麝香保心丸增加大鼠心肌血流灌注量的药效动力学

目的　探讨麝香保心丸的药效动力学参数。方法　以大鼠心肌血流灌注量为指标进行测定。结果　麝香保心丸在大鼠体内呈一室模型特征 ,其最低起效剂量为 0 .5 4mg·kg-1,效应呈现半衰期为 0 .5 3h ,效应消除半衰期为 1.2 1h ,药效作用期为 3.4 8h ,效应达峰时间为 1.13h ,体存生物相当药量的吸收半衰期为 0 .2 3h ,消除半衰期为 1.4 7h ,达峰时间为 0 .88h。结论　麝香保心丸在体内具有吸收快、消除快和作用维持时间较短的特点     

急性心肌梗死心肌血流再灌注评价技术

TIMIFlow作为评价再灌注的方法自20世纪80年代起就一直应用于临床。TIMIFrameCount是较TIMI血流分级更为客观、更具可重复性的联系性变量指标。TMBG和TMP从心肌微血管水平对再灌注进行评价。冠脉内多普勒血流频谱变化常作为造影过程中的附加检查指标评价血管再通及心肌再灌注。同时心肌声学造影、连续心电图ST段监测、核素心肌灌注显像和心肌增强磁共振成像作为无创性的评价方法也显示出其应用价值。     

心肌声学造影估测冠脉血流储备及心内膜下心肌灌注的实？…

目的探讨心肌声学造影定量冠脉血流储备及心内膜下心肌灌注的意义。材料与方法13只开胸犬左旋支临界狭窄状态及静脉注射潘生丁后分别进行心肌声学造影并与放射性微球所测心肌血流量对比。结果静注潘生丁后,正常对照区心肌血流量及心肌造影曲线下面积、峰值强度、最大上升斜率指标均明显增加;而临界狭窄缺血区无明显变化。在临界狭窄缺血区,放射性微球所测的心内膜下／心外膜下心肌血流比率减低;但以造影曲线下面积指标所测则无明显变化。结论心肌声学造影曲线下面积、峰值强度及最大上升斜率是定量评价冠脉血流储备的可靠指标;在当前情况下心肌声学造影技术尚不能用于评价心内膜下心肌灌注。     

发现有血流动力学意义的冠状动脉狭窄:动态CT心肌灌注成像有额外诊断价值

目的探讨动态CT心肌灌注成像发现有血流动力学意义的冠状动脉狭窄的可行性,冠状动脉狭窄的血流动力学改变用血流储备分数(fractional flow reserve,FFR)来定义。材料与方法该研究经伦理委员会批准,并获得病人知情同意     

SPECT心肌血流灌注显像在热射病患者心肌损害评价中的应用价值

<正>热射病(HS)属于重症中暑的一种类型,主要表现为高热和意识障碍,临床分为劳力性热射病(EHS)和非劳力性(典型)热射病(CHS)[1]。其中劳力性热射病患者高热对机体有广泛的损伤作用,易引起多器官功能障碍综合征(MODS),病死率高。高温作业者、部队官兵由于训练强度大,救灾、作战等各种任务中易出现劳力性热射病。热射病具有发病急骤、病残率及病死率高等特点。本研究应用单光子发射体层显像(SPECT)心肌灌注显像技术针对热射病     

家兔实验性心肌挫伤后早期左心功能与血流动力学变化规律的研究

钝性胸部挫伤 (ｂｌｕｎｔｃｏｎｔｕｓｉｏｎｔｒａｕ ｍａ ,ＢＣＴ)是交通伤中较为常见的一种。其中 ,心脏挫伤的发生率为 10 %～16 % [1 ,2 ] 。笔者利用超声心动图左心功能检测 ,结合有创心功能检查方法对比分析了家兔实验性心肌钝挫伤时左心功能的变化规律。一、材料与方法1.动物模型 :采用ＢＩＭ -Ⅱ型水平式生物撞击机撞击兔胸前区 ,撞击中心点在兔胸骨左缘旁 0 .5ｃｍ ,第 4 ,5肋间 ,驱动压 80 0ｋＰａ,撞击面积 1.77ｃｍ2 ,制成家兔胸部钝挫伤模型。于心脏收缩末期致伤 ,可致中至重度心肌挫伤 (ＭＣ) [3] ,经病理活检证实。2 .方法…     

