ST-segment elevation: Distinguishing ST elevation myocardial infarction from ST elevation secondary to nonischemic etiologies

The benefits of early perfusion in ST elevation myocardial infarctions(STEMI) are established; howeverearly perfusion of non-ST elevation myocardial infarctions has not been shown to be beneficial. In additionST elevation(STE) caused by conditions other thanacute ischemia is common. Non-ischemic STE may beconfused as STEMI, but can also mask STEMI on electrocardiogram(ECG). As a result, activating the primarypercutaneous coronary intervention(pPCI) protocooften depends on determining which ST elevation patterns reflect transmural infarction due to acute coronary artery thrombosis. Coordination of interpreting theECG in its clinical context and appropriately activatingthe pPCI protocol has proved a difficult task in borderline cases. But its importance cannot be ignored, asreflected in the 2013 American College of CardiologyFoundation/American Heart Association guidelines concerning the treatment of ST elevation myocardial infarction. Multiples strategies have been tested and studiedand are currently being further perfected. No mattethe strategy, at the heart of delivering the best care lies rapid and accurate interpretation of the ECG. Here, we present the different patterns of non-ischemic STE and methods of distinguishing between them. In writing this paper, we hope for quicker and better stratification of patients with STE on ECG, which will lead to be bet-ter outcomes.     

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ST段抬高型心肌梗死（STEMI）患者治疗后抬高的ST段下降的幅度，评价溶栓治疗过程中ST段改变对STEMI患者心功能的预测价值。方法105例急性STEMI患者，入院后行溶栓治疗，并计算溶栓后2h内ST段抬高总和的下降幅度。结果溶栓治疗2h后，ST段抬高振幅总和较溶栓治疗前下降大于50％时，病人自觉胸痛症状消失，心功能得到较好的保护。而ST段抬高振幅总和较治疗前小于50％时，患者心功能不同程度受损。结论急性STEMI患者经早期溶栓治疗后，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。     

急性下壁心肌梗死患者心电图胸前导联ST段改变的临床意义

目的探讨急性下壁心肌梗死患者心电图胸前导联ST段改变与冠状动脉造影(CAG)所见冠状动脉病变部位的关系及其临床意义。方法 187例急性下壁心肌梗死患者,按入院时18导心电图胸前导联ST段改变分为3组,ST段无变化组(47例),ST段抬高组(16例),ST段压低组(124例);所有患者均行CAG。结果急性下壁心肌梗死伴胸前导联ST段抬高时多为右冠状动脉(RCA)近段闭塞(14例,82.3%),尤其是伴圆锥支动脉闭塞,与RCA中远端闭塞(2例,5.9%)比较差异有统计学意义(P0.01),且14例(73.7%)伴有右心功能不全和血流动力学障碍。下壁心肌梗死胸前导联ST段压低者可见于RCA、回旋支(LCX)闭塞及RCA、LCX闭塞与前降支(LAD)、对角支(D)病变的不同组合,其中LCX闭塞伴RCA病变者多表现为朐前ST V_4～V_6的压低,RCA闭塞伴LAD近端病变多有胸前ST V_1～V_6的压低,RCA伴D病变胸前ST V_1～V_3压低,与对照组比较差异有统计学意义(P0.05)。结论急性下壁心肌梗死合并胸前导联ST段抬高表明为RCA近段或丌口闭塞且多伴右心室心肌梗死和心功能不全;下壁心肌梗死伴胸前导联ST段压低提示为多支病变,ST V_1～V_3压低多伴有对角支严重狭窄,STV_1～V_6压低多伴有前降支的严重狭窄。     

墓碑样ST段抬高的急性心肌梗死的再分析

目的探讨急性心肌梗死（AMI）墓碑形”段抬高的临床意义。方法根据临床资料将28例心电图呈“墓碑样”改变的AMI患者作为观察组（A组）,选取心电图ST段呈常态改变的AMI患者43例作为对照组（B组）。将两组患者的临床资料进行分析并作统计学处理。结果病变多发于前降支,除天门冬氨酸转氨酶（AST）、乳酸脱氢酶（LDH）外,心源性休克、AMI后心绞痛、严重心律失常、心力衰竭、≥3个并发症及病死率、肌酸激酶（CK）、肌酸激酶同功酶（CK—MB）A组与B组相比,差异有统计学意义（P〈0．01）。结论ST段呈墓碑样改变的AMI患者近期预后较凶险。     

