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。     

心肌声学造影研究进展

心肌声学造影研究进展唐志宏综述刘伊丽审校Ｘ线冠状动脉造影是一种解剖学检查方法。它能确定冠状动脉狭窄的部位及严重程度，但它仅能观察大于１００μｍ直径的血管［１］，不能提供心肌血流灌注改变的直接信息。心肌声学造影是一项活体内测量心肌组织血流灌注的影像诊断...     

磁共振心肌灌注成像

磁共振快速成像技术的发展使磁共振心肌灌注成像成为可能，它可用来评估心肌的血流灌注，确定心肌梗死的范围，评价心肌血流的储备。本文综述了磁共振心肌灌注成像的序列、方法、对比剂及其在临床上的应用。     

60Coγ射线心脏局部照射对大鼠离体心脏功能的影响

目的 研究γ射线心脏局部照射对大鼠心脏血流灌注及功能的影响,为放射性心脏损伤的防治提供实验依据.方法 12只Wistar雌性大鼠随机分为未照射组、照射组,每组6只,照射组行60Co γ射线20Gy单剂量照射,每日观察大鼠饮食、行为活动等变化,定期记录大鼠体重变化.照射后120天用超声心肌造影检测大鼠心肌血流灌注变化.照射后180天分离大鼠心脏,采用Langendorff离体心脏灌流法测定左室收缩压(LVSP)和左室内压力变化速率(dp/dtmax、dp/dtmin),并取大鼠心脏进行病理检查,用HE染色观察心肌组织病理变化.结果 照射后180天大鼠的饮食、行为、精神状态无可评价的异常变化,组间动物体重增加无明显差异.照射组大鼠心肌微循环灌注较未照射组明显减低.大鼠离体心脏功能检测示照射组大鼠LVSP、dp/dtmax、dp/dtmin均较未照射组明显减低.心肌组织HE染色显示照射组心肌细胞变性坏死、心肌纤维化.结论 γ射线心脏局部照射可致心肌血流灌注降低,导致心脏功能下降.     

磁共振心肌灌注成像

磁共振快速成像技术的发展使磁共振心肌灌注成像成为可能，它可用来评估心肌的血流灌注，确定心肌梗死的范围，评价心肌血流的储备。本综述了磁共振心肌灌注成像的序列、方法、绎比剂及其在临床上的应用。     

急性缺血再灌注心肌磁共振成像实验研究

目的：通过MR灌注成保评价急性梗死心肌组织血流灌注特点。方法：采用结扎左前降支90min存灌注的方法建立为存灌注梗死心肌组，对6只犬行MRI灌注成保及延迟扫描，观察犬心肌缺血存灌注模型梗死心肌MRI特点。结果：犬心肌缺血存灌注梗死心肌MR灌注成保表现为灌注缺损区，延迟扫描表现为高信号。结论：MR灌注成保有助于评价心肌血流，诊断心肌缺血存灌注梗死心肌。     

放射性核素显像在心力衰竭中的应用

放射性核素显像在测定心室功能，评价心力衰竭的严重程度，了解心肌血流灌注、心肌活力及心脏交感神经功能，鉴别心力衰竭的病因，判断预后，指导临床治疗和评估疗效等多方面都有重要的临床价值。     

CT心肌动态与单次灌注成像对照研究

正目的研究CT心肌动态灌注成像对于冠状动脉狭窄所致心肌血流动力学异常的诊断准确性,并与冠状动脉造影及冠状动脉血流储备分数(FFR)比较。方法本研究经伦     

MRI在评价局部心功能中的应用及其进展

在病理情况下,尤其是缺血性心脏病时,局部血流灌注异常可导致区域性功能变化,引起心室功能失调。近年来,MR成像技术快速发展,使其成为准确评价局部心功能的重要手段。笔者就MR心肌标记（MR—tagging）和MR心肌灌注两种成像技术在局部心功能评价中的应用综述如下。     

PET心肌灌注显像及其定量分析的研究进展

近些年,随着PET/CT设备及心脏正电子示踪剂的快速发展,PET心肌血流灌注显像（PET-MPI）在临床上的作用逐渐加强。心肌血流灌注定量分析提供了心肌血流的客观评价标准,可以客观、准确地发现早期灌注异常,准确地对冠心病进行危险分层、预后评价和客观判断治疗效果,为冠心病临床诊治、心脏的生理和病理生理学领域的活体无创性研究提供重要信息。笔者就PET-MPI及其定量分析的研究进展进行综述。     

The value of the TIMI frame count method in the diagnosis of coronary no-reflow: a comparison with myocardial perfusion SPECT in patients with acute myocardial infarction

