磁共振心肌灌注成像评价心肌梗死PTCA治疗前后心肌存活

目的 评价磁共振心肌灌注成像(MRMPI) 检测心肌梗死存活心肌的作用. 方法 选择心肌梗死患者51 例.采用1.5 T MR扫描仪,反转恢复快速小角度激励( IR-turbo FLASH) 序列,全部患者均在静脉注射钆喷替酸葡甲胺(Gd-DTPA) 0.1 mmol/kg、MRMPI 首过期及5~30 min 延迟期成像.21 例行静息、负荷99锝单光子发射计算机体层摄影术( single photon emission computed tomography, SPECT) 进行对照研究.首过期行短轴面成像,延迟期行短轴面及长轴面成像.结果 51例心肌梗死患者,42 例(82.3%) 首过期显示灌注减低;50 例(98%) 延迟增强.在21例168个心肌段SPECT诊断无活性心肌段48个,MRMPI 示梗死区均有延迟增强,SPECT诊断存活心肌段120 个,MRMPI 示97段无延迟增强.以静息、负荷99m锝SPECT 作为参考标准,MRMPI 的敏感度、特异度分别为100%、80.8%. 结论 MRMPI 可有效地检测心肌梗死的存活和非存活心肌,以及其程度和范围.     

Acute myocardial infarction due to myocardial bridge

Myocardial bridge (MB) is regarded as a common anatomic variant rather than a congenital condition anomaly,defined as the intramyocardial course of a portion of the coronary artery.It was first mentioned by Rayman in 1737 and first described by Grainicianu in the early 1920s.The current gold standard for diagnosing     

Evaluation of Myocardial Viability after Myocardial Infarction with Intravenous Real-time Myocardial Contrast Echocardiography

The myocardial viability after myocardial infarction was evaluated by intravenous myocardial contrast echocardiography. Intravenous real-time myocardial contrast echocardiography was performed on 18 patients with myocardial infarction before coronary revascularization. Follow-up echocardiography was performed 3 months after coronary revascularization. Segmental wall motion was assessed using 18-segment LV model and classified as normal, hypokinesis, akinesis and dyskinesis. Viable myocardium was defined by evident improvement of segmental wall motion 3 months after coronary revascularization. Myocardial perfusion was assessed by visual interpretation and divided into 3 conditions： homogeneous opacification; partial or reduced opaciflcation or subendocardial contrast defect; contrast defect. The former two conditions were used as the standard to define the viable myocardium. The results showed that 109 abnormal wall motion segments were detected among 18 patients with myocardial infarction, including 47 segments of hypokinesis, 56 segments of akinesis and 6 segments of dyskinesis. The wall motion of 2 segments with hypokinesis before coronary revascularization which showed homogeneous opacification, 14 of 24 segments with hypokinese and 20 of 24 segments with akinese before coronary revascularization which showed partial or reduced opaciflcation or subendocardial contrast defect was improved 3 months after coronary revascularization. In our study, the sensitivity and specificity of evaluation of myocardial viability after myocardial infarction by intravenous real-time myocardial contrast echocardiography were 94.7% and 78.9%, respectively. It was concluded that intravenous real-time myocardial contrast echocardiography could accurately evaluate myocardial viability after myocardial infarction.     

心肌声学造影对急性心梗PCI术后心肌灌注的评价

目的:通过心肌声学造影(MCE)对急性心梗经皮冠状动脉支架术(PCI)后心肌灌注的情况进行判断,了解其对左心功能及左室重构的影响.方法:采用病例对照的研究方法,根据PCI术后1周的MCE检查,将急性心梗患者分为灌注正常组、灌注稀疏组和灌注缺失组,并随访检查3个月、6个月的左室射血分数(LVEF)及左室舒张末内径(LVDd)的变化情况,比较组内及组间不同时段LVEF与LVDd的变化.结果:PCI术后3个月灌注稀疏组LVEF恢复到正常;灌注缺损组PCI术后LVEF的平均水平随时间变化而逐渐降低;灌注缺损组患者的LVEF低于灌注稀疏组和灌注正常组(P<0.05);术后6个月灌注缺损组LVDd平均水平高于灌注正常组和灌注稀疏组(P<0.05),灌注缺损组随时间的变化左室内径逐渐增大(P<0.05).结论:急性心梗患者PCI术后心肌微循环较差时,其左室射血分数降低,左室内径增大;MCE有利于对急性心梗患者PCI术后左心功能及左室重构评估.     

