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。     

In inferior myocardial infarction,neither ST elevation in lead V1 nor ST depression in lead I are reliable findings for the diagnosis of right ventricular infarction

Objective

In the presence of inferior myocardial infarction (MI), ST depression (STD) in lead I has been claimed to be accurate for diagnosis of right ventricular (RV) MI. We sought to evaluate this claim and also whether ST Elevation (STE) in lead V1 would be helpful, with or without STD in V2.

急性前壁心肌梗塞时下壁导联心电图ST段变化的意义

探讨ＥＣＧ胸前导联ＳＴ段抬高伴下壁Ⅱ，Ⅲ，ａＶＦ导联ＳＴ段压低与冠状动脉病变的关系。对６０例急性前壁心肌梗塞病例进行回顾分析，所有病人于发病后４周左右行冠状动脉造影检查。结果（１）３３例前降支单支血管病狭窄达９０％－１００％组，７７．８％出现Ⅱ，Ⅲ，ａＶＦ导联ＳＴ段压低０．１≥ｍＶ，狭窄７０％８９％组仅２３．１％出现Ⅱ，Ⅲ，ａＶＦ导联ＳＴ段压低≥０．１ｍＶ，两组间在统计学差异有极显著性。（２）６０     

急性前壁心肌梗死后T波的动态变化与心肌损害和左心室功能关系

目的 :探讨急性心肌梗死 (AMI)后T波的动态变化与心肌损害和左室功能之间的关系。方法 :6 2例前壁Q波型AMI患者 ,其中T波由倒置转为直立 ,即T波正常化 39例 (<3个月 6例 ,>3～ 6个月 14例 ,6～12个月 19例 ) ;T波持续直立 5例 ;T波持续倒置 18例。AMI后常规记录 12导联心电图。采用二维超声心动图、彩色心室壁动力分析和超声学定量 (AQ)技术检测室壁运动和左心室收缩功能状况。结果 :T波持续倒置组血浆肌酸激酶 (CK)峰值和心室壁运动得分指数 (WMSI)明显高于T波直立组 ,而左心室短轴缩短率 (FS)、峰值排空率 (PER)和射血分数 (EF)显著低于T波持续直立组 ;且T波正常化越早左心功能恢复得越好。T波持续直立组血浆CK峰值、WMSI均高于T波直立各亚组和T波持续倒置组 ,而FS、EF和PER均显著低于各亚组。结论 :AMI后 12个月异常Q波导联的T波动态变化能用于评价左心室的局部和整体收缩功能     

左前降支解剖变异对急性前壁心肌梗死时下壁导联ST段变化的影响

分析５２例急性前壁心肌梗死的下壁导联ＳＴ段变化。按左前降支长短分两组，短组（组１．３５例）和长组（组２．１７例）胸前导联ＳＴ段上移的程度无差异，但组２下壁导联ＳＴ段下移的绝对值和相对值（ＳＴ８０　ａＶＦ／ＳＴ８０　Ｖ２）均较组１显著减轻（皆Ｐ＜０．０１）。组２中有５例（２９％）下壁导联ＳＴ８０在等电位线上或轻微上移。组２下壁导联ＳＴ８０下移减轻或不下移，反映了长左前降支闭塞引起的下壁心肌缺血。     

Concomitant left anterior descending coronary artery and right coronary artery occlusion with typical anterior ST depression and inferior ST elevation

We report the case of a 41-year-old man with acute myocardial infarction showing first ST elevation in V1-V6-DI-aVL leads followed by a typical V2-V4 ST depression (concomitant occlusion of proximal diagonal branch with an incomplete left anterior descending occlusion) and DII-DIII-aVF ST elevation. At coronary angiography, a proximal left anterior descending coronary stenosis with right coronary artery thrombosis was found.     

