Computerized classification of proximal occlusion in the left anterior descending coronary artery

Proximal occlusion within the left anterior descending (LAD) coronary artery in patients with acute myocardial infarction leads to higher mortality than does nonproximal occlusion. We evaluated an automated program to detect proximal LAD occlusion.All patients with suspected acute coronary syndrome (n = 7,710) presenting consecutively to the emergency department of a local hospital with a coronary angiogram-confirmed flow-limiting lesion and notation of occlusion site were included in the study (n = 711). Electrocardiograms (ECGs) that met ST-segment elevation myocardial infarction (STEMI) criteria were included in the training set (n = 183). Paired angiographic location of proximal LAD and ECGs with ST elevation in the anterolateral region were used for the computer program development (n = 36). The test set was based on ECG criteria for anterolateral STEMI only without angiographic reports (n = 162). Tested against 2 expert cardiologists' agreed reading of proximal LAD occlusion, the algorithm has a sensitivity of 95% and a specificity of 82%.The algorithm is designed to have high sensitivity rather than high specificity for the purpose of not missing any proximal LAD in the STEMI population. Our preliminary evaluation suggests that the algorithm can detect proximal LAD occlusion as an additional interpretation to STEMI detection with similar accuracy as cardiologist readers.     

心电图诊断冠脉前降支闭塞部位的研究

目的 探讨前壁急性心肌梗死(AMI)体表心电图(ECG)预测前降支(LAD)阻塞部位的准确率.方法 对2010年6月至2013年12月在井冈山大学附属医院心血管科145例前壁AMI患者ECG预测阻塞部位与冠状动脉造影术(CAG)显示阻塞部位进行对比分析.以大对角支(LD)或第一对角支(D1)为界划分LAD为近远段.结果 前间壁AMI 20例,LAD阻塞部位均在LD或D1开口以远.前壁AMI、前壁+下壁AMI共67例LAD阻塞部位大多在LD或D1开口以远(80.6％ vs.86.6％),两种分界法差异无统计学意义(p=0.351).广泛前壁、广泛前壁+高侧壁、前壁+高侧壁AMI共58例LAD阻塞部位多发生LD或D1开口以近(96.55％vs.72.4％),两种分界法差异有显著的统计学意义(p=0.000),以LD为界有较高的阳性预测值(96.55％ vs.72.41％ p=0.000)、特异度(97.3％ vs.83％,p=0.003),心电图判断LAD近段阻塞以LD分界更准确.结论 前壁AMI心电图对预测LAD阻塞部位有较高的准确率.     

aVR导联对急性前壁心肌梗死患者梗死相关血管的预测价值及临床意义

目的 研究aVR导联ST段抬高对急性前壁心肌梗死患者梗死相关血管的预测价值及临床意义.方法 101例首次急性前壁心肌梗死患者根据aVR导联有无ST段抬高分为A组（有ST段抬高）33例和B组（无ST段抬高）68例,对其冠脉造影、心脏彩超结果和临床资料进行比较.结果 ①梗死相关血管为左主干（LM）病变A组9例,B组2例,两组差异有统计学意义（P＜0.01）;梗死相关血管为左前降支（LAD）近端病变A组22例,B组26例,两组差异有统计学意义（P＜0.01）;多支血管病变A组15例,B组16例,两组差异有统计学意义（P＜0.01）.②A组发生心脏事件11例,B组9例,两组差异有统计学意义（P＜0.01）.③A组LVEF值明显低于B组（P＜0.01）.④A组CK-MB峰值明显高于B组（P＜0.01）.结论 aVR导联对急性心肌梗死患者梗死相关血管的判定及预后有重要的临床价值.     

Electrocardiographic differentiation between occlusion of the first diagonal branch and occlusion of the left anterior descending coronary artery

Purpose

We sought to electrocardiographically distinguish ST-segment elevation (STE)-acute myocardial infarction (AMI) caused by occlusion of the first diagonal branch (D1) from STE-AMI caused by occlusion of the left anterior descending coronary artery (LAD).

Methods

We examined 28 patients with STE-AMI caused by D1 occlusion (G-D) and 342 with STE-AMI caused by LAD occlusion (G-L).

Results

G-D had a higher prevalence of STE ≥0.5 mm in each of leads I and aVL and a lower prevalence of STE ≥1 mm in each of leads V₁ through V₆ than G-L. The prevalence of STE ≥0.5 mm in lead aVL without STE ≥1 mm in lead V₁ was higher in G-D (82.1%) than in G-L (9.4%, P < .01).

