Electrocardiographic changes in acute myocardial infarction with acute occlusion of all triple coronary arteries

The 66-year-old woman was diagnosed with “acute myocardial infarction” due to acute triple vessel occlusion based on clinical symptoms, laboratory examination, and coronary angiography (CAG), but her ECG showed ST-segment depression in leads aVR and aVL, in addition to ST-segment elevation in a wide range of leads (V1–V9, V3R–V5R, II, III, and aVF). Thus, a perfect explanation with the existing theory is difficult, and only the case is presented here.     

冠脉结扎法大鼠急性心肌梗死的造模

目的 探讨冠脉结扎法制作大鼠急性心肌梗死模型。 方法 40只Sprauge-Dawley大鼠随机分为冠脉结扎组和假手术组,大鼠经麻醉后,气管插管连接小动物呼吸机,打开左侧胸腔,暴露心脏,结扎左冠状动脉前降支,假手术组只用线穿过左前降支而不结 扎,其余步骤同冠脉结扎组。手术前后均行心电图检查,4周后行血流动力学检测,取出心脏,观察其外形变化,行HE染色后于显微镜下观察其病理变化。 结果 冠脉结扎组制作心梗模型成功率为100%,术后存活率为65%,假手术组术后存活率为80%。冠脉结扎组术后4周取出的心脏,左心室较假手术组扩大,缺血区室壁变薄。 结论 冠脉结扎法制作大鼠心肌梗死模型,效果稳定,成功率高,制作方便,经济易推广。     

动态心电图对急性短暂性心肌缺血的诊断价值（附1例报告）

动态心电图可完整记录心肌缺血发作过程，为诊断心肌缺血提供确凿证据。本文通过对典型病例及动态心电图的记录结果进行相关性分析，指出动态心电图能够发现急性短暂性心肌缺血发作过程，对诊断急性冠脉综合征的价值较大。因此，临床医师应重视动态心电图对急性短暂性心肌缺血的诊断价值，尤其是对无症状心肌缺血的诊断价值。     

银杏黄酮对急性心肌缺血/再灌注的药理作用

目的本研究通过观察银杏黄酮对家兔心肌缺血/再灌注的作用,为其临床应用寻找新的证据。方法家兔随机分为2组,对照组和银杏黄酮组,每组5只,口服给药,连续7d。以常规方法制备兔心肌缺血/再灌注模型。记录心率、血压、左心室内压、左心室内压微分变化。同时观察银杏黄酮对家兔急性心肌缺血/再灌注治疗后减轻心肌梗死的情况。结果心肌缺血及再灌注后心率、血压、左心室内压等在银杏黄酮治疗组与正常对照组无显著差异。左心室内压微分在心肌缺血和缺血/再灌注中,银杏黄酮组与对照组有显著差异（P<0.05）。银杏黄酮治疗后对家兔急性心肌缺血/再灌注可减轻心肌梗死,银杏黄酮组与对照组有显著差异（P<0.01）。结论银杏黄酮对急性心肌缺血/再灌注后心率、血压、心左室内压无明显影响,但却非常明显地减少由于缺血所造成的心肌组织的梗死面积。     

血清微小RNA可能是急性心肌梗死的标志物

目的观察急性心肌梗死患者血清中微小RNA（miRNA）水平的变化。方法采用3＇端加多聚poly（A）尾的反转录后荧光定量PCR的方法测定17例急性心肌梗死患者和11例健康对照者血清中miR-1的水平,并测定其血清肌酸激酶（CK）、肌酸激酶同工酶MB（CK-MB）及心肌肌钙蛋白T（cTnT）水平。结果心梗组miR-1水平较对照组升高（P〈0.01）;心梗组患者血清miR-1较对照组均值升高的倍数与其血清CK-MB较对照组均值升高的倍数存在正相关关系（r=0.52,P〈0.05）。结论 miR-1有可能作为急性心肌梗死的标志物,miR-1水平升高的机制可能与心肌梗死灶周围的缺血组织释放增加有关。     

Mortality in sepsis: Comparison of outcomes between patients with demand ischemia,acute myocardial infarction,and neither demand ischemia nor acute myocardial infarction

Introduction

Elevation in cardiac troponins is common with sepsis despite unclear impact.

Hypothesis

We investigated whether demand ischemia(DI) resulted in variable outcomes compared to acute myocardial infarction(AMI) and those with neither DI nor AMI in sepsis.

Methods

We analyzed data from the 2011‐2014 National Inpatient Sample among patients admitted for sepsis. We compared outcomes among patients with DI i) versus AMI and ii) versus neither DI nor AMI, respectively using propensity matching. Primary study end‐point was in‐hospital mortality.

