二次谐波显像评价冠脉血流储备和狭窄程度的实验研究

目的：探讨二次谐波显像在定量评价冠脉血流储备和冠脉狭窄程度的价值。方法：采用二次谐波显像技术对１１条冠脉不同狭窄程度的动物模型进行心肌声学造影。结果：正常或狭窄冠脉灌注区心肌的造影时间－强度曲线的曲线下面积（ＡＵＣ）在罂粟碱介入前后的相对变化率与用电磁流量计测定的冠脉血流量的相对变化率即冠脉血流储备的相关性良好（ｒ＝０．７７，Ｐ＝０．０００２）；而且狭窄冠脉支配的心肌缺血区在罂粟碱介入前后ＡＵＣ的相对变化率与冠脉狭窄程度也有一定的相关性（ｒ＝０．７２，Ｐ＝０．０２。结论：二次谐波显像技术可以定量评价冠脉狭窄后冠脉血流储备的变化，并且在一定范围内定量反映冠脉狭窄程度

Experimental Study on Assessment of Coronary Blood Flow Reserve and the Severity of Coronary Stenosis By Second Harmonic Imaging

Objective:To determine whether myocardial contrast echocardiography(MCE)with second harmonic imaging(SHI)could accurately assess regional myocardial perfusion resulting from various degrees of coronary stenosis.Method:11 open chest dogs were studied during baseline,following the creation of a coronary stenosis of variable severity and at the peak of papaverine induced hyperemia.An ultrasound system(HP SONOS 5500)with SHI operating at 2 1/4 2 MHz and an off line videodensitometric analysis system was used for data acquisition and analysis.The areas under the background subtracted time intensity curves(AUC)from MCE images in the beds supplied by normal and stenotic vessels were respectively measured at the left ventricular short axis view at mid papillary muscle level.The results were compared with coronary blood flow(CBF) assessed by the electromagnetic flow probe.Results:The ratios of the AUC derived from the stenotic beds after to before papaverine administration correlated well with the index of coronary flow reserve(the ratiwas suggested to be used as an early predictor for high risk patients after AMI.