【作者】 胡丹；

【导师】 方平；

【作者基本信息】 第二军医大学 ， 影像医学与核医学， 2009， 硕士

【摘要】 背景增强型体外反搏(enhanced external counterpulsation,EECP)已被实践证明是当前冠心病综合治疗中一项安全、有效的无创性机械循环辅助治疗,是众多治疗措施中的一项重要补充。EECP治疗冠心病的机制,除了能促进冠状动脉侧枝循环形成和开放、提高心肌血流灌注压、增加心输出量继而改善血流动力学效应之外,调节血管内皮功能也是其重要机制之一。目前,EECP改善血管内皮功能的报道较多,但其对动脉弹性影响的研究则较少,尤其是对EECP治疗前后血管内皮功能和动脉弹性之间关系的认识甚微。因此随着超声技术的发展以及众多评价心脏和血管功能的新指标在临床广泛应用,本课题利用超声技术和新指标研究EECP对冠心病患者血管内皮功能和动脉弹性的影响以及评价EECP治疗前后两者之间的关系。目的1、观察EECP治疗对冠心病患者血管内皮功能和动脉弹性的影响,比较治疗前后两者变化的差异,并分析两者变化的相关性,从而更深入地探讨EECP防治冠心病的机制。2、与传统评价左室舒张功能的指标比较,探讨利用Tei指数评价EECP治疗冠心病患者的整体心功能变化的临床应用价值。方法第一部分:选择25例诊断为冠心病的患者接受EECP治疗,每日反搏1h,一周5天,持续7周。分别于治疗前(before)、治疗第一天后(1d)、治疗第17天(17d)、治疗结束时(35d)以及治疗结束后1个月(one-month follow-up)测量评价血管内皮功能和动脉弹性的指标。血管内皮功能采用超声方法测定基础状态下、内皮依赖性(反应性充血时,FMD)和内皮非依赖性(含服硝酸甘油后,NMD)肱动脉内径,并分别计算出FMD和NMD时较基础状态下的肱动脉内径变化率(FMD%和NMD%)。动脉弹性指标一方面可以通过超声技术得到以下指标,如压力应变弹性系数(Ep)、僵硬度系数(β)以及动脉顺应性(AC)等;另一方面,采用全自动动脉硬化检测装置得到踝臂指数(ABI)、肱踝脉搏波传导速度(BaPWV)以及心踝血管指数(CAVI)等新近研究较热门的用于评价动脉弹性的指标。第二部分:选择25例冠心病患者接受EECP治疗,分别于第一次反搏前、第一次反搏后即刻、第二次反搏前、day 17及day 35行超声心动图检查,测量左心室Tei指数、二尖瓣血流频谱舒张早期和晚期血流峰值速度之比(E/A)、等容舒张时间(IVRT)、肺静脉血流频谱收缩波和舒张波峰值速度之比(S/D)及反向波峰值速度(ARW)。结果第一部分:1、EECP治疗可以降低SBP和DBP(P<0.05),以SBP降低更明显,且治疗结束后一个月的血压仍基本维持在治疗结束时的水平。因此脉压在EECP治疗前后也明显降低,治疗前与day35(或治疗结束后一个月)组间比较差异有统计学意义(P<0.01)。2、在EECP治疗前后肱动脉内径和NMD%值均无明显变化(P>0.05)。EECP治疗可以明显增加FMD%值,虽然治疗前(before)与day1比较无明显差异,但与day 17比较差异有统计学意义(before:7.39±2.6% vs day1: 7.62±2.9% ,P>0.05; vs day 17:9.27±3.2%, P<0.05)。day35与治疗过程中各组比较,差异均有统计学意义(day 35 :11.36±4.2% vs before: 7.39±2.6%,P<0.01; vs day 1: 7.62±2.9%,P<0.01; vs day 17: 9.27±3.2%,P<0.05),此外,治疗结束后一个月的FMD%较day17或day35时显著减少(7.55±2.2% vs 9.27±3.2% or 11.36±4.2%, respectively, P<0.05 or P<0.01),但与治疗前比较无显著差异(7.55±2.2% vs 7.39±2.6%, respectively, P>0.05)。3、颈总动脉内径和IMT在EECP治疗前后差异无统计学意义(P>0.05)。Ep、β、ABI、BaPWV、CAVI的测值在EECP治疗过程中逐渐减低,AC则逐渐升高。治疗过程中各组间比较差异均有统计学意义(P<0.05或P<0.01)。此外,EECP治疗结束后一个月这些指标较治疗结束时(day35)无明显变化(P>0.05)。4、EECP治疗前冠心病患者的FMD%与β、Ep、BaPWV和CAVI呈负相关(r = -0.710,P<0.001;r = -0.700,P<0.001;r = -0.607,P=0.001和r = -0.874,P<0.001),与AC呈正相关(r = 0.695,P<0.001)。EECP治疗结束后一个月FMD%与β、Ep、BaPWV、CAVI和AC无明显相关(r = -0.222,P=0.287;r = -0.376,P=0.064;r = -0.234,P=0.260;r = -0.362,P=0.075和r = 0.255,P=0.219)。第二部分:第一次反搏后即刻较第一次反搏前比较E/A、S/D明显增大,ARW明显减小,差异均有统计学意义(P<0.01),第二次反搏前、day 17、day 35较第一次反搏前比较E/A、S/D逐渐增大,仅day 35与第一次反搏前比较差异有统计学意义(P<0.01),而ARW逐渐减小,各组间比较差异均有统计学意义(P<0.01～0.05),IVRT变化与ARW相同,但各组间比较均无统计学意义(P>0.05),反搏治疗后Tei指数逐渐减低,除第一次反搏后即刻与第一次反搏前比较差异无统计学意义外,其余各组间比较差异均有统计学意义(P<0.01)。结论1、EECP治疗可明显改善冠心病患者血管内皮功能和动脉弹性,但治疗结束后这两者的改变并不平行,似乎对动脉弹性影响更持久,这可能是EECP治疗冠心病的另一作用机制,因此测定动脉弹性可以作为评估体外反搏临床疗效的另一重要项目。2、增强型体外反搏可改善冠心病患者的心功能,Tei指数可简便、敏感地评价心脏整体功能,且不受心脏前后负荷的影响。更多还原