The state of no-reflow (i.e. inadequate myocardial tissue perfusion despite normal arterial flow proven in angiography after pharmacological or mechanical interventions) is considered to be a marker of a poor prognosis. Although the Thrombolysis in Myocardial Infarction (TIMI) flow grade is a valuable and widely used qualitative measure in angiography trials, it is limited by its subjective and categorical nature. Recently, the TIMI frame count method (TFC) was proposed for detecting no-reflow. In our study we aimed to compare TFC values with myocardial perfusion single photon emission computed tomography (SPECT) findings to investigate the additional role of the former method in the evaluation of no-reflow. Twenty patients (16 men and four women; mean age 58+/-9 years) with first acute myocardial infarction were included in the study after thrombolytic therapy. Coronary angiography (CAG) was performed 5-7 days later. The TIMI flow grade and TFC values were determined in angiography examinations. A TIMI flow of less than grade 3 and a TFC value >27 were considered to be pathologically decreased for coronary artery blood flow. Tc tetrofosmin myocardial rest SPECT was carried out 24 h after coronary angiography. SPECT images were scored on a four-point scale in 20 myocardial segments and the total defect score was calculated from the sum of defect scores in 20 segments. Wall motion was assessed using the wall motion score index in echocardiography (ECWSI). The occurrence rates of angiographic no-reflow, pathological TFC and perfusion defects in SPECT were calculated as 40% (8/20), 47% (8/17; non-measurable in three patients with TIMI grade 0), and 55% (11/20), respectively. Perfusion defects were present and the TIMI frame count value was increased in all patients with angiographic no-reflow (TIMI grade <3). The occurrence rate of perfusion defects and increased TFC was equal (42%) in all 12 patients having TIMI grade 3 flow. Increased TFC was demonstrated in four of five patients having perfusion defects and TIMI grade 3 flow (80% compatibility with SPECT). TIMI frame count and ECWSI values were significantly higher in patients having perfusion defects than in patients with normal perfusion ( <0.05). It is concluded that the TIMI frame count is a valuable method in the detection of patients with TIMI grade 3 flow, with no-reflow, and increases the specificity of coronary angiography in the evaluation of the response to thrombolytic therapy. A pathologically increased TFC value with TIMI grade 3 flow during CAG seems to be a good indication for the use of myocardial perfusion SPECT in the definitive diagnosis and/or follow-up of such patients.     

曲美他嗪对急性前壁心肌梗死心肌缺血再灌注损伤的保护作用

 目的 观察急性前壁心肌梗死患者应用曲美他嗪(trimetazidine, TMZ)对急诊经皮冠状动脉介入治疗术(percutaneous coronary interventions, PCI)后心肌缺血再灌注损伤(ischemia reperfusion, I/R)的保护作用。方法 266例初发ST段抬高型急性前壁心肌梗死患者随机分为曲美他嗪组(132例)和对照组(134例)。曲美他嗪组于确诊急性心肌梗死后即刻给予负荷剂量曲美他嗪(60 mg),术后继续应用曲美他嗪(20 mg,3/d)3个月。记录两组患者PCI术中TIMI血流分级和TIMI心肌组织灌注分级(TIMI myocardial perfusiongrade, TMPG)。术后24 h分别测定两组患者血清肌钙蛋白I(cTNI)和肌酸激酶同工酶(CK-MB)水平。在PCI术前及术后1、3个月分别超声心动图测量左室射血分数。结果 与对照组相比,曲美他嗪组PCI术中血流达到TIMI-3级和TMPG-3级例数较多,术后24 h心肌酶TNI[(17.04±1.71)ng/ml vs(14.39±1.42)ng/ml,P=0.001]、CKMB[(90.32±9.26)U/L vs (82.55±8.04)U/L,P=0.001]较显著降低。PCI术后3个月,曲美他嗪组患者左室射血分数明显优于对照组[(54.81±3.27)%比(52.26±2.55)%,P=0.001]。结论 急性前壁心肌梗死患者早期应用曲美他嗪能降低PCI术中心肌缺血再灌注损伤,长期应用曲美他嗪能够改善远期心脏功能。     

Scintigraphic findings in myocardial infarct

Radioisotope studies are currently used mainly to assess the individual risk before and after myocardial infarction. Scintigraphy will be used increasingly to diagnose and localize acute myocardial infarction, to measure the infarct size and to detect reperfusion, whether spontaneous or after lysis, in the infarct area. High sensitivity and specificity are obtained by using tomographic imaging modalities and by the combined and simultaneous use of markers for perfusion and necrosis. This technique allows recognition even of nontransmural infarctions, involvement of the right ventricle, subendocardial necroses, and ischemic injuries in unstable angina pectoris.     

