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。     

ST segment response to acute coronary occlusion: coronary hemodynamic and angiographic determinants of direction of ST segment shift

To assess the relationship between the direction of ST segment response to transient coronary occlusion and collateral function, we studied 25 patients with diagnostic ST segment changes during transient occlusion of the proximal left anterior descending artery (LAD). Electrocardiographic leads I, II, V2, and V5; left ventricular filling, aortic, and distal coronary pressures; and great cardiac vein flow were measured during percutaneous transluminal coronary angioplasty (PTCA) of the LAD. During a 1 min LAD balloon occlusion, 16 patients had reversible ST elevation (group I) and nine patients had ST depression (group II). The ST responses in individual patients were consistent during repeated occlusions, and ST depression never preceded ST elevation. Angiography before PTCA showed less severe LAD stenosis in group I (69 +/- 15%) than in group II (88 +/- 10%; p less than .01) and collateral filling of the LAD in no group I patient but in six of nine patients in group II (p less than .01). During LAD occlusion, determinants of myocardial oxygen demand (left ventricular filling pressure, aortic pressure, heart rate, and double product) were similar in both groups. Group I patients, however, had lower distal coronary pressure (25 +/- 8 vs 41 +/- 16 mm Hg) and residual great cardiac vein flow (33 +/- 14 vs 51 +/- 22 ml/min) and higher coronary collateral resistance (3.1 +/- 2.1 vs 1.5 +/- 0.8 mm Hg/ml/min) than group II patients (all p less than .05). In patients with ST elevation during LAD occlusion, stenosis before PTCA was less severe, visible collaterals were not present, and hemodynamic variables during LAD occlusion reflected poorer collateral function.(ABSTRACT TRUNCATED AT 250 WORDS)     

Mechanism of anterior ST segment depression during acute inferior myocardial infarction. Observations during coronary thrombolysis

Anterior ST segment depression, found in 13 of 17 patients with acute inferior myocardial infarctions, resolved promptly in all 11 patients whose occluded right coronary arteries were opened with an infusion of streptokinase. Failure of streptokinase to open the artery produced no change in the electrocardiogram. Five of the patients with anterior ST segment depression had normal left anterior descending coronary arteries. In the other patients opening the right coronary artery normalized the anterior ST segments without resulting in collateral flow to the anterior wall, or changing blood pressure or heart rate. Anterior ST depression was a manifestation of the inferior infarction and was not due to anterior ischemia.     

急性下壁心肌梗死ST段改变与相关冠状动脉阻塞的关系

目的探讨急性下壁心肌梗死时心电图ST段改变与相关冠状动脉阻塞的关系。方法对30例急性下壁心肌梗死ST段改变与冠状动脉造影结果对比分析。结果急性心肌梗死部位下壁12例、下壁+正后壁5例、下壁+右心室8例、下壁+前壁5例。其中单支病变10例,双支病变12例,三支病变8例。右冠状动脉狭窄87.7%,左回旋支狭窄12.2%。ST段抬高Ⅲ>Ⅱ,压低aVL>Ⅰ,诊断右冠状动脉阻塞,敏感性、特异性分别为95.0%、93.4%。V4导联ST段压低与Ⅲ导联ST段抬高比值>0.5,可诊断左回旋支阻塞,敏感性、特异性分别为84.9%和79.4%,ST段抬高Ⅰ>aVL、压低Ⅱ>Ⅲ,提示左回旋支阻塞,敏感性、特异性分别为52.1%和78%。结论急性下壁心肌梗死心电图ST段抬高Ⅲ>Ⅱ、ST段压低aVL>Ⅰ,提示右冠状动脉阻塞,V4导联ST段压低与Ⅲ导联ST段抬高比值>0.5,ST段抬高Ⅰ>aVL、ST段压低Ⅱ>Ⅲ,提示左回旋支阻塞。     

Right coronary artery occlusion: its role in the mechanism of precordial ST segment depression

