Electrocardiographic differentiation between right coronary and left circumflex coronary arterial occlusion in isolated inferior wall myocardial infarction

The presence of atrioventricular block and ST segment elevation in lead V4R accurately predicts right coronary artery occlusion in patients with inferior wall myocardial infarction. However, these electrocardiographic signs are absent in the majority of patients with inferior myocardial infarction. We studied ST segment elevation in leads II and III, ST segment in lead I and T wave polarity in lead V4R in order to differentiate between right coronary artery and left circumflex coronary artery occlusions in 104 patients with inferior myocardial infarction who subsequently underwent coronary angiography. The ST segment elevation was greater in lead III than in lead II when the right coronary artery was the culprit vessel and vice versa when the left circumflex was the culprit vessel (p < 0.001). An upright T wave in lead V4R and ST segment depression in lead I was common when the right coronary artery was the culprit vessel and not seen with left circumflex occlusion (p < 0.001). ST segment elevation in lead III was higher than in lead II with a sensitivity of 99 percent and a specificity of 100 percent for diagnosing right coronary artery as the culprit vessel. ST segment elevation in lead II was higher than in lead III with a sensitivity of 93 percent and a specificity of 100 percent in identifying the left circumflex as the culprit vessel. Thus, these signs are very useful in identifying the culprit vessel in inferior myocardial infarction.     

246例回旋支不同节段闭塞的心电图特点

目的探讨回旋支闭塞中不同节段,不同优势型,多支病变对心电图变化的影响。方法本研究共入选246例发生急性LCX闭塞的患者（其中男187例,女59例）,根据冠脉造影结果将患者根据冠脉优势型、单支、多支、合并LAD、RCA分组,结合年龄、性别及相关危险因素,对比分析心电图改变与冠脉造影结果及临床特点的关系。结果回旋支闭塞心电图变化受不同冠脉优势型影响,Ⅱ、Ⅲ、aVF、V7~V9导联ST段抬高常见于左优势型的LCX闭塞。V1~V3导联ST段压低常见于均衡型的LCX闭塞,Ⅰ、aVL导联ST段抬高在各优势型中无特异性。在单支LCX闭塞中,V1~V3导联ST段压低常见于近段闭塞,Ⅱ、Ⅲ、aVF导联ST段抬高常见于远段闭塞,V7~V9导联ST段抬高与Ⅰ、aVL导联ST段抬高在各节段闭塞的心电图中无特异性。合并多支病变时LCX心电图变化与单纯LCX闭塞存在差异,在LCX近段闭塞中,合并多支病变的患者更易出现V7~V9导联ST段抬高,单支病变者心电图易出现V1~V3导联ST段压低,在LCX中段闭塞的患者中,单支病变与多支病变的心电图改变大致相同。在LCX远段闭塞的患者中,多支病变患者出现V1~V3导联ST段压低可能性较大。OM闭塞在单支及合并多支病变时的心电图差异无明显统计学意义。在合并LAD或RCA病变的LCX闭塞患者中,心电图改变无明显差异。结论心电图对诊断梗死相关动脉为回旋支的急性心肌梗死有重要的预测价值,结合病史及相关一般资料可对急性心肌梗死患者的预后进行评估。     

Electrocardiographic differentiation of occlusion of the left circumflex versus the right coronary artery as a cause of inferior acute myocardial infarction

To determine whether the admission electrocardiogram can identify left circumflex or right coronary artery occlusion as the cause of an inferior acute myocardial infarction (AMI), findings from electrocardiography and coronary angiography performed within 12 hours of each other were retrospectively assessed in 41 consecutive patients with inferior AMI. All patients had ST-segment elevation in 1 or more inferior leads (II, III or aVF). Of the 12 patients with circumflex coronary artery occlusion, 10 (83%) had ST-segment elevation in 1 or more lateral leads (aVL, V5 or V6) without ST-segment depression in lead I. Similar electrocardiographic findings were noted in only 1 of 29 patients (4%) with right coronary occlusion (p less than 0.001). ST-segment depression in precordial leads V1-V3 was equally prevalent in both groups. Thus, the presence of both ST-segment elevation in 2 or more inferior leads and ST-segment elevation in 1 or more lateral leads with an isoelectric or elevated ST segment in lead I identified circumflex coronary occlusion with a sensitivity of 83%, specificity of 96%, positive predictive accuracy of 91% and negative predictive accuracy of 93%. When these criteria were prospectively applied to an additional cohort of 19 consecutive patients with inferior AMI (5 with left circumflex and 14 with right coronary artery occlusion), presence of left circumflex coronary artery occlusion was predicted with a sensitivity of 80%, specificity of 93%, positive predictive accuracy of 100% and negative predictive accuracy of 93%. Thus, the admission 12-lead electrocardiogram can assist in differentiating left circumflex from right coronary artery occlusion in patients with inferior AMI.     