Inferior ST segment depression as a useful marker for identifying proximal left anterior descending artery occlusion during acute anterior myocardial infarction

To determine whether or not ST segment deviation on admissionelectrocardiograms can identify patients with anterior acutgemyocardial infarction due to proximal left anterior descendingartery occlusion, the magnitude and location of ST segment elevationor depression were compared between patients with proximal leftanterior descending artery occlusion (group A, n=47) and thosewith distal left anterior descending artery occlusion (groupB, n =59). ST segment depression in each of the inferior leadswas significantly greater in group A than in group B. The incidenceof ST segment depression 1 mm in each of the inferior leads(II; 81% vs 27%, III; 85% vs 54%, aVF; 87% vs 47%, P<0·01)was significantly higher in group A than in group B. In addition,the incidence of ST segment depression 1 mm in all of the inferiorleads was significantly greater in group A than in group B (77%vs 22%, P<0·01). In group A, maximal ST segment elevationwas more frequent in lead V alone (43% vs 14%, P<0·01).Group A had greater ST segment elevation in lead a VL than groupB, and the incidence of ST segment elevation 1 mm in lead aVL was significantly higher in group A than in group B (66%vs 47%, P<0·05). ST segment depression 1 mm in allof the inferior leads was most valuable for identifying groupA patients (77% sensitivity and 78% specificity). In contrast,the maximal ST segment elevation in lead V₂ alone or ST segmentelevation 1 mm in lead a VL had a low diagnostic value (43%sensitivity and 86% specificity, 66% sensitivity and 53% specificity,respectively). In conclusion, this study indicates that analysisof ST segment deviation in the inferior leads is useful foridentifying patients with acute anterior myocardial infarctiondue to proximal left anterior descending occlusion.     

心肌梗死后Q波导联ST段持续抬高的临床意义

目的 :探讨心肌梗死 ( MI)后 Q波导联 ST段持续抬高的临床意义。方法 :选取 MI后 Q波导联 ST段持续抬高 (静息心电图 )的患者 3 0例 ( ST段抬高组 ) ,以无 ST段持续抬高的 MI患者 2 6例为对照组 ,两组均行冠状动脉 (冠脉 )造影及左心室造影 ,观察两组病例的左室收缩末期容积 ( ESV)、左室舒张末期容积 ( EDV)、射血分数 ( EF)、局部室壁运动情况及冠脉阻塞部位、程度。结果 :ST段抬高组较对照组 EF减低 ( P <0 .0 1)、ESV增大 ( P <0 .0 5 ) ,冠脉完全闭塞、局部室壁无收缩或矛盾运动比例 ST段抬高组明显高于对照组 ( P <0 .0 5 ) ,而两组 EDV、室壁瘤发生比例差异无显著性意义 ( P >0 .0 5 )。结论 :MI后 Q波导联 ST段持续抬高与冠脉完全的闭塞、大面积的梗死、EF的显著降低、ESV的明显扩大直接相关 ;与室壁瘤、EDV无显著相关 ,是一种简便、无创的临床检测手段 ,对 MI后患者的治疗和预后提供积极的帮助。     

Inferior ST segment depression as a useful marker for identifying proximal left anterior descending artery occlusion during acute anterior myocardial infarction

To determine whether or not ST segment deviation on admissionelectrocardiograms can identify patients with anterior acutgemyocardial infarction due to proximal left anterior descendingartery occlusion, the magnitude and location of ST segment elevationor depression were compared between patients with proximal leftanterior descending artery occlusion (group A, n=47) and thosewith distal left anterior descending artery occlusion (groupB, n =59). ST segment depression in each of the inferior leadswas significantly greater in group A than in group B. The incidenceof ST segment depression 1 mm in each of the inferior leads(II; 81% vs 27%, III; 85% vs 54%, aVF; 87% vs 47%, P<0.01)was significantly higher in group A than in group B. In addition,the incidence of ST segment depression 1 mm in all of the inferiorleads was significantly greater in group A than in group B (77%vs 22%, P<0.01). In group A, maximal ST segment elevationwas more frequent in lead V alone (43% vs 14%, P<0.01). GroupA had greater ST segment elevation in lead a VL than group B,and the incidence of ST segment elevation 1 mm in lead a VLwas significantly higher in group A than in group B (66% vs47%, P<0.05). ST segment depression 1 mm in all of the inferiorleads was most valuable for identifying group A patients (77%sensitivity and 78% specificity). In contrast, the maximal STsegment elevation in lead V₂ alone or ST segment elevation 1 mm in lead a VL had a low diagnostic value (43% sensitivityand 86% specificity, 66% sensitivity and 53% specificity, respectively).In conclusion, this study indicates that analysis of ST segmentdeviation in the inferior leads is useful for identifying patientswith acute anterior myocardial infarction due to proximal leftanterior descending occlusion.     