小容量复苏对失血性休克犬血流动力学及内脏组织灌注的影响

目的 探讨小容量复苏对失血性休克犬早期血流动力学及内脏组织灌注的影响.方法分别给予6 ml/kg高渗盐水(HS组)和6 ml/kg高渗盐水加羟乙基淀粉溶液(HSS组)对失血性休克犬进行容量复苏,并以失血量3倍的等渗盐水(NS组)作对照,观察复苏后早期血流动力学及胃肠黏膜组织灌注指标小肠黏膜pH值(pHi)的变化. 结果 (1)3种溶液均能改善失血性休克犬复苏的早期血流动力学及组织灌注,但在30 min后高渗盐水、HSS及等渗盐水容量指标下降,血流动力学下降,其中高渗盐水及等渗盐水下降最为明显.(2)随着血流动力学下降,3组pHi于120 min后开始下降,而动脉乳酸无升高. 结论 (1)小容量高渗盐水在失血性休克模型中的复苏效果与等渗盐水类似,小容量高渗盐水加羟乙基淀粉溶液的效果优于前两组.(2)pHi是监测组织灌注的良好指标,比动脉乳酸更为敏感.     

PET心肌灌注显像测定心肌血流量及冠状动脉血流储备的研究进展

PET心肌灌注显像可绝对定量测定局部心肌血流量（MBF）和冠状动脉血流储备（CFR）。由于显像剂半衰期短,允许在短时间内重复进行PET心肌灌注显像,获得静息态、冷加压试验和药物负荷试验等不同状态下的MBF,进而评价冠状动脉血管内皮依赖性和非依赖性的CFR功能。在早期诊断冠心病,准确诊断冠状动脉多支病变,评价微血管病变,早期检测冠状动脉内皮细胞功能异常及CFR功能的异常,估测预后,帮助临床治疗方案的制定以及检测疗效等方面,PET心肌灌注显像有重要的临床价值。该文将介绍PET心肌灌注显像相关知识及其在心血管领域的主要应用。     

唇形科香茶菜属二萜类化合物的生物活性研究进展

香茶菜属植物资源丰富,所含化学成分以二萜类化合物为主。二萜类化合物具有广泛的生物活性,以抗肿瘤、抗炎和抑菌活性最为显著。通过生物活性的广泛筛选和作用机制研究,该类化合物结构的活性基团和作甩机制被逐步揭示,而这些研究结果为香茶菜属植物进一步研究开发提供了科学依据。本文对该类化合物的研究进展作一综述。     

肺动脉高压病人左右心室心肌灌注储备与右心室功能及肺血流动力学之间的相关性

目的应用腺苷负荷MR心肌灌注成像评价肺动脉高压(PAH)病人右心室(RV)与左心室(LV)间心肌灌注储备与心室功能及肺血流动力学的关系。材料与方法本研究符     

运用CT动态灌注成像技术测定肝脏血流量的临床研究

目的 探讨CT灌注成像的测定方法和技术原理,以及肝硬化程度与肝脏血流量动态变化关系。资料与方法 肝硬化患者27例,其中Child A级12例,Child B级10例,CMld C级5例。对照组为无肝脏疾病者18例。选取同时含有肝脏、脾、主动脉和门静脉的层面进行CT动态增强扫描,绘制感兴趣区时间-密度曲线(TDC),计算肝脏血流量各参数。结果 (1)肝硬化患者的肝动脉灌注量(HAP)、门静脉灌注量(PVP)和总肝血流量(THBF)均较正常组降低,平均通过时间(MTT)较正常组延长。(2)肝硬化程度不同时,部分肝血流灌注参数存在显著性差异。(3)脾灌注量和门静脉灌注量呈正相关。结论 (1)肝脏CT灌注成像可定量测定肝血流量参数。(2)肝硬化时肝脏血流灌注的变化与疾病的严重程度相关。     

Advances in Myocardial Perfusion MR Imaging: Physiological Implications,the Importance of Quantitative Analysis,and Impact on Patient Care in Coronary Artery Disease

