Biochemical markers in the management of suspected acute myocardial infarction in the emergency department

Objectives—To compare cardiac troponin T, myoglobin, CK, CKMB activity, CKMB mass and the initial electrocardiogram in the early diagnosis of myocardial infarction in the emergency department.

Methods—Biochemical markers were measured at presentation in patients with a possible diagnosis of acute myocardial infarction. Based on the clinical notes, patients were grouped as "definite myocardial infarction" (n = 50), "definite no myocardial infarction" (n = 81) and "uncertain" (n = 96). Sensitivity and specificity and positive and negative predictive values were calculated using the 131 patients with definitely present or absent myocardial infarction.

Results—The initial electrocardiogram was more sensitive than any of the markers in the first six hours from symptom onset—sensitivity 74% (95%CI 61% to 88%). The positive predictive value of the initial electrocardiogram was 97% in the first six hours; the markers ranged from 47% to 67%. The negative predictive value of the initial electrocardiogram was 85% in the first six hours; the markers ranged from 61% to 70%. Four patients with non-diagnostic electrocardiograms presenting beyond six hours after pain onset had a myocardial infarct detected by at least three of the biochemical markers in each case.

Conclusions—The electrocardiogram is of more diagnostic use than biochemical markers in the first six hours after the onset of pain, but biochemical markers give additional positive diagnostic information in patients presenting later than this. The negative predictive accuracy of biochemical markers is too low for a single sample to be useful for excluding myocardial infarction in the first six hours after onset of symptoms.

     

超声心动图诊断急性心肌梗死及其并发症的价值

目的评价超声心动图在急性心肌梗死及其并发症诊断中的应用价值。方法分析本院62例住院急性心肌梗死发病2周内患者的超声心动图特征，并将超声心动图与心电图对心肌梗死部位的判断结果进行比较，并注意观察有无急性心肌梗死并发症发生。结果超声心动图与心电图对心肌梗死部位及范围的判断基本相符。62例急性心肌梗死患者的超声心动图图像显示心肌梗死征象57例，并发症23例（室壁瘤11例，左室附壁血栓2例，室间隔穿孔3例，中、重度二尖瓣反流7例）。结论超声心动图可及时发现急性心肌梗死时心脏的一些特征性的形态和功能变化，检查方法简单准确，可与心电图相互印证与补充。     

Changes in the ratio of lactate dehydrogenase isoenzymes 1 and 2 during the first day after acute myocardial infarction

It is known that the ratio of isoenzyme 1 to total lactate dehydrogenase (LD, EC 1.1.1.27) in serum is increased in all patients with acute myocardial infarction within 24 h of the infarct. We now show that the LD-1/LD-2 ratio for serum more promptly indicates acute myocardial infarction, being for most patients equivalent to measurement of creatine kinase (EC 2.7.3.2) isoenzyme 2 (CK-2, CK-MB) in serum. Of 128 patients with a confirmed diagnosis of myocardial infarction, 66 had normal values for all "cardiac" enzymes at the time of admission, but greater than 75% of them showed a parallel increase in values for CK-2 and the LD-1/LD-2 ratio. Of the 26 patients who had one or more abnormal values for cardiac enzymes on admission, 95% showed a parallel increase in CK-2 and the LD-1/LD-2 ratio, the median time for the beginning of these changes being 9 h from the onset of chest pain. The remaining 36 patients were excluded from the study because CK-2 decreased after admission or because the time of onset of chest pain was uncertain.     

急诊经皮冠状动脉介入术不同时间窗对心肌梗死后心肌瘢痕与心脏功能的影响

目的 观察急诊经皮冠状动脉介入术(PCI)不同时间窗对心肌梗死后心肌瘢痕与心脏功能的影响.方法 对急性心肌梗死(AMI)患者不同时间窗行急诊PCI治疗127例,其中发病3 h急诊PCI组(3 h PCI组)66例,发病6 h急诊PCI组(6 hPCI组)61例.于发病后4、8、12周,应用同步十二导联心电图观察碎裂QRS波(fQRS)、心脏超声斑点追踪成像(STI)观察室壁运动应变比率及心脏超声测定左室射血分数(LVEF).结果 发病后4、8、12周3 h PCI组fQRS阳性导联个数较6 h PCI组明显降低[129个与167个、81个与106个、37个与65个(x2=3.25,5.38,6.13,P均＜0.01)].3 h PCJ组其室壁运动应变改善幅度,LVEF提高的程度,均优于6 h PCI组(P均＜0.05).结论 联合应用fQRS、STI及LVEF评价心肌梗死后心肌瘢痕与心脏功能,优势互补,可明显提高临床诊断心肌瘢痕的阳性预测值,以减少心肌瘢痕形成,保护心脏功能.     

