定量组织速度成像及组织追踪成像对心肌梗死患者左心室收缩功能的评价

目的：探讨定量组织速度成像及组织追踪成像技术评价心肌梗死患者左心室局部心肌的收缩功能。方法：获取标准心尖位左室长轴观、二腔观和四腔观，分别应用定量组织速度成像和组织追踪成像离线分析20例正常人和33例心肌梗死患者左室各节段长轴方向的心肌速度曲线和位移曲线，计算收缩期峰值速度（Vs）及收缩期各取样点向心尖方向位移（Ds），用二维超声心动图测量左室射血分数（LVEF）。结果：心肌梗死组左室各心肌节段Vs及Ds比正常对照组显著降低；心肌各水平节段平均Vs（mVs）与平均Ds（mDs）较正常人明显下降。用QTVI及TTI测量的左心室基底段及中间段的mVs及mDs与用二维超声心动图测量的LVEF显著相关，而心尖段的平均mVs及mDs与LVEF无显著相关。结论：QTVI及TTI能准确判断心肌纵向收缩速度和幅度，是无创评价局部心肌收缩功能定量精确的方法。     

组织追踪法评价肥厚型心肌病左室收缩协调性和纵向运动功能

目的探讨应用组织追踪法(TT)评价肥厚型心肌病(HCM)患者左室收缩协调性和纵向运动功能。方法利用TT技术获取22例HCM患者和20例正常对照者的左室壁运动曲线,分别测量心尖长轴、心尖二腔和心尖四腔切面的二尖瓣环、基底段中部、中段乳头肌水平的收缩期峰值位移(Ds)、相对室壁达峰时间差(△Dt)和峰值位移差(△Ds)。结果与对照组比较,HCM组△Dt明显延长,△Ds明显增大,Ds明显降低,差异有显著性意义。结论HCM患者存在左室收缩协调障碍和纵向运动功能损害,TT能定量评价HCM患者左室收缩协调性和纵向运动功能。     

多普勒超声心动图对急性心肌梗死患者左室舒张功能的评价

目的:采用多普勒超声心动图对急性心肌梗死(AMI)患者左室舒张功能(LVDF)的测定,判断心肌梗死面积和恢复情况,从而了解预后。方法:应用3.25MHz探头对21例AMI患者急性期和恢复期分别行二尖瓣口血流频谱(MVFP)和肺静脉血流频谱(PVFP)检测。结果:AMI患者MVFP中急性期较恢复期舒张早期流速(E峰)增加,舒张晚期流速(A峰)下降,E/A比值增大以限制性异常(左房压增高)充盈波形表现为主;有14例(66.7%)E/A>1.6,DT和IVRT短于恢复期,提示心梗面积较大,左室顺应性降低,舒张功能异常,病情严重。恢复期E峰较急性期降低,A峰则增加,E/A比值下降以松弛性异常(主动舒张迟缓)充盈波形表现为主,有18例(85.7%)E/A<0.8,说明治疗后随着心肌梗死的恢复,梗死心肌愈合,左室舒张功能逐渐改善,提示病情的好转。PVFP中急性期和恢复期S波均相似文献   

斑点追踪成像技术评价梗死心肌和缺血心肌对左心室局部收缩功能的影响

目的应用超声斑点追踪成像(STI)技术分析梗死心肌及缺血心肌节段心肌纵向、径向及周向的收缩期峰值应变及应变率,评价其对左心室局部心肌收缩功能的影响。方法 35例心肌梗死患者(梗死组)、25例心肌缺血患者(缺血组)和25例正常体检者(正常组),接受超声检查,采集左心室长轴观、心尖四腔观,心尖二腔观及左心室短轴观(二尖瓣环水平、乳头肌水平和心尖水平)二维灰阶图像,按左心室18节段划分法,分析各个切面观心肌节段的纵向、径向和周向收缩期峰值应变及应变率。结果心肌缺血组纵向收缩期峰值应变及应变率低于正常组(P<0.05),而径向收缩期峰值应变、应变率和周向收缩期峰值应变、应变率低于正常节段,但差异无统计学意义(P>0.05);心肌梗死组径向、周向、纵向应变及应变率均显著低于正常组节段(P<0.01),也较缺血组节段低(P<0.05)。结论超声斑点追踪成像技术能准确评价梗死心肌和缺血心肌局部运动异常,纵向应变及应变率反映心肌缺血较其他指标敏感。     