Stress myocardial perfusion imaging (MPI) is the preferred test in patients with intermediate-to-high clinical likelihood of coronary artery disease (CAD) and can be used as a gatekeeper to avoid unnecessary revascularization. Cardiac magnetic resonance (CMR) has a number of favorable characteristics, including: (1) high spatial resolution that can delineate subendocardial ischemia; (2) comprehensive assessment of morphology, global and regional cardiac functions, tissue characterization, and coronary artery stenosis; and (3) no radiation exposure to patients. According to meta-analysis studies, the diagnostic accuracy of perfusion CMR is comparable to positron emission tomography (PET) and perfusion CT, and is better than single-photon emission CT (SPECT) when fractional flow reserve (FFR) is used as a reference standard. In addition, stress CMR has an excellent prognostic value. One meta-analysis study demonstrated the annual event rate of cardiovascular death or non-fatal myocardial infarction was 4.9% and 0.8%, respectively, in patients with positive and negative stress CMR. Quantitative assessment of perfusion CMR not only allows the objective evaluation of regional ischemia but also provides insights into the pathophysiology of microvascular disease and diffuse subclinical atherosclerosis. For accurate quantification of myocardial perfusion, saturation correction of arterial input function is important. There are two major approaches for saturation correction, one is a dual-bolus method and the other is a dual-sequence method. Absolute quantitative mapping with myocardial perfusion CMR has good accuracy in detecting coronary microvascular dysfunction. Flow measurement in the coronary sinus (CS) with phase contrast cine CMR is an alternative approach to quantify global coronary flow reserve (CFR). The measurement of global CFR by quantitative analysis of perfusion CMR or flow measurement in the CS permits assessment of microvascular disease and diffuse subclinical atherosclerosis, which may provide improved prediction of future event risk in patients with suspected or known CAD. Multi-institutional studies to validate the diagnostic and prognostic values of quantitative perfusion CMR approaches are required.     

正常成人心肌MR灌注成像的初步研究

目的: 探讨利用MR心肌首过灌注及延迟增强方法评价正常成人心肌灌注特点的价值.材料和方法: 对15例正常志愿者进行MR首过灌注、延迟增强成像及cine-MR成像检查,绘制时间-信号强度曲线.结果: 正常左室前、侧、后壁心肌和室间隔时间-信号强度曲线上升时间,曲线上升斜率,对比增强率及延迟信号强度无统计学差异.结论: 正常成人心肌MR灌注成像的特点对利用MR心肌灌注成像诊断心肌病变具有重要的价值.     

Dynamic CT Myocardial Perfusion Imaging in Patients without Obstructive Coronary Artery Disease: Quantification of Myocardial Blood Flow according to Varied Heart Rate Increments after Stress

ObjectiveThe present study aimed to investigate the association between myocardial blood flow (MBF) quantified by dynamic CT myocardial perfusion imaging (CT-MPI) and the increments in heart rate (HR) after stress in patients without obstructive coronary artery disease.Materials and MethodsWe retrospectively included 204 subjects who underwent both dynamic CT-MPI and coronary CT angiography (CCTA). Patients with more than minimal coronary stenosis (diameter ≥ 25%), history of myocardial infarction/revascularization, cardiomyopathy, and microvascular dysfunction were excluded. Global MBF at stress was measured using hybrid deconvolution and maximum slope model. Furthermore, the HR increments after stress were recorded.ResultsThe median radiation dose of dynamic CT-MPI plus CCTA was 5.5 (4.5–6.8) mSv. The median global MBF of all subjects was 156.4 (139.8–180.4) mL/100 mL/min. In subjects with HR increment between 10 to 19 beats per minute (bpm), the global MBF was significantly lower than that of subjects with increment between 20 to 29 bpm (153.3 mL/100 mL/min vs. 171.3 mL/100 mL/min, p = 0.027). This difference became insignificant when the HR increment further increased to ≥ 30 bpm.ConclusionThe global MBF value was associated with the extent of increase in HR after stress. Significantly higher global MBF was seen in subjects with HR increment of ≥ 20 bpm.     

实验性脑血肿周围组织脑血流变化的CT灌注成像与病理学研究

目的探讨血肿周围组织病理发展进程及其与血肿周围局部脑血流变化的关系。方法采用自体血注射法制备大鼠脑出血模型,对70只大鼠于术后1h、3h、6h、12h、24h、48h和72h7个时间点,利用GELightspeed螺旋CT扫描机灌注成像及计算机辅助系统制作大鼠脑CT灌注参数图,对血肿周围局部脑血流量(rCBF)、局部脑血容量(rCBV)和对比剂平均通过时间(MTT)脑血液动力学参数进行定量测量,并与大鼠脑TTC染色、HE-染色以及超微结构改变进行比较。结果大鼠脑血肿周围可见明显的低灌注梯度,血肿周围rCBF和rCBV显著降低,MTT延长。TTC染色血肿周围未见白色梗死区。HE-染色可见血肿周围区星形细胞肿胀,神经细胞变性、坏死,出血灶周边毛细血管增生伴炎细胞浸润。电镜观察显示,注血早期血肿周围组织星形细胞肿胀,神经细胞改变不明显,髓鞘板层松散;随着注血后时间延长,血肿周围组织损伤呈渐进性加重,星形细胞肿胀明显,神经细胞出现变性,髓鞘板层发生局部断裂、崩解。结论大鼠脑注血早期血肿周围局部脑血流的显著降低引发了血肿周围及远隔区脑组织的缺血性损伤,注血后急性期血肿周围组织细胞损伤呈进行性加重,血肿周围存在涉及多种细胞损伤机制的半暗带。     