Clinical assessment of specific enzyme immunoassay for the human cardiac myosin light chain II (MLC II) with use of monoclonal antibodies

A highly specific enzyme-linked "sandwich" immunoassay was developed for determining cardiac myosin light chain II (MLC II) in serum by using an anticardiac MLC II monoclonal antibody and a solid phase consisting of glass rods coated with another monoclonal antibody. We can detect as little as 0.2 ng of cardiac MLC II per assay. The measurable range of cardiac MLC II concentration in serum is 1 to 30 micrograms/L. The assay demonstrated no cross-reactivity with a skeletal muscle MLC within the measurable range. The mean coefficients of variation were 6.1% within assay and 5.1% between assay. The concentration of cardiac MLC II in sera from healthy subjects ranged from 0 to 4.0 micrograms/L (mean 0.75 micrograms/L and median 0 micrograms/L). The concentrations of cardiac MLC II in serum of patients with skeletal muscle disease due to various causes (n = 15) and patients with effort angina (n = 25), in general, were not significantly elevated above normal. In all patients with myocardial infarction, the concentrations of cardiac MLC II were over 4.0 micrograms/L at 12 h after onset. The mean (+/- 1 SD) peak concentration of cardiac MLC II was 16.2 (+/- 4.4) micrograms/L at 90 h (mean) after onset. On the 5th day, the cardiac MLC II concentrations in all patients with myocardial infarction were significantly elevated above normal; none showed abnormal MB-creatine kinase (CK-MB) activity at this time. Thus, the measurement of cardiac MLC II concentration in serum may be useful to provide a specific and sensitive diagnosis of myocardial necrosis at any time period following myocardial infarction.     

急性下壁梗死发生房室传导阻滞的时间与预后关系

目的观察急性下壁心梗时，心电图检查和希氏束检查房室传导阻滞发生的时间和对预后的影响。方法患者24例，分为：(1)单纯下壁组；(2)下壁后壁或右室组；(3)下壁合并前、侧壁组。均行心电图及希氏束电图检查。结果三组房室传导阻滞发生率相似，多数房室传导阻滞在急性心肌梗死起病后12h内出现(81．8％)。阿托品和异丙肾上腺素治疗14例，AVB都有不同程度的改善，预后良好。结论急性下壁与合并其他部位心梗的AVB发病率相似，大部分出现时间为12h以内，多数AVB未用起搏治疗获得良好预后。     

Dynamics of blood fibronectin level in myocardial infarction

The fibronectin level in the blood of patients with myocardial infarction was measured at varying times from the onset of an angina pectoris attack in order to elucidate the diagnostic importance of blood fibronectin. At the same time these patients were examined over time for the blood content of myoglobin, MB creatine kinase protein and C-reactive protein playing a well-known role in the diagnosis. The blood concentrations of these substances reached the maximal values at different times of myocardial infarction. The mean concentrations of fibronectin in the blood of patients with myocardial infarction ranged within normal starting from the first till the 28th day since the onset of an angina pectoris attack. Moreover, the mean blood fibronectin level in myocardial infarction patients did not differ within the first-third days since the disease onset from that in patients with a clinical picture of unstable angina pectoris which was not accompanied by the development of myocardial infarction. Based on the data obtained it is concluded that measurement of blood fibronectin level does not play any diagnostic role in myocardial infarction. On the other hand, progressive increase in blood fibronectin level throughout 4 weeks starting from the 3d day of the disease and a significantly higher fibronectin content on the 28th day as compared with that on the 3d day is likely to mirror the activity of repair processes occurring in the myocardium.     

