定量组织速度成像对左心室心肌缺血节段同步性的研究

The synchronism study of left ventricular myocardial ischemic segments by quantitative tissue velocity imaging

目的应用定量组织速度成像(QTVI)技术探讨冠心病患者不同程度心肌缺血节段心肌运动的同步性及其对心功能的影响。方法以冠状动脉造影为标准,冠状动脉左前降支(LAD)单支病变患者68例分为缺血Ⅰ组(38例),狭窄率50%～75%;缺血Ⅱ组(30例),狭窄率≥75%;选取造影结果阴性者(狭窄率<50%或无狭窄者)28例为对照组。在QTVI曲线上测量LAD支配的左室心肌5个节段的收缩期峰值速度(Vs)、舒张早期峰值速度(Ve)、舒张晚期峰值速度(Va);收缩期同步性指标Ts和舒张期同步性指标Te。结果与对照组比较,缺血Ⅰ组Vs、Ts差异无统计学意义,Ve和Ve/Va比值减低,Te延长,差异有统计学意义(P<0.05);缺血Ⅱ组与对照组比较Vs、Ve、Va、Ts、Te差异均有统计学意义(P<0.05或P<0.01)。结论QTVI技术能定量分析缺血心肌节段收缩、舒张功能及室壁运动的时间延迟,功能下降和时间延迟程度与局部室壁缺血程度有关,并且舒张期特性指标早于收缩期指标出现变化。

Objective To explore the synchronism of myocardial ischemia segments in patients with coronary artery disease, and to investigate the influence of different degree myocardial ischemia to heart function by quantitative tissue velocity imaging （QTVI）. Methods QTVI was perfomaed in 68 patients who underwent coronary angiography and 28 healthy subjects, then 68 patients were divided into 2 groups： isehemic group Ⅰ included 38 cases with 50% - 75% stenosis rate, and ischemic group Ⅱ included 30 cases with more than 75 % stenosis rate. Peak systolic velocity （Vs）, early diastolic velocity （Ve）, late diastolic velocity （Va）, time to peak systolic velocity（Ts） and time to peak diastolic velocity（Te） were measured by the QTVI curve. Results Compared with control group, there was no significant difference between Vs and Ts in ischemic group Ⅰ, Ve and the ratio of Ve and Va were decreased, Te was prolonged （ P 〈 0.05）. There was significant difference between ischemic group Ⅱ and control group in Vs, Ve, Va, Ts, and Te（ P 〈 0.05, P 〈 0.01）. Conclusion QTVI can quantitatively assess myocardial ischemic segments systolic, diastolic function and the time delay of wall motion, which were related to degree of myocardial ischemic and time delay. The diastolic index is changed earlier than that of systolic index.