ST segment elevation in lead aVR and coronary artery lesions in patients with acute coronary syndrome

INTRODUCTION: Recently, the prognostic value of ST segment elevation in lead aVR in acute coronary syndrome (ACS) and its relationship with significant stenosis of the left main coronary artery (LMCAS) and three-vessel disease have been highlighted. AIM: Analysis of the relationship between ST segment elevation observed in aVR lead and angiographic severity of coronary artery disease in patients with ACS. METHODS: The study involved 134 patients with ACS, including 54 subjects with ST elevation in aVR (group A) and 80 patients without elevation of ST in the same lead (group B), aged 33-78 years, mean 59.9+/-9.7 years. The severity of coronary artery disease was compared between the two groups. The logistic regression model was used for the analysis of factors affecting ST segment in aVR, as well as LMCAS and three-vessel disease probability. RESULTS: In patients with ST elevation in aVR, three-vessel disease prevalence was two times higher (61.1% vs 35.0%; p <0.01), and LMCAS - three times higher (55.6% vs 17.5%; p <0.000001) than in those without ST elevation in aVR. Factors independently associated with ST elevation in aVR were LMCAS (OR 6.1; 95% CI 2.62-14.23; p <0.00005), ST segment elevation in V1 (OR 3.03; 95% CI 1.34-6.86; p <0.01) and diabetes (OR 2.89; 95% CI 1.17-7.15; p <0.05). The predictors of LMCAS were three-vessel disease and ST elevation in aVR, while the predictors of three-vessel disease were: LMCAS, diabetes, male gender and history of myocardial infarction. CONCLUSIONS: Elevation of the ST segment in aVR in the setting of acute coronary syndrome identifies patients with severe coronary artery disease. Only left main coronary artery disease, however, remains independently associated with ST segment elevation in aVR. Three-vessel disease and the left main coronary artery stenosis equivalent are not independent predictors of ST segment elevation in aVR of standard electrocardiograms recorded in patients with acute coronary syndrome.     

Clinical significance of exercise-induced ST-segment elevation in lead aVR and V1 in patients with chronic stable angina pectoris and strongly positive exercise test results

Electrocardiographic abnormalities in lead aVR and V1 are rarely analyzed on exercise electrocardiograms. Clinical significance of exercise-induced ST-segment changes in lead aVR and V1 during strongly positive electrocardiographic exercise test (EET) in patients with chronic stable angina pectoris remains unclear. The aim of the study was to assess the value of lead aVR and V1 on the exercise electrocardiogram for the detection of left main coronary artery stenosis (LMCAS) and its equivalent (LMCASE) in patients with chronic stable angina pectoris and the strongly positive EET result. The study group consisted of 118 consecutive patients (mean age 58.8 +/- 9.5 years, range 38-77 years), including 30 (25.4%) women. Patients were divided into three groups. In group I, 31 patients with ST elevation in lead aVR and V1, in group II 66 patients with isolated ST elevation in lead aVR, and in group III 21 patients without ST elevation in lead aVR, induced with exercise, were included. Coronary arteriography results were compared among these groups. In patients with isolated exercise-induced ST elevation in lead aVR, the prevalence of LMCAS was five times more frequent than in patients without lead aVR ST elevation (25.8% vs 4.8% p<0.05). There were no differences in the prevalence of LMCASE and multi-vessel coronary disease in the studied groups. In patients with LMCAS significant ST elevation in lead aVR during strongly positive EET were observed (0.25 +/- 0,4 mm vs 1.43 +/- 0.6 mm p = 0.003), whereas there were no significant exercise-induced electrocardiographic changes in lead V1 (0.61 +/- 0.6 mm vs 0.77 +/- 0.6 mm p = 0.08). Sensitivity of isolated exercise-induced ST elevation in lead aVR in detection of LMCAS was 85.0%, specificity - 50.0%, positive predictive value - 25.8%, negative predictive value - 94.2%, and total accuracy - 55.9%. Exercise-induced ST elevation in lead aVR on the strongly positive exercise ECG may detect LMCAS in patients with chronic stable angina pectoris.     

运动试验阳性患者aVR及V1导联ST段变化对左主干病变的预测价值

目的 评价运动试验阳性(Duke评分≤-11分)患者中aVR及V1导联ST段变化对于左主干病变的预测价值.方法 回顾性分析了 96例(Duke评分≤-11分)运动试验阳性患者,在运动试验中aVR及V1导联ST段变化,并与冠状动脉造影(CAG)结果比较.结果 单纯aVR导联ST段抬高,在诊断左主干病变的敏感性为85.5%,特异性47.1%,准确率62.5%;而aVR及V1导联ST段均抬高,且STaVR/STV1＞1时,在诊断左主干病变的敏感性为82.1%,特异性83.8%,准确率83.3%.结论 在运动试验中aVR和V1导联ST段抬高(STaVR/STV1＞1),对左主干病变有较高的预测价值.     