The effect of verapamil on the restoration of myocardial perfusion and functional recovery in patients with angiographic no-reflow after primary percutaneous coronary intervention

OBJECTIVE: Angiographic thrombolysis in myocardial infarction (TIMI) flow grade < or = 2 after primary percutaneous coronary intervention (PCI), defined as angiographic no-reflow, predicts poor functional recovery in patients with acute myocardial infarction. We investigated the effect of verapamil on the restoration of myocardial perfusion and functional recovery in patients with angiographic no-reflow after PCI. METHODS: 99mTc tetrofosmin single photon emission computed tomographic (SPECT) imaging was performed (before, immediately after and 1 month after PCI) in 101 consecutive patients with acute myocardial infarction. The defect score was calculated as the sum of perfusion defect in a 13-segment model (scores of 3, complete defect to 0, normal perfusion). The asynergic score, defined as the number of asynergic segments, was assessed by echocardiography before and 1 month later. Multiple logistic regression analysis was performed to elucidate the effect of verapamil administration. RESULTS: Of 101 patients, 32 (31%) had angiographic no-reflow and were divided into two groups: 18 patients with verapamil (group 1) and 14 patients without verapamil (group 2). Sixty-nine patients had TIMI grade 3 reflow after PCI (group 3). The change in the defect score 1 month after PCI in group 1 was significantly larger than that in group 2 (P = 0.003). The asynergic score improved more at 1 month in group 1 compared to that in group 2 (P = 0.007). Moreover, logistic regression analysis revealed that TIMI grade reflow < or = 2 after PCI (P = 0.04, OR = 5.51), the defect score before PCI (P = 0.03, OR = 1.15), the asynergic score before PCI (P = 0.01, OR = 0.64) and the administration of verapamil (P = 0.002, OR = 22.4) were independently associated with successful myocardial reperfusion immediately after PCI. CONCLUSIONS: Intracoronary verapamil restored myocardial perfusion in patients with angiographic no-reflow after PCI and lead to better functional recovery after acute myocardial infarction.     

Prognostic value of myocardial salvage achieved by reperfusion therapy in patients with acute myocardial infarction.

Myocardial salvage assessed by (99m)Tc-sestamibi scintigraphy is a marker of myocardial tissue reperfusion in patients with acute myocardial infarction. The prognostic value of myocardial salvage index in patients with acute myocardial infarction after reperfusion therapy has not, however, been investigated. METHODS: We analyzed 765 patients with acute myocardial infarction randomized to treatment by coronary stenting (383 patients), primary coronary angioplasty (251 patients), or thrombolysis (131 patients) in the setting of 3 randomized trials. Initial (before reperfusion therapy) and follow-up (7-14 d after reperfusion therapy) scintigraphic examinations were performed to assess the initial perfusion defect, final infarct size, and salvage index. Patients were categorized into 2 groups defined by the median salvage index (0.5): the group with salvage index < 0.5 (374 patients) and the group with salvage index >or= 0.5 (391 patients). The primary endpoint of the study was mortality at 6 mo after the index event. RESULTS: Six-month mortality was 5.1% (19 deaths) in the group with salvage index < 0.5, compared with 1.0% (4 deaths) in the group with salvage index >or= 0.5 (odds ratio, 5.1; 95% confidence interval, 1.9-13.3; P = 0.001). Salvage index (median [25th, 75th percentiles] was significantly smaller in nonsurvivors than in survivors (0.19 [0.05, 0.37] vs. 0.50 [0.26, 0.80], P = 0.0004). The Cox proportional hazards model showed that myocardial salvage index (P = 0.0007), initial perfusion defect (P = 0.0007), and age (P = 0.04) were independently associated with 6-mo mortality. CONCLUSION: Myocardial salvage achieved by reperfusion therapy predicts mortality in patients with acute myocardial infarction. Our findings support the use of salvage index as a surrogate of mortality in clinical trials designed to test the efficacy of reperfusion therapies among patients with acute myocardial infarction.     

Quantitative estimation of myocardial salvage after primary percutaneous transluminal coronary angioplasty in patients with angiographic no reflow

Angiographic Thrombolysis in Myocardial Infarction (TIMI) flow grade 相似文献   

The use of perfusion imaging in acute myocardial infarction: Applications for clinical trials and clinical care

