摘要
目的观察比格犬左心室急性心肌缺血前后，节段整体和节段跨壁心肌峰值径向位移（RD）变化，量化评价节段整体和节段跨壁心肌力学特征，为缺血前后不同状态心肌构造与功能的定量研究提供基础力学数据。方法10只健康比格犬开胸模型，结扎冠状动脉左前降支，诱导产生急性心肌缺血。缺血前和结扎冠状动脉后20min分别采集三个心动周期二尖瓣水平、乳头肌水平以及心尖水平短轴观动态组织多普勒速度图像。应用量化组织多普勒工作站，分别获取各短轴观前壁、下间壁、下壁、后壁节段整体和心内膜下心肌（subend）、中层心肌（mid）、心外膜下心肌（subepi）的RD时间曲线并测量RD及其达峰值时间。评价急性心肌缺血前后节段整体和节段跨壁心肌的RD、达峰时间、达峰时间标准差等力学参数变化及其相关性。结果①急性心肌缺血后，二尖瓣水平前壁和乳头肌水平前壁及心尖水平各节段整体及节段跨壁心肌的RD较缺血前呈下降趋势，其余节段呈增高趋势；②急性心肌缺血后，左心室壁12节段跨壁的RD与相应节段整体的RD相关性较缺血前发生改变，乳头肌水平及心尖水平前壁节段跨壁与节段整体的RD相关性丧失。③急性心肌缺血后，左心室节段整体和节段跨壁的心率纠正后RD达峰时间较缺血前延迟，部分节段整体的RD达峰时间延迟较缺血前差异有统计学意义（P〈0．05）。④急性心肌缺血后，左心室节段整体和节段跨壁心肌的RD达峰时间标准差较缺血前增大，差异有统计学意义（P〈0．05）。结论节段整体和跨壁心肌峰值RD降低、相关性破坏、达峰时间延迟、达峰时间标准差增大等终点力学参数变化能够反映急性心肌缺血局部的力学异常状态。
Objective To evaluate the change of myocardial segment and the transmural peak radial displacement（RD） of left ventricular wall before and after acute myocardial ischemia. Methods Left anterior descending coronary artery was ligated to induce acute myocardial ischemia in 10 open-chest Beagle canine models. Two-dimensional gray-scale images with overlaid tissue Doppler velocity imaging in three short-axis views including mitral annulus（MV）,papillary muscle（PM） and apical（AP） levels were acquired before and after acute myocardial ischemia in three complete cardiac cycles. Parameters including RD, RD peak time（RD-TC）,standard deviation of RD peak time（RD-TSD） of anterior wall（AW）, inferoseptal wall （IS）,inferior wall（IW） and posterior wall（PW） at the 12 segments and different myocardial layers（i, e. , subend,mid,subepi） of the same segment of left ventricle were measured and analyzed using quantification tissue Doppler imaging workstation and the difference and co-relationship among them were analyzed also. Results ①After acute myocardial ischemia,the segment and subend,mid,subepi RD of AW of MV,PW and AP were decreased,other counterpart segments were increased without significant difference（ P 〉0.05）. ②After acute myocardial ischemia, the existed RD co relationship revealed between subend,mid, subepi and the segment were changed（i, e. ,the eo relation in AM at PW and AP levels were vanished）. ③Corrected by the heart rate,myocardial RD-Tc at all 12 segments and subend,mid, subepi after acute myocardial ischemia were longer than that before separately. ④ RD-TSD at the 12 segments, subend, mid, subepi were significantly wider after acute myocardial ischemia than that before（ P 〈0.05）. Conclusions The decreased RD,dis connective spatial co-relationship of RD,delayed RD-Tc and wide RD-TSD can be used as potential mechanical parameters for the more sensitive evaluation of regional myocardial dysfunction during acute ischemia.
出处
《中华超声影像学杂志》
CSCD
北大核心
2009年第4期337-342,共6页
Chinese Journal of Ultrasonography
基金
基金项目：国家自然科学基金资助（30670547）
关键词
超声心动描记术
心肌缺血
心室功能
左
径向位移
Echocardiography
Myocardial ischemia
Ventricular function, left
Radial displacement