To investigate the mechanism of precordial ST segment depression during right coronary artery occlusion, precordial ST segment shifts and myocardial lactate metabolism were evaluated during coronary angioplasty in 10 patients with (group A) and 7 patients without (group B) precordial ST segment depression during balloon occlusion of the right coronary artery, and in 17 patients with precordial ST segment depression during balloon occlusion of the left anterior descending artery (group C). A 12 lead electrocardiogram was continuously recorded in each patient. Blood lactate in the aorta and great cardiac vein was measured during the procedure, and the lactate extraction ratio in the anterior wall was determined both before and during balloon occlusion. Eight of the 10 patients in group A and 1 of the 7 patients in group B had a dominant large right coronary artery. There were no significant differences in summed ST segment elevation in leads II, III and a VF between group A (0.56 +/- 0.26 mV) and group B (0.46 +/- 0.19 mV) during balloon occlusion of the right coronary artery, and no significant differences in summed ST segment depression in leads V1 to V6 during balloon occlusion between group A (0.44 +/- 0.26 mV) and group C (0.38 +/- 0.14 mV). Lactate extraction ratio before balloon occlusion was similar among the three groups. Patients in group A had a higher lactate extraction ratio during (38 +/- 11%) compared with before (30 +/- 11%) (p less than 0.05) balloon occlusion despite precordial ST segment depression.(ABSTRACT TRUNCATED AT 250 WORDS)     

急性前壁心肌梗死合并下壁导联ST段下移的临床意义

48例首次急性前壁心肌梗死患者中伴下壁导联ST段平均下移>1mm、持续时间>48h者,CK和CK-MB的平均峰值更高,核素检查左室射血分数<40％,左室下壁运动障碍、出现放射性稀疏或缺损区的发生率也更高(P<0.05或<0.01)。说明这类病人有下壁心肌缺血,且可能心肌坏死面积更广。     

Clinical significance of precordial ST segment depression during acute inferior myocardial infarction

To investigate the mechanisms and clinical significance of precordial (V1-V4) ST segment depression during acute inferior myocardial infarction, stress thallium-201 scintigrams and coronary angiograms were obtained within four to eight weeks after the onset of myocardial infarction in 37 patients experiencing their first acute inferior myocardial infarction. Among 18 patients with precordial ST depression (group 1), 11 with concomitant disease of the left anterior descending artery (LAD) had positive results on exercise test, whereas in seven patients without LAD lesion, only two had positive exercise test (p less than 0.01). In 19 patients without precordial ST depression (group 2), 11 had severe stenosis in the LAD. However, among these 11 patients, only two had positive exercise tests. Patients with precordial ST depression demonstrated a higher frequency of positive exercise tests than those without it (p less than 0.01). On stress thallium-201 scintigraphy, a perfusion defect involving the inferior wall was present in all patients, but additional anterior wall ischemia was present in only five of the 18 patients in group 1. These five patients had chest pain on exercise tests and a severe stenosis greater than 90% in the LAD. There was no significant difference in the frequency of additional posterolateral wall infarction between groups 1 and 2. In 18 patients in group 1, sigma ST (total degrees of ST segment depression in leads V1, V2, V3, and V4 in the acute stage) was significantly greater in 11 patients with LAD lesion than in seven without (p less than 0.05), and sigma ST greater than five mm was observed in 12 of 13 patients who had additional anterior wall ischemia and posterolateral wall infarction on stress thallium-201 scintigraphy (p less than 0.05). Myocardial revascularization, such as aortocoronary bypass surgery or percutaneous transluminal coronary angioplasty (PTCA), was performed in six of the 18 patients in group 1 in the chronic stage, but in only one of the 19 patients in group 2. Thus, in patients with initial acute inferior myocardial infarction, those with precordial ST depression seemed to be a high-risk group. It was suggested that, during the early stage of myocardial infarction, this abnormality on electrocardiograms is related to the summation of effects of anterior wall ischemia and posterolateral wall infarction. Furthermore, the sigma ST evaluation is useful in differentiating a mirror image of inferior wall infarction from anterior wall ischemia and posterolateral wall infarction as the mechanism of precordial ST depression.     

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     

Precordial ST segment elevation in acute ischemia caused by right coronary artery occlusion.