入院24 h平均血糖对急性ST段抬高型心肌梗死患者近期预后的影响

目的 探讨人院24 h平均血糖(mean blood glucose,MBG)与急性ST段抬高型心肌梗死(STEMI)患者近期病死率及不良心血管事件的相关性.比较MBG与入院血糖(admission glucose,AG)对顶后影响的顶测价值.方法 人选病例来自2001至2004年间我国274家中心参加CREATE(Clinical trial of reviparin and metabolic modulation in acute myocardial infarction treatment evaluation)研究数据库、症状出现12 h内STEMI的中国患者7446例,将入院即刻、6 h、24 h血糖值计箅均值,以入院第1个24 h的MBG水平分成6组,即MBG＜4.5 mmol/L组、4.5～5.5 mmol/L组、5.6～7.0 mmol/L组、7.1～8.5 mmol/L组、8.6～11.0 mmol/L组和MBG＞11.0 mmol/L组.以MBG 4.5～5.5 mmol/L组作为对照组,其他血糖水平组与之进行比较.分析7 d和30 d病死率及联合终点事件发生情况.比较MBG与AG对上述事件预测价值的影响.结果 单因素分析显示,7 d、30 d病死率、联合终点事件发生率随着MBG水平升高而逐渐升高.MBG 7.1～8.5 mmol/L及以上组与MBG 4.5～5.5 mmol/L组的患者比较,差异均有统计学意义.多因素logistic回归分析显示MBG 7.1～8.5 mmol/L及以上各组是STEMI患者7 d、30 d病死率、联合终点事件的独立危险因素.MBG 7.1～8.5 mmol/L、8.6～11.0 mmol/L和＞11.0 mmol/L的患者7 d死亡危险分别比对照组患者增加56%(P=0.022)、61%(P=0.018)和230%(P＜0.001),30 d死亡危险分别比对照组患者增加41%(P=0.048)、40%(P=0.032)和185%(P＜0.001).MBG＜4.5 mmol/L组30 d联合终点事件发生危险无明显增加(P=0.085).应用Nested模型对AG及24 h MBG对病死率以及联合终点事件预测模型比较显示,24 hMBG较AG预测价值更大(均P＜0.001).结论 24 h MBG≥7.1 mmol/L与STEMI患者7 d、30 d病死率增高相关.24 h MBG较AG对预后具有更好的预测价值.     

心电图ST段抬高形态与急性心肌梗死预后的关系

在急性心肌梗死 (AMI)发病过程中 ,患者心电图 (ECG)呈现不同形态的 ST段抬高 (STE)。为探讨不同形态 STE与 AMI预后的关系。选择 AMI患者 2 39例 ,观察其 STE的变化规律及幅度 (以 TP段为基线 ,以QRS波群起点后 16 0 ms处为测量点 )。结果显示 ,就诊早者 STE多呈下弧形 ,继之呈现上斜形、上弧形的变化规律 ;就诊晚者多表现为上斜形或上弧形 STE。下弧形 STE持续时间为 2～ 8.5小时 ;上斜形持续时间为 7～ 32小时 ;上弧形持续时间均在 2 4小时以上。发病 6小时后就诊者 ,79.5 %见不到下弧形 STE,其病死率 (15 .4 % )显著高于发病 6小时内就诊者 (80 %表现为下弧形 STE,其病死率为 6 % )。心肌酶 CK峰值与 STE幅度存在显著相关性 (P均 <0 .0 1) ,但与 STE形态无关。提示 AMI时 STE形态呈下弧形 -上斜形 -上弧形的变化规律。下弧形抬高提示损伤早期 ,上斜形抬高为损伤中期 ,上弧形抬高为损伤晚期。可以根据 STE的不同形态来估计 AMI的发生时间 ,判断预后。建议以 QRS起点后 16 0～ 180 ms作为 ST段偏移的测定点     