Value of the electrocardiogram in localizing the occlusion site in the left anterior descending coronary artery in acute anterior myocardial infarction.

OBJECTIVES: The study assessed the value of the electrocardiogram (ECG) as predictor of the left anterior descending coronary artery (LAD) occlusion site in relation to the first septal perforator (S1) and/or the first diagonal branch (D1) in patients with acute anterior myocardial infarction (AMI). BACKGROUND: In anterior AMI, determination of the exact site of LAD occlusion is important because the more proximal the occlusion the less favorable the prognosis. METHODS: One hundred patients with a first anterior AMI were included. The ECG showing the most pronounced ST-segment deviation before initiation of reperfusion therapy was evaluated and correlated with the exact LAD occlusion site as determined by coronary angiography. RESULTS: ST-elevation in lead aVR (ST elevation(aVR)), complete right bundle branch block, ST-depression in lead V5 (ST depression(V5)) and ST elevation(V1) > 2.5 mm strongly predicted LAD occlusion proximal to S1, whereas abnormal Q-waves in V4-6 were associated with occlusion distal to S1 (p = 0.000, p = 0.004, p = 0.009, p = 0.011 and p = 0.031 to 0.005, respectively). Abnormal Q-wave in lead aVL was associated with occlusion proximal to D1, whereas ST depression(aVL) was suggestive of occlusion distal to D1 (p = 0.002 and p = 0.022, respectively). For both the S1 and D1, inferior ST depression > or = 1.0 mm strongly predicted proximal LAD occlusion, whereas absence of inferior ST depression predicted distal occlusion (p < or = 0.002 and p < or = 0.020, respectively). CONCLUSIONS: In anterior AMI, the ECG is useful to predict the LAD occlusion site in relation to its major side branches.     

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     

Electrocardiographic localization of the occlusion site in left anterior descending coronary artery in acute anterior myocardial infarction

BACKGROUND: The site of occlusion of left anterior descending coronary artery is important in acute anterior myocardial infarction because, proximal occlusion is associated with less favorable outcome and prognosis. The present study attempted to evaluate the electrocardiographic correlate of the location of the site of the left anterior descending coronary artery occlusion with respect to first septal perforator and/or the first diagonal branch. METHODS AND RESULTS: The study included 50 patients with a first acute anterior myocardial infarction. The electrocardiogram with the most pronounced ST segment deviation before the start of reperfusion therapy was evaluated and correlated with the left anterior descending occlusion site as determined by coronary angiography. ST segment elevation in lead aVR, ST segment depression in lead V5 and ST segment elevation in V1>2.5 mm strongly predicted left anterior descending occlusion proximal to first septal, whereas abnormal Q wave in V4-6 was associated with occlusion distal to first septal. Abnormal Q wave in lead aVL was associated with occlusion proximal to first diagonal, whereas ST depression in lead aVL was suggestive of occlusion distal to first diagonal branch. For both first septal and first diagonal, ST segment depression > or =1 mm in inferior leads strongly predicted proximal left anterior descending artery occlusion, whereas absence of ST segment depression in inferior leads predicted occlusion distal to first septal and first diagonal. All the patients were followed during their in-hospital stay (median of 7 days), during which four patients in the proximal to first septal and first diagonal group and one patient in the distal to first septal and first diagonal group died (p < or = 0.001). CONCLUSIONS: In acute myocardial infarction electrocardiogram is useful to predict the left anterior descending occlusion site in relation to its major side branches and such localization has prognostic significance.     