Results

We studied 666,154 patients, with mean age 63.7 years and 50.8% female participants. Overall, 94.7% of the included patients had neither DI nor AMI, 4.4% had AMI and 0.83% had DI. Between 2011 and 2014, we observed an increasing trend for DI but decreasing trend for AMI in sepsis. Patients with DI experienced higher rates of atrial and ventricular arrhythmias, had longer length of stay and higher cost of stay compared to patients with neither demand ischemia nor AMI. Despite higher hospital mortality at baseline with DI, post‐propensity matching revealed no difference in hospital mortality between patients with DI and those with neither (26.9% vs. 27.0%, adjusted odds ratio 0.99, 95% confidence intervals 0.92‐1.07;p=0.87). Patients with DI experienced lower hospital mortality compared to those with AMI pre (28.5% vs. 48.3%;p<0.001) and post‐propensity matching (41.1% vs. 29.1%, aOR 0.58, 95% CI 0.54‐0.63;p<0.001).

Conclusion

Among patients with sepsis, those with DI had similar adjusted in‐hospital mortality compared to those with neither DI nor AMI. Patients with AMI had the highest in‐hospital mortality among all groups.     

Electrocardiographic ST-segment changes during acute myocardial ischemia

The recognition and management of patients with acute coronary syndromes has relied to a large extent onthe standard 12-lead electrocardiogram (ECG) for assessing ST-segment changes associated with ischemia.The purpose of this review is to show both the capabilities and the limitations of the 12-lead ECG in recognizingischemia, and to seek alternative electrocardiographic leads, optimized for detection of ischemia originating indifferent regions of the ventricular myocardium. Three such leads are proposed—based on the results obtainedby electrocardiographic body-surface mapping performed during ischemia induced by balloon-inflation coronaryangioplasty. A survey of recent clinical studies shows that the electrocardiographic manifestations of acutemyocardial ischemia observed during coronary angioplasty are in agreement with the ST-segment measurements inadmission ECGs of patients with acute myocardial infarction.     

Intravenous streptokinase in acute myocardial infarction

Intravenous (IV) fibrinolytic therapy, a recent area of research, has a great deal of applicability in emergency medicine. We report our experience with 30 patients treated with this method. Thirty consecutive patients in the early stages of acute evolving myocardial infarction (AMI) were assigned to receive high-dose IV streptokinase, 1.5 million units over a 30-minute period. Patients presented to the treating hospital at a mean time of 1.21 +/- 1.08 hours, and treatment commenced at a mean time of 2.77 +/- 1.31 hours after the onset of symptoms. Using standard clinical criteria, 86.7% (n = 26) of the patients reperfused initially. Two, however, reoccluded within the first 48 hours, and their clinical symptoms of myocardial infarction reappeared. By clinical observation 80% (n = 24) of the patients reperfused, and myocardial salvage was observed. Twenty-four patients with clinical reperfusion and one additional patient had patency of the affected artery, yielding a reperfusion rate of 83.3% (n = 25) as judged by angiography within one week of AMI. Both patients who had reoccluded clinically also were found to be occluded on angiography. Clinical and angiographic methods yield very similar results for the judgment of reperfusion (80% vs 83%, respectively, with no significant difference, P not significant). The results of our study tend to confirm the efficacy of IV streptokinase as a valuable management tool for early myocardial infarction.     

A simple benchmark for evaluating quality of care of patients following acute myocardial infarction

OBJECTIVE—To develop a simple risk model as a basis for evaluating care of patients admitted with acute myocardial infarction.
METHODS—From coronary care registers, biochemistry records and hospital management systems, 2153 consecutive patients with confirmed acute myocardial infarction were identified. With 30 day all cause mortality as the end point, a multivariable logistic regression model of risk was constructed and validated in independent patient cohorts. The areas under receiver operating characteristic curves were calculated as an assessment of sensitivity and specificity. The model was reapplied to a number of commonly studied subgroups for further assessment of robustness.
RESULTS—A three variable model was developed based on age, heart rate, and systolic blood pressure on admission. This produced an individual probability of death by 30 days (P₃₀) where P₃₀ = 1/(1 + exp(−L₃₀)) and L₃₀ = −5.624 + (0.085 × age) + (0.014 × heart rate) − (0.022 × systolic blood pressure). The areas under the receiver operating characteristic curves for the reference and test cohorts were 0.79 (95% CI 0.76 to 0.82) and 0.76 (95% CI 0.72 to 0.79), respectively. To aid application of the model to routine clinical audit, a normogram relating observed mortality and sample size to the likelihood of a significant deviation from the expected 30 day mortality rate was constructed.
CONCLUSIONS—This risk model is simple, reproducible, and permits quality of care of acute myocardial infarction patients to be reliably evaluated both within and between centres.


