超声背向散射积分和回声强度定量在急性心肌缺血与再灌注过程中的变化及其与心肌收缩力的关系

目的： 观察犬心肌组织背向散射积分 （ＩＢ） 及其心动周期变化幅度 （ＣＶＩＢ） 和回声强度 （ＥＩ） 及其心动周期变化幅度 （ＣＶＥＩ） 在急性心肌缺血与再灌注过程中的变化， 以及ＣＶＩＢ 和ＣＶＥＩ与局部心肌收缩力的关系。方法： 用ＨＰ－５５００ 型超声诊断仪和自制ＤＦＹ 型超声图像定量分析诊断仪， 测量了１０ 只犬冠状动脉左前降支阻断前、后及再灌注不同时间左室前壁心肌组织ＩＢ、ＥＩ值和ＣＶＩＢ、ＣＶＥＩ值， 并同时测量室壁厚度 （Ｗ Ｔ） 和收缩期增厚率（ＴＨ％ ） 的动态变化。结果： 冠脉阻断 ２０ 分钟后， 缺血心肌组织ＩＢ 和ＥＩ均增高 （Ｐ＜ ０．０１）， ＣＶＩＢ 和ＣＶＥＩ均降低 （Ｐ 均＜ ０．０１）。再灌注１０ 分钟， ＩＢ 和ＥＩ即恢复正常， 与Ｗ Ｔ 相关。ＣＶＩＢ 和ＣＶＥＩ的恢复相对缓慢， 至再灌注９０ 分钟后方恢复正常， ＣＶＩＢ 和ＣＶＥＩ的变化与ＴＨ％ 的变化密切相关 （ｒ１＝ ０．８７， ｒ２＝ ０．８２， Ｐ＜ ０．０１）。结论： 心肌组织背向散射积分和回声强度在急性缺血与再灌注过程中存在相同的变化规律；ＣＶＩＢ 和ＣＶＥＩ与局部心肌组织收缩功能密切相关； 通过分析ＣＶＩＢ 和ＣＶＥＩ的变化不但能区别正常和缺血心肌组织， 同

Quantitative Analysis of Ultrasonic Integrated Backscatter and Echo Intensity after Acute Myocardial Ischemia and Reperfusion in Relation to Myocardial Contractility

Objective:To investigate the changes of ultrasonic integrated backscatter(IB),echo intensity(EI) and their magnitudes of cyclic variation(CVIB and CVEI) after acute myocardial ischemia and reperfusion,and the relationships between the changes of CVIB,CVEI and regional myocardial contractility.Methods:The values of IB,CVIB,EI and CVEI of anterior wall were measured by HP 5500 ultrasonic instrument and DFY ultrasonic apparatus on the left ventricular short axis view at papillary level in 10 open chest dogs before and 20 minutes after left anterior descending coronary artery occulsion,and followed by reperfusion at selected intervals.The segmental wall thickness(WT) and wall thickening(TH%) were measured at the same time.Results:After 20 minutes of coronary occlusion,WT decreased from 6. 66mm to 5 80mm( P <0 01),TH% decreased from 55 68% to 12 24%( P <0 01).Changes in integrated backscatter and echo intensity associated with these decreases include increase in IB and EI( P <0 01,respectively),decrease in CVIB and CVEI( P <0 01 respectively).After 10 minutes reperfusion,IB and EI recovered to baseline values.CVIB and CVEI recovered to normal,after 90 minutes reperfusion their changes correlated with the changes of TH%(r 1=0 87,r 2=0 82, P <0 01 respectively).Conclusion:The changes of IB and EI were similar after acute myocardial ischemia and followed by reperfusion.CVIB and CVEI correlated well with regional myocardial contractility.We can not only distinguish normal from ischemia myocardium,but also can assess its contractile function by quantitative analysis of CVIB and CVEI.