摘要
目的应用实时三维超声心动图(RT-3DE)定量评价多巴酚丁胺对心肌顿抑犬和心肌梗死犬左心室局部径向距离的作用。方法建立犬的心肌顿抑[冠状动脉(冠脉)结扎15 min,再灌注30 min]和急性心肌梗死(冠脉结扎180 min,再灌注30 min)模型。于冠脉结扎前和冠脉结扎-再灌注后,用微量输液泵经股静脉输注多巴酚丁胺5及10μg.kg-1.min-1,每一剂量持续5 min。应用RT-3DE获取实验犬静息状态及输注多巴酚丁胺10μg.kg-1.min-1后RT-3DE全容积数据库。脱机后,根据心尖长轴观8平面法重建收缩末期左室立体几何形状;以二尖瓣环中点至左室心尖部心内膜的连线为中心轴,将左室等分成与中心轴垂直的1.0 cm厚互相平行的短轴平面,从中选取室壁运动异常(WMA)面积最大者作为研究平面;在此平面上,以轴心与左室后壁连线所在位置为0°,逆时针每隔20°测量心内膜至轴心的距离(即径向距离R,共可测得18个值)。将冠脉结扎-再灌注后两组实验犬输注多巴酚丁胺前、后的平均R值与冠脉结扎前(设为基础状态)输注多巴酚丁胺前、后的相应R值进行比较。结果静息状态下,心肌顿抑组和心肌梗死组中所选研究平面结扎冠脉供血区平均R值均明显增大(均P<0.001)。输注多巴酚丁胺后,心肌顿抑组中上述异常增大的平均R值均明显减小(均P<0.001),但未恢复至基础状态水平(均P<0.05);心肌梗死组中上述异常增大的平均R值均无明显改变(均P>0.05)。结论通过应用RT-3DE分析输注多巴酚丁胺前、后左室局部径向距离的变化,可以识别心肌顿抑和心肌梗死。RT-3DE有望为临床定量评价左室局部几何形状提供一项有效手段。
Objective To evaluate the effects of dobutamine on radial distances of regional left ventricular of stunned and infarcted myocardium in canine models by real-time three-dimensional echocardiography（RT-3DE）. Methods A low infusion rate （5, 10μg·kg^-1·min^-1） dobutamine stress echocardiography were performed in 8 anesthetized open-chest dogs before coronary occlusion and after 15 min of coronary occlusion followed by 30 min of reperfusion（stunned model） and performed in the other 12 anesthetized open-chest dogs before coronary occlusion and after 180 min of coronary occlusion followed by 30 min of reperfusion（infarct model）. RT-3DE volume data sets were recorded at rest and at infusion rate of 10 μg·kg^-1·min^-1. Radial distances of regional left ventricular were analyzed as follows： （1） reconstruct left ventricular （LV） shape in end-systole; （2） a plane that best represented the region of ischemia was identified on the basis of the greatest amount of wall motion abnormality, 18 equally spaced radii（every 20 degree） were generated; （3） the radial distances（R） in end-systole were measured. Results After coronary occlusion followed by reperfusion, at rest, an increase of the mean R in the ischemic region（R6- R11 ） were found not only in the stunned model but also in the infarct model. After dobutamine infusion, in the stunned model, the dogs showed a significantly reduction in R6 - R11, but not reach the level of that before coronary occlusion; in the infarct model, there were no significant change in R6 - R11. Conclusions By analyzing effects of dobutamine on radial distances of regional left ventricular using RT-3DE, stunned and infarcted myocardium can be differentiated. RT-3DE can provide a new quantitative approach to assessment regional left ventricular shape and geometry.
出处
《中华超声影像学杂志》
CSCD
2006年第7期520-524,共5页
Chinese Journal of Ultrasonography
关键词
超声心动描记术
实时三维
心肌顿抑
心肌梗塞
多巴酚丁胺
Echocardiography, real-time three-dimensional
Myocardial stunning
Myocardial infarction
Dobutamine
