急性下壁心肌梗死ST段改变与相关冠状动脉阻塞的关系

目的探讨急性下壁心肌梗死时心电图ST段改变与相关冠状动脉阻塞的关系。方法对30例急性下壁心肌梗死ST段改变与冠状动脉造影结果对比分析。结果急性心肌梗死部位下壁12例、下壁+正后壁5例、下壁+右心室8例、下壁+前壁5例。其中单支病变10例,双支病变12例,三支病变8例。右冠状动脉狭窄87.7%,左回旋支狭窄12.2%。ST段抬高Ⅲ>Ⅱ,压低aVL>Ⅰ,诊断右冠状动脉阻塞,敏感性、特异性分别为95.0%、93.4%。V4导联ST段压低与Ⅲ导联ST段抬高比值>0.5,可诊断左回旋支阻塞,敏感性、特异性分别为84.9%和79.4%,ST段抬高Ⅰ>aVL、压低Ⅱ>Ⅲ,提示左回旋支阻塞,敏感性、特异性分别为52.1%和78%。结论急性下壁心肌梗死心电图ST段抬高Ⅲ>Ⅱ、ST段压低aVL>Ⅰ,提示右冠状动脉阻塞,V4导联ST段压低与Ⅲ导联ST段抬高比值>0.5,ST段抬高Ⅰ>aVL、ST段压低Ⅱ>Ⅲ,提示左回旋支阻塞。     

预测急性下壁心肌梗死相关动脉的心电图特征

目的：探讨下壁急性心肌梗死患者体表心电图对梗死相关动脉的预测价值。方法：根据冠状动脉造影结束将51例下壁急性心肌梗死患者分为右冠状动脉闭塞组35例和左冠状动脉回旋支闭塞组16例,根据aVL导联QRS形态分为Ⅰ型（S／R≤1／3,ST段压低≤1mm)和Ⅱ型（S／R＞1／3,ST段压低＞1mm),结果：右冠状动脉闭塞时,aVL导联QRS波多呈Ⅱ型变化,其敏感性和特异性分别为77．1％,81．3％,左冠状动脉回旋支闭塞时,则为I型变化,其敏感性和特异性分别为81．3％、77．1％。结论：下壁急性心肌梗死患者的心电图aVL导联QRS波导呈Ⅱ型者是右冠状动脉阻塞敏感,特异的标志,呈I型则是左冠状动脉回旋支阻塞敏感,特异的标志。     

心电图判断急性下壁心肌梗死相关动脉的价值

目的:探讨体表心电图改变在判断急性下壁心肌梗死相关动脉的价值.方法:根据冠状动脉造影结果将78例急性下壁心肌梗死患者分为右冠状动脉(RCA)组和左冠状动脉回旋支(LCX)组,比较2组患者的心电图改变.结果:①RCA组患者aVL导联ST段压低≥1 mm的发生率明显高于LCX组患者(92%:24%,P＜0.01);②RCA组患者aVL导联R/S比值明显低于LCX组[(2.7±0.4),(3.4±0.6),P＜0.01],③aVL导联ST段压低≥1 mm和R/S比值≤3判断急性下壁心肌梗死相关动脉为RCA的敏感性、特异性、阳性预测值和阴性预测值分别为92%、90%、96%、77%和86%、95%、98%、70%.结论:aVL导联ST段压低和R/S比值缩小是判断急性下壁心肌梗死病变动脉为RCA的良好指标.     

急性心肌梗死时体表心电图对梗死相关动脉的判断

目的了解急性心肌梗死(AMI)的体表心电图对心肌梗死相关动脉(IRA)及其闭塞位置判断作用.方法对264例急性心肌梗死患者的心电图和冠状动脉造影资料进行回顾性对比分析.结果①下壁AMI时血管闭塞发生在右冠状动脉(RCA)74例(78.7%),左回旋支(LCX)20例(21.3%).Ⅰ、aVL导联ST段压低提示RCA为IRA的敏感性,特异性和阳性预测值分别为94.6%,70%和92.1%.ST段压低Ⅰ＜aVL提示RCA为IRA的敏感性,特异性和阳性预测值分别为83.8%,90%和96.9%.ST段抬高Ⅱ＜Ⅲ提示RCA为IRA的敏感性,特异性和阳性预测值分别为90.5%,90%和97.1%.ST段压低Ⅰ＜aVL和ST段抬高Ⅱ＜Ⅲ提示RCA为IRA的敏感性,特异性和阳性预测值分别为81.8%,100%和100%.非ST段压低Ⅰ＜aVL和非ST段抬高Ⅱ＜Ⅲ提示LCX为IRA的敏感性,特异性和阳性预测值分别为85%,100%和100%.13例合并右室心梗IRA均为RCA.②前间壁AMI时STⅠ、STaVL抬高,STⅡ、Ⅲ、aVF下降均不能提示IRA为LAD或RCA(P分别大于0.05).③前壁AMI时STⅠ、STaVL抬高,STⅡ、Ⅲ、aVF下降判断LAD近段闭塞的敏感性、特异性和阳性预测值分别为70.4%,59.3%,87%,95.7%和86.4%,94.1%.④广泛前壁AMI时STⅠ、STaVL抬高,STⅡ、Ⅲ、aVF下降判断LAD近段闭塞的敏感性、特异性和阳性预测值分别为100%,95.5%,85.7%,100%和97.8%,100%.结论下壁、前壁和广泛前壁AMI时体表心电图对心肌梗死相关动脉(IRA)及其闭塞位置判断具有预测价值.     