急性高血糖对ST段抬高性心肌梗死院内预后的影响

目的探讨急性高血糖对ST段抬高性心肌梗死（STEMI）患者院内预后的影响。方法连续人选356例北京地区17家三级和二级医院所有在24h内人院且符合STEMI诊断标准的患者。以入院血糖水平〉11mmol／L判定为高血糖,分为高血糖组和血糖正常组,观察两组患者院内死亡和心血管病事件的发生情况。院内心血管事件定义为院内再发心肌梗死、新发生的心力衰竭、严重心律失常及卒中。结果356例STEMI患者中,存在急性高血糖患者共81例（22．8％）。其院内病死率较无急性高血糖患者显著增加（13．6％比5．1％,P=0．009）,院内心血管事件发生率亦显著增多（32．1％比20．4％,P=0．027）。logistic回归分析示,人院急性高血糖（OR1．615,95％CI1．116～2．338,P=0．011）为STEMI患者院内不良预后的独立危险因素。结论STEMI急性高血糖患者院内死亡及发生院内心血管事件的危险性显著高于人院血糖正常者。人院高血糖为STEMI患者院内不良预后的独立危险因素。     

急性心肌梗死墓碑形ST段抬高的临床意义

目的探讨急性心肌梗死（acute myocardial infarction，AMI）墓碑形ST段抬高的临床意义。方法将86例AMI患者以ST段抬高的特征分为两组，墓碑形抬高组36例、其他形抬高组50例。观察两组的一般临床资料（年龄、有否合并糖尿病），并比较两组AMI的发生部位、PCI前心梗后心绞痛、并发症及死亡的发生率、首次CK值、各项心电指标及PCI后心肌缺血再灌注损伤的发生率。结果两组各项临床指标及心电图指标差异均有统计学意义；墓碑形ST段抬高组PCI后心肌缺血再灌注损伤的发生率亦明显高于其他形ST段抬高组。结论墓碑形ST段抬高患者梗死部位特殊而广泛、并发症多、死亡率高、易出现心肌缺血再灌注损伤，对此类患者应高度重视并积极预防心肌缺血再灌注损伤的发生。     

ST changes and temporal relation to the J point during heart rate increase and myocardial ischemia

There is no concensus concerning where in the ST segment to measure. We studied the relation between different J point intervals to ST results during tachycardia and ischemia.Symptomatic (anesthetized) patients with coronary artery disease were paced at ascending incremental levels until they became ischemic. ST vector magnitude and ST vector change from baseline (STC-VM) as well as the sum of ST changes from all 12 electrocardiogram (ECG) leads (ECG ST sum) were measured at J point 0 millisecond, J + 20, J + 60, and J + 80 milliseconds for 34 patients.ST segments increased in similar fashion during pacing and ischemia. There was no difference in ST results when measurement was performed at different time intervals for both STC-VM and ECG ST sum.We conclude that ST assessment by ST change from baseline is not affected by different J point intervals during increased heart rate and ischemia in this clinical model of pacing-induced ischemia and vectorcardiographic ST analysis.     

急性心肌梗死溶栓治疗后ST段改变对预后的评估

目的:探讨急性心肌梗死(AMI)溶栓后60、90和180 min心电图sT段下降50％对早期临床预后的价值。方法:将95例AMI患者在溶栓后60、90和180 min记录的心电图分为ST段下降≥50％组和ST段下降<50％组,比较不同时期两组间36 d的心脏性死亡率和功能。结果:在每个研究时间与溶栓前基础心电图的ST段抬高最大导联比较,ST段下降<50％组较ST段下降≥50％组,心脏性死亡率和射血分数降低差异有显著性意义(P<0.01),且这一关系随梗死部位不同有变化。下壁梗死只有60 min心电图可预测心脏性死亡(P<0.05)。前壁梗死只有溶栓后60和90 min心电图ST段下降<50％组较ST段下降≥50％组左心功能明显下降(P<0.05)。结论:用心电图监测AMI溶栓后ST段的变化,是一种预测早期临床预后和检出高危患者简便而可靠的方法。AMI溶栓后60 min心电图预测临床预后似乎比90和180 min心电图更好。     

