Anterior S-T segment depression in acute inferior myocardial infarction: Indicator of posterolateral infarction

Although patients with acute inferior myocardial infarction often manifest S-T segment depression in precordial electrocardiographic leads, the pathophysiologic abnormalities associated with this finding are poorly understood. To examine this problem, electrocardiographic findings on admission were compared with results of radionuclide cineangiography performed within 38 hours of the onset of symptoms in 25 patients with inferior infarction. Summation of S-T depression in leads V₁ through V₄ permitted the separation of patients into two groups: Group A (11 patients with 0.20 mV or less of S-T depression) and Group B (14 patients with 0.45 mV or more of S-T depression). The radionuclide cineangiogram revealed inferior wall dysfunction in all patients. Additional posterolateral dysfunction was seen in 13 patients, all in Group B. Patients in Group B had a relatively larger infarction (peak creatine kinase units = 756 ± 358 in Group A versus 1,566 ± 983 units in Group B, p < 0.01) and greater functional impairment (ejection fraction = 45 ± 12 in Group A versus 33 ± 12 in Group B, p < 0.01). The relation between precordial S-T segment depression and posterolateral dysfunction appears to be largely independent of electrocardiographic evidence of “true posterior infarction.” Thus moderate or severe anterior precordial S-T depression in patients with acute inferior infarction is a sensitive and specific indicator of relatively extensive myocardial damage, primarily involving the posterolateral region.     

ST segment depression in aVL: a sensitive marker for acute inferior myocardial infarction

In a substantial percentage of patients with acute myocardialinfarction, especially in those with inferior wall involvement,no ST elevation is detected on the electrocardiogram. In manyof them, ST depression is found in leads oriented to remotesegments of the heart. The importance of those reciprocal changesfor early diagnosis of acute inferior myocardial infarctionin patients without ST elevation has not been stressed. In orderto find the prevalence of reciprocal ST depression, we evaluatedthe admission electrocardiograms of 107 consecutive patientswith evolving first acute inferior mvocardial infarction. Ninety-threepatients had ST elevation of at least 0.1 mV in at least oneof the inferior leads: II, III or a VF (group A) and in 14 patientsST displacement did not reach 0·1 mV in any of theseleads (group B). In both groups, reciprocal ST depression occurredmore frequently in a VL than in any other lead. Only three patientshad no ST depression in a VL. in eight patients (7·5%ST depression in a VL was the sole early electrocardiographicsign of the inferior infarction, a VL is the only lead thatis facing the superior part of the left ventricle and thus isthe only lead that is truly opponent to the inferior wall. Itseems that ST depression in a VL, by contrast to that in theprecordial leads, is found in the majority of patients withevolving inferior wall myocardial infarction and is not influencedby extension of the infarclion to the right ventricle or tothe posterior wall. We conclude that transient ST depressionin a VL is a sensitive early electrocardiographic sign of acuteinferior wall myocardial infarction.     

Precordial ST segment depression in acute inferior myocardial infarction: the importance of posterolateral wall infarction

To determine whether precordial ST segment depression during acute inferior myocardial infarction indicates posterolateral wall ischemia, anatomical predominance of coronary circulation was examined by coronary angiography and evaluated in 43 patients who experienced first acute inferior myocardial infarction. Among patients who underwent intracoronary thrombolysis within six hours from the onset of symptoms, the infarct-related artery was the right coronary artery (RCA) in 35. In addition, their early 12-lead electrocardiographic features were compared with those in eight patients having the infarct-related left circumflex coronary artery (group Cx). Thirty-five patients with RCA obstruction were categorized in four groups: Four patients with left predominant type (group L), 10 with balanced type (group B), five with right super-predominant type (group SR), and 16 with right intermediate type (group RI). Seventeen of the 21 patients in groups SR and RI demonstrated precordial ST segment depression, whereas it was present in only six of the 14 patients in groups L and B (p less than 0.05). Of the 29 patients in groups SR, Cx and RI, total ST segment depression in leads V1 through V4 (sigma ST) was greater in the 14 patients in groups L and B (p less than 0.05) than in other groups. Furthermore, in these 29, all patients in groups SR and Cx had greater sigma ST than did the patients in group RI (p less than 0.05). There was no significant difference in sigma ST between groups SR and Cx. Precordial ST segment depression did not correlate with concomitant disease of the left anterior descending artery and was not a mirror image of ST segment elevation in inferior leads. On thallium-201 scintigraphy, additional perfusion defects of the posterolateral wall were present in all eight patients in group Cx and in ten of the 21 patients in groups SR and RI. Thus, precordial ST segment depression during acute inferior myocardial infarction seemed to be affected by the pattern of coronary circulation. It was concluded that this ST depression represents more extensive involvement of the posterolateral wall in patients with right predominant coronary circulation as well as in those with left circumflex artery obstruction.     