急性下壁心肌梗死Ⅱ、Ⅲ导联ST段比值与冠状动脉造影对照分析

目的探讨心电图对急性下壁心肌梗死相关冠状动脉梗死相关动脉及合并右心室梗死的判断价值。方法对照分析95例急性下壁心肌梗死入院时的心电图Ⅱ、Ⅲ导联ST段抬高比值及Ⅰ、aVL导联ST段偏移与冠状动脉造影梗死相关动脉的关系。结果95例患者中,74例右冠状动脉(RCA)阻塞所致者ST段抬高Ⅲ/Ⅱ>1、≤1分别为70例、4例;Ⅰ、aVL导联ST段抬高或等电位线4例,压低70例(P<0.05)。而21例左回旋支(LCX)阻塞所致者ST段抬高Ⅲ/Ⅱ>1、<1分别为4、17例。Ⅰ、aVL导联ST段抬高或等电位线17例、压低4例(P<0.05)。合并右心室梗死13例中,以Ⅲ/Ⅱ>1判断,11例合并右心室心肌梗死(P<0.05)。结论急性下壁心肌梗死梗死相关动脉以RCA病变为主,少部分为LCX病变。Ⅰ、aVL导联抬高或等电位线多见于LCX病变,Ⅰ、aVL导联ST段压低则对诊断RCA阻塞具有很高的价值。ST段Ⅲ/Ⅱ>1判定急性下壁心肌梗死合并右心室梗死有一定的价值。     

心电图对老年急性下壁心肌梗死冠状动脉病变部位的预测价值

目的　探讨急性下壁心肌梗死心电图与冠状动脉病变的关系 ,以揭示体表心电图对梗死相关动脉及病变节段的预测价值。方法　对 15 6例老年急性下壁心肌梗死患者的体表心电图和冠状动脉造影资料进行对比分析。结果　梗死相关动脉为右冠状动脉占 79.5 % ,左回旋支占 2 0 .5 %。单纯急性下壁心肌梗死病变节段多发生在第一右心室支开口以远 (77.6 % ) ,合并右心室心肌梗死病变节段多发生在第一右心室支开口前 (87% )。STⅢ 抬高 /STⅡ 抬高 >1,STⅠ、aVL下移≥ 1mm ,提示右冠状动脉为梗死相关动脉的敏感性分别为 87.9%、89.5 % ,特异性分别为 84 .4 %、81.2 % ,阳性预告值分别为 95 .6 %、94 .8% ,两者差异无显著性意义 (P >0 .0 5 )。ST段V1、V2 下移≥ 1mm ,提示左回旋支为梗死相关动脉的敏感性 ,特异性和阳性预告值分别为 84 .4 %、91.9%、73.0 %。结论　急性下壁心肌梗死时心电图对判断梗死相关动脉及病变节段有重要的预测价值     

Ⅱ、ⅢST段抬高比值与ⅠST段偏移对急性下壁心肌梗死相关动脉的诊断价值

目的 探讨急性下壁心肌梗死体表心电图对梗死相关动脉的诊断价值。方法 对照分析61例急性下壁心肌梗死入院时心电图Ⅱ、Ⅲ导联ST段抬高比值及Ⅰ导联ST段偏移与冠状动脉造影梗死相关动脉的关系。结果 14例左旋支阻塞所致者ST段抬高Ⅱ/Ⅲ≥1、＜1分别为12、2例；Ⅰ导联ST段抬高或等点线12例，压低2例。而47例右冠状动脉阻塞所致者ST段反转高Ⅱ/Ⅲ≥1、＜1分别为2、45例；Ⅰ导联ST段抬高或等电位线2例、压低45例。两组差异有显著性意义。结论 心电图ST段拾高Ⅱ/Ⅲ≥1、Ⅰ导联ST段抬高或等电线是诊断左旋支阻塞敏感而特异的指标，而ST段抬高Ⅱ/Ⅲ＜1、Ⅰ导联ST段压低则对诊断右冠状动脉阻塞具有很高的特异性和敏感性。     

