心电图预测急性下壁心肌梗死相关冠脉的研究

目的探讨心电图对急性下壁心肌梗死相关冠脉的预测价值。方法根据冠状动脉造影证实的梗死相关冠脉结果,将153例急性下壁心肌梗死患者分为两组:右冠状动脉(RCA)闭塞组106例,回旋支(LCX)闭塞组47例。对两组患者心电图不同导联典型心肌梗死图形的发生率及ST-T改变发生率进行分析。结果RCA组STaVL↓>STl↓①、STIII↑>STII↑②、①+②、STaVF+V2>0的发生率均明显高于LCX组(x2=14.23,29.86,p<0.01),敏感性分别为75.8%、87.2%、70.9%、84.8%,特异性分别为83.9%、85.1%、100%、100%。LCX组①②两项均不具备、STaVF+V2<0的发生率明显高于RCA组(x2=42.43,49.26,p<0.01),敏感性分别为83.7%和94.0%,特异性均为100%。结论心电图STaVL↓>STl↓①、STIII↑>STII↑②、①+②、STaVF+Ⅴ2>0与①②两项均不具备、STaVF+V2<0对判断急性下壁心肌梗死的梗死相关动脉是RCA或LCX和闭塞位置有高度特异性,有重要的预测价值。     

血清促红细胞生成素水平与急性心肌梗死患者梗死面积有关

目的观察血清促红细胞生成素（EPO）水平与急性心肌梗死（AMI）直接经皮冠状动脉介入（PCI）治疗后梗死面积的关系。方法初次急性ST段抬高型心肌梗死86例,在发病12 h内成功地接受了PCI的患者测定血清EPO和肌酸肌酶（CK）,并计算其CK累积释放量。以EPO中间值（19.6 U/L）分为高EPO组[（39±17）U/L]和低EPO组[（14±4）U/L],对两组CK累计释放量进行比较,并对CK累积释放量的可能影响因素做多元逐步回归分析。结果CK累积释放量在血清高EPO组明显低于低EPO组[（1 150±226）μkat/（L.h）vs（1 740±210）μkat/（L.h）,P<0.05)]。多元逐步回归分析显示,血清EPO水平、PCI术后TIMI血流等级和梗死前心绞痛是CK累积释放量的独立预测因子。结论内源性EPO水平高者AMI成功地直接PCI术后梗死面积较少,两者呈负相关。     

Beta blocker prescribing differences in patients with and without diabetes following a first myocardial infarction.

AIMS: To document the prescribed usage of beta blockers in patients with and without diabetes mellitus discharged from hospital following a first myocardial infarction. METHODS: All patients with diabetes and a group of patients matched for age and sex without diabetes, admitted with a documented first myocardial infarction during the period 1995-1999 at the Royal Liverpool University Hospital, Liverpool, UK were audited. RESULTS: Data were available on 201 patients with diabetes and 199 patients without diabetes. No significant differences existed between the diabetic and non-diabetic groups for age and sex. Twenty-three per cent of patients with diabetes were prescribed a beta blocker compared to 52% of non-diabetic patients (P < 0.01). Patients with diabetes had a higher frequency of perceived contraindications than patients without diabetes (36 vs. 27%, P < 0.001). Thirty-five per cent of patients with diabetes and 18% of non-diabetic patients had no contraindication to the use of beta blocker but were not prescribed one (P < 0.001). CONCLUSIONS: Although beta blockers can provide useful benefits in patients with diabetes following a myocardial infarction, this study suggests that a significant proportion of patients with diabetes and without a contraindication to treatment are still not receiving beta blockers after myocardial infarction.     