Re-evaluation of the diagnostic utility of serum total creatine kinase and creatine kinase-2 in myocardial infarction

The diagnostic utility of total creatine kinase activity (I), creatine kinase-2 isoenzyme activity (II), and II as a percentage of I, was examined by receiver-operating characteristic curve and likelihood ratio (LR) analyses in 310 persons admitted to the Coronary Care Unit (151 proven cases of myocardial infarction and 159 non-myocardial infarction controls), from whom blood was sampled at 6-h intervals for 48 h after the onset of chest pain. I was ineffective either as a "rule-in" or as a "rule-out" test within the first 6 h of the onset of chest pain; thereafter, it was an effective test. II was the most effective test during the entire 48-h period. III was more effective than I in the first 24-h period, but was less effective than I during the next 24-h period. The decision threshold for high test sensitivities varies with time over the entire 48-h period, but remains constant for high test specificities. It is essential to tabulate the LR(+) and LR(-) values for both test sensitivity and specificity at constant values to determine the utility of each test at each time interval for respectively ruling out or ruling in a diagnosis of myocardial infarction.     

心脏型脂肪酸结合蛋白对早期急性心肌梗死的诊断价值

目的：探讨心脏型脂肪酸结合蛋白在早期急性心肌梗死中的诊断价值。方法收集因“胸痛、胸闷3 h 以内”就诊,拟诊为急性心肌梗死患者186例,检测所有入选者的血浆肌酸磷酸激酶同工酶（CK-MB）、肌钙蛋白-I（CTn-I）和心脏型脂肪酸结合蛋白（H-FABP）。比较3种指标对早期急性心肌梗死诊断的敏感性和特异性。结果与非心肌梗死组和对照组相比,急性心肌梗死组患者血浆 CK-MB、CTn-I 及 H-FABP 明显升高（P ＜0．05）;与 CK-MB 和 CTn-I 相比,H-FABP 对3 h 以内的急性心肌梗死诊断的敏感性较高,而特异性则低于 CTn-I,但高于 CK-MB。结论对于发病3 h 内的急性心肌梗死患者,检测 H-FABP 可以在一定程度上提高对早期急性心肌梗死的诊断率。     

组织谐波成像在急性心肌梗死诊断中的应用--与冠状动脉造影对照研究

目的 探讨组织谐波成像(THI)技术在急性心肌梗死诊断中的应用价值。方法 分析经THI及冠状动脉造影检查的101例急性心肌梗死患者的临床资料。结果 图像满意和较满意率达96．0％。THI对急性心肌梗死检出率为91．1％。THI与心电图估测心肌梗死部位及范围基本一致。THI估测心肌梗死部位与冠状动脉造影所示梗死相关动脉供血区域基本相符(准确率87．1％)，其中以检出左前降支病变所致心肌梗死的准确率最高(96．8％)；下壁、后壁或右室梗死常合并其他部位心肌梗死，较易漏诊。结论 THI是检测急性心肌梗死敏感而准确的方法，可与心电图相互印证、相互补充。检查中应特别注意有无合并下壁、后壁或右室梗死，以免漏诊。     

Serum galactosylhydroxylysyl glucosyltransferase in acute myocardial infarction and during subsequent collagen scar formation

Changes in serum galactosylhydroxylysyl glucosyltransferase, an enzyme catalysing one of the intracellular post-translational modifications in collagen biosynthesis, were studied in twenty-four patients with acute myocardial infarction. The enzyme activity was monitored for 18 days from the onset of infarction, and at least a two-peaked pattern was observed. The first peak corresponded to the stage of acute myocardial injury, there being a highly significant correlation between the maximal values for serum glucosyltransferase and alpha-hydroxybutyrate dehydrogenase. An average decreasing in serum glucosyltransferase activity of 41%, was noted during the following 24 h. A new gradual rise in serum glucosyltransferase activity, interpreted as indicating myocardial collagen scar formation, was observed 5 days after the onset of infarction, when the serum enzyme activities indicating myocardial injury had already declined. The average daily values for serum glucosyltransferase between 6 and 18 days correlated highly significantly with the maximal value for serum alpha-hydroxybutyrate dehydrogenase, which serves as a relative estimate of the size of the original myocardial infarction area. The data further suggest that certain other factors including heart failure and/or various drug treatments may also affect the magnitude of this second peak.     