多普勒组织成像对高血压左心室肥厚患者左心室舒张功能的评价

目的 应用多普勒组织成像（DTI）技术评价高血压左心室肥厚患者左心室舒张功能，并与二尖瓣血流频谱作对比。方法 研究对象为35例临床与超声诊断的高血压左心室肥厚患者（高心组）和20例正常人（对照组）。采用心尖四腔观，选取室间隔中段，左室侧壁中段，二尖瓣环-室间隔交界处、二尖瓣环一侧壁交界处为取样点，分别显示各部位组织的运动情况，并测量心肌收缩峰速度（Vs）、心肌舒张早期峰值速度（Ve）、舒张晚期峰值速度（VA）及VE与VA比值（VE/VA）。常规测量二尖瓣血流频谱，与DTI参数作对比。结果 与对照组相比，高心组室间隔中段，侧壁中段、二尖瓣环VE、VE/VA均显著下降，各部位VE/VA均与二尖瓣血流频谱E/A之间存在高度相关性；DTI对高血压左心室肥厚患者左心室舒张功能异常的诊断灵敏度高于二尖瓣血流频谱。结论 DTI技术可以定量评价高血压左心室肥厚患者的左心室舒张功能，并且比常规脉冲波多普勒二尖瓣血流参数更加敏感。     

Longitudinal left ventricular function is globally depressed within a week of STEMI

Sixty percent of stroke volume (SV) is generated by atrioventricular plane displacement (AVPD) in a healthy left ventricle (LV). The aims were to determine the effect of ST‐elevation myocardial infarction (STEMI) on AVPD and contribution of AVPD to SV and to study the relationship between AVPD and infarct size (IS) and location. Patients from CHILL‐MI and MITOCARE studies with cardiovascular magnetic resonance within a week of STEMI (n = 177, 59 ± 11 years) and healthy controls (n = 20, 62 ± 11 years) were included. Left ventricular volumes were quantified in short‐axis images. AVPD was measured in six locations in long‐axis images. Longitudinal contribution to SV was calculated as AVPD multiplied by the short‐axis epicardial area. Patients (IS 17 ± 10% of LV) had decreased ejection fraction (48 ± 8%) compared to controls (60 ± 5%, P<0·001). Global AVPD was decreased in patients (11 ± 2 mm versus 15 ± 2 mm in controls, P<0·001) and this held true for both infarcted and remote segments. AVPD contribution to SV was lower in patients (58 ± 9%) than in controls (64 ± 8%) (P<0·001). There was a weak negative correlation between IS and AVPD (r²=0·06) but no differences in global AVPD linked to infarct location. Decrease in global and regional AVPD occur even in remote myocardium within 1 week of STEMI. Global AVPD decrease is independent of MI location, and MI size has only minor effect. Longitudinal pumping is slightly lower compared to controls but remains to be the main component to SV even after STEMI. These results highlight the difficulty in determining infarct location and size from longitudinal measures of LV function.     

Tissue Doppler, a fundamental tool for parametric imaging

Tissue Doppler has been used for clinical applications since 1989. It has been developed from a pulsed Doppler acquisition tool towards a method where extraction of velocities can be performed from colour-coded images. This has introduced a further development into different forms of parametric images describing different myocardial functions as colour-coded information, like deformation imaging, motion imaging and phase imaging. The technical requirements have been established with temporal requirements of frame rates in acquisition exceeding 100 frames s(-1). The most powerful application of the tissue Doppler technique today is perhaps to quantify the myocardial functional reserve, during stress echocardiography, making the method applicable to diagnose the presence of coronary disease with an accuracy exceeding that of nuclear and other non-invasive techniques. The method has also great potential for future developments with introduction of more regional measuring variables.     