Prediction of acute left main coronary artery obstruction by 12-lead electrocardiography. ST segment elevation in lead aVR with less ST segment elevation in lead V(1).

OBJECTIVES: We sought to determine the electrocardiographic (ECG) features associated with acute left main coronary artery (LMCA) obstruction. BACKGROUND: Prediction of LMCA obstruction is important with regard to selecting the appropriate treatment strategy, because acute LMCA obstruction usually causes severe hemodynamic deterioration, resulting in a less favorable prognosis. METHODS: We studied the admission 12-lead ECGs in 16 consecutive patients with acute LMCA obstruction (LMCA group), 46 patients with acute left anterior descending coronary artery (LAD) obstruction (LAD group) and 24 patients with acute right coronary artery (RCA) obstruction (RCA group). RESULTS: Lead aVR ST segment elevation (>0.05 mV) occurred with a significantly higher incidence in the LMCA group (88% [14/16]) than in the LAD (43% [20/46]) or RCA (8% [2/24]) groups. Lead aVR ST segment elevation was significantly higher in the LMCA group (0.16 +/- 0.13 mV) than in the LAD group (0.04 +/- 0.10 mV). Lead V(1) ST segment elevation was lower in the LMCA group (0.00 +/- 0.21 mV) than in the LAD group (0.14 +/- 0.11 mV). The finding of lead aVR ST segment elevation greater than or equal to lead V(1) ST segment elevation distinguished the LMCA group from the LAD group, with 81% sensitivity, 80% specificity and 81% accuracy. A ST segment shift in lead aVR and the inferior leads distinguished the LMCA group from the RCA group. In acute LMCA obstruction, death occurred more frequently in patients with higher ST segment elevation in lead aVR than in those with less severe elevation. CONCLUSIONS: Lead aVR ST segment elevation with less ST segment elevation in lead V(1) is an important predictor of acute LMCA obstruction. In acute LMCA obstruction, lead aVR ST segment elevation also contributes to predicting a patient's clinical outcome.     

静息心电图在诊断冠状动脉病变中的作用

目的探讨常规12导联心电图指标对静息状态下冠状动脉病变的预测价值。方法回顾性分析1998年3月～2006年1月拟诊不稳定型心绞痛并行冠状动脉造影患者（104例）的造影资料及冠脉造影前心电图。以左主干、前降支、回旋支、右冠状动脉中任一支狭窄≥50％者为阳性，将患者分为阴性组（8例）、单支病变组（41例）、双支病变组（25例）、三支病变组（16例）、左主干病变组（14例，可合并单支、双支或三支病变）。各组病例的年龄、性别、化验检查等指标进行统计学分析；计数各组病例心电图aVR导联ST段抬高病例数、异常导联数、ST段移位绝对值之和、异常导联数＋ST段移位绝对值之和、ST段时间，在单支病变组、双支病变组、三支病变组和左主干组之间进行统计学分析。结果①年龄：单支病变组与左主干病变组比较有显著性差异（P〈0.05），其它各组间比较无显著性差异（p〉0．05）。（参avR导联ST段抬高、异常导联数、ST移位、异常导联＋ST段移位：单支病变组与三支病变组、左主干病变组之间比较有显著性差异（P〈0．05）；ST段改变时间：单支病变组与左主干病变组之间比较有显著性差异（p〈0.05），但与三支病变组比较无显著性差异（P〉0．05）。③aVR导联抬高、ST段移位、异常导联＋ST段移位：双支病变组与三支病变组、左主干组比较有显著性差异（p〈0．05）；异常导联，双支病变组与三支病变组、左主干病变组比较无显著性差异（p〉0．05）；ST段时间：双支病变组与左主干病变组比较有显著性差异（p〈0．05），而与三支病变组比较无显著性差异（p〉0．05）。结论aVR导联抬高、ST段移位、异常导联＋ST段移位是识别单支病变或双支病变与三支病变或左主干病变的敏感指标；ST段时间是识别单支病变或双支病变与左主干病变的敏感指标，但对识别三支病变不敏感；异常导联数对识别单支病变与三支病变或左主干病变敏感，但对识别双支病变与三支病变或左主干病变不敏感。     