炎性因子和白细胞在心肌梗死急性发作期与稳定期的变化及其意义

目的探讨白介素6（interleukin-6,IL-6）、超敏C反应蛋白（high-sensitivity C-reactive protein,hsCRP）和白细胞（white blood cell,WBC）在急性心肌梗死的发作期和稳定期的水平和意义。方法测定55例心肌梗死患者急性发作期血液中IL-6、hsCRP、WBC和血脂的水平,并与健康对照组进行比较。根据血清胆固醇的含量将患者分为高中低三组,分别统计各组中IL-6、hsCRP和WBC的含量。对54例病情好转患者在稳定期第30d检测IL-6、hsCRP和WBC的水平,并与健康对照组进行比较。结果心肌梗死患者急性发作期IL-6、hsCRP和WBC含量明显高于对照组（P〈0.01）。不同水平的胆固醇组中上述炎性因子无统计学差异。在急性心肌梗死稳定期除了IL-6高于对照组外（P〈0.05）,hsCRP和WBC与健康对照组比较无统计学意义。结论在心肌梗死的急性发作期,炎症反应是高血脂外的一个独立发病因素,炎性因子IL-6、hsCRP和WBC的含量与冠状动脉的病变程度密切相关,在心肌梗死的稳定期以血管壁的局部炎症为主,此时IL-6是适宜的炎症标记物。     

急性心肌梗死病人就医院前延误状况及其影响因素

[目的]了解急性心肌梗死病人就医院前延误情况,分析影响病人就医延误的因素。[方法]采用问卷调查法,对急性心肌梗死病人的就医延误状况和影响因素进行调查与分析。[结果]病人就医院前延误中位时间为2.26h,在发病1h、2h、6h内就医者分别为20.7%、39.6%、75.0%;影响延误的因素包括:将症状归因于心脏和症状加剧促使病人及早就医;而非ST段抬高心肌梗死、凌晨发病、在家中或外出时发病以及现有吸烟史使病人就医延误。[结论]急性心肌梗死病人就医延误状况不容忽视。影响延误的因素涉及认知-行为、临床特点和环境因素。     

急性心肌梗死并糖尿病患者窦性心率震荡的临床观察

目的:观察糖尿病对急性心肌梗死(AMI)病人窦性心率震荡(HRT)的影响。方法:将2004年1月~2006年1月收治的56例急性AMI病人按是否合并糖尿病分为两组,合并糖尿病组26例,无糖尿病组30例,另入选30例正常对照组。三组病人入院1周内行24小时动态心电图(Holter)检查,计算HRT的两个参数震荡初始(TO)和震荡斜率(TS),并进行统计学分析。结果:与正常对照组比较,急性AMI合并糖尿病组和无糖尿病组心率震荡现象均减弱,存在统计学差异(P<0.05);合并糖尿病组和无糖尿病组比较,心率震荡现象无统计学差异。结论:急性AMI病人窦性心率震荡现象较非冠心病人群减弱,是否合并糖尿病对急性AMI病人的窦性心率震荡似乎无明显影响。     

The initial electrocardiogram in patients seen by a mobile coronary care unit

The advent of thrombolytic therapy for patients with suspected acute myocardial infarction has highlighted the importance of the initial electrocardiogram (ECG) in decision making. Thus we analysed the initial ECGs of 94 consecutive cases with suspected myocardial infarction who were seen within six hours after the onset of chest pain by a mobile coronary care unit. The study included 91 patients (three patients admitted twice) (61 male), aged 27-83 years (mean 60.5). Median time from onset of chest pain to arrival of the mobile coronary care unit was 75 minutes (range 15-345), and mean mobile coronary care unit response time was 12.3 +/- 7 (SD) minutes (range 5-45). The majority of cases (65 of 94, 69.1 per cent) were seen within two hours of the onset of symptoms. A final diagnosis of myocardial infarction was made in 48 of 94 (51.1 per cent) cases; 38 had unstable angina and eight other diagnoses. Of the 48 with myocardial infarction the initial ECG showed ST segment elevation in 37, ST depression and or T wave inversion in six, Q waves only in three and left bundle branch block in two. No patient with an initially normal ECG had a myocardial infarction. Thrombolytic therapy was given out of hospital to 33 of 38 patients with ST segment elevation. In seven patients with ST elevation (median delay time to intensive care 60 minutes), rapid resolution of ST segment elevation occurred following thrombolytic therapy and there was no significant elevation of cardiac enzymes, suggesting that the infarct had been aborted.(ABSTRACT TRUNCATED AT 250 WORDS)     

急性心肌梗死患者1个月内预后的临床相关因素分析

[目的]明确影响急性心肌梗死预后的独立危险因素.[方法]纳入2006年6月到2011年6月期间在广元市中心医院出院和死亡病历中诊断为急性心肌梗死的408例患者的病历资料,设计调查量表及资料提取表格.根据资料中急性心肌梗死患者发病后1个月内的死亡情况,将患者资料分为已死亡患者组和未死亡患者组进行对比分析,明确年龄、血压、血脂等是否为影响急性心肌梗死预后的独立危险因素.[结果]年龄增加、血压升高、血糖增加、血脂升高、曾有脑卒中事件可增加急性心肌梗死患者的病死率,而心肌酶及血红蛋白含量降低也有同等效应.[结论]通过回归分析可知,血压、年龄、甘油三脂、胆固醇、吸烟是影响急性心肌梗死患者入院后1个月内死亡的重要独立预测因素,其中年龄因素最为重要.     

