aVR导联对非ST段抬高型急性冠脉综合征冠状动脉病变的预测价值简

目的 通过与冠状动脉造影对比,研究aVR导联ST段改变的特征对非ST段抬高型急性冠脉综合征病变血管的预测价值.方法 分析625例非ST段抬高型急性冠脉综合征患者一般资料、心电图、超声心动图及冠状动脉造影结果.结果 aVR导联无ST段抬高组（n=537）、ST段抬高0.05～0.1 mrn组（n=58）、ST段抬高＞0.1 mm组（n=30）的左心室射血分数分别为53.6％±7.2％、50.2％±6.8％、48.2％±6.4％,3组比较差异有统计学意义（P=0.003）;恶性心律失常（室性心动过速或心室颤动）发生率分别为3.4％、8.6％、13.3％,3组比较差异有统计学意义（P=0.008）;病死率分别为2.2％、5.2％、10％,3组比较差异有统计学意义（P=0.026）;左主干和（或）三支病变的发生率分别为24.8％、37.9％、56.7％,3组比较差异有统计学意义（P＜0.0005）.结论 非ST段抬高型急性冠脉综合征患者出现aVR导联ST段抬高对判断左主干或三支病变有预测价值,应引起高度重视.     

Study on relationship of acute left main coronary artery occlusion and ST segment elevation in lead aVR

Objective We sought to evaluate the relationship between the ST-segment elevation in lead aVR in the acute myocardial infarction and the acute left main coronary artery obstruction.     

aVR 导联对急性心肌梗死中左主干病变的诊断意义

目的：通过分析急性心肌梗死患者12导联心电图,探讨心电图对左主干病变的诊断意义。方法对急性心肌梗死并行冠脉造影术的4914例患者进行分层随机抽样,根据造影结果,将样本分为左主干病变组及非左主干病变组。记录两组一般临床资料,盲法测量两组心电图,对比两组得出预测左主干病变的指标。结果二元 logistic 回归分析表明,aVR 导联 ST 段抬高≥0．05 mV（OR：8．160,P ＜0．05）是左主干病变的独立预测因子。联合 aVR 导联ST 段抬高≥0．05 mV、V4～V6导联 ST 段压低、≥5个导联 ST 段压低、aVF 导联低电压、QRS 波群时限＞100 ms 这5个无创性指标,可将确诊左主干病变的概率从25．19％提高到69．24％。5个心电图指标的阳性预测值分别为52．63％、32．73％、26．39％、16．22％和22．22％。结论心电图对急性心肌梗死中左主干病变的预测是可行的。aVR 导联 ST 段抬高≥0．05 mV 是预测左主干病变良好的心电图指标,联合多指标可提高心电图对左主干病变的诊断价值。     

Significance of lead aVR in acute coronary syndrome

The 12-lead electrocardiogram(ECG)is a crucial tool in the diagnosis and risk stratification of acute coronary syndrome(ACS).Unlike other 11 leads,lead aVR has been long neglected until recent years.However,recent investigations have shown that an analysis of ST-segment shift in lead aVR provides useful information on the coronary angiographic anatomy and risk stratification in ACS.ST-segment elevation in lead aVR can be caused by(1)transmural ischemia in the basal part of the interventricular septum caused by impaired coronary blood flow of the first major branch originating from the left anterior descending coronary artery;(2)transmural ischemia in the right ventricular outflow tract caused by impaired coronary blood flow of the large conal branch originating from the right coronary artery;and(3)reciprocal changes opposite to ischemic or non-ischemic ST-segment depression in the lateral limb and precordial leads.On the other hand,ST-segment depression in lead aVR can be caused by transmural ischemia in the inferolateral and apical regions.It has been recently shown that an analysis of T wave in lead aVR also provides useful prognostic information in the general population and patients with prior myocardial infarction.Cardiologists should pay more attention to the tracing of lead aVR when interpreting the12-lead ECG in clinical practice.     

Off-pump bypass grafting in patients with significant left main coronary artery stenosis

The aim of this study was to investigate and determine whether patients with significant (%50) left main coronary artery stenosis could undergo coronary bypass on the beating heart and compare the results to those obtained using the conventional method. Prospectively collected data of patients with significant left main coronary artery disease who had undergone coronary bypass on the beating heart (group A, n = 100) or with the conventional method (group B, n = 100) were evaluated retrospectively. EuroSCORE values, preoperative and operative details, postoperative morbidity and mortality, and early results were compared. Groups were similar in terms of EuroSCORE, demographics, and preoperative variables. Number of distal anastomoses per patient was 3.1 ± 0.9 in the beating heart group while it was 3.3 ± 0.9 in the conventional group (P = 0.09). Patients operated on with the conventional method had higher levels of peak creatine kinase-myocardial band, blood and blood product transfusions, and inotropic requirements, while mechanical ventilation times and hospital stay were longer. The incidence of postoperative atrial fibrillation, mediastinitis, and intra-aortic balloon usage were comparable between the groups. There was no neurological complication in group A whereas five major neurological complications (three transient ischemic attacks, two strokes) occurred in group B (P = 0.06). Thirty-day mortality occurred in one patient in the beating heart group whereas five early deaths were observed in the conventional group (P = 0.21). In significant left main coronary artery stenosis coronary bypass on the beating heart is a safe and effective alternative to the conventional method with the same or better early results. The long-term results need to be evaluated.     

Iatrogenic left main coronary artery stenosis

Iatrogenic left main coronary artery stenosis is a potentially life-threatening complication of cardiac valve replacement surgery due to injury by perfusion cannulas. This requires prompt clinical recognition and diagnosis by repeat coronary angiography, and treatment by early coronary artery bypass grafting. We present 3 patients who had normal coronary arteries prior to valve replacement surgery, and who developed severe left main coronary artery stenosis after surgery. Accelerating angina and refractory ventricular arrhythmia were presenting clinical manifestations. Coronary artery bypass grafting was successfully performed in all 3 patients.     