多普勒组织成像技术评价尿毒症患者左心室舒张功能

目的　探讨脉冲多普勒组织成像 (PW DTI)技术在评价尿毒症患者心脏舒张功能中的价值。方法2 0例对照者 ,3 5例尿毒症患者均行常规超声心动图及PW DTI检查。PW DTI分析二尖瓣环 4个位点的DTI平均指标 :舒张早期峰值速率 (VE)、舒张晚期峰值速率 (VA)、VE/VA 比值。结果　根据常规超声心动图检查结果将尿毒症患者分为射血分数 (EF)正常组与EF降低组。与对照组比较 ,尿毒症EF正常组与EF降低组患者二尖瓣环 4个位点平均VE、VE/VA 均显著降低 (P <0 .0 1) ;与尿毒症患者二尖瓣口血流E/A值比较 ,该组患者二尖瓣环 4个位点平均VE/VA<1所占比率显著增高 (P <0 .0 5 )。结论　PW DTI可较准确评价尿毒症患者心脏舒张功能且不受其左心室收缩功能影响。     

核素心室显像对前壁、下壁急性心肌梗死左室局部收缩功能的评价

目的 :评价前壁及下壁急性心肌梗死 (AMI)左室局部收缩功能。方法 :于AMI发病后第三周应用门控平衡法核素心室显像检测两壁左室整体及局部射血分数 (LVEF、rEF) ,轴缩短率 (RS) ,局部轴缩短率 (rRS)。结果 :前壁组LVEF (31 5 3± 10 38% )显著低于下壁组(46 5 2± 8 6 5 % ) ,P <0 0 1;前壁组平均室壁运动积分 (1 86± 0 6分 )亦显著低于下壁组 (2 2 0± 0 6分 ) ,P <0 0 1。结论 :AMI急性期左室局部收缩功能和室壁运动状态均与梗死部位有关。前壁AMI左室收缩功能受损程度较下壁AMI更为显著。     

Echocardiographic assessment of left atrioventricular plane displacement as a complement to left ventricular regional wall motion evaluation in the detection of myocardial dysfunction

Aim: We aimed to find out if abnormal left atrioventricular plane displacement (AVPD) is a sign of myocardial dysfunction, even in patients with normal left ventricular (LV) regional wall motion (RWM). Methods: We prospectively performed echocardiography in 1350 consecutive patients referred to our echocardiography laboratory. Left AVPD and LV RWM were evaluated in all patients. We prospectively selected all patients with normal LV RWM but impaired left AVPD for further analysis of clinical parameters. Results: Eighty-eight of the 1350 patients had completely normal LV RWM but impaired left AVPD (10 mm) in at least one region (septal, lateral, posterior, anterior). Of these, 60.2% had prior and/or acute myocardial infarction, predominantly non-Q-wave, whereas 33.0% had angina without infarction and 2.3% had hypertension. In 49 (55.7%) patients coronary angiography was performed. All were abnormal. In 4.5% (n = 4) of the patients no obvious reason for the AVPD decrease was found, but was not precluded. Conclusion: Almost all patients with abnormal left AVPD and completely normal LV RWM had clinical cardiac disease. Thus, decreased AVPD despite normal LV RWM seems to be a true sign of myocardial dysfunction, predominantly indicating subendocardial dysfunction. In screening for patients with myocardial dysfunction assessment of left AVPD may be useful as a complement to LV RWM evaluation. The prognosis in such patients is currently being evaluated.     

