整体旋转角度、整体径向和环向应变及应变率,并计算左心室峰值扭转角度。结果与对照组比较,两组AHCM患者LAD、LVMTmax、心尖部旋转角度、左心室扭转角度、左心室心尖部环向应变和应变率增加(P<0.01),ESV、EDV、基底部径向应变率、心尖部径向应变和应变率减低(P<0.01),重度肥厚组基底部环向应变和应变率、旋转角度增加(P<0.01);与轻度肥厚组比较,重度肥厚组LAD、LVMTmax、基底部环向应变、应变率、旋转角度和扭转角度增加(P<0.01),EDV、ESV、心尖部径向应变和应变率明显减低(P<0.01)。结论 AHCM患者左心室旋转和扭转发生明显改变,可能是心肌收缩功能受损的代偿机制;随着心肌厚度增加,其代偿机制亦发生改变。

Purpose To explore two-dimensional speckle tracking imaging in evaluating the effect and mechanism of maximum thickness of myocardium（MTM） on left ventricular（LV） rotation and torsion in apical hypertrophic cardiomyopathy（AHCM）.Materials and Methods Nineteen AHCM patients and 15 controls were recruited in the study.AHCM patients were divided into two groups according to MTM： mild cardiac hypertrophy group（10 cases） and severe cardiac hypertrophy group（9 cases）.The left atrium dimension（LAD）,the maximum thickness of LV wall（LVMTmax）,end-diastolic volume of LV（EDV）,end-systolic volume of LV（ESV）,ejection fraction of LV（LVEF） were measured by dimensional and M-mode echocardiography.The basal rotation（BR）,apical rotation（AR） and torsion of LV,basal radial strain（BRS） and strain rate（BRSR）,apical radial strain（ARS） and strain rate（ARSR）,basal circumferential strain（BCS） and strain rate（BCSR）,apical circumferential strain（ACS） and strain rate（ACSR） were measured by speckle-tracking imaging.Left ventricular peak torsion angle was calculated.Results LAD,LVMTmax,AR and torsion of LV,ACS and ACSR were increased in AHCM group when compared with those of control group（P＆lt;0.01）.EDV,ESV,BRSR,ARS and ARSR in AHCM patients were decreased（P＆lt;0.01）.BCS,BCSR and BR of LV in severe cardiac hypertrophy group were increased（P＆lt;0.01）.Compared with mild cardiac hypertrophy group,LAD,LVMTmax,BCS,BCSR and BR and torsion of LV in severe cardiac hypertrophy group were increased（P＆lt;0.01）.And LVEDV,LVESV,ARS and ARSR of LV in severe cardiac hypertrophy group were decreased（P＆lt;0.01）.Conclusion The rotation and torsion of left ventricle are significantly changed in AHCM patients,which could be a compensatory mechanism to dysfunction of myocardium.The compensatory mechanism will change with increased myocardial thickness.