应用组织追踪和彩色多普勒冠状动脉血流显像结合多巴酚丁胺负荷试验评价缺血再灌注心肌的收缩储备和冠状动脉血流储备

Assessment of myocardial contractile reserve and coronary flow reserve in reperfused myocardium by tissue tracking and color Doppler coronary flow imaging during dobutamine stress

目的应用组织追踪和彩色多普勒冠状动脉血流显像(CDCFI)结合多巴酚丁胺负荷试验分析不同时间的缺血再灌注对左室心肌收缩功能和冠状动脉血流的影响,以期为评估心肌存活性提供简便快捷的定量指标。方法健康杂种犬25条,随机分为顿抑组和梗死组。应用组织追踪和CDCFI技术观测顿抑组和梗死组缺血区(前间隔)于基础状态、再灌注30min以及再灌注90min多巴酚丁胺负荷前后二尖瓣环收缩期向心尖方向运动的最大位移(MVD)以及左前降支中远段舒张期冠状动脉血流储备(CFR)的动态变化。结果多巴酚丁胺负荷试验后,不同再灌注时间顿抑心肌和梗死心肌前间隔MVD的增加率(ΔD%)和左前降支的CFR值均明显低于基础状态(P<0.001,P<0.05),顿抑组的ΔD%以及CFR值均明显高于梗死心肌(P<0.001,P<0.05),并随再灌注时间延长,有逐渐好转趋势(P<0.05,P<0.05);而梗死心肌则无此变化趋势(P>0.05,P>0.05);CFR与二尖瓣环收缩期向心尖运动的最大位移变化率之间有良好的相关性(r=0.719,P<0.05)。结论结合组织追踪技术和CDCFI技术动态观察缺血再灌注心肌多巴酚丁胺负荷后心肌收缩功能和冠状动脉血流动力学变化,可以提高判断存活心肌的准确率。

Objective To investigate the feature of reperfused wall motions and the change of coronary blood flow in different conditions by tissue tracking （TT） and color Doppler coronary flow imaging （CDCFI） during dohutamine stress. Methods Twenty-five anaesthetized mongrel dogs were randomly divided into two groups： stunning group and infarction group, dobutamine stress was performed at baseline, reperfusion 30 and 90 minutes. The increasing degree of systolic maximum mitral annular displacement （△D%） of anterior septal wall and the coronary flow reserve （CFR） of LAD were obtained. Results The △D% and the CFR in different reperfusion time were lower than that in baseline （P 〈 0.001, P 〈 0.05）. The △D% and CFR of different reperfusion time in stunning group was higher than those in infarction group. With the duration of reperfusion, these two parameters in stunning group had increasing trend （P 〈 0.05, P 〈 0.05）, however, there was no significant change in infarction group （P 〉 0.05, P 〉 0.05）. There was good correlation between △D% and CFR （r = 0.719, P 〈 0.05）. Conclusions Using TT and CDCFI, the changing of the contractile function and coronary hemodynamics of ischemia-reperfusion myocardium could be observed serially. It could improve the accuracy to detect the viable myocardium.