Relationship between electrocardiographic patterns and angiographic features in isolated left circumflex coronary artery disease.

The relation of electrocardiographic (ECG) patterns to clinical and angiographic features was assessed in 89 patients with isolated left circumflex coronary artery (LCx) disease (46 with and 43 without myocardial infarction). ECG abnormalities were present in 75 patients; there were isolated Q waves in 20, an abnormal R wave in lead V1 with or without inferior and/or lateral Q waves in 21, and isolated ST-T wave changes in 34 cases. Inferior abnormalities on the electrocardiogram were similar in patients with proximal or distal stenoses of the LCx, but an abnormal R wave in lead V1 correlated with proximal LCx stenosis (p less than 0.01). Lateral abnormalities were more common in stenoses of the obtuse marginal branch and proximal LCx than in distal stenosis (all p less than 0.01). Compared with patients without myocardial infarction with or without ST-T-wave changes and those with infarction without an abnormal R wave in lead V1, patients with LCx-related infarction and an abnormal R wave in lead V1 associated with inferior and/or lateral Q waves had larger left ventricular end-diastolic and end-systolic volumes, lower ejection fraction, higher incidence of total occlusion of proximal LCx without collateral vessels, and more cardiac events during follow-up. This study suggests that an abnormal R wave in lead V1 associated with lateral abnormalities on the standard electrocardiogram may be clinically useful in predicting proximal LCx stenosis and identifying a subset of postinfarction patients with left ventricular dysfunction due to a large infarct size.     

Electrocardiogram patterns in acute left main coronary artery occlusion

Acute coronary syndrome with subtotal occlusion of the left main coronary artery is rather frequently encountered in the catheterization laboratory, whereas survival to hospital admission of sudden total occlusion of the left main coronary artery is rare. The typical electrocardiographic (ECG) finding in cases with preserved flow through the left main is widespread ST-segment depression maximally in leads V4-V6 with inverted T waves and ST-segment elevation in lead aVR. In acute myocardial ischemia without (or with minor) myocardial necrosis, the ECG pattern is transient, whereas persistent ECG changes, usually without development of Q waves, are indicative of myocardial injury. In acute total left main occlusion, severe ischemia may be manifested in the ECG by life-threatening tachyarrhythmias, conduction disturbances, and ST-segment deviation. Because of the potential for life-saving therapeutic options by invasive therapy, the ECG markers of the serious condition should be recognized by the medical profession. Left main occlusion should be suspected in severely ill patients with widespread ST-segment depressions, especially in leads V4-V6 with inverted T waves or ST elevation involving the anterior precordial leads and the lateral extremity leads I and aVL. In addition, lead aVR ST elevation accompanied by either anterior ST elevation or widespread ST-segment depression may indicate left main occlusion.     

Significance of right precordial ST elevation in experimental right ventricular infarction

We produced experimental isolated right ventricular infarction (RVI) with closed chest method, and examined ECG changes of right precordial leads and changes of cardiac output (C. O) in 19 dogs. As a result, ECG showed ST depressions in leads, II, III, aVF and V2-V6 and ST elevations in a VR lead in all 15 cases of the proximal occlusion of right coronary artery (RCA). In 10 of 15 dogs ST elevations in some right precordial leads occurred, and the sensitivity of ST elevation in single right precordial lead was 60% (V5R), 53% (V4R) and 47% (V3R and V1), respectively for the detection of RVI. When left circumflex artery (LCX) was occluded, ST elevation in V4R lead after RCA occlusion was blocked. Therefore, it is thought that the sensitivity of ST elevation in right precordial lead may be lower than expectation in identifying RVI. Concerning anterior chest leads, none of 15 dogs with RVI showed ST elevations in leads V2-V6 in this study. If ST elevations in right precordial leads did not appear, variation of C.O was small and C.O reduced in proportion to the extension of ST elevations in right precordial leads.     

Electrocardiographic identification of the infarct-related artery in acute inferior myocardial infarction.