急性前壁心肌梗死R波、Q波和ST段演变速度的观察

目的 通过心电图对急性心肌梗死的诊断提供更多的信息。方法 对21例急性前壁心肌梗死患者进行R波、Q波和ST段变化进行同步12导联心电图动态观察。将开始到结束的7次标测分成6个时间间隔．分别计算各个时间间隔的∑R、∑Q、和∑ST的平均值和标准差。结果∑R于胸痛发作后12h内迅速下降；∑Q逐渐增大，24h内变化最显著；EST 12h内迅速下降，48h后渐趋稳定。12例（57％）R波消失，Q波在发病后12h内形成；另9例（43％）于24h内形成。结论心肌梗死后ST段抬高、R波下降和Q波形成在快速型和慢速型心肌梗死患者中不同。     

ST段持续抬高与室壁瘤、室壁运动异常与左室大小的关系

目的　探讨Q波急性前壁心肌梗死患者心电图胸前导联ST段持续抬高与室壁瘤、室壁运动异常和左室大小的关系。方法　连续首次发病的 4 2例急性前壁心肌梗死患者 ,发病 2周时行 12导联心电图和超声心动图检查 ,分别测量心电图上胸前导联ST段抬高的程度 ,左室心内膜面积指数 (ESAi)和室壁运动异常区心内膜面积 (AWMa)和室壁运动异常得分。结果　在V2导联、抬高最大的导联上 ,室壁瘤和非室壁瘤组ST段抬高程度 ,差异无显著性 (p >0 0 5 )。V1至V6导联ST段抬高之总和室壁瘤组大于非室壁瘤组 (P <0 0 5 )。室壁瘤组的室壁运动积分明显高于非室壁瘤组 (P <0 0 1) ,但AWMa和ESAi,两组均无显著差别 (P >0 0 5 )。V2导联、抬高最大的导联和V1至V6导联ST段抬高之总和 ,室壁运动异常积分≥ 8分组显著高于室壁运动异常积分 <8分组 (P均 <0 0 1)。但入院时ESAi增大组和正常组之间无显著差别 (P >0 0 5 )。结论　梗死后 2周 ,心电图胸前导联持续抬高与左室前壁、心尖部和室间隔的运动异常程度有关 ,它并不能帮助明确诊断室壁瘤存在 ,也与左室大小无关     

冠状动脉前降支闭塞致急性心肌梗死的心电图ST段偏移特点分析

目的探讨冠状动脉前降支(LAD)单支闭塞所致急性心肌梗死(AMI)的心电图(ECG)特点。方法回顾性分析51例LAD急性闭塞所致AMI患者心电图ST段改变与冠状动脉造影结果。结果 V_2导联ST段抬高<0.2 mV预测LAD远段闭塞敏感度为52.9%,特异度为88.2%,在胸导联ST段抬高的情况下,特异度增高(96.2%)。V_6导联ST段压低预测LAD近段闭塞敏感度为26.5%,特异度100%,在胸导联ST段抬高的情况下,V_1导联ST段抬高≥0.2 mV预测LAD近段闭塞敏感度53.8%,特异度88.9%。下壁导联Ⅱ、Ⅲ、aVF ST段压低预测LAD近段闭塞特异度较高,Ⅲ、aVF导联组合较Ⅱ、Ⅲ、aVF导联组合判断LAD近段闭塞特异度及阳性预测值高。结论 V_1导联ST段抬高、V_6导联ST段压低、下壁导联ST段压低有助于判断LAD近段闭塞,V_2导联ST段抬高<0.2 mV有助于判断LAD远段闭塞。     

Electrocardiographic characteristics in angiographically documented occlusion of the dominant left circumflex artery with acute inferior myocardial infarction: limitations of ST elevation III/II ratio and ST deviation in lateral limb leads

Background

The prognosis of dominant left circumflex artery (LCx) occlusion-related inferior acute myocardial infarction (AMI) patients is poor, but the electrocardiographic (ECG) characteristics of this AMI entity have not been described.

