摘要
目的:探讨二维斑点追踪技术评价兔急、慢性心肌梗死心肌整体圆周应变及应变率的变化。方法 :将25只新西兰兔分成假手术组(n=5),仅开胸;实验组(n=20),开胸,结扎左回旋支90 min后松开活结,分别于术前、术后1周、7周测量左室短轴观3个水平(二尖瓣、乳头肌及心尖水平)的心肌整体圆周应变(GCS)和应变率(GSrC),以绝对值进行分析。实验结束后,行在体心脏磁共振(c MRI)检查和离体心肌氯化三苯基四氮唑(TTC)染色,分别测量心肌梗死面积(MI size%)等。结果:二尖瓣水平:与术前比较,术后1周组GCS及GSr C均显著增高(P<0.05);与术后1周组比较,术后7周组GCS及GSrC均显著降低(P<0.05),基本回落到术前基础状态(P>0.05)。乳头肌和心尖水平:与术前比较,术后两组GCS及GSrC均显著降低(P<0.05),而术后两组比较,GCS及GSr C差异均无统计学意义(P>0.05)。假手术组:3个水平各时间段GCS、GSrC比较,均无统计学意义(P>0.05)。相关性分析显示:乳头肌水平GCS、GSr C分别与LVEF(US)、LVEF(cMRI)、MI size%相关性较好(r分别为-0.943、-0.916、-0.749、-0.615、0.807、0.641,P<0.05)。结论 :二维斑点追踪技术可以评价兔急、慢性心肌梗死心脏局部及整体功能,并判断心肌梗死部位及范围。
Objective： To evaluate the global myocardial circumferential strain and strain rate in rabbits with acute and chronic myocardial infarction by two-dimensional speckle tracking imaging. Methods： Twenty New Zealand rabbits with liga- tion of the left circumflex artery were observed as experimental group and 5 rabbits without ligation of the artery as control group. The degree of global myocardial circumferential strain（GCS） and strain rate（GSrC） at mitral valve, papillary muscle and apical level were compared by speckle tracking imaging before, one week and seven weeks after surgery, respectively. And the fate of the animals, cardiac magnetic resonance imaging（cMRI） and triphenyltetrazolium chloride（TTC） staining were studied for myocardial infarction sizes （MI size%）. Results： Compared with the preoperative parameters, there were significant increases in GCS and GSrC one week after the surgery （P〈0.05） at mitral valve level. Compared with those parameters 1 week postopera- tive, there were significant decreases in GCS and GSrC at the 7th week postoperative （P〈0.05）, which had no obvious changes than those of the basic status. Compared with the preoperative parameters, there were significant decreases in GCS and GSrC at the 1st and 7th week postoperative at papillary muscle and apical level（P〈O.05）, but there was no significant difference be- tween the 1st and the 7th week postoperative. Conversely there were no much changes of the degree of GCS and GSrC of myocardium at each time point in the control group（P〉0.05）. The degree of GCS and GSrC of myocardium at papillary muscle level had correlations with LVEF（US）, LVEF（cMRI） and MI size%（r=-0.943, -0.916, -0.749, -0.615, 0.807, 0.641, respectively, all P〈0.05）. Conclusion： Two-dimensional speckle tracking imaging can objectively quantify regional and global heart function in rabbits, and can help to analyze the location and size of the myocardial infarction.
出处
《中国临床医学影像杂志》
北大核心
2017年第6期420-424,共5页
Journal of China Clinic Medical Imaging