急性下壁心肌梗死心电图与冠脉造影对照分析

目的探讨急性下壁心肌梗死心电图判断罪犯血管的准确性。方法对照分析2013年~2015年我院收治的急性下壁心肌梗死患者100例入院时心电图Ⅱ、Ⅲ标准导联的ST段抬高比例及Ⅰ、AVL导联的ST段是否偏移与冠状动脉造影显示的梗死相关罪犯血管的对应关系。结果 100例患者中,76例右冠状动脉急性闭塞所致ST段抬高Ⅲ/Ⅱ1占71例,ST段抬Ⅲ/Ⅱ≤1占5例;Ⅰ、AVL导联ST段抬高或等电位线5例,Ⅰ、AVL导联ST段压低71例;24例左回旋支急性闭塞所致者ST段抬高Ⅲ/Ⅱ1占5例、ST段抬Ⅲ/Ⅱ≤1占19例;Ⅰ、AVL导联ST段抬高或等电位线19例,Ⅰ、AVL导联ST段压低5例。结论急性下壁心肌硬死相关罪犯血管以右冠状动脉病变为多,少部分为回旋支病变;Ⅰ、AVL导联抬高或等电位线多见于回旋支闭塞,Ⅰ、AVL导联ST段压低则对诊断右冠状动脉闭塞具有很高的价值。     

急性下壁心肌梗死时心电图对判断心肌梗死相关动脉和闭塞位置的作用

目的：探讨下壁急性心肌梗死（AMI）的心电图对判断心肌梗死相关动脉和闭塞位置的作用。方法：对90例下壁AMI患者的心电图和冠状动脉造影资料进行分析。结果：①血管闭塞发生在右冠状动脉占87．8％,回旋支占12．2％,合并右心室心肌梗死（RVI）占41．4％。②下壁AMI右冠状动脉为心肌梗死相关动脉时,血管闭塞位置多发生在第1右心室支开口以远（73.8％）,合并RVI时其闭塞多发生在第1右心室支开口前（64．9％）;下后壁伴侧壁AMI回旋支为心肌梗死相关动脉时,其闭塞位置均在钝缘支发出前。③下壁AMI时Ⅰ、aVL导联ST段呈对应性压低,提示右冠状动脉为心肌梗死相关动脉的敏感性为9.·5％,特异性为93．9％,ST段呈等电位线或轻度抬高,提示回旋支闭塞的敏感性为54.5％,特异性为75．0％。与传统RVI诊断相比ST段抬高幅度Ⅲ＞Ⅱ导联,提示RVI的敏感性为100．0％,特异性为49．3％。结论下壁AMI时心电图对判断梗死相关动脉和闭塞位置有重要的预测价值。     

aVR导联对急性下壁心肌梗死患者梗死相关血管判断的价值

目的探讨心电图(ECG)对急性下壁心肌梗死(MI)患者梗死相关血管(IRA)判断的价值。方法选择2002年7月～2004年12月的急性下壁MI患者90例,回顾性分析其症状发作后24h内ECG改变。结果90例中,IRA为右冠状动脉(RCA)者70例,为左回旋支(LCX者)20例;Ⅰ导联ST段抬高和(或)V1和V2导联ST段压低提示IRA在LCX,而ST段抬高Ⅲ导联大于Ⅱ导联和(或)导联V4RST段抬高≥0.5mm提示IRA在RCA;aVR导联ST段压低≥1mm判断IRA为LCX,其敏感性为70.0%,特异性为94.3%。结论Ⅰ导联ST段抬高、ST段抬高Ⅲ导联>Ⅱ导联、导联V4RST段抬高≥0.5mm、V1和V2导联ST段抬高或压低以及aVR导联ST段压低等5项标准可用于判断急性下壁MI患者的IRA,而aVR导联ST段压低为一项新的标准。     

Value of the myocardial performance index in myocardial infarction

The myocardial performance index represents an easy and reproducible parameter of both systolic and diastolic left ventricular function for the risk stratification of patients following acute myocardial infarction.     

经静脉心肌声学造影评价心肌梗死后存活心肌的价值

目的　探讨经静脉心肌声学造影 (MCE)对心肌梗死后存活心肌的诊断价值。方法　 2 4例心肌梗死患者用二维超声评价室壁运动情况 ,同时经静脉进行MCE ,以 3个月后静态超声心动图左室心肌节段性运动改善为依据评价MCE对心肌梗死后存活心肌的诊断价值。结果　在 2 4例病人的 384个心肌节段中 ,运动异常节段 184个。在运动异常的 184个节段中 ,MCE1分 39段 ,0 5分 5 0段 ,0分 95段。 3个月复查 79个节段有运动改善 ,其中 39段来自MCE1分的心肌 ,4 0段来自MCE0 5分的心肌。MCE对预测心肌梗死后室壁运动改善的敏感性、特异性、阳性预测值、阴性预测值及准确率分别为 :10 0 %、89 7%、84 8%、10 0 %和 94 6 %。结论　MCE能比较准确地预测心肌梗死后心肌的存活性     