Conclusion

ST-segment elevation ≥0.5 mm in lead aVL without STE ≥1 mm in lead V₁ may be useful to distinguish STE-AMI caused by occlusion of the D1 from STE-AMI caused by occlusion of the LAD.     

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。     

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.     

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.     

平板运动试验对左前降支单支病变部位的预测价值

目的 探讨平板运动试验对左前降支（LAD）单支病变部位的预测价值.方法 选取2008年1月至2013年7月平板运动试验阳性,且冠状动脉造影为LAD单支病变患者64例,根据病变部位分成两组,LAD近端病变组34例,LAD中远端病变组30例,回顾性对比分析平板运动试验与LAD病变部位的关系.结果 LAD近端组的aVR导联抬高幅度明显高于LAD中远端组（P＜0.01）,伴胸闷、胸痛例数LAD近端组明显多于LAD中远端组（P＜0.05）,Duke评分LAD近端组明显低于LAD中远端组（P＜0.05）.运动时间、ST段改变开始时间、累积ST段下移幅度、达到目标心率的比率两组比较差异无统计学意义（P＞0.05）.LAD近端病变组出现aVR导联ST段抬高≥0.10 mV患者例数明显多于LAD中远端病变组（64.7％比20.0％,P=0.000）.aVR导联ST段抬高≥0.10 mV预测LAD近端病变的敏感度为64.71％、特异度为80.00％、阳性预测值78.57％、阴性预测值66.67％、准确率为71.88％.结论 平板运动试验诱发aVR导联ST段抬高对早期预测LAD近端病变有重要价值.     

Electrocardiographic criteria for predicting total occlusion of the proximal left anterior descending coronary artery in anterior wall acute myocardial infarction

BACKGROUND: Patients with occlusion of the left anterior descending coronary artery (LAD) proximal to both the first septal branch and the first diagonal branch may benefit most from early reperfusion therapy due to extensive area at risk. HYPOTHESIS: The aim of the study was to examine whether 12-lead electrocardiograms (ECGs) in the acute phase of acute myocardial infarction (AMI) could identify total occlusion of the LAD proximal to both the first septal and the first diagonal branch. METHODS: A 12-lead electrocardiogram was recorded on admission in 128 patients with anterior AMI within 12 h from symptom onset. Patients were divided into three groups according to the culprit lesion: 33 patients had total occlusion of the LAD proximal to both the first septal perforator and the first diagonal branch (Group P), in 51 it was proximal to either the first septal perforator or the first diagonal branch (Group D-a), and in 44 it was distal to both the first septal perforator and the first diagonal branch (Group D-b). RESULTS: Sensitivity and specificity of a greater degree of ST-segment depression in lead III than that of ST-segment elevation in lead aVL were 85 and 95%, respectively, which was better than the results derived by all other ECG criteria (p< 0.001). CONCLUSIONS: We conclude that a greater degree of ST-segment depression in lead III than that of ST-segment elevation in lead aVL is a useful predictor of proximal LAD occlusion in patients with anterior AMI.     

aVR导联ST段抬高对急性心肌梗死预后的价值

目的探讨心电图aVR导联ST段抬高对急性前壁心肌梗死患者预后的价值。方法首次入院急性前壁心肌梗死患者57例，对其心电图和冠状动脉造影及临床资料进行对比分析。根据心电图aVR导联ST段变化分为抬高组、无偏移组。结果梗死相关血管为左主干病变的ST段抬高组、ST段无偏移组分别为5例（21．7％）、1例（2．9％），两组统计有显著性差异（p〈0．01）；病变范围为多支病变ST段抬高组、ST段无偏移组分别为10例（43．4％）、8例（23．5％），两组统计有显著性差异（p〈0．05）；发生心脏事件ST段抬高组、ST段无偏移组分别为8例（34.8％）、3例（8．8％），两组有显著性差异（p〈0．01）。结论aVR导联ST段抬高对预测急性前壁心肌梗死患者的预后有重要的价值，应高度重视。     

Determinants of ST-segment level in lead aVR in anterior wall acute myocardial infarction with ST-segment elevation

Background

This study aimed to clarify the determinants of ST-segment level in lead aVR in anterior wall acute myocardial infarction (AAMI).

