组织多普勒成像检测等容收缩期运动评价心肌梗死患者心肌存活性的研究

目的 探讨静息状态下局部心肌等容收缩期运动指标评价陈旧性心肌梗死患者心肌存活性的临床价值.方法 应用组织多普勒成像(TDI)对30例陈旧性心肌梗死患者和30例正常人局部心肌等容收缩期运动系列指标进行检测,于胸骨旁左室长轴观,心尖左室长轴观、两腔观和四腔观,将取样门宽分别置于左室基底段和中段内膜下心肌层,获取16个节段的TDI,测量等容收缩期正、负向波(IVC1,IVC2)峰值速度(V,VIVC2)及其差值(DIVC)等,并与单光子发射计算机断层成像(SPECT)所测心肌存活分数(VF)对比分析,以VF<30%定为梗死区内无存活心肌.结果 与对照组相应部位相比,心肌梗死组梗死部位VIVC1,DIVC减低(P<0.05～0.01),VIVC2及IVC2持续时间(TIVC2)增大(P<0.05);IVC1持续时间(TIVC1)两组差异无统计学意义(P>0.05);非梗死部位与对照组相比变化多不显著(P>0.05);心肌梗死节段横向DIVC明显小于同一节段纵向DIVC,差异有统计学意义(P<0.05).相关分析显示TDI所测心肌横向及纵向DIVC值与SPECT心肌灌注显像所测VF呈显著正相关,相关系数分别为0.837(P<0.001)和0.797(P<0.001).若以横向DIVC>-1.50为截断值预测局部心肌具有存活性的敏感性为75%,特异性达75%;以纵向DIVC值>0.92为截断值预测局部心肌具有存活性的敏感性达77.8%,特异性为87.5%.结论 心肌梗死患者梗死区等容收缩期TDI具有特征性变化,应用横向及纵向DIVC均可作为静息状态下评价心肌存活性的新指标.

Research of myocardial viability in patients with old myocardial infarct by examine isovolumic myocardial contract motion with Doppler tissue imaging

Objective To detect the clinical value of evaluating myocardial viability in patients with old myocardial infaretion(OMI) by measuring myocardial isovolumie contraction motion indices with tissue Doppler imaging(TDI) under the quiescent condition. Methods The myocardial isovolumic contraction motion indices of 30 normal subjects and 30 patients with OMI were examined by TDI. The sample gate was located at left ventricular postero-septal,lateral,anterior,inferior,antero-septal and posterior walls in basal and middle segments separately. The peak positive and negative veiocities(VIVC1 ,VIVC2 ) during myocardial isovohimic contraction phase, and the difference(DIVC) between VIVC1 and VIVC2 were measured, which were analysed combined with the viable fraction(VF) calculated by single photon emission computed tomography (SPECT). Results VIVC1, DIVC were significantly decreased,and VIVC2 was significantly increased in infarct zones of patients with OMI than those of the normal subjects( P <0.05). Compared with normal subjects, myocardial isovolumic contraction motion indices of non-infarct wails in patients with OMI were steady( P >0.05). In OMI group,DIVC of short axis was significantly decreased than that in long axis( P <0.05). Statistic analysis showed that DIVC values on both of short and long axis had significant positive correlations with VF derived from SPECT,and the correlation coefficients were 0. 837 ( P<0. 001) and 0. 797( P<0. 001 ) ,respectively. The sensibility and specificity of evaluating viable myocardium was 75% and 75% separately supposing the cutoff of DIVC on short axis was more than - 1.50,and the sensibility and specificity was 77. 8% and 87.5% separately if the cutoff of DIVC on long axis was more than 0.92. Conclusions Myocardial isovolumic contraction's TDI of infarct zones in patients with OMI had characteristic changes. DIVC on both of short and long axis could be as a new method of evaluating myocardial viability.