Methods

One hundred thirty-five patients with first dominant right coronary artery (RCA) or dominant LCx-related inferior AMI were included. The characteristics of ECG obtained on admission for 55 patients with culprit lesions proximal to the first major right ventricular (RV) branch of dominant RCA (group proximal dominant RCA), 62 patients with culprit lesions distal to the first major RV branch of dominant RCA (group distal dominant RCA), and 18 patients with culprit lesions in dominant LCx (group dominant LCx) were compared.

Results

There were no significant differences among the 3 groups in the prevalence regarding an S/R ratio greater than 1:3 in aVL, ST elevation in aVR (ST↑_aVR), ST depression in aVR (ST↓_aVR) of 1 mm or more, and atrioventricular block. Greater ST elevation in lead III than in II and greater ST depression in aVL than I showed specificity of 17% and 44% to identify dominant RCA as culprit lesion, respectively. All 3 groups could be distinguished on the basis of ST↑_V4R, ST↓_V4R, ST↓_V3/ST↑_III of 1.2 or less, and ST↓_V3/ST↑_III of more than 1.2.

Conclusions

Greater ST elevation in lead III than in II, greater ST depression in aVL than I, and an S/R ratio of greater than 1:3 in aVL were not useful to discriminate between dominant RCA and dominant LCx occlusion-related inferior AMI. ST-segment deviation in lead V₄R and the ratio of ST↓_V3/ST↑_III were useful in predicting the dominant artery occlusion-related inferior AMI.     

Electrocardiographic identification of the culprit coronary artery in inferior wall ST elevation myocardial infarction

BACKGROUND:

Electrocardiograms (ECGs) are essential in identifying the type and location of acute myocardial infarction. In the setting of inferior wall myocardial infarction (IWMI), identification of the right coronary artery (RCA) as the culprit artery is important because of the potential complications associated with its involvement.

OBJECTIVES:

To evaluate previous ECG criteria used for the identification of RCA involvement and validate them in the Assessment of the Safety and Efficacy of a New Treatment Strategy with Percutaneous Coronary Intervention (ASSENT 4 PCI) cohort; and to develop an improved simplified score to identify RCA involvement.

METHODS:

ASSENT 4 PCI patients with IWMI (n=710) were included in the present study. A literature review was conducted to identify previously published criteria to detect RCA involvement. Logistic regression was used to develop a new simplified algorithm for identifying RCA involvement.

RESULTS:

The sensitivities and specificities of six previous ECG criteria were substantially lower when applied to the ASSENT 4 PCI population. A new algorithm found that ST segment depression in leads I, aVL and V6, and ST segment elevation of greater than 1 mm in lead aVF was associated with a higher likelihood of RCA involvement, and any ST segment depression in V1 and V3 was associated with a lower likelihood of RCA involvement. A simplified risk score found a prevalence of RCA involvement of over 90% among patients with scores of greater than two.

CONCLUSIONS:

The ECG is useful in identifying RCA involvement in IWMI before angiography. Previously published criteria appear to be inadequate, and the simple algorithm presented in the current study may be a useful tool in identifying RCA involvement at the bedside.     

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.     

Dobutamine- vs exercise-induced ST segment elevation early after Q wave myocardial infarction. Prediction of functional recovery after revascularization.

