速度向量成像技术评价腹主动脉缩窄致高血压兔模型心功能演变的实验研究

发布时间：2019-06-01 15:18

【摘要】：研究背景：高血压是多种心血管疾病的重要病因和危险因素,容易出现心力衰竭,心功能的监测对指导临床治疗有及重要的意义,常规二维超声心动图不能早期反映心脏局部功能受损,而新近发展的速度向量成像技术(velocity vector imaging, VVI)基于斑点追踪技术,能及时、准确地判断心肌局部功能的变化。目前国内外研究主要针对高血压某个发展阶段的心脏功能状态进行检测,不能反映高血压心脏功能的动态演变过程。有关VVI监测高血压心功能演变的报道很少。目的：建立新西兰大白兔高血压的动物模型,应用VVI技术对正常兔及造成高血压后8周内不同时间点局部心肌运动和心脏整体功能的动态变化进行分析,探讨兔正常心肌力学特点,以及高血压心脏局部及整体功能的动态演变特点。对象及方法：新西兰大白兔40只,随机分为手术组(n=25)和对照组(n=15),对照组和手术组兔分别于术前、术后即刻、术后2周、4周、8周测量血压及腹主动脉内径和流速。所有实验动物于手术前、术后2周、4周、6周和8周行常规超声心动图检查,并采集左心室长轴切面,左心室短轴切面二尖瓣水平、乳头肌水平和心尖水平动态图像,脱机行VVI分析。结果：术后即刻血压明显增高,与对照组比较有非常显著性差异(P0.001),术后2周血压较术后即刻时低,有统计学意义,至术后4周、8周血压呈进行性增高,与对照组及与前次比较差异有统计学意义。对照组兔腹主动脉无变化。手术组兔实验过程中腹主动脉缩窄程度未见明显变化,缩窄处呈高速射流,4周后逐渐降低。与术前及对照组比较,内径和流速均有非常显著性差异(P0.01)：缩窄后血管内径呈进行性增宽,4周后与术前及对照组比较有显著性差异(P0.05),缩窄后流速亦呈高速射流,但低于狭窄处,4周后流速逐渐减低。正常对照组兔长轴方向上心肌运动速度由基底节段向心尖方向递减,应变和应变率无明显改变；同一水平各节段间短轴速度前间隔和前壁最大,应变和应变率前壁和侧壁大于其它各节段。手术组兔长轴和短轴方向上,与术前比较及与对照组比较,手术组术后2周开始至术后8周各节段Ss、SRs、SRd均可见逐渐减低,与对照组比较差异均有统计学意义(P0.05),术后4周各节段Ss、SRs、SRd较术后2周有所减低,但差异无统计学意义,至术后6周、8周各参数呈进行性减低,与对照组及前一时间点比较均有显著性差异(P0.01)。Vs、Vd术后2周可见减低趋势,无统计学意义,术后4周开始至8周呈进行性减低(P0.05) 结论：腹主动脉缩窄致高血压动物模型操作简单,成功率高,该方法切实可行,可作为高血压模型的制作方法。VVI技术能用于定量评价高血压兔心肌结构力学的变化。正常新西兰大白兔心脏的长轴及短轴运动有一定的规律。高血压兔长轴和短轴方向上应变和应变率于术后2周开始即出现明显减低,并呈进行性减低,较速度参数更加敏感。VVI技术能够无创性早期检测高血压所致心功能损害,为高血压心功能损害的早期诊断提供了一种新的无创的、可靠的定量工具。
[Abstract]:Background: Hypertension is an important cause and risk factor of a variety of cardiovascular diseases. It is easy to have heart failure. The monitoring of heart function is of great significance to the clinical treatment. The routine two-dimensional echocardiography can not reflect the local function of the heart in the early stage. The recent development of velocity vector imaging (VVI) is based on the speckle tracking technique, and can accurately and accurately judge the change of the local function of the myocardium. At present, the research of the heart function in a certain development stage of the high blood pressure is mainly studied at home and abroad, and the dynamic evolution of the heart function of the hypertension cannot be reflected. There are few reports about the evolution of the heart function of VVI in the monitoring of hypertension. Objective: To establish an animal model of high blood pressure in New Zealand white rabbits. The dynamic changes of the local myocardial motion and the whole function of the heart at different time points in the normal rabbits and 8 weeks after the high blood pressure were analyzed by VVI technique, and the normal myocardial mechanics of the rabbits were discussed. The dynamic evolution of the local and global functions of the heart and the heart of the hypertensive heart Methods:40 rabbits were randomly divided into operation group (n = 25) and control group (n = 15), and the control group and the operation group were randomly divided into operation group (n = 25) and control group (n = 15). The blood pressure and the inner diameter of the abdominal aorta were measured at 2,4 and 8 weeks after operation. and the left ventricular long axis section, the left ventricular short axis section mitral valve level, the papillary muscle level and the apex horizontal dynamic image, the offline line VV, The results showed that the blood pressure in the control group was significantly higher than that in the control group (P 0.001). The blood pressure in the 2-week post-operation was lower than that of the control group. Statistical significance. Control group rabbit There was no change in the abdominal aorta. There was no significant change in the degree of coarctation of the abdominal aorta during the experimental group. The inner diameter and the flow rate were significantly different after 4 weeks (P 0.01): the inner diameter of the vessel was gradually widened after narrowing, and there was a significant difference between the pre-operative and the control group after 4 weeks (P0.05), and the posterior flow was narrowed. The speed is also high-speed jet, but below the stenosis,4 weeks The velocity of the myocardial movement in the long axis direction of the normal control group was decreased from the basal segment to the apex, and the strain and strain rate were not changed significantly; the front and the front wall of the short axis at the same horizontal segment and the front wall and the front wall of the front wall were the largest, the strain and the strain rate were the front wall and the anterior wall. The side wall of the operation group was greater than that of the other sections. The long axis and the short axis of the operation group were compared with the control group before and after the operation, and the number of Ss, SRs and SRd after 2 weeks after the operation of the operation group was gradually reduced, and the difference between the control group and the control group was statistically significant (P0.05). The scores of Ss, SRs and SRd in the 4 weeks were lower than that of the second week after operation, but there was no significant difference in the difference between the control group and the previous time point (P0.01). Vs and Vd were seen 2 weeks after the operation. The trend was reduced, no statistical significance,4 weeks after operation and 8 weeks after operation. Conclusion: The operation of the animal model is simple and the success rate is high, and the method is feasible. can be used as a preparation method of the hypertension model, and the VVI technology can be used for quantitative evaluation, The changes of the structural mechanics of the myocardial structure of the hypertensive rabbits. The heart of the normal New Zealand white rabbit. The major axis and the short axis movement have a certain rule. The strain and strain rate in the long axis and the short axis direction of the high blood pressure rabbits are obviously reduced at the beginning of 2 weeks after the operation and are in progress. VVI can detect the heart function damage caused by high blood pressure in the early stage, and provides a kind of early diagnosis for hypertensive heart function damage.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R-332

【参考文献】