INTRODUCTION: Mortality and morbidity from acute inferior myocardial infarction (MI) are determined, among other factors, by the infarct-related artery (IRA). Several electrocardiographic (ECG) criteria have been proposed to differentiate between the right coronary artery (RCA) and the left circumflex coronary artery (LCx) as the IRA in inferior MI. Recently, a new criterion has been proposed (ST segment depression in lead aVR). It was our objective to evaluate the old and the new ECG criteria in identifying the IRA in patients with inferior MI. METHODS: Patients with inferior MI treated by primary angioplasty were included, following evaluation of the admission ECG. Patients with a previous history of Q-wave myocardial infarction and complete bundle branch block were excluded. The artery with the most severe lesion was considered the IRA. The following ECG criteria were assessed: ST depression in lead DI; ST depression in leads V1 and V2, ST elevation in lead DIII > DII, ST depression in V3/ST elevation in DIII ratio > 1.2 (classical criteria) and ST depression in lead aVR. ST-segment elevation or depression was measured 0.06 sec after the J point. RESULTS: 53 patients were included (mean age 59.1 +/- 13.9 years, 38 males). The RCA was the IRA in 38 patients and the LCx in 15. Baseline characteristics (age, gender, TIMI flow, Killip class, and pain-to-balloon time) were similar in both groups. All the classical criteria were able to identify the IRA. The new criterion--ST depression in lead aVR--identified the IRA in a small number of patients (sensitivity 33%, specificity 71%, p = NS). CONCLUSIONS: The 4 classical criteria were useful in identifying the IRA in patients with inferior MI. ST depression in lead aVR (a recently proposed new criterion), on the other hand, showed limited utility in differentiating between RCA and LCx.     

常规心电图对急性前壁心肌梗死时前降支闭塞部位预测价值的临床研究

目的探讨急性前壁心肌梗死时的常规心电图（ECG）对前降支（LAD）闭塞部位的预测价值。方法根据冠状动脉造影的结果，以第一间隔支（S1）为标志将患者分为S1近端病变（PS）组（61例）和S1远端病变（DS）组（40例）。分别测量常规ECG12导联ST段的偏移程度及出现的频率，以计算、比较两组之间的差异及其对近、远段病变部位的预测性诊断价值。结果（1）各导联诊断LAD近端病变的敏感性和特异性分别为：aVR导联ST段抬高为43％和85％（P=0．004）；aVL导联ST段抬高≥1．5mm为16％和97％（P=0．031）；Ⅱ导联ST段下移≥1．0mm为39％和85％（P=0．009）；Ⅲ导联ST段下移≥2．0mm为23％和98％（P=0．005）；aVF导联ST段下移≥1．0mm为38％和88％（P=0．006）；V5导联ST段下移为20％和86％（P=0．037）；aVR导联ST段抬高同时伴V5导联ST段下移为18％和100％（P=0．005）；aVR导联ST段抬高同时伴V6导联ST段下移为30％和93％（P=0．008）；（2）各导联诊断LAD远端病变的敏感性和特异性分别为：Ⅲ导联ST段居于等电位线或抬高为53％和90％（P=0．000）；V5导联ST段抬高≥1．5mm为50％和82％（P=0．001）；（3）近、远端患者的梗死面积和心功能水平未见明显差异。结论（1）aVR导联ST段抬高同时出现V5、V6导联ST段下移；下壁导联Ⅱ、Ⅲ、aVF导联ST段明显下移（Ⅱ，aVF导联ST段下移≥1．0mm，STⅢ下移≥2．0mm）以及Ⅰ，aVL导联ST段抬高，尤其是aVL导联ST段抬高≥1．5mm均提示LAD近端病变。（2）下壁导联（尤其是Ⅲ导联）ST段居于等电位线或升高，V5导联ST段抬高≥1．5mm均提示LAD远端病变。     

Right and left ventricular ejection fraction in acute inferior wall infarction with or without ST segment elevation in lead V4R