Quantitative myocardial contrast echocardiography for prediction of thrombolysis in myocardial infarction flow in acute myocardial infarction

Clinical evaluation of arterial patency in acute ST-elevation myocardial infarction (STEMI) is unreliable. We sought to identify infarction and predict infarct-related artery patency measured by the Thrombolysis In Myocardial Infarction (TIMI) score with qualitative and quantitative intravenous myocardial contrast echocardiography (MCE). Thirty-four patients with suspected STEMI underwent MCE before emergency angiography and planned angioplasty. MCE was performed with harmonic imaging and variable triggering intervals during intravenous administration of Optison. Myocardial perfusion was quantified offline, fitting an exponential function to contrast intensity at various pulsing intervals. Plateau myocardial contrast intensity (A), rate of rise (beta), and myocardial flow (Q = A x beta) were assessed in 6 segments. Qualitative assessment of perfusion defects was sensitive for the diagnosis of infarction (sensitivity 93%) and did not differ between anterior and inferior infarctions. However, qualitative assessment had only moderate specificity (50%), and perfusion defects were unrelated to TIMI flow. In patients with STEMI, quantitatively derived myocardial blood flow Q (A x beta) was significantly lower in territories subtended by an artery with impaired (TIMI 0 to 2) flow than those territories supplied by a reperfused artery with TIMI 3 flow (10.2 +/- 9.1 vs 44.3 +/- 50.4, p = 0.03). Quantitative flow was also lower in segments with impaired flow in the subtending artery compared with "normal" patients with TIMI 3 flow (42.8 +/- 36.6, p = 0.006) and all segments with TIMI 3 flow (35.3 +/- 32.9, p = 0.018). An receiver-operator characteristic curve derived cut-off Q value of <11.3, representing impaired myocardial flow, was 73% sensitive and 67% specific for TIMI <3 flow at angiography. Thus, qualitative MCE identifies patients with STEMI but provides no information regarding infarct-related artery patency, whereas quantitative MCE can predict impaired flow in patients with acute STEMI.     

Assessment of myocardial oxidative stress in patients after myocardial revascularization

A homogeneous group of six patients, who underwent coronary artery bypass surgery, was studied to determine the presence of oxidative stress caused by oxygen-derived free radicals and its relationship with reperfusion cell damage. Biopsies were performed before ischemia and 10 minutes after reperfusion. The samples were assayed for hydroperoxide-initiated chemiluminescence and histochemical succinic dehydrogenase activity; the specimens were also studied by electron microscopy. The preischemic biopsy specimens showed chemiluminescence of 40 +/- 2 (cpm/mg protein) x 10(3), normal succinic dehydrogenase activity (grade 4), and generally preserved ultrastructure (necrotic/normal cells 5/100). However, the reperfusion biopsy specimens showed an increase in chemiluminescence to 91 +/- 19 (cpm/mg protein) x 10(3) (p less than 0.025), a partial loss of enzymatic activity (grade 2.6), and ultrastructural changes characterized by mitochondrial swelling and focal myofibrillar disorganization (necrotic/normal cells: 15/100; p less than 0.001). These observations seem to indicate the presence of oxidative stress during reoxygenation, a situation that may play a major role in the genesis of reperfusion injury. It appears to be the first observation relating free radical-induced oxidative stress to reperfusion injury in humans.     

Emergency myocardial revascularization in acute evolving myocardial infarct

Immediate coronary artery bypass for acute evolving myocardial infarction could be the elective therapy if provided on useful time, because myocardial salvage can be achieved by early reperfusion. Thirty eight patients had emergency coronary artery by-pass graft for acute evolving myocardial infarction during the early phase: 35 were male, the mean age was 51 years (34 to 74). The mean interval between the onset of symptoms and surgery in this series of patients was two hours and a half. This interval seems to be also the time limit in our experience to get a partial or complete recovery of ischemic area. Four patients died in hospital, but they were in severe cardiogenic shock before emergency surgery. Twenty nine cases were free of symptoms at a mean follow-up of 18 months (6 to 36) and two suffered for residual angina. Three patients died after discharge few months later: two during redo emergency vein grafts operations, one in deep left ventricular failure, while he was waiting for heart transplant. All these patients operated on as emergency developed acute myocardial infarction during their stay in hospital waiting for catheter study, surgical operation or during percutaneous transluminal coronary angioplasty. Saphenous vein grafts, were used in twenty nine patients, left internal mammary artery in nine cases, single in four and associated to saphenous vein in five, with an average number of anastomoses of 2.6 (1 to 6) for patient. ECG was found to be normal in 76% of the patients operated on within two hours and a half from the beginning of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)