The stability of myocardial area at risk estimated electrocardiographically in patients with ST elevation myocardial infarction

In patients with ST-elevation myocardial infarction (STEMI) the amount of myocardial area at risk (MaR) indicates the maximal potential loss of myocardium if the coronary artery remains occluded. During the time course of infarct evolution ischemic MaR is replaced by necrosis, which results in a decrease in ST segment elevation and QRS complex distortion. Recently it has been shown that combining the electrocardiographic (ECG) Aldrich ST and Selvester QRS scores result in a more accurate estimate of MaR than using either method alone. Therefore, we hypothesized that the combined Aldrich and Selvester score, indicating MaR, is stable until myocardial reperfusion therapy.     

急性心肌梗死时心电图不同形态ST段抬高的机制和意义

目的 :探讨急性心肌梗死时心电图不同形态 ST段抬高的机制和意义。方法 :结扎家兔冠状动脉的不同分支制造急性心肌梗死模型。结果 :ST段抬高的形态随心肌缺血时间的延长而呈“下弧形—上斜形—上弧形”的规律性变化。结论 :ST段抬高的不同形态反映心肌损伤的不同时相 ,下弧形抬高提示心肌缺血的早期 ,上弧形抬高提示心肌损伤的晚期 ,上斜形抬高介于二者之间。     

Vectorcardiographic ST deviations related to increased heart rate in the absence of ischemia in an experimental pig model

The electrocardiographic ST segment may change when heart rate (HR) increases. We aimed to analyze vectorcardiographic ST relation and myocardial conditions during controlled HR increases in anesthetized pigs. The relative parameters ST change vector magnitude and ST change vector angle were calculated at paced HRs ranging from 85 to 175 beats per minute. ST change vector magnitude increased from baseline 6.3 +/- 1.3 to 26.0 +/- 3.1 microV (P < .01; range, 4-50 microV) at HR 175 beats per minute with similar changes in ST change vector angle, whereas the absolute parameter ST vector magnitude demonstrated a heterogeneous pattern without any systematic relation to HR changes. Microdialysis results from left ventricular wall, with analysis of glucose, lactate, and pyruvate, showed no sign of ischemia during pacing. Potassium concentrations did not change during pacing. We conclude that significant HR-related ST vector changes can occur in the absence of myocardial ischemia.     

Smartphone ECG for evaluation of ST-segment elevation myocardial infarction (STEMI): Design of the ST LEUIS International Multicenter Study

In patients experiencing an ST-elevation myocardial infarction (STEMI), rapid diagnosis and immediate access to reperfusion therapy leads to optimal clinical outcomes. The rate-limiting step in STEMI diagnosis is the availability and performance of a 12–lead ECG. Recent technology has provided access to a reliable means of obtaining an ECG reading through a smartphone application (app) that works with an attachment providing all 12–leads of a standard ECG system. The ST LEUIS study was designed to validate the smartphone ECG app and its ability to accurately assess the presence or absence of STEMI in patients presenting with chest pain compared with the gold standard 12–lead ECG. We aimed to support the diagnostic utility of smartphone technology to provide a timely diagnosis and treatment of STEMI. The study will take place over 12 months at five institutions. Approximately 60 patients will be enrolled per institution, for a total recruitment of 300 patients.     

