12导联动态心电图对冠状动脉病变预测价值的探讨

目的 探讨12导联动态心电图(DCG)对冠脉病变的预测价值.方法 选择287例DCG检查示心肌缺血性ST段压低阳性者行冠脉造影(CAG),结果对照分析.结果 DCG心肌缺血性ST段压低点多个导联有阳性改变者,诊断冠脉病变较肯定;ST段压低幅度、持续时间、出现阵次均与冠脉狭窄程度、病变范围有关.结论 DCG对冠脉病变具有重要预测价值.     

急性下壁心肌梗死时胸前和(或)侧壁导联ST段压低的意义

目的:探讨急性下壁心肌梗死(AIMI)时心电图胸前导联和侧壁导联ST段压低的意义.方法:36例AIMI患者依据有无胸前导联和(或)侧壁导联ST段压低分为ST段压低组(甲组)和无ST段压低组(乙组).对两组间肌酸激酶峰值,射血分数及病变冠状动脉血管分布、多支冠状动脉病变进行了比较,并对临床可能的危险因子进行了Logistic多元回归分析.结果:侧壁导联ST段压低危险度与Ⅱ、Ⅲ、aVF导联的ST段抬高值相关(OR=4.185 9,P＜0.05),与V1～3导联ST段压低值相关(OR=5.068 7,P＜0.05),同时,随着左回旋支(LCX)狭窄的加重,侧壁导联ST段压低概率有增加倾向(OR=3.377 4,P＞0.05).胸前导联ST段压低危险度仅与Ⅰ、aVL导联的ST段压低值相关(OR=5.374 3,P＜0.05).结论:AIMI侧壁导联ST段压低与Ⅱ、Ⅲ、aVF抬高程度有关,同时提示可能伴有LCX病变,而胸前导联ST段压低则反映了侧壁心肌缺血.     

冠状动脉造影对急性下壁心肌梗塞时前侧壁导联ST段压低的分析

应用冠状动脉(冠脉)造影,对31例急性下壁心肌梗塞患者,心电图存在前壁或侧壁导联.ST段压低的情况下进行分析。结果发现冠脉双支或双支以上病变者,特别是左旋支存在病变者,易发生侧壁导联ST段压低.JP<0.05。前壁导联ST段压低者中,也以双支或双支以上病变为多。提示急性下壁心肌梗塞时,出现前侧壁导联的ST段压低,为心肌缺血扩展的标志。     

12导联同步动态心电图诊断冠心病心肌缺血的临床研究

目的 评价12导联同步动态心电图诊断冠心病心肌缺血的临床价值. 方法 根据ST段改变情况将170例冠状动脉造影结果可疑患者分为缺血性ST段改变组(观察组,105例)和无缺血性ST段改变组(对照组,65例),分析ST段改变与冠状动脉造影结果的关系. 结果 (1)观察组患者冠状动脉造影阳性率81.91%,对照组24.62%,差异有显著统计学意义(P<0.01);(2)12导联同步动态心电图诊断心肌缺血的敏感性和特异性分别为84.31%和72.06%,精确度79.41%;(3)12导联同步动态心电图诊断多支病变的敏感性高于单支病变,差异有统计学意义(P<0.05). 结论 同步12导联动态心电图对诊断冠心病心肌缺血的敏感性、特异性与精确度较高.可作为诊断心肌缺血的无创性检查方法.     

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。     

胸前导联ST段压低范围和幅度在急性下壁心肌梗塞的意义

目的 :评价胸前导联 ST段压低对急性下壁心肌梗塞的临床意义及探讨其可能发生机理。　　方法 :回顾分析了 1992年～ 1997年期间首次住院诊断急性下壁心肌梗塞患者 183例。将患者分为 4组 :无胸前导联ST段压低组 ( 组 ,n=5 6 ) ;胸前导联 ST段 V1～ 3压低组 ( 组 ,n=31) ;胸前导联 ST段 V4～ 6 压低组 ( 组 ,n=2 3) ;胸前导联 ST段 V1～ 6 压低组 ( 组 ,n=73)。资料分析包括心电图、心肌酶谱、左心室和冠状动脉造影及心肌梗塞的并发症和病死率。　　结果 :胸前导联 ST段压低患者比无胸前导联 ST段压低患者存在较大梗塞范围 ,心肌梗塞并发症和住院病死率较高。广泛 ST段压低时更显著 ,其心律失常、心功能不全发生率和住院病死率分别为 45 .0 %、12 .3% (P<0 .0 5 )和 8.2 %(P<0 .0 1)。胸前导联 ST段广泛压低总和≥ 0 .8m V显示预后更差 ,住院病死率 9.4% ,同 ST段压低 <0 .2 m V比差异显著 (P<0 .0 5 )。 组和 组存在左前降支病变或合并多支冠状动脉病变明显高于 组 ,有统计学差异。　　结论 :胸前导联 ST段压低分布范围和压低幅度对急性下壁心肌梗塞患者的预后判断和危险分层有一定价值。可能提示心肌梗塞范围较大 ,或同时存在前降支病变和多支冠状动脉病变。     