The use of perfusion imaging in the acute phase of myocardial infarction has been facilitated by the introduction of technetium 99m-labeled sestamibi (^99mTc-sestamibi). Because of minimal redistribution, myocardium at risk can be quantified without delaying reperfusion therapy. The use of perfusion imaging with ^99mTc-sestamibi has been extensively validated in a series of important animal studies in contrast to other methods used to assess outcome from acute myocardial infarction. This has important implications regarding the assessment of reperfusion therapy. With an accurate means to define myocardium at risk, myocardial salvage can be measured for specific therapies or patient subsets. Such measures also have clinical utility for the care of individual patients. Infarct size measures with ^99mTc-sestamibi are accurate and predictive of subsequent left ventricular remodeling as well as prognosis. The identification of jeopardized myocardium in patients with nondiagnostic electrocardiograms and the noninvasive prospective measurement of collateral blood flow before reperfusion therapy are two new areas where perfusion imaging has special clinical use. Because of the ability of perfusion imaging with ^99mTc-sestamibi to measure most of the variables known to determine infarct size, comparative clinical trials can be accomplished by using relatively small sample sizes. This has important implications regarding the assessment of new therapies for acute myocardial infarction.     

Teboroxime is a marker of reperfusion after myocardial infarction

Background  

It has been shown that serial teboroxime imaging can rapidly assess coronary perfusion in viable myocardial distributions. However, the myocardial uptake of teboroxime after reperfusion of acutely infarcted myocardium has not been critically evaluated. The study object was to assess whether teboroxime uptake in acutely infarcted myocardium is linearly related to blood flow.     

Factors influencing myocardial salvage with primary angioplasty

Background

The purpose of this study was to evaluate the factors influencing the salvage of jeopardized myocardium in patients treated with primary angioplasty for acute myocardial infarction.

Methods and Results

This multicenter study involved 59 patients with acute myocardial infarction who underwent primary angioplasty without antecedent thrombolytic therapy and paired baseline (before angioplasty) and predischarge tomographic perfusion imaging by quantitative ^99mTc-labeled sestamibi techniques for assessing the initial area at risk and eventual infarct size. Of the 59 patients who underwent primary angioplasty, Thrombolysis In Myocardial Infarction (TIMI) level 3 perfusion was restored in the infarct vessel in 54 patients (92%). On average, approximately one third of the left ventricular myocardial mass was initially jeopardized by the infarction in progress; eventual infarct size was 18%±15% of the left ventricle; myocardial salvage was 16%±17% of the left ventricle. Primary angioplasty salvaged 46%±50% of initially jeopardized myocardium. Factors correlated with myocardial salvage included elapsed time from onset of pain to reperfusion, infarct location (anterior infarcts had more myocardial salvage than inferior infarcts), and residual flow to the infarct zone at preangioplasty baseline levels. In the five patients reperfused less than 2 hours from onset of pain, 80% of the jeopardized myocardium was salvaged. Myocardial salvage beyond 2 hours was much more variable.

Conclusion

Primary angioplasty was highly effective at restoring normal perfusion in the infarct vessel and salvaging jeopardized myocardium. The myocardial salvage was highly variable and correlated with elapsed time to reperfusion, baseline residual flow to the infarct zone, and infarct location.     

Use of <Superscript>99m</Superscript>Tc-sestamibi gated SPECT to assess the influence of anterograde flow before primary coronary angioplasty on tissue salvage and functional recovery in acute myocardial infarction

Purpose Preserved thrombolysis in myocardial infarction (TIMI) flow before percutaneous coronary intervention (PCI) in acute myocardial infarction is related to improved outcome. Gated single-photon emission computed tomography (SPECT) allows the simultaneous assessment of left ventricular perfusion and function. We evaluated the initial risk area and subsequent evolution of perfusion and function according to TIMI flow before successful primary PCI.Methods In 36 patients, treated with abciximab, primary PCI and stenting, ^99mTc-sestamibi was injected before PCI and gated SPECT acquired thereafter. Gated SPECT was repeated 7 and 30 days later. Perfusion defect, wall motion score index, left ventricular ejection fraction and volumes were examined.Results Before PCI, 14 patients (group A) showed TIMI flow 2–3 and 22 (group B) TIMI flow 0–1, but no differences in clinical variables, initial risk area, wall motion score, ejection fraction or volumes. Perfusion defect was smaller in group A at 7 (9%±11% vs 19%±14%, p<0.02) and 30 days (7%±7% vs 16%±12%, p<0.02) and the salvage index was higher at 30 days (77%±22% vs 55%±28%, p<0.02). Wall motion score was lower in group A at 30 days (p<0.05). Ejection fraction significantly improved in both groups at 7 and 30 days. End-diastolic volume showed a trend towards a reduction in group A, whilst it was significantly increased in group B. Conversely, end-systolic volume was significantly decreased in group A but remained unchanged in group B.Conclusion In the setting of optimal myocardial reperfusion for myocardial infarction, preserved TIMI flow before PCI does not limit the initial risk area but it does improve myocardial salvage and functional recovery.