斑点追踪显像技术评价压力负荷，容量负荷及心肌收缩力改变对左心室扭转和解旋功能影响的实验研究

发布时间：2018-08-30 18:58

【摘要】：目的：经大量研究证实,斑点追踪显像技术能准确评价左室扭转和解旋功能,目前容量和压力负荷等因素对左室扭转和解旋的影响依旧存在争议,本研究旨在探讨压力负荷、容量负荷及心肌收缩力改变对犬左心室扭转功能的影响。方法：1.10只雌性比格犬经股静脉注射甲氧明(5-10μg/kg/min)和酚妥拉明(5-10μg/kg/min),分别建立压力负荷的增加和下降模型。2.经股静脉放置球囊充盈、加压及注射生理盐水(0.9%,0.2ml/kg/min)分别建立前负荷的减少和增大模型。3.经股静脉先后注射艾司洛尔溶液(5-10μg/kg/min)和多巴酚丁胺溶液(5-10p.g/kg/min)分别建立心肌收缩力减弱和增强模型。分别采集基线状态和压力负荷、容量负荷、心肌收缩力改变时的二维超声图像,采用斑点追踪显像(speckle tracking imaging, STI)技术评估左心室扭转和解旋,并行左心导管检查。结果：1.压力负荷改变的影响：与基线状态相比.注射甲氧明后左心室收缩末期容积(ESV)减小,射血分数(LVEF)增加；注射酚妥拉明后左心室舒张末期容积(EDV)减小、ESV增加、LVEF降低,差异均有统计学意义(P0.05)。与基线状态相比,注射甲氧明后左心室心尖、心底及整体峰值扭转角度(Ptw)增加,左心室心尖、心底及整体扭转角度达峰时间(tPtw)延迟；注射酚妥拉明后左心室心尖、心底及整体Ptw减小,左心室心尖、心底和整体tPtw延迟,差异均有统计学意义(P0.05)。与基线状态相比,注射甲氧明和酚妥拉明后的左心室收缩压(LVSP)和舒张末压(LVEDP)升高,左心室压力最大上升及下降速率(±p/dtmax)下降,差异均有统计学意义(P0.05或P0.01)。注射甲氧明(r=0.656,P=0.03)和酚妥拉明(r==0.701,P=0.02)后的整体Ptw均与左心室收缩功能指标(+dp/dtmax)呈正相关。2.容量负荷改变的影响：与基线状态相比,置入股静脉球囊后左室舒张末内径(LVDd)、EDV减低,LVEF减低,注射盐水后LVDd、EDV增加,LVEF增加,差异均有统计学意义(P0.05)。与基线状态相比,置入股静脉球囊后后左室心尖Ptw降低、心底和整体Ptw略有增加,tPtw均延迟；扩容后左室心尖、心底和整体Ptw均增加,tPtw均缩短,其中心底段和整体扭转的变化差异具有统计学意义(P0.05)。置入股静脉球囊后的LVSP和LVEDP降低,差异有统计学意义,± dp/dtmax略有下降趋势,但差异无统计学意义；注射盐水后LVSP和LVEDP较前负荷降低时升高,± dp/dtmax较基线组升高,差异皆有统计学意义(P0.05)。注射盐水后的Ptw-G与左室收缩功能指标(+dp/dtmax)呈正相关(r=0.657,P=0.034)。3.心肌收缩力改变的影响：与基线状态相比,注射艾司洛尔后ESV增加,LVEF降低,注射多巴酚丁胺后ESV减低、LVEF增加,差异均有统计学意义(P0.05)。与基线状态相比,注射艾司洛尔后左室心尖、心底和整体Ptw均降低,tPtw均延迟,其中心尖段和整体扭转的变化差异具有统计学意义(P0.05)；注射多巴酚丁胺后左室心尖、心底和整体Ptw均增加,其中心尖段和整体扭转的变化差异具有统计学意义(P0.05),tPtw差异不明显。与基线状态相比,注射艾司洛尔后的LVSP和LVEDP降低,±dp/dtmax下降,注射多巴酚丁胺后的LVSP和LVEDP升高,±p/dtmax升高,差异均有统计学意义(P0.05)。注射艾司洛尔(r=0.623,P=0.032)和多巴酚丁胺(r=0.712,P=0.023)后的整体Ptw均与左心室收缩功能指标(+dp/dtmax)呈正相关。结论：犬左心室心尖、心底及整体Ptw随压力负荷、容量负荷、心肌收缩力改变而改变,STI技术可以有效评估压力负荷改变对犬左心室扭转功能的影响。
[Abstract]:OBJECTIVE: Speckle tracking imaging has been proved to be an accurate method for evaluating left ventricular torsion and rotation. The effects of volume and pressure load on left ventricular torsion and rotation are still controversial. The purpose of this study was to investigate the effects of pressure load, volume load and myocardial contractility on left ventricular torsion in dogs. 1.10 female beagles were injected with methoxymine (5-10 ug/kg/min) and phentolamine (5-10 ug/kg/min) through femoral vein to establish the models of increase and decrease of pressure load respectively. Myocardial contractility was modeled by injection of esmolol solution (5-10 ug/kg/min) and dobutamine solution (5-10 p.g/kg/min), respectively. Two-dimensional echocardiographic images of baseline state, pressure load, volume load, and myocardial contractility were collected, and speckle tracking imaging (STI) was used to evaluate the left ventricle. Result: 1. Effect of pressure load change: Compared with baseline state, left ventricular end-systolic volume (ESV) decreased and ejection fraction (LVEF) increased after methoxymine injection, left ventricular end-diastolic volume (EDV) decreased, ESV increased and LVEF decreased after phentolamine