The esterification of cholesterol in plasma after acute myocardial infarction.

The rate of plasma cholesterol esterification (LCAT activity) and the concentration of eight proteins in the plasma have been studied in the ten male patients during the course of acute myocardial infarction. Samples were drawn 22 hr, 3 days, 8 days, 2 weeks, and 7 weeks after the onset of the acute myocardial infarction. The changes of the plasma proteins were typical for the acute-phase reaction. LCAT activity decreased initially during the illness. The lowest values were found after 8 days. Concomitantly, a reducation in the plasma concentration of total and free cholesterol and cholesteryl esters was demonstrated. The rate of cholesterol esterification correlated significantly with the concentration of prealbumin, alpha-lipoprotein, and albumin. Seven weeks after onset of the infarction, the LCAT values were equal to those in a reference group. The results suggest that the synthesis of LCAT was decreased during the acute-phase reaction.     

Factors associated with prehospital delay in patients with ST-segment elevation acute myocardial infarction in China

Background

Prehospital delay is the most critical factor to prognosis of ST-elevation myocardial infarction (STEMI). Few study had examined a series of predictors of prehospital delay by multivariate analysis of sociodemographic and clinical characteristics, onset features, and symptom condition of STEMI in China.

Methods

A total of 1088 hospitalized STEMI participants were screened to collect sociodemographic data, medical history information, and symptom onset status from clinical medical records. Factors associated with prehospital delay were examined using bivariate and multivariate analysis method.

Results

The median prehospital delay time (PDT) was 130 minutes in STEMI participants. Multivariate regression models examining 8 predictors were associated with prehospital delay, including senior high school or above educational level, myocardial infarction (MI) history, vertigo onset symptom, ambulance transportation, onset in daytime (6:00-18:00), onset at home, anterior wall MI, and posterior wall MI. Mortality in PDT more than 120 minutes group was 5.5%, whereas it was 4.3% in PDT 120 minutes of less group without significant statistically difference (P > .05).

Conclusions

Multivariate analysis results found that symptom onset–related variables strongly influenced PDT. Onset-related status of STEMI needed to be combined into interventions of participants, and more emergency education should be recommended to both participants and their relatives. Most importantly, more efforts should be taken to educate the public about the symptoms and signs to increase the recognition of STEMI.     

老年血清胱抑素C水平与急性心肌梗死相关性研究

目的 观察70岁以上老年心肌梗死急性期血清胱抑素C(cystatin C,CysC)水平,探讨急性心肌梗死后CysC水平变化的意义.方法 顺序入选2010年7月- 2011年7月期间70岁以上急性心肌梗死患者58例及正常对照58例.入选对象均经冠状动脉造影检查确诊或排除诊断,记录急性心肌梗死患者梗死部位和梗死相关血管,...     

Adenosine myocardial perfusion single photon emission computed tomographic stress testing 24-72 h after uncomplicated myocardial infarction

Safety of performing adenosine myocardial perfusion stress testing as early as 24 h after acute uncomplicated myocardial infarction is not known. We evaluated 31 (14 females and 17 males, average age 72, range 46–89 years) consecutive patients with uncomplicated myocardial infarction, who underwent adenosine myocardial perfusion stress imaging, 24–72 h after infarction for risk stratification. Adenosine was infused at a rate of 140 g/kg/min for 6 min. Twenty patients were presented with non-ST-elevation myocardial infarction. Eleven patients were admitted with acute ST-elevation myocardial infarction. Patients were monitored for signs of complication during and immediately after the stress test. The average time from admission to performance of stress tests was 51 ± 19 h, ranging from the minimum of 24 h to maximum 72 h. No complications related to adenosine infusion were detected. In conclusion, our data suggest that a further large study of early adenosine myocardial perfusion SPECT imaging may be safe in a carefully selected group of patients after uncomplicated myocardial infarction.