Radiation-induced stenosis of the left main coronary artery

Isolated left main coronary artery stenosis induced by mediastinal radiation is a well-documented but rare entity. Its clinical manifestations can be latent for many years, but its ominous sequela cannot be ignored. We report here such a patient presenting 16 yr postmediastinal radiation, the longest documented latency to date.     

Radiation-induced stenosis of the left main coronary artery

A case of isolated left main coronary artery stenosis ten years following irradiation of the mediastinum for Hodgkin's disease is presented. Aortic biopsies were consistent with changes suggestive of radiation arteritis.     

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.     

Off-pump coronary revascularization for left main coronary artery stenosis

Experience of on- and off-pump coronary artery bypass in 379 patients with significant left main coronary artery stenosis was retrospectively reviewed. Beating-heart operations were performed on 219 patients between January 2001 and October 2007. Their results were compared with 160 who underwent revascularization under cardiopulmonary bypass during the same period. All patients had multivessel grafting via a median sternotomy. Both groups were comparable demographically. Off-pump patients received significantly fewer grafts per patient (3.21 +/- 0.86 vs 3.74 +/- 0.82). The use of moderate or high doses of inotropics (> 5 microg kg(-1) min(-1)) was more frequent in the on-pump group (44% vs 26%). Postoperative blood transfusion requirement was lower in off-pump patients, and fewer of them experienced worsening of preexisting renal insufficiency. There were 2 operative deaths in the on-pump group and 1 in the off-pump group. The off-pump procedure is safe and effective in patients with left main coronary artery disease.     

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.     

Stenting of unprotected left main coronary artery stenosis

Unprotected left main stenosis greater than 50% has traditionally been managed with coronary artery bypass surgery. There is now emerging evidence to support a percutaneous strategy adopting drug-eluting stents, especially in patients at high risk for surgery. This paper will review recent outcomes of both bare-metal and drug-eluting stent use for unprotected left main stenosis and summarise results of an Australian registry. Results of studies comparing the percutaneous approach to surgery will also be reviewed together with ESC and AHA/ACC current guidelines. Although percutaneous intervention of unprotected left main has been shown to be a safe and feasible procedure, unanswered questions remain. Large multi-centre randomised trials underway comparing percutaneous to surgical intervention will help clarify these ongoing issues.     

Progression of left main coronary artery stenosis following left anterior descending coronary artery angioplasty

Although recent clinical experience indicates a high success rate, percutaneous transluminal coronary angioplasty (PTCA) is still associated with serious complications which usually occur during or shortly after the procedure and are principally related to the lesion or segment of vessel being dilated. We report 2 cases of subacute progression within months of left main stenosis following successful, uncomplicated left anterior descending (LAD) coronary PTCA. Identification of left main trunk involvement may mandate earlier follow-up or intervention.     

Pericatheterization risk factors in left main coronary artery stenosis

Patients with left main (LM) coronary artery disease (CAD) have an unexplained high incidence of complications during diagnostic cardiac catheterization. This study identifies pericatheterization risk factors for major complications in patients with LM CAD (stenosis at least 50%). Complications were defined as ventricular fibrillation not related temporally to coronary injection, persistent angina, acute myocardial infarction, profound hypotension and death during or within 24 hours of catheterization. One hundred seven consecutive cases of LM CAD (11 with complications and 96 without) were reviewed with respect to variables potentially related to complications. Patients who had angina in the 24 hours before catheterization were at increased risk. Four of 13 patients with angina (31%) and 7 of 94 (7%) without angina had complications (p less than 0.05). Distance from the catheter tip to the lesion also was related to complications (9 of 38 [24%] with tip 6.0 mm or less from lesion and 2 of 65 [3%] with tip more than 6.0 mm from lesion, p less than 0.05). No relaxation was found between complications and New York Heart Association functional class, technique (femoral vs brachial), performance of ventriculography, number of coronary injections, amount of contrast injected, severity of LM stenosis, number of major arteries with 75% or more diameter stenosis, mean arterial pressure, left ventricular end-diastolic pressure and left ventricular ejection fraction.     

Patch angioplasty in isolated left main coronary artery stenosis

A 50 year old male with isolated left main coronary artery disease was surgically treated with saphenous vein patch angioplasty. Surgery results are reviewed by coronariography 2 months later and we comment its use as alternative technique in selected cases.     

Percutaneous coronary intervention for unprotected left main coronary artery stenosis

Hemodynamically significant left main coronary artery stenosis (LMCA) is found in around 4% of diagnostic coronary angiograms and is known as unprotected LMCA stenosis if the left coronary artery and left circumflex artery has no previous patent grafts. Previous randomized studies have demonstrated a significant reduction in mortality when revascularization by coronary artery bypass graft (CABG) surgery was undertaken compared with medical treatment. Therefore, current practice guidelines do not recommend percutaneous coronary intervention (PCI) for such a lesion because of the proven benefit of surgery and high rates of restenosis with the use of bare metal stents. However, with the advent of drug-eluting stents (DES), the long term outcomes of PCI with DES to treat unprotected LMCA stenoses have been acceptable. Therefore, apart from the current guidelines, PCI for treatment of unprotected LMCA stenosis is often undertaken in individuals who are at a very high risk of CABG or refuse to undergo a sternotomy. Future randomized studies comparing CABG vs PCI using DES for treatment of unprotected LMCA stenosis would be a great advance in clinical knowledge for the adoption of appropriate treatment.