实时三维斑点追踪显像技术评价心肌缺血患者左心室局部功能

目的 应用实时三维斑点追踪显像(3D-STI)技术评价冠状动脉左前降支(LAD)不同狭窄程度缺血患者左心室心肌局部应变变化。方法 根据冠状动脉造影(CAG)结果将138例临床疑诊冠心病患者分为对照组(34例)和狭窄组(104例),另将狭窄组分为轻度狭窄亚组(A亚组,n=34)、中度狭窄亚组(B亚组,n=36)和重度狭窄亚组(C亚组,n=34)。测量LAD供血区域心肌的应变指标:峰值径向应变(PLS)、峰值面积应变(PAS)、应变显像舒张指数(SI-DI),分析2D-STI及3D-STI测值的相关性。结果 对照组3D-STI的PLS较2D-STI值偏低(P<0.05),相关性良好(r值:0.58~0.76)。A亚组PAS与对照组相比差异无统计学意义(P>0.05)。与对照组比较,C亚组全部节段及B亚组前壁中间段及心尖段、前间隔中间段及前间隔心尖段的PAS值减低(P<0.05),C亚组全部节段及B亚组前壁基底段及心尖段、前间隔中间段及前间隔心尖段的SI-DI值减低(P<0.05);与B亚组比较,C亚组的前壁中间段及心尖段的PAS值减低(P<0.05),前壁中间段及心尖段和前间隔心尖段的SI-DI值减低(P<0.05)。结论 3D-STI可有效评估心肌缺血患者左心室局部心肌纤维早期形变特征。     

多普勒组织成像定量分析心肌梗死后左心室局部与整体的舒缩功能

目的　采用多普勒组织成像技术 (DTI)观察心肌梗死后左心室壁及二尖瓣环运动 ,定量分析左心室局部与整体的舒缩功能。方法　 18例健康人 ,3 6例心肌梗死患者均行常规二维超声 (2DE)及DTI检查。采用DTI分析心肌梗死后左室壁及二尖瓣环 4个位点的DTI指标 :峰值收缩速度 (VS)、舒张早期速度 (VE)及二尖瓣环 4个位点平均收缩与舒张速度 (VMS、VME)。结果　与健康人比较 ,心肌梗死患者室壁运动异常节段VS、VE显著降低 (P <0 .0 1) ,心肌梗死节段相对应二尖瓣环位点VS 显著降低 (P <0 .0 1) ,心肌梗死节段与非心肌梗死节段相对应二尖瓣环 4个位点VE 均降低 (P <0 .0 1) ;心肌梗死患者射血分数 (EF)与VMS(r =0 .76,P <0 .0 1)、VME(r =0 .68,P <0 .0 1)呈显著正相关 ;VMS≥ 7.0cm/s预测EF≥ 5 0 %的敏感性、特异性分别为76.0 %、81.8%。结论　DTI可定量分析心肌梗死后左室壁局部与整体的舒缩功能 ,为心肌梗死后合理选择治疗措施及预后判断提供新的定量指标     

高血压患者左心室舒张功能与心房电机械时间的关系

目的 采用组织多普勒成像(TDI)研究原发性高血压患者不同心室舒张功能与心房电机械时间(P-A)的关系.方法 选择原发性高血压患者90例共分3组,每组30例:左心室舒张功能弛缓性降低组(I组),左心室舒张功能假性正常化组(Ⅱ组),左心室舒张功能限制性充盈障碍组(Ⅲ组);另选择健康人30例作对照组(Ⅳ组).用TDl分别测量P波起始点至左心室侧壁二尖瓣环和右心室侧壁三尖瓣环处P-A,分别记为LP-A、RP.A,计算电机械时间离散度(Pd).结果 左心室舒张功能与心房电机械时间(LP-A)在Ⅳ、I、Ⅱ及Ⅲ组间呈逐渐延长趋势,(61.67±6.78)ms、(68.01±4.53)ms、(74.15±5.50)ms、(85.52±2.79)ms,4组间两两比较差异有统计学意义(P<0.01);右心室舒张功能与心房电机械时间(RP-A)在Ⅳ、I、Ⅱ及Ⅲ组间呈逐渐延长趋势(32.80±4.20)ms、(35.66±3.33)ms、(37.86±2.97)ms、(44.49±2.52)ms,各组间两两比较差异有统计学意义(P<0.01或<0.05);Pd在Ⅳ、I、Ⅱ及Ⅲ组间亦呈逐渐延长趋势,(28.87±4.89)ms、(32.39±4.12) ms、(36.29i±2.96)ms、(41.03±1.56)ms,各组闻两两比较差异有统计学意义(P<0.01或<0.05).结论 原发性高血压患者P-A、Pd随左心室舒张功能受损加重逐渐延长,以限制性充盈障碍时延长的最明显,为临床早期控制高血压改善心室舒张功能避免,心房颤动发生提供理论依据.     