ST段压低在急性左主干病变中的诊断价值

目的探讨ST段压低在急性左主干病变中的诊断价值。方法选取2000年1月～2007年3月间因急性心肌梗死住院的患者134例,经冠状动脉造影证实其中16例左主干病变(LMCA组)、85例前降支病变(LAD组)和33例右冠状动脉病变(RCA组)。患者入院即刻描记12导联心电图,分析各组患者ST段压低情况。结果单因素分析发现,II、III、aVF和V2～V6导联ST段压低在LAD和LMCA组间差异有统计学意义,II、III、aVL、aVF、V2和V6导联ST段压低在LMCA和RCA组间比较,差异有统计学意义。多因素判别分析结果表明,与LAD组相比,II、aVF和V2导联ST段压低对左主干病变有良好的诊断价值,敏感性31.3%,特异性可达98.8%,阳性预测价值83.3%;与RCA组相比时,aVF和V6导联ST段压低亦有良好的预测价值,敏感性62.5%,特异性和阳性预测价值均为100%。结论12导联心电图ST段压低在急性左主干病变诊断中有较高的特异性和阳性预测价值。     

急性下壁心肌梗死胸导ST段压低与冠脉病变的相关性

多项研究认为急性下壁心肌梗死出现的胸前导联ST段压低可能是下壁导联ST段抬高的对应性改变,也可能为前壁心肌缺血和左冠状动脉病变所致。本组资料分析了我院51例急性下壁心肌梗死患者的心电图、冠状动脉造影结果及临床资料,探讨胸前导联ST段压低与冠脉病变的关系及临床意义,报告如下。     

下壁ST段压低与急性前壁心肌梗死的相关性

目的　探讨心电图下壁导联ST段压低与急性前壁心肌梗死 (AMI)的相关性。方法　连续评价 6 3例前壁AMI病人 ,选择病人就诊初始 4h心电图测量其ST水平。住院 1～ 2周行冠状动脉造影 (CAG)同位素心肌灌注显像检查结果对照分析 ;结果　①选择性冠状动脉造影显示冠状动脉病变支数无显著差异 ,左心室造影下壁运动无明显减弱 ;②同位素心肌灌注显示下壁ST段压低组 86 2 1%无下壁心肌缺血表现 ;③下壁导联ST压低组V1 3 导联ST抬高的平均值明显高于不伴下壁导联ST压低组 ,ECG下壁ST段压低明显与V1 3 导联抬高有相关性 ,(r =- 0 5 2 ,P <0 0 5 )。结论　下壁导联ST段压低可能是前壁AMI时V1 3 导联ST抬高的镜影反映而不是下壁心肌缺血表现。     

心电图aVR导联变化对严重左主干狭窄病变的诊断意义

【】 目的 探讨冠状动脉左主干慢性严重狭窄病变的心电图特点。方法 单中心前展性连续选取典型心绞痛发作时12导联心电图aVR导联ST段抬高≥1mm,其他导联ST段压低或不抬高者作为研究对象,心绞痛缓解后aVR导联ST段抬高≥1mm恢复到等电位线。符合这一标准者共计76例住院急性冠脉综合症患者。依冠状动脉造影结果,分析左主干病变特点和其他冠状动脉病变特征。目测狭窄程度≥70%,为严重左主干狭窄病变。结果 单纯左主干严重狭窄54例(54/76, 71.1%),左主干病变 前降支近端近开口病变6例(6/76,7.9%);单纯左回旋支狭窄3例(3/76,3.9%); 其他复杂三支血管病变13例(13/76,17.1%)。冠状动脉正常者为零。左主干严重狭窄患者,aVR导联ST段抬高比非左主干患者更明显(0.25±0.10mV vs 0. 20±0.11mV, P<0.001); ST段压低导联多见于II III aVF和V3-V6导联,左主干严重狭窄患者,ST压低导联ST段压低程度比非左主干患者更明显(p<0.001)。这一特点诊断左主干严重狭窄的敏感性为72.7%, 假阳性54.4%,特异性45.4%,符合率61.9%。     

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.     