水飞蓟素通过抑制心肌细胞凋亡减轻心肌梗死

目的：观察水飞蓟素对心肌梗死小鼠的血流动力学、梗死面积及梗死边缘区凋亡蛋白表达情况。方法：将60只小鼠随机分为心肌梗死组、假手术组、心肌梗死+水飞蓟素组和心肌梗死溶剂组。建模成功4周后检测小鼠血流动力学变化,进行心脏超声检查,评价梗死面积、细胞凋亡指数以及凋亡蛋白Bcl-2、Bax、Cleaved-Caspase3的表达。结果：与心肌梗死组小鼠相比,水飞蓟素可显著减轻心肌梗死,改善心梗小鼠心功能,降低心肌细胞凋亡指数,增强Bcl-2蛋白表达和减弱Bax和Cleaved-Caspase3蛋白表达。结论：水飞蓟素能够减轻心肌梗死,改善心梗小鼠心室收缩功能,保护心肌,减少心肌细胞的凋亡,其机制与升高Bcl-2蛋白、降低Bax和Cleaved-Caspase3蛋白表达水平有关。     

超声心肌造影技术对心肌梗塞患者心肌微循环的定量评价

目的：探讨超声心肌造影技术在心肌梗塞(简称心梗)患者心肌微循环灌注改变中的应用价值。方法：对30例急性心梗患者进行超声心动图及心肌造影检查,观察患者梗塞区域(AMI组,同时以患者非梗塞区域为自身对照组)心肌微循环灌注并以CPS造影软件进行分析。结果：心肌梗塞患者梗塞区域心肌微循环灌注开始时间(AT)、达峰时间(APT)较同一切面内的非梗塞区域明显延长（P<0.05）,梗塞区域造影剂灌注的峰值强度(PI)及灌注速度(β)均明显低于同一切面内的非梗塞区域（P<0.05）。结论：超声心肌造影技术可以定量评价心梗患者心肌微循环灌注,具有重要的临床应用价值。     

“肾阳虚证”下心肌梗死模型与单纯心肌梗死模型大鼠心肌形态学、心肌酶学及血液流变学的比较

目的：建立大鼠“肾阳虚证”下心肌梗死模型,探讨其与单纯心肌梗死模型大鼠在心肌形态学、心肌酶学及血液流变学方面的差异,为评价治疗胸痹心痛中药的药效学提供理论依据。方法：60只Wistar大鼠随机分为空白对照组、肾阳虚模型组、心肌梗死假手术组、单纯心肌梗死模型组及“肾阳虚证”下心肌梗死模型组,每组12只。在大鼠 “肾阳虚”情况下复制急性心肌梗死模型,测定各组大鼠心肌梗死面积 (MIS),血清天门冬氨酸氨基转化酶（AST）、肌酸磷酸激酶（CK）及乳酸脱氢酶（LDH）活性,同时测定血小板黏附率（PAR）、血小板聚集率（PAG）、红细胞沉降率（ESR）、红细胞压积（HCT）、体外血栓长度、血栓干重与湿重以及血栓弹力图等参数。结果： 大鼠“肾阳虚证”下心肌梗死模型与单纯心肌梗死模型在MIS,血清AST、CK及LDH活性,PAR、PAG、ESR及HCT增加程度差异无统计学意义（P>0.05）;肾阳虚模型组、单纯心肌梗死模型组及“肾阳虚证”下心肌梗死模型组大鼠体外血栓干重及长度均明显增加（P<0.05或P<0.01）,“肾阳虚证”下心肌梗死模型组的增加程度大于单纯心肌梗死模型组及肾阳虚模型组,但三者之间差异无统计学意义（P>0.05）;尽管“肾阳虚证”下心肌梗死模型组大鼠血栓弹力图r、k值的缩短程度及ma值的增大程度高于单纯心肌梗死模型组,但2组之间差异无统计学意义（P>0.05）。结论：大鼠“肾阳虚证”下心肌梗死模型与单纯心肌梗死模型心肌梗死面积、血清心肌酶学、红细胞压积、血沉、血小板功能、体外血栓重量及血栓弹力图等指标均无明显差异。     