心电图在诊断急性心肌梗死相关动脉中的价值

目的分析急性心肌梗死患者不同梗死部位心电图表现及梗死相关动脉的分布特点,评价心电图诊断梗死相关动脉的价值。方法对132例急性心肌梗死患者心电图和冠状动脉造影资料进行回顾性比较分析。结果心电图显示心肌梗死发生率以心脏下壁、前间壁和广泛前壁最高,分别为31例(23.5%)、26例(19.7%)和22例(16.7%);造影显示梗死相关动脉的发生率分别为左主干(LM)3例(2.3%)、前降支(LAD)73例(55.3%)、回旋支(LCX)18例(13.6%)、右冠状动脉(RCA)38例(28.8%);前壁心肌梗死(55例)的梗死相关动脉多为LAD(51例,92.7%),下壁心肌梗死(31例)的梗死相关动脉多为RCA(22例,71.0%)或LCX(7例,22.6%),且与冠状动脉优势类型密切相关,前壁梗死合并aVR、aVL导联ST段抬高对诊断LAD近段闭塞的特异性较高,分别为86.7%和90.0%。结论急性心肌梗死心电图表现与梗死相关动脉存在明显相关性,有较高的临床诊断价值。     

Usefulness of the 12-lead electrocardiogram in detection of myocardial infarction: Electrocardiographic-anatomic correlations—Part II

Part II of this two-part series on electrocardiographic-necropsy correlation of infarct location focuses on lateral and posterior (“inferior”) infarctions. The value of infarct location regarding complications and prognosis is also discussed.     

Risk stratification according to the initial electrocardiogram in patients with suspected acute myocardial infarction

Previously developed initial electrocardiogram (ECG) prediction rules were modified to stratify 426 patients with suspected acute myocardial infarction into low-, intermediate-, and high-risk groups (normal, abnormal, and positive ECG categories) for development of acute myocardial infarction and complications of coronary ischemia. Compared with patients with normal ECGs, patients with positive ECGs had a 2.9 times greater risk of interventions, a greater risk of life-threatening complications, and a 14.2 times greater risk of acute myocardial infarction. Compared with patients with abnormal ECGs, patients with positive ECGs had a 1.7 times greater risk of interventions, a 2.6 times greater risk of life-threatening complications, and a 4.9 times greater risk of acute myocardial infarction. This prediction scheme was further improved by assigning "high" risk to any patient requiring an acute intervention during the initial evaluation in the emergency department. Otherwise, risk was assigned according to the ECG category, with normal, abnormal, and positive ECGs corresponding to "low," "intermediate," and high risk, respectively. Hospitals with limited intensive care beds may be able to use these prediction rules as an aid in determining in-hospital disposition of patients with suspected acute myocardial infarction.     

Effect of labetalol on indices of myocardial necrosis in patients with suspected acute infarction

The role of combined alpha and beta blockade as a means of limitinginfarct size has been studied in a randomised controlled trialusing labetalol. Only 166 of 630 (26%) consecutive patientsadmitted to a cardiac care unit with suspected myocardial infarctionwere deemed suitable for inclusion; most of the remainder haddelayed admission to hospital, were over the age limit of 75,or had complications which precluded the use of labetalol. Thoseon active treatment received a loading dose followed by a slowintravenous infusion over six hours, and oral therapy for thesubsequent five days. Doses were adjusted to maintain systolicpressure in the range 100 to 120 mmHg. The control group receivedonly conventional therapy. Labetalol caused lowering of theblood pressure and heart rate during the phase of intravenoustreatment, but little effect occurred subsequently because oraldosage was constrained by low systolic pressures. The groupthat received active treatment had significantly greater releaseof CKMB enzyme. Little difference was observed in R wave scoresor ejection fraction. Only low doses of labetalol can be usedfor most patients with acute myocardial infarction. Labetalolcannot be recommended as routine treatment for normotensivepatients admitted to hospital with suspected infarction.     