Anterior ST segment depression during acute inferior myocardial infarction: evidence for the reciprocal change theory

We evaluated the recently proposed concern that ECG anterior ST segment depression in patients with acute inferior wall myocardial infarction represents an additional area of ischemia and therefore implies worsened prognosis. We studied patients enrolled in the Aspirin Myocardial Infarction Study (AMIS), ages 30 to 69 years, who sustained an inferior myocardial infarction within 6 months from the start of the study. Two hundred nineteen patients who met those criteria were followed for an average of 38.2 months. One hundred ten patients had significant anterior lead ST depression (greater than or equal to 0.1 mV) during their acute inferior infarction and their 3-year mortality rate was 9.1%. One hundred nine patients had no anterior ST abnormality and a mortality rate of 10.1% (p = ns). Only one patient with significant depression had a subsequent anterior wall myocardial infarction. Anterior ST depression correlated closely with the magnitude of inferior ST segment elevation. Since ST depression does not alter long-term mortality but relates to magnitude of ST elevation, it probably represents a reciprocal change.     

急性下壁心肌梗死胸前导联ST段下移的临床意义

目的 探讨下壁急性心肌梗死时胸前导联心电图前壁ST段下移的意义。方法 对60例急性下壁心肌梗死病人的早期心电图及入院后3周内冠状动脉造影和心肌酶检查结果对照分析。结果 胸前导联ST段下移者41例(68%),多支病变39例,单支病变2例,胸导联ST段无下移者19例,多支病变4例,单支病变15例(P<0.01),而且前者有较高的CK峰值(P相似文献   

急性下壁心肌梗死伴胸前导联ST段压低的临床意义

评价急性下壁心肌梗死伴胸前导联ＳＴ段压低的临床意义。方法３３例急性下壁心肌梗死患者早期心电图与入院后３周冠脉造影对照，观察急性下壁心肌梗死伴胸前导联ＳＴ段压低与左前降支、多支血管病变、心肌酶峰值、ＳＴⅡ抬高〉ＳＴ；及右冠病变部位关系。     

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。     

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     

急性前壁心肌梗死下壁导联ST段压低的临床价值

目的 探讨急性前壁透壁性心肌梗死时下壁导联ST段压低的临床价值。方法 比较任一下壁导联ST段压低≥1.0mm的17例与压低均＜1．0mm的16例的CK－MB值、超声心动描记术、冠状动脉造影等结果。结果 前组CK－MB值更高,射血分数减低更显著,左室收缩与舒张末期容积更大,造影术示致梗死狭窄病变多位于左前降支近端或呈多支病变。结论 急性前壁心肌梗死下壁导联ST段压低≥1.0mm时,其梗死面积较大,会发生较严重的左室射血功能损害及左心室重构。     

Anterolateral ST segment depression in acute inferior myocardial infarction: angiographic and clinical implications

We examined the relationship between coronary anatomy and anterolateral ST segment depression during inferior acute myocardial infarction (AMI) in 84 consecutive survivors of inferior AMI, who underwent prospective coronary angiography a median time of 2 weeks after AMI. Multivessel disease was defined as two or more significantly (greater than 70%) stenosed vessels. A QRS scoring system was used to estimate myocardial infarct size. Patients with ST depression had more multivessel disease compared to patients with no ST depression (53% vs 6%, p less than 0.01), more left anterior descending stenoses (36% vs 10% p less than 0.05), and higher QRS scores (5.8 +/- 3.2 vs 2.6 +/- 1.8, p less than 0.01) indicating larger infarcts. Patients with ST depression and one-vessel disease (47%) still had higher QRS scores compared to patients with no ST depression (4.8 +/- 2.9 vs 2.6 +/- 1.8, p less than 0.001) and had an increased prevalence of infarct-related vessels with a terminal branch supplying the left ventricular lateral wall or apex. We conclude that anterolateral ST depression during inferior AMI may indicate the presence of additionally stenosed vessels or that the infarct-related vessel has a large vascular territory. The absence of ST depression virtually precludes multivessel disease.     

Angiographic correlates of anterior ST segment depression in acute inferior wall myocardial infarction.