The purpose of this study is to determine why precordial ST elevation (V1 lead) occurs during acute occlusion of the right coronary artery (RCA). Nineteen patients with vasospastic angina, in whom ergonovine administration into RCA provoked spasms, were divided into 2 groups by precordial ST change during spasms. Group I (n = 6) had precordial ST elevation; group II (n = 13) had no precordial ST elevation. A subgroup, IIA was comprised 6 patients in group II with spasms in the RCA proximal segment (segment number less than 2 of AHA coronary classification). None had left coronary dominancy. There was no difference in collateral flow during spasms. Location of spasms in group I was in the RCA proximal segment, and was significantly more proximal compared to group II. There was no difference in sigma ST in II, III, aVF between group I and II or IIA. Max ST elevation time by which duration of ischemia was estimated was significantly longer in group I than in group IIA. Three patients in group I displayed precordial ST depression before elevation, in all of whom in sigma ST in II, III, aVF was higher during precordial ST elevation than during depression. During acute occlusion in the RCA proximal segment, precordial ST elevation is caused by ischemia of the right ventricular anterior wall. Furthermore, precordial ST elevation can occur in a patient with RCA dominance, even if ischemic injury in the left ventricular infero-posterior wall increases progressively.     

Prognostic significance of an ST segment depression of patients with an acute coronary attack

An ST-segment depression was studied in the ECGs recorded on the first and third day after admission of 580 patients with an acute heart attack. An acute myocardial infarction was found in 86% of the 115 patients in whose ECG the J-point was depressed 2 mm. or more and the ST-segment was horizontal or sloping downwards in at least one lead (a definite ST-segment depression).The degree of the J-point depression was deemed of prognostic significance. During the first four weeks, the mortality rate was lowest (4.7%) in patients with a J-point depression less than one millimeter or no depression. The corresponding figure for patients with a definite ST-segment depression was three times (21.7%) that of the patients without the pattern (7.3%).The definite ST-segment depression in an acute coronary attack seemed to be accompanied by a severe degree of coronary heart disease. Significant differences between the patients with a definite ST-segment depression and those without the pattern were found in the $\text{C}\text{T}$ ratio, in the degree of pulmonary congestion, in the ECG signs of LVH, and in the digitalis treatment.It is concluded that the definite ST-segment depression has an important clinical and prognostic significance in cases of acute coronary attacks.     

Correlation between resting ST segment depression, exercise testing, coronary angiography, and long-term prognosis

Resting ST segment depression has been identified as a marker for adverse cardiac events in patients with and without known coronary artery disease. To correlate this with exercise testing, coronary angiography, and how it impacts on long-term prognosis, a retrospective study was performed on 476 patients, of whom 223 had no clinical or electrocardiographic evidence of prior myocardial infarction while 253 were survivors of an infarction. All patients performed a standard exercise test and underwent diagnostic coronary angiography within an average of 32 days of their exercise test (range 0 to 90 days). Exclusions were women, those with left bundle branch block, left ventricular hypertrophy, use of digoxin, previous revascularization procedures, or significant valvular or congenital heart disease. Long-term follow-up was carried out for an average of 45 months (+/- 17). Of the patients without prior infarction, 23 (10%) had persistent resting ST segment depression, and of those with a prior history of infarction, 37 (15%) also had resting ST segment depression. Patients with resting ST segment depression and no prior myocardial infarction had a higher prevalence of severe coronary disease (three-vessel and/or left main) (30%) than those without resting ST segment depression (16%) (95% confidence interval [CI] for observed difference -5.0% to 33.9%, p = 0.12). The criterion of greater than or equal to 2 mm of additional exercise-induced ST segment depression was a particularly useful marker in these patients for the diagnosis of any coronary disease (likelihood ratio 3.35, 95% CI 0.56 to 19.93, p = 0.06). Patients with resting ST segment depression and a prior myocardial infarction had a 2.5 times higher prevalence of severe coronary artery disease compared with patients without resting ST segment depression (43% versus 17% prevalence, respectively, 95% CI for observed difference 9.38% to 42.8%, p less than 0.001) and also had larger left ventricles postinfarction (left ventricular end-diastolic volume index 102 ml/m2 compared with 96 ml/m2, p less than 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)     

Arteriographic features of angina pectoris associated with ST segment depression during coronary arterial spasm

To examine the angiographic features of vasospastic angina associated with ST segment depression, we attempted to analyze the coronary arteriograms of 12 patients who exhibited ST segment depression during the ergonovine provocative test. Right and left coronary arteriograms were obtained successively within a short period when the ergonovine administration revealed ST segment depression. Eight out of 12 patients showed non-total spastic obstructions in one of the major coronary arteries. Among them, a collateral augmentation was found only in one patient. Two cases exhibited the well-developed collateral channels during non-anginal periods and in one case a collateral blood supply was reduced by the spasm occurred in the donating artery. In another one, the collateral circulation did not change during anginal period. Three out of 4 patients who showed total spastic obstructions demonstrated transiently augmented collateral circulation which was supplied by the non-spastic artery. These findings may indicate that ST segment depression during coronary artery spasm could attribute to a subendocardial ischemia caused by an incomplete occlusion of large coronary artery and transient reduction or augmentation of collateral blood flow.     