老年人急性心肌梗死近期转归分析

目的探讨老年急性心肌梗死（ＡＭＩ）患者近期转归的影响因素，为降低病死率提供理论依据。方法连续住院的３０５例首次ＡＭＩ老年患者，男１４６例，女１５９例，对比分析其临床基础情况、梗死表现、治疗及临床经过、住院病死率及死亡原因，并对影响转归的变量进行多元回归分析。结果老年女性并存高血压和糖尿病的百分率较男性高（分别为５６％对２９％，３３％对１８％），男性吸烟者较女性多（４０％对２％），差异均有显著性（均为Ｐ＜０．０１）。老年女性的心力衰竭、休克、机械并发症和住院病死率均高于男性（均为Ｐ＜０．０５）。然而，多元回归分析显示，性别并不是住院死亡的独立危险因子（ＯＲ，０．７３；９５％ＣＩ，０．２５～２．２３），而心功能Ｋｉｌｉｐ分级（ＯＲ，６．８２；９５％ＣＩ，２．５０～１８．９１）、机械并发症（ＯＲ，５３．１８；９５％ＣＩ，１１．５６～４０１．３０）、肌酸激酶（ＣＰＫ）峰值（ＯＲ，１．６９；９５％ＣＩ，１．１８～２．４７）等可能有重要预后价值。结论老年ＡＭＩ患者死亡危险性增加与心脏本身的危险因子有关，而性别无重要影响。     

Prognostic importance of previous myocardial infarction in patients receiving thrombolytic therapy for acute infarction

This study evaluated the prognostic significance of reinfarction location by considering the previous site or type of myocardial infarction (MI) among 1601 patients with a history of previous MI who took part in the International (non-Italian) tPA/STK trial and/or the Israeli GUSTO study population. These patients were accordingly divided and hospital mortality was compared by six location groups as follows: acute inferior with previous inferior (8.1% hospital mortality), acute inferior with previous anterior (12.8%), acute anterior with previous inferior (13.3%), acute anterior with previous anterior (11.1%), acute inferior with previous non-Q-wave MI (7.6%), and acute anterior with previous non-Q-wave MI (11.2%) (p = 0.17 for comparison between the six groups). Hospital mortality tended to increase among patients with an anterior reinfarction compared with those with an inferior one (12.1% vs. 9.5%, p = 0.12). Among patients with a reinfarction at a different ECG location from the previous event, mortality tended to be higher compared with patients with two MIs at the same location (13.1% vs. 9.7%, p = 0.07). Recurrent MI following a previous Q-wave MI did not cause a higher mortality compared with a previous non-Q-wave type of MI (11.5% vs. 9.5%, p = 0.24). Among patients sustaining reinfarction, overall mortality did not differ between STK- and tPA-treated patients (11.0% vs. 11.4%, p = NS). In conclusion, the current study identified trends for higher mortality rates in patients with anterior compared with inferior reinfarction, with remote compared with the same ECG location of the two infarctions but not following a previous non-Q-wave compared with Q-wave MI. However, no particular combination of successive MIs location was significantly associated with a higher risk for hospital mortality.     

Characteristics and outcome of patients with acute myocardial infarction according to presenting electrocardiogram (from the MONICA/KORA Augsburg Myocardial Infarction--Registry)

Acute myocardial infarctions (AMIs) are categorized according to presenting electrocardiography into ST-elevation (STE), non-STE, and bundle branch block AMIs. Data on the characteristics and risks of these categories originate mainly from voluntary registries or clinical trials and may be hampered by selection and information bias. This study evaluated these different categories, with the additional differentiation of non-STE AMIs into ST-depression (STD) AMIs and those with nonspecific electrocardiographic signs (no-ST) in an unselected cohort. From 1985 to 2004, all consecutive patients aged 25 to 74 years who were hospitalized with AMI at the study region's major clinic were registered prospectively. A total of 6,748 patients were identified, of whom 45.8% had STE, 14.0% STD, 32.4% no-ST, and 7.8% bundle branch block AMIs, respectively. There were substantial differences in medical history, presentation, and therapy among the AMI types. Even after adjusting for the latter factors, the odds ratios of 28-day case fatality compared with no-ST were 1.26 (95% confidence interval 1.01 to 1.59) for STE, 1.84 (95% confidence interval 1.39 to 2.44) for STD, and 3.18 (95% confidence interval 2.37 to 4.27) for bundle branch block. In conclusion, after considering in-hospital therapy, the difference between STE and no-ST was nonsignificant, whereas the case-fatality difference between no-ST and STD persisted, suggesting some other unknown underlying factors associated with STD.     