Methods

We analyzed ST-segment levels in all 12 leads on admission and emergency coronary angiographic findings in 261 patients with a first AAMI with ST-segment elevation. The length of the left anterior descending coronary artery (LAD) was classified as follows: short = not reaching the apex; medium = perfusing less than 25% of the inferior wall; long = perfusing 25% or more of the inferior wall.

Results

The ST-segment level in lead aVR correlated significantly with the ST-segment levels in leads I, II, III, aVF, V₁, and V_3-6, especially with those in leads II and V₆ (r = −0.63, P < .001; r = −0.61, P < .001; respectively). Patients with a proximal LAD occlusion had a greater ST-segment level in lead aVR than those with a distal LAD occlusion (P < .001). Patients with a long LAD had a lower ST-segment level than those with a short or medium LAD (P < .05).

Conclusions

The ST-segment levels, especially in leads II and V₆, the site of the LAD occlusion, and the length of the LAD affect the ST-segment level in lead aVR in ST-segment elevation AAMI.     

急性前壁心肌梗死时心电图下壁导联ST段改变与左前降支长度和病变部位的关系

目的 探讨急性前壁心肌梗死时下壁ST段改变与左前降支（LAD）长度和病变部位的关系。方法 对75例急性前壁心肌梗死患者的临床资料进行回顾性分析，根据心肌梗死初期是否伴有下壁ST段改变而将患者分成3组，即伴有下壁ST段压低者为I组，伴有下壁ST段抬高者为Ⅱ组，下壁ST段无改变者为Ⅲ组，并与冠状动脉造影结果进行对照。结果 I组中72％患者为LAD非优势近端病变。Ⅱ组中60％患者为LAD优势远端病变；Ⅲ组中LAD优势近端病变与LAD非优势远端病变所占比例相似。结论 急性前壁心肌梗死时下壁ST段改变可能与LAD长度和病变部位有关。     

Significance of a prominent Q wave in lead negative aVR (−aVR) in acute anterior myocardial infarction

Purpose

The aim of this study was to clarify the significance of a Q wave in lead negative aVR (−aVR) in anterior wall acute myocardial infarction (AMI).

Methods

Eighty-seven patients with a first anterior wall AMI were classified into 2 groups according to the presence (n = 17, group A) or absence (n = 70, group B) of a prominent Q wave (duration ≥20 milliseconds) in lead −aVR at predischarge. Group A had a higher prevalence of a long left anterior descending coronary artery (LAD), a lower left ventricular ejection fraction, and more reduced regional wall motion in the apical and inferior regions than group B. None of group A patients had an LAD that did not reach the apex.

Conclusion

A prominent Q wave in lead −aVR in anterior wall AMI is related to severe regional wall motion abnormality in the apical and inferior regions, with an LAD wrapping around the apex.     

aVR、V1导联心电图对左主干及前降支近端明显狭窄的诊断价值

目的探讨aVR、V1导联对冠状动脉左主干及前降支近端狭窄诊断的阳性预测价值。方法对比分析120例冠造结果为左主干病变患者典型aVR、V1导联心电图改变的几率，对比分析120例心电图有典型变化患者的冠脉造影结果。结果①有68例（占56．7％，68／120，）的左主干病变患者出现了典型的aVR、V1导联心电图表现，即典型“左主干”心电图对左主干病变诊断的敏感性为56．7％；②有31例（占37.3％，31／83）典型aVR、V1导联心电图患者冠造结果为左主干病变，有81例（占97．6％，81／83）的典型aVR、V1导联心电图患者冠造结果为左主干及前降支病变，37例患者未检查冠造，典型“左主干”心电图对左主干病变的阳性预测价值为37.3％．而对左主干及／或前降支近段狭窄病变的预测价值为97．6％，二者的差异有显著性（p〈0．001）。结论心电图出现aVR、V1导联ST抬高〉1mm，且aVR导联ST段抬高〉V1导联，V4-6导联ST段下移≥2mm，Ⅱ、Ⅲ、aVF导联ST段下移≥1mm对诊断左主干或前降支近段明显狭窄有很好的阳性预测价值。     

Acute occlusion of the left main trunk presenting as ST-elevation acute coronary syndrome

Acute obstruction of the left main coronary artery (LMCA) is not frequently encountered. Electrocardiographic findings are important to early diagnosis in determining an acute obstruction of the LMCA, which requires immediate aggressive treatment, in this extremely unstable condition. However, there is no single typical electrocardiographic pattern representing acute occlusion of the LMCA. We describe a rare electrocardiographic finding that suggested ST-elevation acute coronary syndrome of the anterior zone due to left main trunk total occlusion.     