多普勒组织成像定量分析155例冠心病左心室局部收缩和舒张功能

目的 应用多普勒组织成像（ＤＴＩ）技术定量定位分析生理和病理（心肌缺血）状态下左心室局部收缩和舒张功能。方法 研究对象为１５５例确诊冠心病的患者（冠心病组）和４１例年龄匹配的正常人（对照组）。采用心尖四腔、心尖二腔和心尖长轴切面,每个室壁又选择两个取样点分别位于该室壁的基底部和中部,分别显示左心室６个室壁１２个节段运动的情况。ＤＴＩ测量参数包括收缩功能指标：心肌收缩峰值速度（Ｖｓ）和ＶＥ与舒张晚期峰值速度（ＶＡ）的比值（ＶＥ／ＶＡ）。结果 与对照组相比,冠心病组ＤＴＩ可敏感地定量显示出收缩和舒张峰值速度显著下降以及峰值时间的显著延长;前壁心肌梗死时可见病变区多个节段多项ＤＴＩ收缩和舒张功能参数异常,ＤＴＩ收缩与舒张速度指标之间、收缩速度与左室射血分数之间以及舒张功能参数ＶＥ／ＶＡ均值与二尖瓣血流频谱Ｅ／Ａ比值之     

定量组织速度成像评价急性心肌梗死犬左心室局域舒张功能

目的探讨犬急性心肌梗死后左心室局域心肌等容舒张期、快速充盈期在长轴方向的舒张运动特点.方法对24只急性心肌梗死犬在定量组织速度成像(QTVI)条件下采集冠状动脉结扎前、结扎后4 h心尖二腔心、心尖四腔心及心尖五腔心切面各3个心动周期动态图像,并应用QTVI定量分析功能对梗死前、后左心室各节段长轴方向的运动特点进行分析.取样容积分别置于基底部、乳头肌水平、心尖部心内膜水平的左心室前壁(AW)、下壁(IW)、侧壁(LW)、后室间隔(PS)、前室间隔(AS)和后壁(PW),分别记录舒张早期峰值速度(Ve)、等容舒张期峰值速度(Vivrp),包括等容舒张期负向及正向峰值速度(Vivrp1,Vivrp2)及对应时间(T1,T2),并计算等容舒张期平均加速度(a).结果急性心肌梗死后受累节段的Ve明显低于正常时的相应节段(P＜0.05或P＜0.01);受累节段Vivrp1下降(P＜0.05),而Vivrp2无明显变化(P＞0.05).心尖部梗死节段AW、AS的a大于正常时的相应节段(P＜0.05或P＜0.01),而相邻及相对节段LW、PS和IW、PW的a则小于正常时的相应节段(P＜0.01);中部梗死节段AW、AS的a大于正常时的相应节段(P＜0.05),相邻PS的a则小于正常时的相应节段(P＜0.01);基底部与梗死节段相邻的PS、AS、AW的a也小于正常时的相应节段(P＜0.05或P＜0.01).结论QTVI能敏感、直观,且无创定量评价左心室局域心肌舒张功能,对早期诊断急性心肌梗死具有重要价值.     