心电图在急性下壁心肌梗死相关动脉判定中的意义

目的 :探讨应用心电图判断急性下壁心肌梗死患者梗死相关动脉 （IRA）的可行性与准确性 .方法 :回顾性分析 36例首次急性下壁心肌梗死患者的入院心电图与冠状动脉造影资料 .结果 :急性下壁心肌梗死患者多有右冠状动脉 （RCA）病变 （88.6 % ） ,多数 （6 6 .7% ）患者有两支以上病变。IRA的分布也是 RCA多于左旋支 （L CX） ,分别占 86 .1%和 13.9%。对心电图指标 （ST ,STa VL,STV1 或 V2 ,STV2 + a VF,STV2 + ,STV5 或 V6 ,ST / ）与 IRA关系的统计分析表明 ,前五组未出现显著差异。STV5 或 V6 在 RCA组多为下降 ,L CX组多为抬高而无 1例下降 （P<0 .0 5 ） ;但排除 RCA和 L CX皆有显著病变的病例后 P>0 .0 5。 ST / 在 RCA组绝大多数小于 1而 L CX组多大于 1（P<0 .0 1） ;排除 RCA和 L CX皆有显著病变的病例后仍然 P<0 .0 1。结论 :ST / 比值是判断急性下壁心肌梗死患者IRA的较准确的心电图指标。     

Effects of propranolol, atenolol, and chlordesmethyldiazepam on response to mental stress in patients with recent myocardial infarction

Stress testing was carried out by two stressors, mental arithmetic and Sacks-Levy's test in randomized sequence, in 64 male patients with a mean age of 51 +/- 7 years in NYHA Classes I or II within 3 months after acute myocardial infarction. The stress profile was obtained after drug withdrawal by continuous recording of electrocardiogram, frontal electromyogram, and peripheral skin temperature and conductance. Blood pressure was measured each minute by cuff. The patients were subdivided into 4 groups of 16 each and were studied in an identical fashion after a 48-h oral treatment with propranolol 120 mg daily, atenolol 100 mg daily, chlordesmethyldiazepam 2 mg daily, or placebo. During stress, signs of myocardial ischemia or pump failure were not observed; minor arrhythmias were recorded. Cardiovascular activation was observed with significant increments (p less than 0.001) in heart rate, systolic and diastolic blood pressures in all 4 groups for both stressors with a slightly greater effect of mental arithmetic; Sacks' test was more effective on the frontal electromyograph response. Following beta blockade the stress profile of heart rate was significantly lower and flattened. The stress profile of blood pressure was also lower, but the reduction in the increment during stress was not significant. No differences were observed in the effects of the two beta blockers; no significant changes were evident in the stress profile of the noncardiovascular psychophysiologic indexes. Stress profiles were not altered by the benzodiazepine. In conclusion beta-blocker agents seem to be more useful than anxiolytic drugs in preventing cardiovascular activation induced by mental stress in patients with recent myocardial infarction.     

Early assessment of infarct size and prediction of functional recovery by quantitative myocardial blush grade in patients with acute coronary syndromes treated according to current guidelines

Purpose : To determine whether quantification of myocardial blush grade (MBG) during cardiac catheterization can aid the determination of follow‐up left ventricular (LV)‐function in patients with ST‐elevation and non‐ST‐elevation myocardial infarction (STEMI and NSTEMI). Methods : We prospectively examined patients with first STEMI (n = 46) and NSTEMI (n = 49). ECG‐gated angiographic series were used to quantify MBG by analyzing the time course of contrast agent intensity rise. Hereby, the parameter G_max/T_max was calculated, derived from the plateau of grey‐level intensity (G_max), divided by the time‐to‐peak intensity (T_max). Cardiac magnetic resonance imaging (CMR) deemed as the standard reference for the estimation of infarct size, transmurality and of the LV‐function at 6 months of follow‐up. Results : Cut‐off values of G_max/T_max=5.7/sec and 3.8/sec, respectively, yielded similar accuracy as infarct transmurality for the prediction of follow‐up ejection fraction >55% (AUC = 0.86 for STEMI and AUC = 0.90 for NSTEMI, by G_max/T_max and AUC = 0.85 for STEMI and AUC = 0.89 for NSTEMI, by infarct transmurality, respectively, P = NS). Both clearly surpassed the predictive value of visual MBG (AUC = 0.69 for STEMI and AUC = 0.68 for NSTEMI, P < 0.05). Conclusion : G_max/T_max is an easy to acquire but highly valuable surrogate parameter for infarct size, which yields equally high accuracy with infarct transmurality and favorably compares with visually assessed blush grades for the prediction of follow‐up LV‐function in patients with acute ischemic syndromes. © 2010 Wiley‐Liss, Inc.     

