速度向量成像技术评价肥厚型心肌病心脏扭转运动

摘要

Objective To assess global and regional cardiac twist function in hypertrophic cardiomyopathy(HCM) patients by velocity vector imaging(VVl).Methods Thirty HCM patients and 33 normal subjects were enrolled into this study.Two dimensional echocardiographic images of parasternal left ventricular basal level,middle and apical level short axis plane,apical four-and two-chamber plane were obtained.Maximal rotation degree,peak rotation rate,circumferential strain (CS) and strain rate (CSR),radial strain(RS) and strain rate(RSR) in systole were measured using VVI offline software.In addition,diastolic peak un-rotation rate,untwisting rate(unTwR) were measured.Each parameters was analyzed both in subendocardial and subepicardial layer.Results There was no significant difference in left ventricular ejection fraction between two groups.EDV,ESV,SV were significantly decreased (P＜0.01) in HCM group.Left ventricular twist(LVtw),CS of subendocardial layer were higher in HCM group than control group(P＜0.05),while the peak rotation rate,un-rotation rate,CS,CSR were lower of subepicardial layer (P＜0.05).The RSR of each short axis level were significantly decreased in HCM group (P＜0.01).The diastolic unTwR was decreased in HCM group (P＜0.05).For further analysis of the two subgroups in HCM,more regional torsion deterioration occurred in patients with left ventricular outflow tract obstruction than those without obstruction.Conclusions The global cardiac twist angle of HCM was higher than normal person,but the circumferential deformation ability of regional myocardium was impaired,left ventricular outflow tract obstruction may aggravate the regional myocardial dysfunction.%目的 应用超声心动图速度向量成像(VVI)技术对肥厚型心肌病(HCM)患者心脏扭转运动(cardiac twist)进行初步分析,探讨HCM患者在左室射血分数(LVEF)正常时心脏局部和整体扭转功能是否已有改变.方法 对30例HCM患者(其中左室流出道梗阻13例)和33例正常人(对照组)行常规超声心动图检查,测量LVEF、左室舒张末期容积(LVEDV)、左室收缩末期容积(LVESV)、每搏量(SV)等.采用VVI技术测量左室基底部腱索水平、乳头肌水平和心尖水平收缩期心内膜下心肌和心外膜下心肌的最大旋转角度、峰值旋转速率、圆周应变(circumferential strain,CS)、圆周应变率(circumferential strain rate,CSR)、径向应变(radial strain,RS)、径向应变率(radial strain rate,RSR);测定舒张期峰值解旋转速率和解扭转率,以分析两组的心脏旋转和扭转运动.结果 HCM组与正常组相比,LVEF差异无统计学意义,LVEDV、LVESV、SV明显减低,心内膜下心肌的左室扭转角度、CS较正常人明显增高,心外膜下心肌的旋转速率、解旋转速率、CS、CSR均明显减低(P＜0.05),HCM组左室三个短轴水平的RS、RSR均明显低于对照组(P＜0.01);舒张期解扭转率低于对照组.HCM组分组资料显示:左室流出道梗阻组患者心外膜下心肌的旋转速率、解旋转速率、CS、CSR进一步减低.结论 HCM患者心脏整体扭转角度较正常人增大,局部心肌圆周方向变形能力下降,左室流出道梗阻加剧局部心功能的损伤.