Keywords: acute myocardial infarction; risk model     

Transient hyperglycemia in patients with acute myocardial infarction: time to define optimal glucose levels

Although hyperglycemia during acute myocardial infarction (AMI) is associated with worse short and long-term cardiovascular outcomes, whether control of glycemia is sufficient to reduce morbidity and mortality is not proven at the present time. On the other hand, the target glucose levels in patients with AMI have yet to be defined. We believe that future major outcome studies will clearly define optimal glucose concentrations in patients with AMI.     

冠状动脉前降支心肌桥致急性心肌梗死一例

<正>1病例资料患者男性,47岁。主因"间断胸痛12 d"入院。患者入院前12 d,于夜间睡眠中突发胸痛,位于心前区,手掌大小范围,无放射痛,持续不缓解。5 h后于当地医院就诊,诊断"急性前壁心肌梗死",负荷剂量阿司匹林及氯吡格雷口服,并予"尿激酶150万U"溶栓。此后,患者于日常体力活动时仍间断出现胸痛,位于心前区,手掌大小范围,无放射痛,每     

Multislice MR perfusion imaging and regional myocardial function analysis: complimentary findings in chronic myocardial ischemia

Purpose: The purpose of this study is to assess the reliability of multislice MR perfusion imaging in comparison to regional wall function and nuclear medicine and to test different qualitative and quantitative parameters for perfusion assessment. Material and methods: 15 patients with chronic myocardial ischemia underwent CINE and first-pass perfusion MR imaging. Functional myocardial imaging was performed using a segmented CINE FLASH sequence and systolic myocardial wall thickening was assessed after semiautomated segmentation. MR first-pass perfusion studies were performed using a multislice saturation recovery TurboFLASH sequence. Different parameters were calculated for assessment of hypoperfused segments and results of MR imaging compared to ^99mTc-SestaMIBI SPECT. Results: MR perfusion imaging showed a sensitivity of 72% and a specificity of 98%. In combination with MR CINE imaging and wall thickening analysis we calculated a sensitivity of 100% and a specificity of 93%. Qualitative and quantitative perfusion parameter analysis showed significant differences between normal and hypoperfused segments for the signal intensity increase (p < 0.001), the signal intensity upslope (p < 0.001) as well as for the myocardial mean transit time (p < 0.001). Conclusion: The combination of systolic wall thickening analysis and myocardial perfusion can markedly improve the sensitivity of MRI in depiction of LV myocardial perfusion abnormalities. For assessment of hypoperfusion, different quantitative and qualitative parameters can be calculated showing significant differences between normal state and hypoperfusion.     

Silent myocardial ischemia: prognostic significance and therapeutic implications

Evidence is now accumulating which strongly suggests that prognosis of patients with painless myocardial ischemia determined either by ambulatory ECG monitoring or exercise testing may be no different than the prognosis of patients who have overt clinical manifestations of myocardial ischemia associated with transient ischemic ECG changes. In my view the goal of therapy for patients with clinical manifestations of coronary artery disease should be the elimination of myocardial ischemia. Medical therapy, coronary angioplasty, or coronary artery surgery should be rendered and then followed by objective documentation of therapeutic efficacy.     

急性心肌梗死患者经皮冠状动脉介入治疗术后心肌灌注水平对心肌存活性的影响

目的:应用TIMI心肌灌注分级(TMP)分析急性心肌梗死(AMI)患者行经皮冠状动脉介入治疗(PCI)后心肌灌注状况对心肌存活性的影响。方法:所有使梗死相关动脉(IRA)达到TIMI3级血流的AMI患者,根据PCI后即刻冠状动脉造影的TMP分级评价的心肌灌注状况,分为A组(TMP为2～3级,57例),B组(TMP为0～1级,31例)。运用静息及含服硝酸甘油介入99mTc-MIBI心肌灌注断层显像(MPI)来评价2组的存活心肌并于12周再次行静息99mTc-MIBI心肌灌注断层显像(MPI)评价存活心肌的恢复情况。结果:术后1周心肌存活面积A组高于B组[(5.43±4.89):(4.12±4.15),P<0.05],术后12周A组心肌缺损面积改善程度较B组明显[A组由(26.54±12.71)降至(17.86±11.59),P<0.05),B组由(39.37±16.31)降至(37.19±10.79),P>0.05]。结论:AMI患者行PCI术后心肌组织灌注TMP分级2～3级,可提高存活心肌的数量,心肌恢复较快。     

HbA_1c检测在急性心肌梗死患者中的临床意义

目的 研究HbA_1c检测在急性心肌梗死患者中的临床意义. 方法 对96例急性心肌梗死住院患者进行HbA_1c、心肌酶学、心电图、血脂等检测. 结果 有相当人数的急性心肌梗死患者HbA_1c水平升高. 结论 在急性心肌梗死伴空腹高血糖患者中检测HbA_1c对于鉴别应激高血糖和糖尿病具有重要价值.     