ST段抬高型急性心肌梗死溶栓后心电图改变的临床意义

目的通过分析急性心肌梗死抬高的ST段下降幅度,评价溶栓治疗过程中ST段改变对患者心功能的预测价值。方法96例ST段抬高型急性心肌梗死患者,入院后行溶栓治疗,并计算溶栓后2h内ST段抬高振幅总和(ΣSTE)的下降幅度。结果溶栓治疗2h后,ΣSTE较溶栓治疗前下降大于50%时,病人自觉胸痛症状消失,心功能得到较好保护。而ΣSTE较治疗前下降小于50%时,患者心功能不同程度受损。结论ST段抬高型急性心肌梗死的患者经早期溶栓治疗后,其抬高的ST段下降幅度可作为心肌血供能否恢复的间接预测指标,从而能较准确地反映心肌再灌注情况及预测心功能状态。     

The impact of time to thrombolytic treatment on outcome in patients with acute myocardial infarction. For the CORE investigators (Collaborative Organisation for RheothRx Evaluation)

OBJECTIVES—To examine the impact of time to thrombolytic treatment on multiple acute outcome variables in a single trial of thrombolysis in acute myocardial infarction.
DESIGN AND PATIENTS—Mortality and reinfarction rate were measured in 2770 patients with acute myocardial infarction who received thrombolysis within 12 hours in CORE, an international, dose ranging trial of poloxamer 188. Tc-99m sestamibi infarct size and radionuclide angiographic ejection fraction substudies included 1099 and 1074 patients, respectively.
RESULTS—Time to thrombolysis, subgrouped by intervals (< 2, 2-4,  4-6, and  6 hours), was significantly associated with infarct size (median 15.0%, 18.5%, 22.0%, 18.5% of left ventricle; p = 0.033), mean (SD) ejection fraction (51.5 (12.0)%, 48.3 (13.9)%, 48.2 (13.3)%, 48.2 (15.0)%; p = 0.006), 35 day mortality (5.7%, 7.1%, 7.9%, 12.5%; p = 0.0004), six month mortality (7.3%, 8.6%, 10.4%, 15.5%; p < 0.0001), and 35 day reinfarction rate (6.1%, 3.2%, 4.0%, 0.9%; p = 0.0001).
CONCLUSIONS—In this single large trial, the beneficial effect of time to thrombolysis on infarct size and ejection fraction was restricted to treatment given within two hours of symptom onset, while the effect on mortality was evident over all time intervals. Reinfarction rate was higher in patients treated with earlier thrombolysis.


Keywords: myocardial infarction; thrombolysis; infarct size     

根据心电图异常特征对急性心肌梗死患者进行危险判定及预后分析

目的探讨急性心肌梗死患者的心电图异常特征,对急性心肌梗死进行危险判定及预后分析。方法回顾性分析381例急性心肌梗死患者住院期间的临床及心电图资料,对有无多导联病理性Q波、多导联ST段抬高、心房颤动和束支传导阻滞等10项异常心电图指标合并心源性休克、心力衰竭及病死率进行比较分析。结果有多导联病理性Q波患者较无异常患者心源性休克(58.1%vs 21.4%)、心力衰竭(54.3%vs 23.2%)和病死率(40.0%vs6.5%)明显升高(P<0.05),有多导联ST段抬高、心房颤动等8项异常指标较无异常患者的心源性休克、心力衰竭和病死率明显升高(P<0.05,P<0.01)。仅有无二度以上房室传导阻滞的患者心源性休克、心力衰竭和病死率无明显差异(P>0.05)。结论多导联病理性Q波等异常心电图指标能够作为急性心肌梗死危险判定及预后依据。