Simpson法、基于阈值区域生长法和三维模型法评估左心室功能

目的 比较Simpson法、基于阈值的区域生长法（阈值法）和三维模型法（模型法）评估左心室功能的差异。方法 纳入60例因疑诊冠状动脉疾病而接受冠状动脉CT血管成像（CCTA）患者,分别采用Simpson法、阈值法和模型法计算左心室舒张末期容积（EDV）、收缩末期容积（ESV）和射血分数（EF）,并观察各值差异。结果 模型法、阈值法和Simpson法的EDV分别为166.55（144.55,209.53）ml、144.25（126.25,186.88）ml和137.23（121.78,159.29）ml,ESV分别为55.53（38.34,80.83）ml、47.50（29.00,74.25）ml和46.10（28.68,67.63）ml,EF分别为64.75%（58.25%,72.35%）、69.15%（60.05%,76.33%）和66.70%（58.48%,77.05%）。以Simpson法、阈值法和模型法所获左心室EDV、ESV及EF差异均有统计学意义（P均<0.001）;以模型法所获EDV和ESV均明显高于阈值法和Simpson法（P均<0.05）,而EF明显低于阈值法（P<0.05）。3种算法计算左心室EF的一致性均好,且阈值法与Simpson法所获左心室EDV及ESV差值均小于模型法与Simpson法（Z=-6.486、-6.574,P均<0.001）。3种算法所获左心室EDV、ESV及EF均呈极强相关（r均>0.8,P均<0.05）。结论 采用Simpson法、阈值法和模型法计算的左心室EDV、ESV及EF均有显著差异,但一致性均好,且EDV、ESV及EF均呈极强相关;以阈值法与Simpson法所获左心室EDV及ESV的差值均小于模型法与Simpson法差值。     

二尖瓣环不同部位组织多普勒波形对评价左心室舒张功能的影响

目的了解二尖瓣环的部位不同对组织多普勒(TDI)测量结果及衍生指标评价左心室舒张功能的影响。方法 182例接受常规超声心动图检查者,于心尖四腔切面测量二尖瓣口舒张期血流频谱,于心尖四腔、两腔及左心三腔切面分别测量二尖瓣环室间隔、左心室侧壁、前间隔、后壁、前壁及下壁6个位点的TDI舒张期波形,计算二尖瓣口舒张早期血流E峰与舒张晚期血流A峰的比值(MV-E/A)、TDI二尖瓣环舒张早期e波与舒张晚期a波的比值(TDI-e/a)及E峰值与二尖瓣环6个位点e波平均值与E峰的比值(E/e-mean),同步记录心电图。结果根据二尖瓣口血流波形E/A比值不同,将182例患者分成两组,组Ⅰ:二尖瓣E/A≥1.0,共76例;组Ⅱ:二尖瓣E/A<1.0,共106例;组Ⅰ中同时有4个位点e/a≥1.0的患者多于组Ⅱ(59.21%,8.49%),而组Ⅱ中二尖瓣环6个位点e/a比值均<1.0的患者明显较多(64.15%,14.47%,P<0.05);即使同一组内,任意两位点之间的E/a比值多有不同或显著差别,测值相近的位点在组Ⅰ、组Ⅱ中分别占28.57%和14.29%,其中组Ⅰ中仅有左心室后壁、下壁2个与E/a-mean相近的位点,而组Ⅱ中则没有与E/a-mean相近的位点。结论临床应用二尖瓣口舒张早期血流E峰值与二尖瓣环舒张早期e波值比(E/e-ann)与二尖瓣E/A指标评估左心室舒张功能时,需注意二尖瓣环位点不同对测定结果的影响,而取二尖瓣环6个位点E/e-mean,有助于减少此类指标在评价左心室舒张功能中的偏颇。     

Effects of trimetazidine,a partial inhibitor of fatty acid oxidation,on ventricular function and survival after myocardial infarction and reperfusion in the rat

Trimetazidine (TMZ), a partial inhibitor of fatty acid oxidation, has been effective in treating chronic angina, but its effects on the development of post‐myocardial infarction (MI) left ventricular remodeling are not defined. In this study, we tested whether chronic pre‐MI administration of TMZ would be beneficial during and after acute MI. Two‐hundred male Wistar rats were studied in four groups: sham + TMZ diet (n = 20), sham + control diet (n = 20), MI + TMZ diet (n = 80), and MI + control diet (n = 80) splitted into one short‐term and one long‐term experiments. Sham surgery consisted of a thoracotomy without coronary ligation. MI was induced by coronary occlusion followed by reperfusion. Left ventricle (LV) function and remodeling were assessed by serial echocardiography throughout a 24‐week post‐MI period. LV remodeling was also assessed by quantitative histological analysis of post‐MI scar formation at 24 weeks post‐MI. During the short‐term experiment, 10/80 rats died after MI, with no difference between groups (MI + control = 7/40, MI + TMZ = 3/40, P = 0.3). In the long‐term experiment, the deaths occurred irregularly over the 24 weeks with no difference between groups (MI + control = 16% mortality, MI + TMZ = 17%, P = 0.8). There was no difference between groups as regard to LV ejection fraction (MI + control = 36 ± 13%, MI + TMZ = 35 ± 13%, P = 0.6). In this experimental model, TMZ had no effects on the post‐MI occurrence of LV dysfunction or remodeling. Further investigations are warranted to assess whether the partial inhibition of fatty acid oxidation may limit the ability of the heart to respond to acute severe stress.     