入院血糖水平对ST抬高急性心肌梗死预后的影响

目的 探讨入院时血糖水平对ST段抬高急性心肌梗死(STEMI)患者30 d死亡和主要心血管不良事件(MACE)发生率的预测价值.方法 对7446例12 h内STEMI患者以入院时不旧的血糖水平和有否糖尿病史分成4组(高血糖定为入院血糖>10 mmol/L),Ⅰ组:无糖尿病史且血糖正常组(对照组);Ⅱ组:有糖尿病史但血糖正常组;Ⅲ组:无糖尿病史但高血糖组;Ⅳ组:有糖尿病史且高血糖组.结果 入院高血糖两组患者30 d病死率和MACE的发生率明显高于对照组(病死率Ⅰ组8.6%比Ⅲ组17.1%、组Ⅳ18.6%;MACE Ⅰ组21.6%比Ⅲ组36.3%、Ⅳ组38.8%;P值均<0.001).Ⅱ组与对照组相比,30 d病死率没有明显增加(11.6%比8.6%,P=0.096).多因素回归分析显示Ⅲ、Ⅳ组的死亡危险分别为Ⅰ组患者的1.51倍(P<0.001)和1.83倍(P<0.1301);入院血糖水平是30 d死亡的独立危险因素,血糖水平每升高1 mmol/L,病死率增加5%(OR 1.05,95%CI1.04～1.07,P<0.001),而糖尿病史对30 d病死率不具有独立预测价值(OR 1.11,95%CI 0.87～1.42,P=0.412).结论 入院高血糖STEMI患者30 d病死率和MACE的发生率显著高于入院血糖正常者,入院高血糖为近期预后不良的独立危险因素,糖尿病史与近期病死率并无明显相关性.     

The relationship of ST segment elevation shape with preserved myocardium and signal-averaged electrocardiography in acute anterior myocardial infarction

Although a relation between magnitude of ST segment elevation and myocardial damage has been shown in the early period of acute myocardial infarction (AMI), such a relation between the shape of the ST segment elevation, myocardial damage, and the clinical course remains obscure. For this purpose 62 first anterior AMI patients admitted in the first 6 h were enrolled for the study. On the basis of precordial V3 derivation prior to thrombolytic therapy, the shape of the ST elevation was separated into three groups: concave (n = 26), straight (n = 24), or convex types (n = 12). The relation between the shape of the ST elevation recorded on admission, and the results of predischarge low-dose dobutamine stress echocardiography (LDE) performed (n = 53) and signal-averaged ECG values were investigated. The basal wall motion score index (WMSI) and response to LDE in the concave group were better in the infarct zone. Additionally, the average akinetic segment number in the infarct zone was higher, and improvement in these segments was less in the convex and straight groups (concave 3.78 ± 2 vs 2.17 ± 2.1, P < 0.01; straight 5.15 ± 2.7 vs 4.45 ± 2.8, not significant (NS); convex 5.4 ± 2.3 vs 4.8 ± 2.1, NS; basal vs LDE). While only 13% (3/23) of the patients did not respond to LDE (P < 0.05 vs group B and P < 0.01 vs group C), 35% (7/20) of group B and 60% (6/10) of group C patients did not respond to LDE. Although no relation was found between better left ventricular function (WMSI < 2) and shape of the ST elevation in basal evaluation by multiple logistic regression analysis (P = 0.06), an independent relation was found between them following LDE (P = 0.01, odds ratio (OR) 4.5, 95% Confidence Interval (CI) 1.3–14.7). The incidence of ventricular late potential (LP) positivity was 11% (3/26) in the concave group, 16% (4/24) in the straight group, and 58% (7/12) in the convex group (P < 0.001 vs concave and P < 0.05 vs straight groups). We found that shape of the ST elevation could significantly predict the presence of late potentials in multiple logistic regression analysis (P = 0.003, OR 10.7, 95% CI 2.2–51.7). There was no in-hospital death in the concave group, whereas five patients died in either the straight or the convex group. Furthermore, arrhythmia was lower in the concave group during this period (P < 0.05), and exercise capacity was lower. In conclusion, we determined that there was a higher viable myocardium, and lower LP(positivity) and in-hospital mortality in patients with concave ST elevation on admission. Received: August 6, 2001 / Accepted: December 18, 2001     