Exercise-induced precordial ST-segment depression in prior inferior myocardial infarction with single-vessel disease; with special reference to its mechanisms and distinction from multi-vessel disease

We investigated the mechanisms of exercise-induced precordial ST-segment depression on the electrocardiogram in prior inferior myocardial infarction with single-vessel disease and attempted to differentiate the ST-segment depression between single- and multi-vessel disease. Subjects included three groups: group Ia (n = 11), inferior myocardial infarction with single-vessel disease that showed no precordial ST-segment depression; group Ib (n = 7), inferior myocardial infarction with single-vessel disease accompanied by precordial ST-segment depression; and group II (n = 10), inferior myocardial infarction with multi-vessel disease. The subjects underwent 12-lead exercise electrocardiography, stress Tl-201 myocardial imaging and stress radionuclide ventriculography. Exercise-induced precordial ST-segment depression observed in group Ib was associated with large infarction and infarction extending into the inferoseptal wall of the left ventricle on myocardial image. On stress ventriculography, worsening of the septal wall motion was more frequently observed in group Ib than in group Ia. Coronary arteriography revealed a higher rate of rich collateral vessels to the infarcted zone in group Ib than in group Ia. When we compared the diagnostic ability for detecting multi-vessel disease in prior inferior myocardial infarction, although sensitivity was not different among three tests, both exercise electrocardiography and radionuclide ventriculography had poor specificity and predictive value compared to stress Tl-201 myocardial imaging. Thus we concluded that exercise-induced precordial ST-segment depression observed in prior inferior myocardial infarction with single-vessel disease should reflect a peri-infarctional ischemia located in the inferoseptal wall of the left ventricle, and that stress Tl-201 myocardial imaging is the most accurate method for diagnosing multi-vessel disease in prior inferior myocardial infarction.     

Electrocardiographic ST-segment changes during acute myocardial ischemia

The recognition and management of patients with acute coronary syndromes has relied to a large extent onthe standard 12-lead electrocardiogram (ECG) for assessing ST-segment changes associated with ischemia.The purpose of this review is to show both the capabilities and the limitations of the 12-lead ECG in recognizingischemia, and to seek alternative electrocardiographic leads, optimized for detection of ischemia originating indifferent regions of the ventricular myocardium. Three such leads are proposed—based on the results obtainedby electrocardiographic body-surface mapping performed during ischemia induced by balloon-inflation coronaryangioplasty. A survey of recent clinical studies shows that the electrocardiographic manifestations of acutemyocardial ischemia observed during coronary angioplasty are in agreement with the ST-segment measurements inadmission ECGs of patients with acute myocardial infarction.     

New electrocardiographic criteria for posterior wall acute myocardial ischemia validated by a percutaneous transluminal coronary angioplasty model of acute myocardial infarction

The standard 12-lead electrocardiogram (ECG) fails to detect ST-segment elevation in patients with posterior wall acute myocardial ischemia. However, additional posterior leads V(7-9) provide limited additional diagnostic information to the standard 12-lead ECG when an ischemic criterion of 1-mm ST elevation is used. No study is available to delineate the ischemic criteria in the posterior electrocardiographic leads. Continuous 15-lead ECGs (standard 12 lead + V(7-9)) were recorded in 53 subjects undergoing elective left circumflex coronary angioplasty (posterior ischemia model). ST amplitudes (J + 60 ms) at preangioplasty baseline were subtracted from maximal ST amplitudes during balloon occlusion to create a positive or negative change score (DeltaST) for each of the 15 leads. During 53 left circumflex occlusions, 26 subjects (49%) had DeltaST elevation of > or = 1 mm and 24 subjects (45%) had DeltaST elevation ranging from 0.5 to 0.95 mm in > or = 1 posterior leads. Five subjects (9%) had DeltaST elevation of > or = 1 mm in the posterior leads without DeltaST elevation anywhere in any of the 12 leads. The sensitivity in detecting myocardial ischemia using 15-lead ECGs (58%) was not statistically different from the standard 12-lead ECG (49%) (p = 0.06). Adjusting the ischemic criterion from 1 to 0.5 mm in V(7-9) significantly improved the sensitivity from 49% in the 12-lead ECG to 94% in the 15-lead ECG (p = 0.000). In addition, 12 subjects (23%) had posterior ST-segment elevation without anterior ST-segment depression. Thus, posterior leads V(7-9) contribute significant additional diagnostic information above and beyond the standard 12-lead ECG only when a new ischemic criterion of 0.5 mm instead of 1 mm ST elevation is applied to the posterior leads.     