To detect right ventricular involvement, lead V4R was recorded within 10 hours of the onset of chest pain in 42 consecutive patients admitted with acute inferior wall myocardial infarction. One week after the acute infarction, multigated equilibrium radionuclide ventriculography was performed to assess right and left ventricular ejection fraction. Two weeks after the acute infarction, coronary angiography was performed to determine the site and location of the obstruction leading to the infarction. Seventeen patients had an obstruction in the right coronary artery proximal to the first branch to the right ventricular free wall (group 1); all of these had ST segment elevation in lead V4R. Fourteen patients had an obstruction in the right coronary artery distal to the first branch to the right ventricular free wall (group 2); only two of these patients had ST segment elevation in lead V4R. In 11 patients, the obstruction was located in the circumflex coronary artery (group 3); none of these had ST segment elevation in lead V4R. Nineteen patients had ST segment elevation of 1 mm or greater in lead V4R (group 4). Left ventricular ejection fraction was not different among the four groups of patients, although the right ventricular ejection fraction was significantly lower in group 1 and group 4 patients. It is concluded that ST segment elevation in lead V4R reliably identifies the group of patients with inferior wall myocardial infarction with depressed right ventricular function. This phenomenon persists for at least 1 week after infarction.     

11例急性单纯后壁心肌梗死心电图及梗死相关动脉特点分析

目的 分析急性单纯后壁心肌梗死（不包括同时合并下壁及右室心肌梗死）的心电图及冠状动脉造影特点。方法 总结自2001年至2006年门、急诊收治的急性单纯后壁心肌梗死患者11例,随访心电图特点,并行冠状动脉造影确定梗死相关动脉。结果 11例患者除了V7-V9导联ST段有典型的弓背向上抬高1．0—2．0mm外,9例（81．8％）V1-V2导联R／S≥1,5例（45．5％）V1-V4导联ST段压低1．0—2．0mm,4例（36．4％）Ⅰ、aVL导联ST段抬高0．5-1．5mm,5例（45．5％）V5-V6导联ST段抬高0．5—1．5mm。冠状动脉造影显示梗死相关动脉均为左回旋支（LCX）。梗死部位1例在第一钝缘支（OM1）发出前,为95％管状狭窄;6例（54．5％）在OM1发出后,其中4例为100％闭塞,1例为99％次全闭塞,1例为90％长段狭窄;4例（36．4％）在OM1,其中2例为100％闭塞,1例为99％次全闭塞,1例为95％局限性狭窄。单支病变3例（27．3％）,合并左前降支（LAD）病变4例（36．4％）,合并右冠状动脉（RCA）病变2例（18．2％）,同时合并LAD及RCA病变2例（18．2％）。结论12导联心电图,如有V1-V2导联R／S≥1,V1-V4导联ST段压低等特点时,结合临床与心肌酶学改变,高度怀疑急性后壁心肌梗死,需做后壁导联和冠状动脉造影加以证实,而梗死相关动脉多为左回旋支。     

Diagnosis of acute myocardial infarction in angiographically documented occluded infarct vessel : limitations of ST-segment elevation in standard and extended ECG leads.

STUDY OBJECTIVES: The majority of thrombolysis studies require defined ST-segment elevations as an inclusion criterion for the diagnosis of acute myocardial infarction (AMI). However, depending on the occluded infarct vessel and the criteria applied, the ECG diagnosis of AMI can be difficult to establish. Accordingly, this study was performed to evaluate the sensitivity of ST-segment elevation of standard and extended ECG leads in a cohort of patients with angiographically confirmed diagnosis of AMI. PATIENTS AND METHODS: In 418 patients (mean +/- SD age, 60 +/- 13 years) with AMI (pain onset, 4.8 +/- 3.0 h), coronary angiography with percutaneous transluminal coronary angioplasty/stenting of the culprit lesion was performed. The diagnosis of AMI was confirmed by emergency coronary angiography and laboratory analyses. ST-segment elevation (in two contiguous leads) of 1 mm in standard lead I through aVF and ST-segment elevations of 2 mm (or 1 mm, corresponding values presented in parentheses) in V(1) through V(6) were considered significant. In a subset of 102 AMI patients, additional right precordial leads V(3)R through V(6)R for evaluation of right ventricular infarction and additional chest leads V(7) through V(9) for evaluation of posterior infarction were recorded. ST-segment elevations of 1 mm in the right precordial leads and 1 mm or 0.5 mm in the posterior leads were considered significant. RESULTS: Standard leads I through V(6) showed ST-segment elevation in 85% (96%) of patients with left anterior descending artery occlusion, in 46% (61%) of patients with left circumflex coronary artery (CX) occlusion, and in 85% (90%) of patients with right coronary artery occlusion. On consideration of additional ECG tracings in the subgroup of 102 patients (V(3)R through V(6)R and V(7) through V(9)), the respective numbers increased by 2 to 8% depending on different criteria for ST-segment elevation; in patients with CX occlusion, the increase amounted to 6 to 14%. There was a trend toward an extended infarct size (maximum creatine kinase [CK] values) with concomitant ST-segment elevation in additional ECG leads as assessed by maximum CK levels. CONCLUSIONS: The sensitivity of the ECG diagnosis of AMI is only marginally increased by extended precordial chest leads. There is a trend toward an extended infarct size in those patients with concomitant ST-segment elevation in additional ECG leads.     