【Abstract】 BackgroundEnhanced external counterpulsation(EECP) is currently proved to be a safe, effective, noninvasive mechanical adjunctive therapy for coronary heart disease(CHD) by practice, it is also an important supplement of numerous therapeutic measures. Improvement in endothelial function is another important mechanism of EECP, besides improvement in hemadynamics, including promotion of collateralization, enhancement of myocardial perfusion pressure and improvement in cardiac output and so on. Although the research on the mechanism of improvement in endothelial function by EECP is comparative maturity presently, but the report of EECP’s effects on arterial stiffness is few , the research on the relationship between endothelial function and arterial stiffness during and after treatment are even less. With the development of new ultrasonographic technology and the widespread cilincal application of some new ultrasonographic indexs, we investigate the effects of long-term EECP on endothelium function and artery stiffness with CHD and explore the relationship of them before and after treatment.Objective1. To observe the change between endothelial function and artery stiffness in patients with coronary heart disease(CHD) treated with enhanced external counterpulsation(EECP), To compare the difference and to analyse the correlation in both of them, and then to explore the mechanism of EECP therapy deeply.2. To study the clinical value of Tei-index for evaluation the heart function of patients with coronary heart disease(CHD) treated by enhanced external counterpulsation(EECP) compared traditional diastolic heart function index .MethodsFirst part: Twenty five subjects with CHD underwent a standard 35-h course of EECP therapy ( 1 hour daily, 5 days one week, over 7 weeks). Some indexs which reflect endothelial function and arterial stiffness were respectively measured before EECP, day 1, day 17, day 35 and one-month follow-up after finished. We respectively measured brachial artery diameter at baseline, endothelial-dependent(flow-mediated dilatation, FMD) and endothelial-independent (nitroglycerin-mediated dilatation, NMD), Then calculated the rate of brachial artery diameter at FMD and NMD compared baseline which reflect endothelial function. Otherwise,some artery stiffness indexs ,such as Ep,βstiffness index and artery compliance(AC) can calculated with systolic diameter and diastolic diameter of carotid artery which measured by ultrasound techniques; In addition, we also can get some popular artery stiffness indexs such as ankle-brachial index(ABI), brachial-ankle pulse wave velocity(BaPWV) and cardio-ankle vascular index(CAVI) by arteriosclerosis monitoring unit.Second part: Twenty five patients with CHD were treated with one course of EECP,left ventricular Tei-index, E/A ratio at mitrial orifice(E/A),isovolumic relaxation time(IVRT),ratio of systolic wave to diastolic wave of pulmonary vein flow(S/D) and atrial reversal wave(ARW) were respectively measured by Doppler Echocardiography before EECP、the first time of EECP instantly、before the second time of EECP、day 17 and day 35.ResultsFirst part:1. EECP decreased SBP and DBP(P<0.05), but SBP decreased more obviously, the blood pressure of one-month follow–up sustained the level of day 35 on the whole. Then EECP decreased PP(P<0.05), the difference of PP at the group comparison had statistical significance between before (or day17) and day35.2. The