Relation of myocardial bridge to myocardial infarction: a meta-analysis

Background Small case series have suggested an association of coronary myocardial bridge （MB） with myocardial infarction （MI）.However,the relationship between MB and major adverse cardiac events （MACE） remains largely unknown.The aim of this study was to assess the relationship between MB and MACE involving MI.Methods We performed a systematic search of MEDLINE,PreMEDLINE,and all EMB Reviews as well as a reference list of relevant articles according to the SPICO （Study design,Patient,Intervention,Control-intervention,and Outcome） criteria using the following keywords：myocardial bridging,myocardial bridge,intramural coronary artery,mural coronary artery,tunneled coronary artery,coronary artery overbridging,etc.Bibliographies of the retrieved publications were additionally hand searched.Studies were included for the meta-analysis if they satisfied the following criteria：（1） they evaluate the association of MB with cardiovascular endpoint event; （2） they included individuals with MB and those without MB; 3） they excluded individuals with obstructive coronary artery disease （CAD）.Studies were reviewed by a predetermined protocol including quality assessment.Dates were pooled using a random effect model.Results Seven observational studies that followed 5 486 patients eligible for the enrolled criteria were included from 7 136 initially identified articles.The prevalence of MB was 24.8％ （1 363/5 486）.During 0.5-7.0 years of follow-up of this cohort of population,crude outcome rates were 8.0％ in the MB group and 7.7％ in the non-MB group.The odds ratio of overall MACE and MI were 1.34 （95％ confidence interval （CI）：0.57-3.17,P=0.51,n=7 studies） and 2.75 （95％ CI：1.08-7.02,P ＜0.03,n=5 studies） respectively for subjects of MB compared to non-MB.Conclusion Relationship between MB and MI appears to be a real one,although the study did not reveal a connection of MB to MACE,suggesting whether the necessity of antiplatelet therapy needs to be further studied in a larger cohort of patients with MB prospectively.     

Self-induced myocardial infarction

A case of acute myocardial infarction and peripheral vascular insufficiency following overdose with ergotamine is described.     

Factors affecting thrombolysis in myocardial infarction myocardial perfusion frame count: insights of myocardial tissue-level reperfusion from a novel index for assessing myocardial perfusion

Background  Myocardial tissue-level perfusion failure is associated with adverse outcomes following ST-elevation myocardial infarction (STEMI) despite successful epicardial recanalization. We have developed a new quantitative index—thrombolysis in myocardial infarction (TIMI) myocardial perfusion frame count (TMPFC)—for assessing myocardial tissue level perfusion. However, factors affecting this novel index of myocardial perfusion are currently unknown.

Methods  A total of 255 consecutive STEMI patients undergoing primary angioplasty were enrolled. Myocardial tissue level perfusion was assessed by TMPFC, which measures the filling and clearance of contrast in the myocardium using cine-angiographic frame counting. We differentiate three groups with two cut off values for TMPFC: a TMPFC of 90 frames was the upper boundary of the 95% confidence interval (CI) for the TMPFC observed in normal arteries, and a TMPFC of 130 was the 75th percentile of TMPFC.

Results  STEMI patients with TMPFC >130 frames (68 patients, 26.7%) had higher clinical and angiographic risk factor profiles as well as a higher 30-day MACE rate compared with those with TMPFC ≤90 frames and those with TMPFC >90 and ≤130 frames. Multivariable analysis identified that the independent predictors of TMPFC >130 frames were age ≥75 years (OR 2.08, 95% CI 1.21 to 3.58, P=0.007), diabetes (OR 1.37, 95% CI 1.01 to 1.86, P=0.042), Killip class ≥2 (OR 1.52, 95% CI 1.05 to 2.21, P=0.027), and prolonged pain-to-balloon time (OR 1.73, 95% CI 1.07 to 2.79, P=0.013). TMPFC >130 frames was identified as the strongest independent predictor of 30-day major adverse cardiac event (MACE) (OR 2.77, 95% CI 1.21 to 6.31, P=0.008), along with age ≥75 years (OR 2.19, 95% CI 1.11 to 4.33, P=0.016), female gender (OR 1.67, 95% CI 1.03 to 2.70, P=0.038), and Killip class ≥2 (OR 1.83, 95% CI 1.07 to 3.14, P=0.021).

