组织多普勒成像在急性心肌缺血心功能异常中的实验研究

目的 运用组织多普勒成像（TDI）技术对急性心肌缺血区域和二尖瓣环侧壁处的运动速度、移动振幅进行检测，探讨TDI在急性心肌缺血、心肌梗死中的应用价值。方法 10只开胸猪结扎左冠状动脉前降支（LAD），通过TDI技术速度模式检测缺血区域和心尖四腔观二尖瓣环侧壁处的色泽变化及收缩、舒张期运动速度（VS，VE，VA）、移动振幅（CD，MDe，MDa）、等容收缩期时间，并与基础状态对照分析。结果 LAD结扎后，缺血区域和二尖瓣环处色泽暗淡，局部心肌色彩缺失，结扎15s时收缩期、舒张早期运动速度、移动振幅显著降低，等容收缩期时间延长。结论 TDI技术能准确反映血梗死区域运动异常，精确测定局部收缩、舒张期运动速度、移动振幅，尤其二尖瓣环处的运动能反映整体心肌的运动，为临床早期评价局部心肌缺血及心功能异常提供了一种无创性的检查手段。

Experimental study of Doppler tissue imaging on functional abnormality of the acute myocardial ischemia in pigs

Objective To determine the motion velocity and mobile amplitude of acute myocardial ischemia(AMI), myocardial infarcted region and lateral wall of mitral annular using tissue Doppler imaging (TDI) and to study the available value of TDI on AMI and myocardial infarction.Methods Ligated descending anterior branch of left coronary artery(LAD) of 10 open chest pigs, determined the color changes of ischemia region and view mitral annular apital four chamber lateral wall and measwred the systotic and diastotic motion velocities (V S, V E, V A), displacement (MD, MDe, MDa) and isometric contraction time interval, and compared them with that of basal states.Results The colors of ischemia region and mitral annular were faint, local myocardial color lost after ligatured LAD. After having ligated for 15 s, the systolic and diastolic early motion velocities and mobile amplitude were decreased, time of isometric contraction was prolonged.Conclusions TDI can accurately reflect ischemia, infarcted regional motion abnormality, accurately determine local systolic and diastolic motion velocities and displacement. Especially, the motion of mitral annular can reflect the total myocardial motion. It provides a non invasive method for clinical to early evaluate local myocardial ischemia and abnormal myocardial function.