实时三维斑点追踪技术评价缺血及再灌注后犬顿抑心肌左室收缩功能

发布时间：2018-08-02 08:41

【摘要】：目的本研究应用实时三维斑点追踪显像技术，通过建立缺血再灌注后犬顿抑心肌模型，从局部和整体等方面对左室收缩功能进行评价，明确缺血再灌注后顿抑心肌的结构及功能变化，从而为临床早期、无创冠心病心绞痛诊断提供新的思路。方法结扎9只成年杂种犬左冠状动脉前降支，15min后行再灌注，分别于缺血前、缺血5min、缺血15min、再灌注30min、60min、90min及120min采集心尖切面三维图像及二维图像，应用双平面Simpson's法在心尖两腔心切面及四腔心切面测量常规指标：左室舒张末期容积(LVEDV)、左室收缩末期容积(LVESV)、左室舒张末期内径(LVDD)、左室收缩末期内径(LVDS)、左室射血分数(LVEF)。应用实时三维斑点追踪显像技术检测缺血(前基底、前中部、隔前基底及隔前中部)及非缺血(后基底及后中部)心肌节段纵向、径向、圆周及面积峰值应变（LSpeak、RSpeak、CSpeak、ASpeak），整体峰值应变（GLSpeak、GRSpeak、GCSpeak、GASpeak）,并分析整体峰值应变与LVEF相关性，从而评价左室局部及整体收缩功能。结果 1、犬缺血及再灌注后左室常规超声指标比较：LVESV、LVEDV、LVDS、LVDD在缺血期间均增大，与缺血前相比差异有统计学意义（P＜0.05）；LVEF在缺血期间减低，与缺血前相比差异有统计学意义（P＜0.05）。再灌注后30min恢复正常，与缺血前相比差异无统计学意义（P＞0.05）。 2、实时三维斑点追踪技术测量左室整体收缩功能比较：与缺血前相比，，缺血期间左室各整体应变参数均减低，差异有统计学意义（P＜0.05）。随再灌注时间延长逐渐恢复， GASpeak恢复时间最长（120min），与缺血前相比差异无统计学意义（P＞0.05）。实时三维斑点追踪显像技术测量缺血前后各时点各整体应变参数均与LVEF呈正相关，其中以GASpeak与LVEF的相关性最高。 3、实时三维斑点追踪技术测量左室局部收缩功能比较：缺血心肌Speak的变化：与缺血前相比，缺血期间缺血节段各应变指标均降低，差异有统计学意义（P＜0.05），应变逐渐恢复正常（随再灌注时间延长），但直至120min时仍未达到正常，与缺血前相比差异有统计学意义（P＜0.01）。非缺血心肌Speak的变化：与缺血前相比，缺血期间非缺血节段各应变指标均升高，差异有统计学意义（P＜0.05），于再灌注30min均恢复正常，与缺血前相比差异无统计学意义（P＞0.05）。结论 1、常规超声检查仅可以检测出缺血期间左室整体收缩功能减低的情况，而实时三维斑点追踪显像技术对左室局部心肌顿抑现象的评价有较大的应用价值。 2、缺血再灌注后犬左室心肌整体收缩功能延迟恢复，即存在心肌顿抑现象。 3、缺血再灌注后犬左室心肌局部收缩功能延迟恢复，且与整体功能相比，局部功能恢复时间更长。 4、实时三维斑点追踪显像技术指标中，面积应变指标最为敏感，有望成为早期诊断冠心病心绞痛的新指标。
[Abstract]:Objective to evaluate the left ventricular systolic function by establishing a canine model of myocardial arrest after ischemia reperfusion using real time 3D speckle tracing imaging. The changes of myocardial structure and function after ischemia reperfusion were determined, which provided a new idea for the early diagnosis of angina pectoris of non-invasive coronary heart disease. Methods the left anterior descending coronary artery of 9 adult mongrel dogs was ligated for 15 minutes and then reperfused. Before ischemia, 5 minutes of ischemia, 15 minutes of ischemia, 30 minutes of reperfusion, 60 minutes or 90 minutes of reperfusion, and 120min, 3D and 2D images of the apex were collected. Biplane Simpson's method was used to measure the normal indexes of the apical two chamber incisor and four chamber section: left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular end-diastolic diameter (LVDD), left ventricular end-systolic diameter (LVDS), left ventricular ejection fraction (LVEF).; left ventricular end-diastolic volume; left ventricular end-systolic dimension; left ventricular ejection fraction (LVEF).; left ventricular end-systolic dimension (LVDS), left ventricular ejection fraction (LVEF). The longitudinal and radial segments of ischemic (anterior basal, middle septal, anterior septal and middle septal) and non-ischemic (posterior and posterior middle) myocardial segments were detected by real-time 3D speckle tracing imaging. The peak circumference and area strain (LSpeak-RSpeak-CSpeak-ASpeak) and the global peak strain (GLSpeak-GRCSpeak-GCSpeak-GASpeak) were analyzed, and the correlation between the global peak strain and LVEF was analyzed to evaluate the local and global systolic function of left ventricle. Results 1. Compared with the normal ultrasound indexes of left ventricle after ischemia and reperfusion in dogs, the LVDD of LVDS / LVDD increased significantly during ischemia (P < 0.05), and the LVEF decreased during ischemic period (P < 0.05), and the LVDD of LVDS / LVDD in LVESVV / LVEDVV / LVDS / LVDD / LVDD was significantly lower than that before ischemia (P < 0.05). The difference was statistically significant compared with that before ischemia (P < 0.05). 30min returned to normal after reperfusion (P > 0. 05). 2. Real-time 3D speckle tracing technique was used to measure the global systolic function of left ventricle. The global strain parameters of the left ventricle decreased during ischemia (P < 0.05). With the prolongation of reperfusion time, the recovery time of GASpeak was the longest (120min), which had no significant difference compared with that before ischemia (P > 0. 05). Real time 3D speckle tracing imaging was used to measure the global strain parameters at different time points before and after ischemia, which was positively correlated with LVEF. Among them, the correlation between GASpeak and LVEF was the highest. 3. Real time 3D speckle tracing technique was used to measure the left ventricular regional systolic function. The changes of Speak in ischemic myocardium were compared with those before ischemia. The difference was statistically significant (P < 0. 05), the strain gradually returned to normal (with the time of reperfusion), but still did not reach normal until the time of 120min (P < 0. 01) compared with that before ischemia (P < 0. 01). Changes of Speak in non-ischemic myocardium: compared with those before ischemia, all the strain indexes of non-ischemic segments increased during ischemia (P < 0. 05), but 30min returned to normal after reperfusion, but there was no significant difference compared with that before ischemia (P > 0. 05). Conclusion 1. Conventional ultrasound can only detect the decrease of global left ventricular systolic function during ischemia. Real-time 3D speckle tracing imaging is of great value in evaluating left ventricular regional myocardial arrest. 2. The global systolic function of left ventricle is delayed after ischemia reperfusion in dogs. There was myocardial depression. 3. The regional systolic function of left ventricle was delayed after ischemia reperfusion in dogs, and compared with the global function. The recovery time of local function is longer. 4. Among the technical indexes of real-time 3D speckle tracing imaging, the area strain index is the most sensitive one, which is expected to be a new index for early diagnosis of angina pectoris of coronary heart disease.
【学位授予单位】：辽宁医学院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R445.1

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