Conclusions  STEMI patients with poor myocardial perfusion assessed by TMPFC had higher risk factor profiles. Advanced age, diabetes, higher Killip class, and longer ischemia time were independent predictors of impaired TMPFC after primary percutaneous coronary intervention. These results emphasize that particular attention should be paid on myocardial microvascular reperfusion in STEMI patients with these risk factors.

     

丁苯酞抑制大鼠急性心肌缺血导致的心肌损伤

目的探讨丁苯酞( NBP)在大鼠心肌梗死后对心肌细胞线粒体损伤、心肌梗死面积及心肌细胞凋亡的作用。方法92只雄性SD大鼠分为假手术组8只,模型组、NBP低剂量组、中剂量组和高剂量组各21只。其中模型组和NBP组通过结扎冠状动脉左前降支建立急性心肌梗死模型,假手术组仅开胸,不结扎冠状动脉。采用TUNEL法检测模型组和NBP低、中、高剂量组大鼠梗死区心肌细胞凋亡。电子透射显微镜观察模型组和NBP高剂量组梗死交界区的心肌细胞超微结构。 TTC染色分析模型组和NBP高剂量组心肌梗死面积,Western blot法检测模型组和NBP高剂量组大鼠心肌梗死4 h后抗凋亡蛋白Bcl-2和促凋亡蛋白Bax的表达水平。结果在大鼠急性心肌梗死实验过程中,NBP预处理过的大鼠与模型组相比,NBP中、高剂量组显著减少心肌细胞凋亡(P<0.05);NBP高剂量组可显著缩小大鼠急性心肌梗死面积(P<0.01),同时可有效抑制线粒体损伤(P<0.05);NBP高剂量组可显著提高Bcl-2蛋白表达水平( P<0.05)及Bcl-2/Bax的比值( P <0.05)。结论 NBP 通过提高 Bcl-2蛋白表达水平及Bcl-2/Bax的比值,减少线粒体损伤,降低心肌梗死过程中细胞凋亡指数,缩小心肌梗死面积,有效地抑制急性心肌缺血导致的心肌损伤。     

心肌损伤生化标物与急性心肌梗死

心肌损伤生化标志物检测是临床确诊急性心肌梗死的重要手段。就此目的而言 ,“早期”、“确认”是必需的 ,而且检验过程应在 1h或 <1h完成 ,这些已达成共识。综合分析认为 ,肌红蛋白 (Mb)是最符合“早期”需要的标志物 ,而肌钙蛋白 (Tn)则符合“确认”要求 ,其敏感性足以检测到微小心肌损伤     

急性心肌梗死急诊不同再灌注方案的临床分析

目的探讨长沙地区急性心肌梗死不同院前心肌再灌注方案的实际执行状况和效果。方法本研究为非随机、前瞻性试验。入选的急性心肌梗死病例被分为尿激酶(UK)组、重组组织型纤溶酶原激活剂(r-tPA)组、经皮冠状动脉介入治疗(PCI)组和非再灌注组,非再灌注组的病例予以低分子肝素、阿司匹林治疗,观察不同方案的实际实施状况及近期疗效、并发症和费用-效果比。结果①106例AMI病人,87例施行了再灌注治疗(82%),急诊PCI组24例(23%),r-tPA组27例(25%),UK组36例(34%);非再灌注19例(18%)。②再通率为UK组61.3%,r-tPA组81.5%,PCI组95.8%;入院至开始再灌注时间为UK组(38.52±16.21)min,r-tPA组(46.23±17.13)min,PCI组(98.47±20.42)min;入院至再通时间为UK组(73.21±11.34)min,r-tPA组(122.12±23.46)min,PCI组(132.73±13.67)min。③住院期心绞痛发生率,再发心肌梗死率,心衰发生率,病死率在PCI组优于r-tPA组,r-tPA组优于UK组,三组均显著低于非再灌注组。④费用-再通率比为PCI组33893.16元,r-tPA组16717.53元,UK组3037.52元。结论在AMI的实际临床治疗中,大部分病人接受了急诊再灌注治疗。UK方案仍是采用最多的方案,可以在较短时间内实现IRA再通,且费用-效果比低,但再通率偏低,近期效果不满意。急诊PCI的再通率和近期临床效果最佳,但容易受多因素影响而耽误开始再灌注治疗的时间,且费用-效果比高。r-tPA的再通率、近期临床效果均明显高于UK,恢复IRA再通的时间与PCI接近,费用-效果比显著低于急诊PCI,是个比较理想可行的AMI急诊再灌注方案。     