磁共振灌注成像在急性心肌梗死诊断中的价值

目的研究磁共振灌注成像在急性心肌梗死诊断中的价值。方法使用1.5T超导型磁共振扫描仪,对29例经临床诊断的急性心肌梗死病人行灌注成像,其中17例进行冠状动脉造影术,全部病例通过AW4.0工作站处理,计算出首过时间及首过最大上升斜率,同时测定正常心肌与心室腔的首过时间及最大上升斜率。对比剂总量20ml,注射流率首过3ml/s,共9ml,以后以1ml/s注射。结果29例心肌梗死病例显示延迟病灶明显强化及首过最大上升斜率降低,28例首过时间延迟,17例行冠状动脉造影,14例发现冠状动脉狭窄,未发现冠状动脉狭窄的3例,均为心内膜下或心外膜下梗死。结论急性心肌梗死MR灌注成像具有特征性表现。     

CT Fractional Flow Reserve for the Diagnosis of Myocardial Bridging-Related Ischemia: A Study Using Dynamic CT Myocardial Perfusion Imaging as a Reference Standard

ObjectiveTo investigate the diagnostic performance of CT fractional flow reserve (CT-FFR) for myocardial bridging-related ischemia using dynamic CT myocardial perfusion imaging (CT-MPI) as a reference standard.Materials and MethodsDynamic CT-MPI and coronary CT angiography (CCTA) data obtained from 498 symptomatic patients were retrospectively reviewed. Seventy-five patients (mean age ± standard deviation, 62.7 ± 13.2 years; 48 males) who showed myocardial bridging in the left anterior descending artery without concomitant obstructive stenosis on the imaging were included. The change in CT-FFR across myocardial bridging (ΔCT-FFR, defined as the difference in CT-FFR values between the proximal and distal ends of the myocardial bridging) in different cardiac phases, as well as other anatomical parameters, were measured to evaluate their performance for diagnosing myocardial bridging-related myocardial ischemia using dynamic CT-MPI as the reference standard (myocardial blood flow < 100 mL/100 mL/min or myocardial blood flow ratio ≤ 0.8).ResultsΔCT-FFR_systolic (ΔCT-FFR calculated in the best systolic phase) was higher in patients with vs. without myocardial bridging-related myocardial ischemia (median [interquartile range], 0.12 [0.08–0.17] vs. 0.04 [0.01–0.07], p < 0.001), while CT-FFR_systolic (CT-FFR distal to the myocardial bridging calculated in the best systolic phase) was lower (0.85 [0.81–0.89] vs. 0.91 [0.88–0.96], p = 0.043). In contrast, ΔCT-FFR_diastolic (ΔCT-FFR calculated in the best diastolic phase) and CT-FFR_diastolic (CT-FFR distal to the myocardial bridging calculated in the best diastolic phase) did not differ significantly. Receiver operating characteristic curve analysis showed that ΔCT-FFR_systolic had largest area under the curve (0.822; 95% confidence interval, 0.717–0.901) for identifying myocardial bridging-related ischemia. ΔCT-FFR_systolic had the highest sensitivity (91.7%) and negative predictive value (NPV) (97.8%). ΔCT-FFR_diastolic had the highest specificity (85.7%) for diagnosing myocardial bridging-related ischemia. The positive predictive values of all CT-related parameters were low.ConclusionΔCT-FFR_systolic reliably excluded myocardial bridging-related ischemia with high sensitivity and NPV. Myocardial bridging showing positive CT-FFR results requires further evaluation.     

门控心肌灌注断层显像、平衡法心血池显像和心动超声图测定左室射血分数的比较

目的：探讨门控心肌灌注断层显像（GMPT）、平衡法心血池显像（GBPI）与心动超声（UCG）测定左室射血分数（LVEF）的差别。材料和方法：入选冠心病患者10例，非冠心病患者12例，在72h内完成GMPT、GBPI和UCG检查，获得LVEF值。结果：三种方法测得的LVEF存在显著差异，UCG测得的LVEF明显高于GBPI和GMPT（P均小于0．01）。三种方法测得的LVEF有很好的相关性（P均小于0．01）；GMPT—GBPI之间和GBPI—UCG之间的相关性在冠心病组明显低于非冠心病组（r值分别为：0．640对0．912和0．670对0．892）。结论：GMPT、GBPI和UCG三种方法测定的LVEF在数值上存在差异，GBPI在冠心病患者中应用价值高于另外两种方法。