经皮穿刺球囊封堵冠脉建立犬急性心肌梗死模型的实验研究

目的:探讨应用PTCA球囊封堵冠状动脉犬急性心肌梗死动物模型的实验方法。方法:选用杂种犬20只,麻醉后经股动脉置入PTCA球囊至左前降支（LAD）和左旋支（LCX）,封堵血流90min。结果:2只因指引导管致前降支闭塞发生心室纤颤死亡,2只因球囊封堵前降支近端约30min后发生心室纤颤死亡,4只在球囊拔除后发生心室纤颤死亡,1只封堵左旋支中段犬在心肌梗死后20h死亡。其余11只动物成功建立急性心肌梗死模型。前降支封堵术后1周,行超声心动图检查出现室间上部及前壁局部运动异常,室壁也变薄。结论:运用PTCA球囊封堵冠状动脉成功建立急性心肌梗死动物模型,可为研究提供较好的实验模型。     

高氧液对家兔心肌缺血再灌注损伤的保护作用

目的 :观察高氧液对家兔心肌缺血再灌注损伤的保护作用。方法 :结扎兔冠状动脉左室支中段 ,40 min后解除结扎行再灌注 ,制成心肌急性缺血再灌注模型。于缺血前 10 min、再灌注前 10 m in,分别静滴平衡盐液、高氧平衡盐液 ,观察在急性缺血及再灌注状态下心电图、血浆肌酸磷酸激酶 （CK）、丙二醛 （MDA）和超氧化物岐化酶 （SOD）的变化。结果 :高氧平衡盐液能使抬高的心电图 S- T段明显下降 ,缺血再灌注心肌 CK活性明显降低 ;并能保护SOD的活性 ,降低脂质过氧化反应代谢产物 MDA的含量。结论 :高氧平衡盐液对家兔在体心肌缺血再灌注损伤具有明显的保护作用。     

Myocardial contrast echocardiography in acute myocardial infarction: Pathophysiological background and clinical applications

Myocardial contrast echocardiography is a technique used inexperimental and clinical settings in order to visualize thepattern of intramyocardial perfusion. In the acute phase ofmyocardial infarction, regional absence of flow during myocardialcontrast echocardiography delineates the area at risk of necrosis,while the definitive non-perfused area expresses infarct size.Reopening the infarct-related artery, which may be achievedspontaneously by thrombolysis or percutaneous transluminal coronaryangioplasty, is not a reliable indicator of intramyocardialreperfusion. If myocardial ischaemia due to coronary occlusionhas been sufficiently prolonged and severe, not only myocyteviability, but also microvascular integrity is lost. Myocardialcontrast echocardiography, using intracoronary injection ofsonicated contrast medium, gives information about microvascularintegrity and the effective presence of intramyocardial reflow.Anatomical integrity of microvasculature does not necessarilyimply preserved function, and thus the microvessel vasodilatingreserve may also be impaired. Myocardial contrast echocardiographyhas the potential to assess alterations in microvascular function,showing, in the myocardial area with reduced coronary reserve,a relatively reduced increase in echocontrast signal intensitywhen an intravenous vasodilator agent is administered. (Eur Heart J 1996; 17: 344–353)     

Age-related changes in treatment strategies for acute myocardial infarction: a population-based study

OBJECTIVES: To compare across four age groups (<65, 65-74, 75-84, > or =85) the determinants of coronary reperfusion therapy (CRT) use in ST-segment elevation acute myocardial infarction (STE-AMI). DESIGN: Population-based, observational study. SETTING: Performed in the health district of Florence, Italy, where percutaneous coronary intervention (PCI) is the preferred CRT. PARTICIPANTS: Nine hundred thirty patients with STE-AMI prospectively enrolled in the Florence AMI registry. MEASUREMENTS: Use of CRT, clinical factors associated with CRT use. RESULTS: CRT use was reduced from 71% at younger than 65 to 31% at aged 85 and older (P<.001). After adjusting for chronic comorbidity, Killip class, admission hospital category, hospitalization delay, and AMI location, CRT use was 29% (P=.17) lower at age 75 to 84 and 63% (P<.001) lower at age 85 and older than at younger than 65. Within each age group, the probability of receiving CRT was three to five times greater in patients directly admitted to the hospital with PCI facilities. Acute cardiac failure and chronic comorbidity were associated with lower CRT use only in patients aged 65 and older. Patients aged less than 85 years who received reperfusive therapy had a significantly lower risk of death (-44%, P=.045) at 1 year, whereas it was less evident and nonsignificant (-27%, P=.27) in patients aged 85 and older. CONCLUSION: Results confirm that, although they might substantially benefit from CRT during STE-AMI, older patients are excluded from CRT even when eligible. This further indicates that clinicians are not yet completely prepared to manage most efficiently frail elderly with AMI, a task requiring a specific interdisciplinary training program in geriatric cardiology.