严重冠脉病变的心电图分析

目的分析左主干、前降支近端或三支病变冠心病心绞痛患者的心电图改变。方法13例冠脉造影诊断为左主干、前降支近端或三支病变的患者,对其静息时、心绞痛发作时心电图有无aVR、V1导联的ST段抬高及临床资料进行分析。结果胸痛发作时11例出现了aVR、V1导联典型改变,静息时2例aVR、V1导联改变。结论心电图aVR、V1导联ST段抬高,尤其STaVR〉STV1,V4～V6导联ST段下移,合并Ⅱ、Ⅲ、aVF导联或Ⅰ、Ⅱ导联ST段下移与冠脉左主干、前降支近端严重狭窄及三支病变有良好的相关性。     

Significance of exercise-induced ST changes in leads aVR,V5, and V1. Discrimination of patients with single- or multivessel coronary artery disease

BACKGROUND: It is known that exercise-induced ST-segment elevation in lead V1 (V1-E) detects left anterior descending (LAD) stenosis. It was also postulated that ST elevation in aVR and simultaneous ST depression in V5 (aVR-E + V5-D) is a marker of ischemia due to significant stenosis of the LAD in patients with single-vessel disease. HYPOTHESIS: This study was undertaken to investigate the significance of the concomitant appearance of both electrocardiographic (ECG) ischemic markers, and of each of them alone during exercise, to detect either LAD stenosis as single-vessel coronary artery disease (CAD), or multivessel CAD involving LAD stenosis. METHODS: A total of 196 consecutive patients (152 men and 44 women, mean age 54 +/- 7 years) with at least one of these ECG markers, who underwent treadmill exercise testing with the Bruce protocol and coronary arteriography, were studied. RESULTS: Patients were divided into three groups. In Group A (83 patients with V1-E + aVR-E & V5-D), 93% of patients with single-vessel disease had significant LAD stenosis (p<0.001), whereas 75% of patients with double-vessel disease had significant stenoses of the LAD and the left circumflex (LCx) coronary arteries (p<0.01). In Group B (97 patients with aVR-E & V5-D but without V1-E), 43% of patients with single-vessel disease had significant LAD stenosis (p<0.08), whereas 85% of patients with double-vessel disease had significant stenoses of the LAD and the right coronary artery (RCA) (p<0.01). In Group C (16 patients with only V1-E), 60% of patients with single-vessel disease had significant LAD stenosis (p<0.05), whereas 75% of patients with double-vessel disease had significant LAD and LCx stenoses (p<0.05). CONCLUSIONS: The concomitant appearance of exercise-induced ST elevation in lead V1, ST elevation in lead aVR, and ST depression in lead V5, as well as the isolated appearance of ST elevation in lead V1 detect significant LAD stenosis as single-vessel disease, or significant stenoses of LAD and LCx arteries in patients with double-vessel disease, whereas the appearance of ST elevation in aVR & ST depression in V5 but without ST elevation in V1 correlates strongly with significant LAD and RCA stenoses and usually indicates double-vessel disease.     

STaVR抬高对急性冠状动脉综合征预后评估的价值

目的探讨心电图STaVR抬高对急性冠状动脉综合征预后评估的价值。方法回顾性分析68例急性冠状动脉综合征患者的心电图和冠状动脉造影资料、临床资料。根据STaVR抬高是否≥0.05mV分为抬高组（n=23）和非抬高组（n=45）。结果病变血管涉及左主干和左前降支近段的分别为抬高组13例（56.5％）和非抬高组1例（2.2％）,病变范围为多支病变的分别为9例（39.1％）和8例（17．8％）,发生心脏事件分别为7例（30.4％）和4例（8.9％）,两组差异均有非常显著性意义（P〈0．01）。结论急性冠状动脉综合征患者STaVR抬高提示左主干和左前降支近段病变、多支病变的可能,对判断预后有参考价值。     

QRS波宽度及aVR导联ST段抬高对NSTE-ACS左主干或三支病变的预测作用

目的研究非ST段抬高型急性冠脉综合征(NSTE-ACS)患者心电图的QRS波宽度及aVR导联抬高幅度对冠状动脉左主干/三支病变的诊断价值。方法分析106例NSTE-ACS患者的体表心电图QRS波宽度及aVR导联ST段抬高幅度,通过与冠状动脉造影结果对比,研究其对诊断左主干/三支病变的敏感性、特异性和相关性。结果 QRS波宽度及aVR导联ST段抬高是左主干/三支病变的独立预测因子,OR值分别为9.04(95%CI,4.88～16.7)、7.10(95%CI,4.91～76.2);QRS间期≥90ms和aVR导联ST段抬高≥0.5mm预测左主干/三支病变的敏感性及特异性分别为88%、76%及88%、86%。结论 QRS波增宽及aVR导联ST段抬高是NSTE-ACS患者左主干/三支病变较为灵敏的预测因子。     