急性心肌梗死急诊不同再灌注方案的临床分析急性心肌梗死急诊不同再灌注方案的临床分析

目的探讨长沙地区急性心肌梗死不同院前心肌再灌注方案的实际执行状况和效果。方法本研究为非随机、前瞻性试验。入选的急性心肌梗死病例被分为尿激酶（UK）组、重组组织型纤溶酶原激活剂（r-tPA）组、经皮冠状动脉介入治疗（PCI）组和非再灌注组，非再灌注组的病例予以低分子肝素、阿司匹林治疗，观察不同方案的实际实施状况及近期疗效、并发症和费用-效果比。结果①106例AMI病人，87例施行了再灌注治疗（82%），急诊PCI组24例（23%），r-tPA组27例（25%），UK组36例（34%）；非再灌注19例（18%）。②再通率为UK组61.3%，r-tPA组81.5%，PCI组95.8%；入院至开始再灌注时间为UK组（38.52±16.21）min，r-tPA组（46.23±17.13）min，PCI组（98.47±20.42）min；入院至再通时间为UK组（73.21±11.34）min，r-tPA组（122.12±23.46）min，PCI组（132.73±13.67）min。③住院期心绞痛发生率，再发心肌梗死率，心衰发生率，病死率在PCI组优于r-tPA组，r-tPA组优于UK组，三组均显著低于非再灌注组。④费用-再通率比为PCI组33893.16元，r-tPA组16717.53元，UK组3037.52元。结论在AMI的实际临床治疗中，大部分病人接受了急诊再灌注治疗。UK方案仍是采用最多的方案，可以在较短时间内实现IRA再通，且费用-效果比低，但再通率偏低，近期效果不满意。急诊PCI的再通率和近期临床效果最佳，但容易受多因素影响而耽误开始再灌注治疗的时间，且费用-效果比高。r-tPA的再通率、近期临床效果均明显高于UK，恢复IRA再通的时间与PCI接近，费用-效果比显著低于急诊PCI，是个比较理想可行的AMI急诊再灌注方案。     

超声检测心内外膜下跨壁速度梯度在心肌缺血诊断中的应用

目的：探讨跨壁速度梯度（MVG）在诊断心肌缺血中的应用价值。方法：检测38例冠心病患者（病例组）和28例健康志愿者（对照组）心尖四腔观、两腔观各节段心肌收缩期跨壁速度梯度（MVG-L＋）、舒张期跨壁速度梯度（MVG—L-）。结果：对照组MVG—L＋和MVG—L-由基底段、中间段至心尖段差异无显著性意义。病例组缺血节段的MVG-L＋和MVG—L-较对照组相应节段明显降低。结论：MVG可定量评价局部心肌运动状态，为临床心功能评价提供有效指标。     

急性心肌梗死心肌蛋白检测的临床评价

目的探讨心肌损伤标志物心肌蛋白检测在急性心肌梗死(AcuteMyocardialInfarction,AMI)诊断时的应用价值,减少急性心肌梗死漏诊、误诊发生率。方法测定35例AMI病人在发病的第4小时、8小时、24小时,5天等四个时间段的血清肌钙蛋白(IcTnI)、肌钙蛋白T(cTnT)及肌红蛋白(Mb)浓度,和对照组30例健康者体检时的血清相应项目数据对比并进行统计学处理。结果AMI患者发病后4￣8小时血清cTnI、cTnT开始上升,24小时达到峰值,5天仍维持在较高水平,其浓度以及阳性率与正常对照组比较均有显著性差异(P<0.05);而血清Mb在4￣8小时上升幅度更大,但24小时后浓度以及阳性率与正常对照组比较差异不显著(P>0.05)。结论在心肌梗死的早期诊断指标中,Mb的优势明显;cTnI、TnT可用于AMI的早期诊断,但更适用于那些因就诊时间较晚、心肌酶已正常的心梗病人。三者联测可更早、更可靠地提高心肌梗死诊断的准确率。