Inferior ST segment depression during acute anterior myocardial infarction: clinical and angiographic correlations

This study was performed to determine whether inferior ST segment depression during early stages of acute transmural anterior myocardial infarction identifies patients with multivessel coronary artery disease and additional inferior ischemia. Coronary and left ventricular angiography were performed within 3.4 months in 33 patients with acute transmural anterior infarction. Initial electrocardiograms, 2 to 5 hours after onset of chest pain, revealed significant ST segment depression (greater than or equal to 0.1 mV) in at least two of leads II, III and a VF in 15 patients (45%) (group B); in 18 patients (group A) this finding was absent. Compared with group A, patients in group B had greater anterior ST elevation (1.2 versus 0.7 mV, p less than 0.025); higher serum peak creatine kinase (2,475 versus 1,147 IU/liter, p less than 0.005); higher Killip scores (2.1 versus 1.3, p less than 0.001); more in-hospital complications (60 versus 17%, p less than 0.05); lower mean left ventricular ejection fraction (34 versus 55%, p less than 0.001); more frequent regional left ventricular dysfunction in anterolateral (91 versus 44%, p less than 0.05), posterolateral (36 versus 0%, p less than 0.05) and inferior (100 versus 6%, p less than 0.005) regions; greater wall motion abnormality scores (10.0 versus 5.5, p less than 0.005); higher frequency of concomitant left circumflex or right coronary artery disease, or both (80 versus 28%, p less than 0.01); more frequent postinfarction angina (100 versus 39%, p less than 0.001) and lower New York Heart Association functional classification scores (1.7 versus 2.4, p less than 0.05) at 6 month follow-up. The time course of inferior ST depression differed from that of anterior ST elevation. Thus, inferior ST depression was maximal in the first 48 hours and decreased (p less than 0.05) thereafter. In contrast, ST elevation in leads V1 to V6 and I appeared to decrease (p = NS) between days 4 and 7. However, inferior ST depression "mirrored" ST elevation in lead aVL, which also decreased (p less than 0.05) after 48 hours. Thus, inferior ST depression during anterior infarction is associated with more extensive infarction, greater morbidity and higher frequency of multivessel coronary disease. Such inferior ST depression might reflect not only "reciprocal change," but also ischemia in adjacent lateral and remote inferior regions.     

Exercise induced ST segment depression preceding ST segment elevation

A case of exercise induced ST segment depression preceding ST segment elevation in precordial leads and persistent ST segment depression in inferior leads is reported. Such an exercise response should suggest significant fixed coronary stenosis in addition to coronary spasm.     

运动试验ST段压低幅度与冠状动脉病变特点的相关性分析

目的:了解运动试验ST段压低不同幅度患者的冠状动脉病变和临床特点,并探讨其相关性。方法:选取114例运动试验阳性和可疑阳性同时行冠状动脉造影的患者为研究对象,按ST段压低幅度分为0.5～0.9mm组、1.0～1.9mm组和≥2.0mm组,比较3组患者冠状动脉病变和临床特点。结果:3组患者间的性别、年龄、心绞痛、高血压、糖尿病和室壁运动障碍人数差异无统计学意义(P0.05),但经皮冠状动脉介入治疗术后的患者人数差异有统计学意义(P=0.032);在冠状动脉病变数目、发生部位方面差异无统计学意义(P0.05);3组患者间血管狭窄90%以上者差异有统计学意义(P=0.035)。经进一步Logistic回归分析发现,血管狭窄90%以上是ST段压低幅度的独立影响因素。结论:运动试验诱发的ST段压低幅度可间接反映冠状动脉病变狭窄程度,且血管狭窄90%以上是ST段压低幅度的独立影响因素。但ST段压低幅度不能反映冠状动脉病变数目和发生部位。     

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.