Comparison of ST depression recorded by Holter monitors and 12-lead ECGs during coronary angiography and exercise testing

Data from previous studies are debatable regarding whether Holter monitors are a reliable electrocardiographic indicator of ischemia, for which the 12-lead electrocardiogram (ECG) is the standard. Simultaneous 12-lead and Holter ECGs were performed on 30 patients with typical angina pectoris during coronary angiography or exercise testing. ST depression recorded by both methods was directly compared, using the 12-lead ECG as the reference. The Holter tapes were also scanned by two automated ST analysis programs and the results were compared to 12-lead ECGs. Only 66 of the 178 12-lead ECG ST depression events were also present on the Holter recordings (37.1% Holter sensitivity). ST depression was underestimated by the Holter recordings compared to the 12-lead ECGs (p < 0.0001). The majority (67.0%) of ST depression events identified by one computer program were false positive events. The degree of ST depression was overestimated compared to 12-lead ECGs by the second program (p = 0.0033). Holter-detected ST depression may not be a reliable ECG indicator of myocardial ischemia.     

ST-segment deviation analysis of the admission 12-lead electrocardiogram as an aid to early diagnosis of acute myocardial infarction with a cardiac magnetic resonance imaging gold standard.

OBJECTIVES: The purpose of this study was to validate existing 12-lead electrocardiographic (ECG) ST-segment elevation myocardial infarction (STEMI) criteria in the diagnosis of acute myocardial infarction (AMI) and the application of similar ST-segment depression (STEMI-equivalent) criteria with contrast-enhanced cardiac magnetic resonance imaging (ceMRI) as the diagnostic gold standard. BACKGROUND: The admission ECG is the cornerstone in the diagnosis of AMI, and ceMRI is a new diagnostic gold standard that can be used to validate existing and novel 12-lead ECG criteria. METHODS: One hundred fifty-one consecutive patients with their first hospital admission for chest pain underwent ceMRI. The 116 patients without ECG confounding factors were included in this study, and AMI was confirmed in 58 (50%). The admission ECG was evaluated on the basis of the lead distribution of ST-segment deviation according to current American College of Cardiology/European Society of Cardiology (ACC/ESC) guidelines. RESULTS: A sensitivity of 50% and specificity of 97% for AMI were achieved with the currently applied ST-segment elevation criteria. Consideration of ST-segment depression in addition to elevation increased sensitivity for detection of AMI from 50% to 84% (p < 0.0001) but only decreased specificity from 97% to 93% (p = 0.50). There were no significant differences in AMI location or size between patients meeting the 12-lead ACC/ESC ST-segment elevation criteria and those only meeting the ST-segment depression criteria. CONCLUSIONS: In patients admitted to hospital with possible AMI, the consideration of both ST-segment elevation and depression in the standard 12 lead-ECG recording significantly increases the sensitivity for the detection of AMI with only a slight decrease in the specificity.     

Comparison of ST-segment deviation to scintigraphically quantified myocardial ischemia during acute coronary occlusion induced by percutaneous transluminal coronary angioplasty

This study compared ST-segment changes during acute coronary artery occlusion with measurements of ischemia by myocardial scintigraphy. Forty patients who were referred for elective prolonged percutaneous transluminal coronary angioplasty underwent 12-lead electrocardiographic recording before the procedure (baseline) and continuously during the entire balloon inflation (occlusion). For each patient, the summed ST-segment deviation was calculated as the maximal absolute difference, elevation or depression, between baseline and occlusion recordings in all 12 leads. Each patient underwent 2 myocardial scintigraphies, 1 with technetium-99m sestamibi injected during the balloon inflation and 1 on the following day as a control study. Ischemia that was induced by balloon occlusion was quantified in terms of extent and severity. Results for the entire study group showed that summed ST deviation correlated with extent (r = 0.59, p < 0.0001) and severity (r = 0.61, p < 0.0001) of ischemia. The location of maximal ST deviation differed for the 3 arteries. For occlusion of the left anterior descending artery, maximal ST deviation was elevated in lead V3. For occlusion of the left circumflex artery, maximal ST deviation was depressed in lead V2. Occlusion of the right coronary artery caused ST elevation in lead III and ST depression in lead V2. In conclusion, this study demonstrated a significant correlation between summed ST deviation and myocardial ischemia during coronary occlusion that is induced by percutaneous transluminal coronary angioplasty.     