Anomalous origin of the right coronary artery from the proximal left anterior descending artery and a single coronary artery anomaly: Three case reports

The anomalous origin of the right coronary artery (RCA) as a branch of the left anterior descending (LAD) artery is a very rare variation of single coronary artery. We have reported three cases in the last 10 years. Among 15,000 coronary angiograms, at least 40 cases have been described previously in the literature. The vast majority of previous reports have described a single anomalous vessel with its origin after the first septal perforator of the LAD. Two of our patients presented with acute coronary syndrome and were found to have three vessel disease and left main. They underwent coronary artery bypass graft surgery (CABG) and third case presented with tachycardia had only mild coronary artery disease (CAD) and was treated medically.     

aVR导联对前壁心肌梗死相关血管定位的作用

目的通过与冠状动脉造影（CAG）对比，研究aVR导联ST段改变的特征。对急性前壁心肌梗死（AAMI）的梗死相关动脉（IRA）阻塞部位的定位。方法对比89例急性前壁心肌梗死病人．其中左前降支近段（PS）闭塞43例、左前降支远段（DS）闭塞46例，胸痛发作12h内的心电图。结果两组胸导联的ST段抬高无明显差异，PS组aVR导联ST段抬高较明显（0．94±0．48mmvs0．30±0．56mm．p=0．021）：PS组Ⅱ、Ⅲ、aVF导联ST段压低较显著（分别为-1．21±0．72mm vs S-0．64±0．53mm。p=0．010；-1．63±0．92mmvs-0．98＋0．39mm．／9=0．016；-1．40±0．66mm vs -0．85±0．32mm，／9=0．000）。在胸导联ST段抬高的同时．aVR导联ST段抬高预测左前降支（LAD）近段闭塞的敏感性（Se）、特异性（Sp）、符合率（CR）、阳性预测值（PPV）、阴性预测值（NPV）分别为60．47％、93．48％、77．53％、89．66％、71．67％。结论在胸导联ST段抬高的同时合并aVR导联ST段抬高和／或下壁导联的ST段压低，可预测左前降支近段闭塞。     

Electrocardiographic prediction of short-term prognosis in patients with acute myocardial infarction associated with the left main coronary artery

Purpose

The purpose of this study was to assess the usefulness of electrocardiogram on admission to predict short-term prognosis in patients with acute myocardial infarction (AMI) associated with left main coronary artery (LMCA).

Methods

Electrocardiogram was obtained on admission in 41 patients with AMI associated with LMCA who underwent reperfusion therapy. Electrocardiographic findings were compared between nonsurvivors and survivors.

Results

There were 24 nonsurvivors and 17 survivors during 30-day follow-up. Nonsurvivors had ST-segment elevation in both leads aVR and aVL (54% vs 18%, P < .05), left anterior fascicular block (83% vs 41%, P < .05), and right bundle-branch block (54% vs 18%, P < .05) more frequently, and ST-segment depression in lead V₅ (17% vs 59%, P < .05) less frequently than survivors among patients with AMI associated with LMCA.

Conclusions

Our data suggested that electrocardiogram on admission might be useful to predict short-term prognosis in patients with AMI associated with LMCA.     

急性心肌梗死左主干与前降支近段病变心电图ST段压低的对照分析

目的探讨12导联心电图ST段压低在急性心肌梗死左主干与前降支近段病变鉴别中的价值。方法选取因急性心肌梗死住院的患者,依冠状动脉造影结果,分为冠状动脉左主干病变(LM组)和左前降支近端病变(LAD组)。回顾性分析患者入院即刻的12导联心电图,比较两组ST段压低改变的特点。结果入选符合标准的患者共74例,LM组15例,LAD组59例。LM组Ⅰ、Ⅲ、aVL和aVF导联ST段压低比例显著高于LAD组(P均<0.05),V2～6ST段压低比例两组亦有差异(P均<0.01)。同时,V2～6导联ST段改变值两组亦有差异。多元分析表明Ⅲ、V2和V6导联ST段压低对急性左主干病变有预测价值(P均<0.001),其诊断的敏感度为26.7%、特异度100%、阳性预测值100%和准确度85.1%。结论Ⅲ、V2和V6导联ST段压低有助于鉴别急性左主干与左前降支近段病变。