ST段抬高急性心肌梗死患者心电图对应导联ST段改变不同类型的临床预后

目的探讨ST段抬高急性心肌梗死（STEMI）患者心电图（ECG）对应导联ST段改变（R-ST-D）不同类型与罪犯冠状动脉病变及临床预后的关系。方法选择住院初发STEMI资料完整967例,根据R-ST-D振幅分4种类型,即R-ST-D振幅无下移（I组）143例;R-ST-D下移振幅小于或等于梗死区ST段抬高振幅（1I组）664例;R-ST-D下移振幅大于梗死区ST段抬高振幅（Ⅲ组）93例;R-ST-D和梗死区ST段均抬高（IV组）67例;分析其ECGR-ST-D4种类型与罪犯冠状动脉病变和临床高危预后的关系。结果R-ST-D4种类型中I组、Ⅱ组、Ⅲ组发生率分别为14．8％,68．7％,9．6％,并以前降支为主单支病变多见。Ⅳ组发生率6．9％,主要累及复合前壁,前降支,回旋支及右冠状动脉。泵衰竭、低血压、严重心律失常、AMI扩展、室壁运动失调、左室射血分数≤50％及住院病死率分别为71．6％,41．8％,61．2％,34．3％,100．0％,40．3％和16．4％（P〈0．05或P〈0．01）。结论STEMI患者ECGR．ST-D不同类型对罪犯冠状动脉病变和临床近期预后具有预测作用。     

急性ST段抬高性心肌梗死直接经皮穿刺冠状动脉成形术后早期ST段变化的意义

目的探讨急性ST段抬高性心肌梗死(STEMI)直接经皮穿刺冠状动脉成形术(PCI)术后梗死相关动脉(IRA)完全开通、前向血流恢复后,早期ST段变化的临床意义。方法回顾性分析2001-01~12北京朝阳医院心脏中心收治的216例直接PCI后、IRA完全开通、前向血流恢复正常病人的临床、冠脉造影和心电图资料。直接PCI术后,ST段抬高指数≥50%的病人41例,为病例组。从其余175例ST段抬高指数<50%的病人中随机抽取50例,为对照组。结果两组病人的ST段抬高指数、Q波计数、室壁运动积分和平均肌酸激酶值差异有显著性意义(P<0·05);术后2周,ST段早期恢复较ST段持续抬高病人的室壁运动改善,左室射血分数(LVEF)、心排指数(CI)、每搏指数(SVI)增加(P<0·05)。ST段早期恢复合并心功能不全的病人,术后2周室壁运动增强,LVEF、CI、SVI增加(P<0·05),左室舒张末容积、左室收缩末容积减少(P<0·01)。结论STEMI直接PCI后IRA完全开通、前向血流恢复正常而ST段持续抬高病人的梗死范围扩大,左室舒缩功能不全严重,可能与心肌组织没有有效地恢复血流灌注或无复流有关。     

平均空腹血糖对ST段抬高型心肌梗死患者住院预后的影响

目的 评价平均空腹血糖对ST段抬高型心肌梗死(STEMI)患者住院顶后的影响.方法 对357例发病3 d内入院的无糖尿病史的STEMI患者进行回顾性分析,依据入院后72 h内平均空腹血糖水平分为＜5.6、5.6～7.0和＞7.0 mmol/L 三组.比较其临床特征、住院治疗经过和主要心脏事件及死亡的发生率,通过受试者工作特征(ROC)曲线评估平均空腹血糖对住院死亡的预测价值.结果 平均空腹血糖＜5.6、5.6～7.0和＞7.0 mmol/L的三组患者分别为165、122和70例,其广泛前壁心肌梗死的比例分别占18.2%、29.5%和45.7%(P＜0.05.各组患者在年龄、既往梗死史及溶栓或经皮冠状动脉介入治疗等差异无统计学意义(P＞0.05).入院时心率、白细胞计数、CK-MB峰值随着平均空腹血糖升高而增加(P＜0.05).随着血糖升高,左心室射血分数降低,心力衰竭、恶性心律失常发生率及住院病死率明显增加(P＜0.05).多因素分析显示入院72 h内平均空腹血糖是住院病死率的独立危险因素(OR=1.31,95%CI:1.10～1.57;P=0.003),其顶测住院死亡ROC曲线下面积为0.758(P＜0.001),而单次入院随机血糖、空腹血糖预测住院死亡的ROC曲线下面积分别为0.674和0.717.结论 入院72 h内平均空腹血糖是STEMI住院患者死亡的独立危险因素,其预测价值高于单次的入院随机血糖或空腹血糖.