斑点追踪显像结合腺苷负荷超声观察心肌旋转运动评价其存活性的研究

摘要

Objective To evaluate viable myocardium through rotational motion by speckle tracking imaging combined with adenosine stress echocardiography. Methods An acute myocardial infarction and reperfusion model in 21 healthy mongrel dogs were made by ligating anterior descending coronary artery for 90 minutes followed by 120-minute reperfusion. Measurements of the regional Peak Rotation and Peak-systole Rotation Rate at the mitral, papillary muscle and apical levels on anterior wall and anterior septum were performed respectively. TTC staining served as a "gold standard" to define viable and nonviable myocardium. The infarct size was assessed with TTC, and the equal or less than 50% area of infarction was considered viable (SN/S≤50%). Results At baseline and after reperfusion, there was no significant difference of PRot and PRRs between viable and nonviable myocardium group. PRot and PRRs decreased after adenosine administered compared with reperfusion in viable group while there were no changes in nonviable group. Compared with nonviable group, PRot and PRRs in viable group increased significantly at mitral and apical levels. There was a positive correlation between PRot and PRRs with SN/S at mitral level, but a negative correlation between PRot and PRRs with SN/S at apical level. Combined with APRot and APRRs. the sensitivity and specificity for distinguishing..viable from nonviable segment could reach 87. 5% and 81. 8%. Conclusions Observed myocardial rotational motion by speckle tracking imaging combined with adenosine stress echocardiography could accurately detect viable and nonviable myocardium.%目的 探讨斑点追踪显像结合腺苷负荷超声观察心肌旋转运动评价存活性的方法.方法 21条健康杂种犬,结扎其冠状动脉前降支90 min后,恢复血流120 min灌注制作急性心肌梗死再灌注模型.分别于基础状态下(结扎前)、再灌注后采集短轴各水平的图像.随后泵入腺苷并重复采集图像.运用二维斑点追踪技术评价不同状态下前壁、前间壁的峰值旋转角度( peak rotation,PRot)及收缩期峰值旋转率(peaksystole rotation rate,PRRs).以氯化三苯基四氮唑溶液(2,3,5triphenyl tetrazolium chloride,TTC)染色结果测量梗死面积(SN)与该节段总面积(S)的百分比(SN/S),SN/S≤50％即为存活心肌,将前壁、前间壁各节段分为存活及非存活心肌组进行比较.结果 (1)基础状态和再灌注后,存活与非存活组心肌间比较差异无统计学意义；腺苷负荷后的存活心肌PRot、PRRs与非存活心肌比较差异有统计学意义.(2)腺苷负荷后,二尖瓣水平PRot、PRRs与SN/S呈正相关,心尖水平则呈负相关.(3)结合腺苷负荷后△PRot(％)与△PRRs(％)两项指标,其识别存活心肌的敏感性和特异性分别为87.5％、81.8％.结论 斑点追踪显像结合腺苷负荷超声心动图观察心肌旋转运动能较准确地区分存活与非存活心肌.