Value of lead V4R for recognition of the infarct coronary artery in acute inferior myocardial infarction

In 84 patients with an acute inferior wall myocardial infarction (MI) admitted within 10 hours after the onset of chest pain, a right precordial lead V4R electrocardiogram was recorded in addition to the standard 12-lead electrocardiogram. The presence or absence of ST-segment elevation in lead V4R was correlated with results of coronary angiography performed 2 to 26 weeks (mean 10) after MI. Patients were classified into 3 groups: (1) those with a critical stenosis or occlusion proximal to the first right ventricular (RV) branch (27 patients); (2) those with stenosis distal to the right ventricular branch of the right coronary artery (36 patients); and (3) those with stenosis in the left circumflex coronary artery (21 patients). The presence of ST-segment elevation greater than or equal to 1 mm in lead V4R has a sensitivity of 100% and a specificity of 87% for occlusion of the right coronary artery above the first RV branch; the predictive accuracy is 92%. Seven of 36 patients with a distal occlusion of the right coronary artery showed ST-segment elevation of 1 mm or more in lead V4R . The absence of ST-segment elevation greater than or equal to 1 mm in lead V4R excluded proximal occlusion of the right coronary artery. ST-segment elevation in lead V4R was not seen either in 29 of 36 patients with a distal occlusion of the right coronary artery or in all patients with an occlusion of the left circumflex artery. Recording of lead V4R within 10 hours after onset of acute inferior wall MI can give information rapidly about the vessel responsible for MI.(ABSTRACT TRUNCATED AT 250 WORDS)     

Electrocardiograms during acute occlusion of the left circumflex artery as compared with that of the right coronary artery

To assess the characteristic electrocardiographic (ECG) ST changes during acute occlusion of the left circumflex artery (LCX), we observed ECG changes during percutaneous transluminal coronary angioplasty (PTCA) of the LCX and compared the results with those obtained during right coronary angioplasty. Results were as follows: 1. In the 30 patients who had LCX angioplasty (group LCX), ST-segment elevation occurred most frequently in lead V6 (67.7%) and in lead III (46.7%), but rarely in leads and aVL. ST depression occurred most frequently in lead V3 (80.0%) and in lead V2 (73.3%), but rarely in other leads except for leads I and aVL (23.3%, 33.3%). 2. Four types of ST change in lead combinations were observed. These included: (1) ST elevation in the inferior leads (II, III and aVF), (2) ST elevation in the lateral leads (V5 and V6), (3) ST depression in the anterior leads (V2-V4) and (4) ST depression in the high lateral leads (I and aVL). In group LCX, nine cases (30.0%) manifested all four changes, and six cases (20.0%) revealed only ST depression in the anterior leads without ST changes in other leads. 3. ST depression in the anterior leads and ST elevation in the inferior and lateral leads were observed in nearly equal frequency in patients who received PTCA at the proximal site (Seg. 11) and at the distal site (Seg. 13) in the group LCX. However, ST depression in the high-lateral leads was more frequently observed in the distal than in the proximal cases (66.7% vs 33.3%).(ABSTRACT TRUNCATED AT 400 WORDS)     

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。     

Acute myocardial infarction due to the left main coronary artery occlusion: Electrocardiographic patterns,angiographic findings,revascularization and in-hospital outcomes