静息状态下心电图指标对冠心病多支病变诊断价值的比较

目的探讨静息状态下常规十二导联心电图对冠心病患者（非急性心肌梗死、无胸痛发作状态）冠状动脉（冠脉）多支病变的诊断价值。方法观察分析1999年11月至2006年1月于济南市第四人民医院心内科入院拟诊不稳定型心绞痛行冠状动脉造影（CAG）患者（104例）的造影资料及CAG前ECG资料。选择性多体位左、右冠状动脉造影,以左主干、前降支、回旋支、右冠状动脉中任一支狭窄≥50%者为阳性,将患者分为阴性组（8例）、多支病变组[30例,LAD+LCX+RCA和（或）左主干病变]和非多支病变组（66例,单支病变+双支病变）。其中,左主干病变14例（可并发单支、双支或3支病变）。计数各组病例心电图aVR导联ST段抬高病例数、异常导联数、ST段移位绝对值之和、异常导联数+ST段移位绝对值之和、ST段时间,进行统计学分析。结果异常导联数+ST移位、异常导联数、ST段时间、aVR导联ST段抬高,多支病变组与非多支病变组比较有显著差异。异常导联数+ST移位、异常导联数和ST移位的敏感性显著高于aVR导联ST抬高,异常导联数+ST移位的敏感性明显高于ST移位。aVR导联ST抬高和ST移位特异性最好,两者之间无明显差异。结论异常导联数+ST移位、异常导联数、ST移位是诊断冠心病多支病变的敏感指标,且均优于aVR导联ST抬高;异常导联数+ST移位的敏感性明显高于ST移位。     

急性冠脉综合征三支病变患者心电图表现

目的研究急性冠脉综合征(ACS)三支病变患者心电图表现。方法241例冠状动脉(冠脉)造影明确的ACS分成非ST段抬高型急性冠脉综合征(NSTE-ACS)(n=173)与急性ST段抬高型心肌梗死(STEMI)(n=68)两种群体,比较各群体中三支病变与非三支病变患者心电图指标。结果NSTEMI-ACS三支病变与左主干病变患者多表现为V₄~V₆、Ⅰ、Ⅱ导联ST段压低伴随aVR导联ST段抬高的心电图模式。与STEMI非三支病变患者相比,STEMI三支病变患者Ⅰ、aVL、V₆导联ST段抬高数占比较多,且多有aVR导联T波直立与低电压表现;冠脉造影提示STEMI三支病变患者右冠及左回旋支狭窄程度更重。结论NSTEMI-ACS三支病变与左主干病变患者具有相对特定的心电图表现,STEMI三支病变患者心肌梗死部位广泛,易合并侧壁心肌梗死。     

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.     

Clinical presentation and prognosis of left main coronary artery disease in the 1980s

Clinical presentation and course were studied in 127 consecutive patients with angiographically proven left main coronary artery disease. Mean age was 62 (37-79) years. Thirteen patients (10%) had no history of chest pain, seven (5%) had atypical chest pain, and the remaining 107 (85%) typical angina pectoris. Eighty-two patients (65%) had unstable angina, 73 had suffered a myocardial infarction (MI) in the past, and 50 (68%) had post MI angina pectoris. The electrocardiogram was analysed in 102/125 patients during an episode of chest pain and also when they were without chest pain. Outside an episode of chest pain the ST segment was normal in 42 patients (32%), the T wave was normal in 50 patients (38%) and both the ST and T were normal in 33 patients (25%). During chest pain all patients had an abnormal ECG, the most frequent pattern being ST segment depression in leads V3, V4 and V5 (with maximal depression in V4), and ST segment elevation in leads V1 and aVR. The average number of leads with ST-T abnormalities was 6.4. A symptom-limited exercise test on a treadmill with 12-lead ECG monitoring was performed in 89 patients. The exercise test was abnormal in 88 patients (99%), most of whom (74 patients) were already in the first or second stage of the Bruce protocol. The most frequently observed abnormality was ST segment depression of 2 mm or more in leads V4, V5, and V6, and ST segment elevation in leads V1 and aVR. The systolic blood pressure during exercise fell or remained at the same level in 38 patients (43%).(ABSTRACT TRUNCATED AT 250 WORDS)     

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。     

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.     