Transient myocardial ischemia is an independent predictor of adverse in-hospital outcomes in patients with acute coronary syndromes treated in the telemetry unit

OBJECTIVE: The purpose of this study was to determine whether transient myocardial ischemia (TMI) is predictive of adverse in-hospital outcomes among patients admitted to a telemetry unit with acute coronary syndrome (ACS). Design and Setting: The study was designed as a prospective clinical trial in a telemetry unit of a large, urban, university medical center. SAMPLE: The sample was comprised of adult patients admitted to the telemetry unit for treatment of acute myocardial infarction, unstable angina, or coronary artery disease warranting cardiac catheterization or percutaneous coronary intervention. METHODS: Continuous 12-lead electrocardiographic (ECG) ST-segment monitoring was initiated in patients admitted to the telemetry unit. TMI was defined as a change in ST amplitude of > or = 100 microV (elevation or depression) in > or = 1 ECG lead lasting > or = 60 seconds, comparing a baseline 12-lead ECG with an event ECG. Frequencies, measurements of central tendency, t test, chi(2) test, and logistic regression analysis were used for data analysis. A P value of <.05 was adopted as the critical value to determine statistical significance. RESULTS: In 237 telemetry unit patients, 39 patients (17%) had ischemia. Overall, 46% of the patients with ischemia had in-hospital complications compared with 10% of the group without ischemia (P <.001). After controlling for other predictors of adverse outcomes (eg, age, gender, Norris prognostic indicator), patients with TMI were 8.5 times more likely to have in-hospital complications (95% CI, 3.71 to 19.71). CONCLUSION: TMI is an independent predictor of in-hospital complications among patients with ACS treated in the telemetry unit setting. Continuous 12-lead ECG ST-segment monitoring provides prognostic information for risk stratification of patients admitted to the hospital for treatment of ACS.     

Precordial ST-segment mapping 4. Experience with mapping of ST-segment depression in anterior transmural myocardial infarction

In order to assess the relative significance of precordial ST-segment elevations and depressions, 32 patients with anterior transmural myocardial infarction were studied utilizing serial 49-lead precordial maps. Theoretically, zones of ST-segment depression adjacent to major zones of ST-segment elevation might represent border areas of mild ischemia, and hence could be more readily amenable to intervention therapy. As expected, an extensive zone of ST-segment elevation was observed precordially in each of these patients. However, zones of ST-segment depression in adjacent areas were noted to occur inconsistently, were limited in distribution and magnitude, and bore no fixed relationship to zones of ST-segment elevation. Thus, mapping of precordial ST-segment depression in anterior transmural infarction probably has a limited role in assessing evolution of ischemic injury or therapy in these patients. This finding does not, however, vitiate the significance of ST-segment depressions in angina, intermediate coronary syndrome, or non-transmural infarction, conditions which may deserve further study using mapping techniques.     

Quantitative relation of ST-segment depression during exercise to the magnitude of myocardial ischemia as assessed by single-photon emission computed tomographic myocardial perfusion imaging

The mechanism of ST-segment depression during exercise electrocardiographic treadmill testing (ETT) is unknown. The relatively good correlation between the results of ETT and myocardial perfusion imaging suggests that ST-segment depression may be related to the magnitude of ischemia. Previous studies that investigated this relation have produced conflicting results. We evaluated 1,006 patients who underwent symptom-limited ETT and technetium-99m single-photon emission computed tomographic myocardial perfusion imaging at rest and during stress at a single institution. The magnitude, extent, and duration of ST-segment depression were each strongly associated with the magnitude of myocardial ischemia (p <0.001 for all). The magnitude, extent, and duration of ST-segment depression were highly correlated with each other and had similar relations to the magnitude of ischemia. After adjustment for significant clinical and ETT parameters, these relations remained highly significant. The location of myocardial ischemia was unrelated to ST-segment depression. This large study found that ST-segment depression during ETT is strongly associated with the magnitude of ischemia. These data support a causative role for the magnitude of ischemia in the generation of ST-segment depression.