BackgroundPrimary angioplasty improves outcomes of acute myocardial infarction (AMI). However, in the highest risk subgroups, the mortality remains high despite modern catheter-based reperfusion therapy. This study analyzed patients with AMI caused by the left main coronary artery unstable lesion, a subgroup considered to be associated with very high early mortality.MethodsA multicenter registry enrolled 6742 consecutive patients with AMI. Ninety-seven patients (1,4% of the entire study population) had left main as the infarct related artery. Baseline clinical characteristics, ECG patterns, coronary angiographic and echocardiographic data were correlated with the revascularization therapies used and with in-hospital outcomes.ResultsTwenty-five patients (25,8%) died during the hospital stay. The deceased patients were older, had more freqently bundle branch block on the admission ECG, had higher Killip class on presentation, more frequently had TIMI flow <3 and PCI success rate was 72% (vs. 100% among survivors). Left main coronary artery (LMCA) lesion impaired distal flow (TIMI flow 0–2 on presentation) in 35 patients: the most frequent ECG presentation pattern for these LMCA occlusions was ST segment elevation (n=17), followed by RBBB (n=9; with LAH 6 and without LAH 3), LBBB (n=6) and ST segment depression (n=3). In other words: acute LMCA occlusion presents in 51% with ECG changes other than ST segment elevations. Patients with TIMI flow 0–2 had higher Killip class on admission, lower ejection fraction and higher in-hospital mortality (37% vs. 20%), when compared to those with TIMI flow 3 on the initial angiogram.ConclusionsDespite modern interventional therapy, acute myocardial infarction caused by the left main coronary artery obstruction bears high early mortality. The presence of bundle branch block, diminished TIMI flow on the initial angiogram, higher age and Killip class are related with increased mortality.     

体表心电图对老年急性前壁心肌梗死左前降支闭塞部位的预测价值

目的探讨体表心电图对老年急性前壁心肌梗死左前降支（LAD）闭塞部位的预测价值。方法对62例老年急性前壁心肌梗死患者的入院心电图和冠状动脉造影资料进行回顾性分析,寻找可以预测LAD闭塞部位的心电图改变。结果62例老年急性前壁心肌梗死患者均为LAD闭塞,其中近段闭塞者45例（72.6%）,远段闭塞者17例（27.4%）。经χ2检验,STⅠ抬高、STaVL抬高、STaVF压低或至少2个下壁导联ST段压低等指标提示LAD近段闭塞（P均〈0.05）。其中,STaVF压低或至少2个下壁导联ST段压低的特异度和阳性预测值最高,为94%左右,灵敏度以STaVL抬高最高,为56%;反之,STaVL压低和STⅢ抬高则在预测LAD远段闭塞上有显著意义（P均〈0.05）,特异度和阳性预测值以STaVL压低为最高,均为100%。结论急性前壁心肌梗死时,体表心电图对预测LAD闭塞部位有重要价值。     

Acute myocardial infarction with significant left main coronary artery stenosis, significant 3-vessel coronary artery disease and elevated troponin-I at admission

Exercise-induced ST-segment elevation in lead aVR accompanied by ST-segment elevation in lead V1 might be a specific finding of left main coronary artery (LMCA) stenosis. Lead aVR and lead v1 ST segment elevation has been reported, during an attack of chest pain, in patients with LMCA disease with ST segment depression in leads V3, V4 and V5 (with maximal depression in V4). ST-segment elevation in lead aVR in patients with angina at rest can be related to transmural ischemia of the basal part of the interventricular septum, frequently due to LMCA or multivessel coronary disease too. 3-vessel coronary artery disease (CAD) and LMCA disease show a frequent combination of leads with abnormal ST segments during chest pain with ST-segment depression in leads I II V4-V6, and ST-segment elevation in lead aVR. When ST-segment status in lead aVR combines with troponin T, ST-segment elevation in lead aVR and positive troponin T on admission are useful predictors of LMCA or 3-vessel CAD. We present a case of acute myocardial infarction with significant left main coronary artery stenosis, significant 3-vessel coronary artery disease and elevated troponin I at admission in an 83-year-old Italian woman. Also this case focuses attention on the importance of the recognition of the patterns suspected for LMCA and/or 3-vessel coronary disease.