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。     

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.     

aVR ST段抬高对急性冠状动脉综合征患者罪犯病变的预测价值

目的 探讨aVR ST段抬高对非ST段抬高性急性冠状动脉综合征患者罪犯病变的预测价值.方法 选择因非ST段抬高性急性冠状动脉综合征入院的患者213例,根据aVR ST段分为抬高组和不抬高组,分析心电图与冠状动脉造影结果及冠状动脉病变范围及狭窄程度（以Gensini积分表示）的关系.结果 抬高组Gensini积分（58.16±43.85）高于不抬高组（23.53±26.80）,差异有统计学意义（P＜0.05）.而ST段抬高的3个亚组（抬高＜0.10mV、0.10～0.15mV、＞0.15mV）Gensini积分差异均无统计学意义（均P ＞0.05）.aVR ST段抬高0.5mV以上对左主干病变的敏感度、特异度、阳性预测值、阴性预测值分别为77.8%、59.5%、34.0%、90.9%;对三支病变分别为82.1%、67.1%、53.4%、89.1%;对左主干合并三支病变分别为88.5%、57.2%、22.3%、97.3%.结论 aVR ST段抬高者病变较重,但抬高幅度并不能预测狭窄程度.aVR ST段抬高是急性冠状动脉综合征左主干和（或）三支病变较强的预测因子.     

aVR导联临床应用的新视点

aVR导联是一个经常被忽略的导联,但是,近几年的研究显示aVR导联在诸多方面都发挥着重要的作用。aVR导联经典的临床应用包括窦性心律的确认、电轴的确定、右位心和左右手反联及心室肥厚的诊断。其临床应用的新发现包括:急性冠脉综合征时,aVR导联ST段抬高提示左主干、左前降支近端或三支病变;在ST段抬高型心肌梗死中aVR导联ST段抬高或下移是住院患者死亡率的独立预测因子,可用于危险分层;分析心律失常时,aVR导联可用于鉴别宽QRS型、窄QRS型心动过速;体表心电图的aVR导联结合V1、V2导联可以估算右房房颤周长,并且aVR导联P波振幅是心脏手术术后房颤发生的强有力的预测因子;Brugada综合征时出现"aVR征"有助于危险分层;右室负荷过重时,aVR导联ST段抬高是急性肺栓塞的死亡预测因子(单变量回归分析)和并发症的预测因子;aVR导联R波延迟是慢性右室压力负荷过重的独立预测因子且多见于肺动脉狭窄患者;特发性肺动脉高压的患者中,aVR导联R波>4mm,结合V1导联R波>6mm、R/SV1>1,R/SV5与R/SV1比值<0.04,Ⅱ导联P波>2.5mm可以诊断右室肥厚;当疑似预激综合征时,利用体表心电图同时出现PR间期≤120ms和PR离散度≥20ms、aVR导联缺少初始正向波(间隔R波)和V1导联水平面QRS移行提前这3步可识别心室预激,且具有较高的特异性和敏感性;连续监测aVR导联R波和R/S比例有助于预测三环类抗抑郁药物中毒时意识的恢复;急性心包炎时,aVR导联ST段压低、PR段抬高形成了急性心包炎的特征性表现,即"关节征",并且可能是急性心包炎最早甚至是唯一的心电图改变,具有早期诊断价值。     

Electrocardiographic predictors of Brugada type response during Na channel blockade challenge.

AIM: To identify ECG predictors of Brugada type response during Na channel blockade challenge. METHODS: We studied prospectively 103 patients (M = 76, 45 +/- 13 years) in whom ECGs were collected during ajmaline challenge. ECG recordings included the high right precordial leads (-2V(1) and -2V(2)). A positive response was defined by a >0.2 mV J point or ST segment elevation and a down-sloping pattern of the ST segment in at least one right precordial lead. RESULTS: Ajmaline challenge was positive in 48 (47%) of the 103 cases. Baseline J wave elevation was greater in -2V(1) (0.077 +/- 0.078 mV vs. 0.038 +/- 0.046 mV, P = 0.003) and -2V(2) (0.149 +/- 0.103 mV vs. 0.043 +/- 0.088 mV, P < 0.001) in cases with a subsequent positive response. In contrast, ST segment elevation and T wave amplitudes were reduced in V(1), V(2) and V(3). Logistic regression showed that J wave elevation in -2V(2) and decreased T wave amplitude in V(3) at baseline were independent predictors of a positive response. Baseline J wave elevation >0.16 mV in -2V(2) had a specificity of 100%, a sensitivity of 40%, a positive predictive value of 100% and a negative predictive value of 28%. CONCLUSION: J wave elevation >0.16 mV in -2V(2) was the strongest predictor of a Brugada type response to Na channel blockade challenge when Brugada syndrome was suspected on a baseline ECG.