diameter of brachial artery and NMD% among the treatment of EECP had no significant change(P>0.05). FMD% increased gradually during the treatment, though FMD% had no significant change after the first day treatment, it had statistical significance between before and day 17(before:7.39±2.6% vs day1: 7.62±2.9% ,P>0.05; vs day 17:9.27±3.2%, P<0.05).the comparison between day 35 and all other groups during the treatment had the statistical significance(day 35 :11.36±4.2% vs before: 7.39±2.6%,P<0.01; vs day 1: 7.62±2.9%,P<0.01; vs day 17: 9.27±3.2%,P<0.05; vs one-month follow-up: 7.55±2.2%, P<0.01).In addition, FMD% at one-month follow-up decreased obviously compared with day 17 or day 35, but had no statistical significance compared with before.3. The diameter and IMT of common carotid artery among EECP had no statistical significance(P>0.05). the value of Ep、β、ABI、BaPWV and CAVI gradually decreased at the course of EECP treatment, but the value of AC was opposite. The difference of all group comparisons had statistical significance (P<0.05 or P<0.01). In addition, the difference of these indexs between day35 and one–month follow-up had no statistical significance (P>0.05).4. The indexs such asβ、Ep、BaPWV and CAVI have the negative correlation with FMD% in patients with CHD before EECP(r = -0.710,P<0.001;r = -0.700,P<0.001;r = -0.607,P=0.001 and r = -0.874,P<0.001, respectively), but AC has the positive correlation with FMD% before EECP(r = 0.695,P<0.001). When finished the treatment of EECP, all indexs have no significant correlation with FMD%(β: r = -0.222,P=0.287;Ep: r = -0.376,P=0.064;BaPWV : r = -0.234,P=0.260;CAVI: r = -0.362,P=0.075 and AC: r = 0.255,P=0.219). Second part: The E/A、S/D ratio obviously increased ,while ARW obviously deseased in the first time of EECP instantly compared with before EECP(P<0.01).Then E/A、S/D ratio gradually increased at the last three times measurements compared with before EECP,there has significant differences only between before EECP and day 35 (P<0.01).At the same time ARW gradually deseased and there has significant differences between two groups(P<0.01～0.05).The change of IVRT is same as ARW,but there has no significant differences betweens two groups(P>0.05).Tei-index gradually deseased after therapy,there has significant differences between two groups(P<0.01) except between before EECP and the first time of EECP instantly(P>0.05).Conclusion1. EECP can improve obviously endothelial function and artery stiffness in patients with CHD. but the change of them after EECP was not parallel and it seemed that EECP affected artery stiffness much longer than endothelial function, so arterial stiffness may be another important program to evaluating the long-term clinical therapeutic effects of EECP.2. It is demonstrated that EECP can effectively improved the heart function in patients with CHD ,the Tei-index is a simple and sensitive parameter for evaluation heart allomeric function, and it isn’t effected by the preload and afterload of heart.更多还原