应变率成像评价急性缺血再灌注左心室功能与心肌细胞凋亡的相关性

目的 探讨应变率成像评价急性缺血再灌注后左心室功能与心肌细胞凋亡的相关性及其应用价值。方法 健康杂种犬30只，分为对照组（10只），缺血组（10只）和再灌注组（10只）。缺血组于第一对角支1cm以下套扎左冠状动脉前降支30min，再灌注组套扎30min后再灌注120min，对照组游离左冠状动脉前降支不结扎。应变率成像测定左室局部收缩功能，Simpson’s法测量左室射血分数（LVEF）、舒张末容积（EDV）及收缩末容积（ESV），TUNEL法检测缺血区心肌细胞凋亡指数。结果 收缩期应变率（SRs）与LVEF及TUNEL阳性细胞指数（AI）呈良好的相关性。SRs在三组间差异有统计学意义（P〈0．05），LVEF、EDV及ESV在三组间差异无统计学意义（P〉0．05），再灌注组AI与对照组间差异有统计学意义（P〈0．01）。结论 应变率成像为临床提供了一个敏感、简便的评价早期心肌局部收缩功能的指标，局部心功能与心肌细胞凋亡相关。

Correlation between of cell apoptosis and left ventricular segmental function in acute myocardial ischemia reperfusion using strain rate imaging

Objective To evaluate the capability of strain rate imaging(SRI)for left ventrical systolic function and to investigate the correlation between apoptosis and left ventricular segmental function following acute ischemia reperfusion in dogs.Methods Thirty dogs were divided into ischemia(10 cases),reperfusion(10 cases),and control(10 cases)groups.Left anterior descending coronary artery(LAD)were occluded for 30 min in ischemia group,dogs in reperfusion group were studied at LAD 30 min ligation,followed by 120 min reperfusion.Dogs without LAD ligation were used as control group.The left ventricular segmental function were detected by SRI technique.Left ventricle ejection fraction(LVEF),end diastolic volume(EDV)and end systolic volume(ESV)was measured by bi-Simpson's method.The apoptosis index(AI)of ischemic myocardium in left ventricle was detected by terminal deoxynudeotidy transferease-mediated biotinylated deoxyuridine triphosphate nick end labeling(TUNEL).Results Systolic strain rate(SRs)of left ventricular wall were correlated with LVEF and with myocardial cell AI.SRs was significantly decreased in ischemia and reperfusion groups compared with control group(P<0.01).There was no significant difference in LVEF,EDV,ESV among three groups(P>0.05).AI was significantly increased in reperfusion group(P<0.01).Conclusions SRI provides a sensitive,convenient and reliable tool to evaluate left ventricular segmental function,which is related to myocardial cell apoptosis.