AIMS: The association between stress-induced ST elevation and functional recovery following revascularization after myocardial infarction remains unclear. We assessed the relative accuracy of dobutamine- and exercise-induced ST elevation in Q wave leads in predicting functional recovery following revascularization, and we investigated the relationship of ST elevation to different wall motion responses to dobutamine. METHODS AND RESULTS: Thirty-nine patients underwent dobutamine stress echo and exercise test 8+/-2 days after Q wave myocardial infarction. All patients underwent angiography and subsequent revascularization. Follow-up echocardiograms were obtained 7+/-4 weeks after revascularization. Functional recovery was assessed by the difference between the baseline and the follow-up asynergy index. Nineteen patients (48%) developed dobutamine- and exercise-induced ST elevation. There was significant agreement between the tests (k=0.58, P<0.001). We found a significant correlation between dobutamine and exercise-induced ST elevation with functional recovery following revascularization (r=0. 45, P<0.005 and r=0.7, P<0.001, respectively). The parameters with the highest predictive value for functional recovery were: (a) the biphasic response during dobutamine infusion, (b) the development of ST elevation in both tests, and (c) the development of exercise-induced ST elevation in more than three leads. CONCLUSION: There is a strong association between dobutamine- and exercise-induced ST elevation with functional recovery following revascularization. Exercise-induced ST elevation in more than three leads and a biphasic response during dobutamine infusion accurately predict functional recovery.     

Acute anterior wall myocardial infarction entailing ST-segment elevation in lead V3R, V1 or aVR: electrocardiographic and angiographic correlations

Background

The correlation between ST-segment elevation (ST↑) in lead V₃R (ST↑_V3R), lead V₁ (ST↑_V1), and lead aVR (ST↑_aVR) during anterior wall acute myocardial infarction (AMI) and the culprit lesion site in the left anterior descending (LAD) coronary artery and the nature of the conal branch of the right coronary artery has not been throughly described.

Methods

One hundred forty-two patients with first anterior wall AMI were included. The 15-lead electrocardiogram with the standard 12 leads plus leads V₃R through V₅R showing the most pronounced ST-segment deviation before initiation of reperfusion therapy was evaluated and correlated with the exact LAD occlusion site in relation to the first septal perforator (S1) and the nature of the conal branch of the right coronary artery as determined by coronary angiography.

Results

ST-segment elevation in lead aVR, ST↑_V1 of at least 2 mm, and ST↑_V3R of at least 1 mm were more prevalent among patients with occlusions proximal to S1 than patients with occlusions distal to S1 (41.7% vs 4.9%, P < .01; 30.0% vs 7.3%, P < .01; and 91.7% vs 4.9%, P < .01, respectively). Of the 60 patients with occlusions proximal to S1, 20 patients had a small conal branch (18 patients with ST↑_aVR and 15 patients with ST↑_V1 ≥2 mm), and 24 patients had a large conal branch (all patients with non-ST↑_aVR and ST↑_V1 <2 mm; P < .01). The sensitivity of ST↑_V1 of more than 1 mm, of at least 2 mm, ST↑_V3R of at least 1.5 mm, and ST↑_aVR for detecting a small conal branch was 65.1%, 81.8%, 84.0%, and 90%, respectively; the specificity was 68.5%, 64%, 66.7%, and 64.9%, respectively.

Conclusions

In patients with anterior wall AMI, ST↑_V3R of at least 1 mm combined with ST↑ in leads V₂ through V₄ were strongly predictive of LAD occlusion proximal to S1; furthermore, ST↑_aVR and ST↑_V1 of at least 2 mm were found to be useful in identifying LAD occlusion proximal to S1. ST↑_aVR, ST↑_V3R of at least 1.5 mm, and ST↑_V1 of at least 2.0 mm were also associated with the presence of a small conal branch not reaching the intraventricular septum during anterior wall AMI.     

Correlation between ST segment shift and cardiac diastolic function in patients with acute myocardial infarction

Background

Diastolic dysfunction is the early sign of myocardial ischemia that usually occurs earlier than ECG changes.

Appropriateness of anteroseptal myocardial infarction nomenclature evaluated by late gadolinium enhancement cardiovascular magnetic resonance imaging

Background

In traditional literature, it appears that “anteroseptal” MIs with Q waves in V1-V3 involve basal anteroseptal segments although studies have questioned this belief.

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