injection. (P 0.05). Compared with baseline state, the peak torsion angles (Ptw) of left ventricular apex, cardiac fundus and whole were increased, the peak time (tPtw) of left ventricular apex, cardiac fundus and whole torsion angles were delayed, and the left ventricular apex, cardiac fundus and whole Ptw were decreased, left ventricular apex, cardiac fundus and whole tPtw were delayed after injection of phentolamine. Comparing with baseline state, left ventricular systolic pressure (LVSP) and end-diastolic pressure (LVEDP) increased, and the maximal rate of increase and decrease of left ventricular pressure (+p/dtmax) decreased significantly after injection of methoxamine and phentolamine (P 0.05 or P 0.01). The difference was statistically significant (P 0.05 or P 0.01). Metoxamine (r = 0.656, P = 0.03) and phentolamine (r = 0.701, P = 0.02). The overall Ptw was positively correlated with left ventricular systolic function index (+dp/dtmax). 2. Volume load changes: Compared with baseline state, LVDd, EDV, LVEF decreased after femoral vein balloon implantation, LVDd, EDV increased, LVEF increased after saline injection, the difference was statistically significant (P 0.05). After femoral vein balloon implantation, left ventricular apical Ptw decreased, cardiac fundus and global Ptw increased slightly, and tPtw delayed; after dilatation, left ventricular apex, cardiac fundus and global Ptw increased, and tPtw shortened, with significant difference in the changes of central base and global torsion (P 0.05). After femoral vein balloon implantation, LVSP and LVEDP decreased, the difference was statistically significant. Significance, +dp/dtmax decreased slightly, but there was no significant difference; LVSP and LVEDP increased after saline injection compared with preload reduction, +dp/dtmax increased compared with baseline group, the difference was statistically significant (P 0.05). Ptw-G after saline injection was positively correlated with left ventricular systolic function index (+dp/dtmax) (r = 0.657, P = 0.034). EFFECTS OF VARIATION: Compared with baseline state, ESV increased, LVEF decreased, ESV decreased and LVEF increased significantly after Esmolol injection (P Compared with baseline state, LVSP and LVEDP decreased, + DP / dtmax decreased, and after dobutamine injection, LVSP and LVEDP decreased. LVSP and LVEDP increased, + P / dtmax increased, the difference was statistically significant (P 0.05). After injection of esmolol (r = 0.623, P = 0.032) and dobutamine (r = 0.712, P = 0.023), the overall Ptw was positively correlated with the left ventricular systolic function index (+ DP / dtmax). Conclusion: Left ventricular apex, fundus and whole Ptw were positively correlated with pressure load, volume load, and myocardial receipt. STI technique can effectively assess the effect of pressure change on left ventricular torsion in dogs.
【学位授予单位】：复旦大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R540.45

【相似文献】