超声评价缺血后适应对兔缺血再灌注模型心脏局部收缩功能的保护作用

目的 应用超声对兔缺血再灌注模型心功能进行检测,探讨缺血后适应对该模型心肌的短期保护作用.方法 健康日本大耳兔28只随机分为缺血后适应组及对照组,实验前及实验后2周对两组兔进行超声检测.常规超声心动图测定左室舒张末期内径(LVDd)、左室前壁舒张末期厚度(AW)、左室射血分数(LVEF),定量组织速度成像与应变率成像定量分析左室前壁、前室间隔基底段、中段收缩期峰值运动速度(Vs)及收缩期径向峰值应变率(SRs).结果 实验前,两组各常规超声参数无差异;与实验前比较,实验后2周对照组与缺血后适应组LVDd显著增大,AW显著变薄,LVEF显著降低,差异有统计学意义(P<0.05);实验后2周,与对照组比较,缺血后适应组LVDd显著减小,AW显著增厚,LVEF显著增高,室壁运动异常节段显著减少,差异有统计学意义(P<0.05).实验前,两组前壁及前室间隔基底段及中段Vs、径向SRs无差异;实验后2周,与实验前比较,对照组与缺血后适应组前壁及前室间隔基底段及中段Vs、径向SRs显著降低(P<0.05);与对照组比较,缺血后适应组前壁及前室间隔基底段及中段Vs、径向SRs显著较高,差异有统计学意义(P<0.05).结论 缺血后适应对兔缺血再灌注模型心脏局部收缩功能有一定短期保护作用,应变率成像技术可有效评价此保护作用.     

Effects of atriopeptin III on renal function, regional blood flows and left ventricular function in conscious dogs in presence or absence of hypovolaemia

Abstract. The effects of atriopeptin III (AP III) on the left ventricular and renal functions were studied in thirteen chronically instrumented conscious dogs and compared to those of the solvent (saline). In the normovolaemic state, an AP III infusion (1 μg kg^-1 min^-1 i.v.) had no effects on heart rate, on mean arterial or left ventricular pressure, on (dP/dt) Max (2989±119 vs. 3007±155 mmHg s^-1; NS) or on the relaxation rate. The left ventricular endocardial and epicardial coronary blood flows (radioactive microspheres) and the renal flow in the outer cortex (707–683 ml (min^-1 100 g^-1); NS) or in the inner cortex (563–570; NS) were also insignificantly affected by AP III infusion. However, AP III increased urinary flow from 24±6 to 36±7 ml h^-1 (P<0·025) and the Na⁺ and Cl^- excretions by 92 and 98%, respectively, (P<0·025 and P<0·05 vs. saline group) without altering significantly K⁺, urea and creatinine eliminations. In the moderately hypovolaemic state (mean reduction in renal flow: outer cortex -15%; P<0·05, inner cortex -5%; NS), AP III infusion at two doses (1 and 3 μg kg^-1 min^-1) still had no effects on arterial pressure and on the indexes of left ventricular inotropic state and relaxation but in this setting, the diuretic effect of AP III became variable. Five dogs markedly increased their excretion of water, Na⁺ and Cl^- whereas no change was noted in the seven remaining dogs. Regional renal blood flows and urinary output before infusion were similar in the responders and non-responders but the mean arterial pressure (81±2 vs. 73±3 mmHg; P<0·01) was lower in the non-responders. It is concluded that AP III has no effect on left ventricular contractility or on the coronary vasculature; at small doses, its diuretic effects appear independent of a renal vasodilation and are rapidly blunted in the presence of hypotension.