This study was conducted prospectively to assess the correlation between the pattern of anterior ST segment depression on the admission electrocardiogram and the in-hospital morbidity and mortality in patients with acute inferior wall myocardial infarction. Coronary angiography was also done to assess its correlation, if any, with pattern of anterior ST segment depression. Our study cohort comprised of 165 consecutive patients with acute inferior wall myocardial infarction divided into four groups based on admission electrocardiogram. Group I (n = 33): patients with no anterior ST segment depression; group II (n = 16): patients with ST segment depression in leads V1-V3; group III (n = 71): patients with ST segment depression in leads V4-V6, I and aVF, and; group IV (n = 45): patients with ST segment depression in all anterior leads (V1-V6, I, aVL). The outcomes were analysed in terms of high grade atrioventricular block, Killip class II or higher failure, and in-hospital mortality. Coronary angiography was performed to analyse coronary anatomy. Group IV patients had increased incidence of complete heart block (37.8% vs 15.2% in the total group) (p < 0.001) and increased mortality (11.1% vs 4.2% in the total group) (p < 0.05). This group also had greater incidence of triple vessel disease (76.7%) (p < 0.001). Group II patients had greater incidence of double vessel disease (88.9%) (p < 0.05) and had no triple vessel disease. Group III patients had double vessel disease (76.5%) (p < 0.05) or triple vessel disease (23.5%) (p = NS) and no single vessel disease. Coronary angiography in group II showed greater incidence of involvement of left circumflex artery and right coronary artery while in group III there was left anterior descending artery and right coronary artery disease. We conclude that patients with anterior ST segment depression in group III and group IV categories are in high risk subset with acute inferior wall myocardial infarction.     

急性下壁心肌梗死伴有胸前导联ST段压低的临床意义

目的 分析急性下壁心肌梗死（acute inferior myocardial infarction,AIMI）伴有胸前导联ST段压低的冠状动脉病变特点及临床意义。方法 回顾分析2006年8月～2007年8月住院的AIMI患者91例。按胸前导联ST段是否压低将患者分为4组:胸前导联ST段无压低组（n=27）;胸前导联仅V1～4 ST段压低组（n=26）;胸前导联仅V5～6 ST段压低组（n=12）;广泛胸前导联ST段压低组（n=26）。结果 AIMI伴有胸前导联V1～4 ST段压低与冠状动脉多支病变呈负相关,ORⅢ=0.38,无统计学意义;AIMI伴有胸前导联V1～6 ST段压低与冠状动脉多支病变呈正相关,ORⅣ=5.25,P<0.01,有显著统计学意义。胸前导联V1～6 ST段压低组与其他组相比较,左室射血分数（LVEF）低,差异显著（P<0.05）;该组前降支病变率高（73.1%）,但与其他3组相比无统计学差异。结论 AIMI伴有胸前导联V1～6 ST段压低提示多支病变,且心功能不全发生率高。     

急性下壁心肌梗死伴左胸导联ST段压低的临床意义

的　探讨急性下壁心肌梗死伴胸导联 ST段压低的临床意义。方法　选择收住院并行冠状动脉造影术的首发急性下壁心肌梗死患者 88例 ,按照胸导联有无 ST段下移分为不伴胸导联 ST段压低组 45例 ( ST段无压低或 ST段压低 <0 .1m V)及伴胸导联 ST段压低组 43例 ( ST段压低≥ 0 .1m V)。结果　伴胸导联 ST段压低组合并心力衰竭、严重心律失常、低血压及住院病死率较不伴胸导联 ST段压低组明显增高 ,冠状动脉造影显示左前降支病变及多支病变者显著增多。结论　急性下壁心肌梗死伴胸导联 ST段压低者其临床合并症多 ,预后差 ,冠状动脉多支病变及合并左前降支病变者显著增多 ,临床上应高度重视。     

Isolated inferior wall ST segment depression as an early sign of acute anterior wall myocardial infarction

Abstract

Background: Reciprocal changes may accompany ST segment elevation in the ischemic territory during acute myocardial infarction (AMI). We examined the hypothesis that isolated inferior ST segment depression on admission is an early sign of anterior wall infarction. Methods: 49 patients admitted to the coronary care unit between January 1996 and June 2008 who presented with inferior ST segment depression in the absence of ST segment elevation. Electrocardiograms (ECGs) obtained on admission and at 24–48 h were reviewed. Culprit artery was determined based on angiographic and echocardiographic data. Results: All patients had ST segment depression in the inferior leads on admission. A subgroup (55%) presented with concomitant ST segment depression in V5–V6. Follow-up ECG showed that 35% developed ST segment elevations and/or T wave inversions in anterior wall leads over 24–48 h. The left anterior descending (LAD) artery or one of its branches was the culprit in 60% of the patients. Sum of ST segment depression, V5–V6 involvement or presence of ‘hyperacute’ T waves did not predict LAD involvement. Conclusion: Isolated ST segment depression in the inferior wall leads during ACS is usually an early sign of anterior wall AMI, in which the LAD or one of its branches is the culprit artery.     

Dipyridamole echocardiography evaluation of acute inferior myocardial infarction with concomitant anterior ST segment depression

The significance of anterior ST segment depression in inferioracute myocardial infarction (AMI) remains controversial. Theaim of this study was to relate precordial ST segment depressionto the topography of residual myocardial ischaemia, with myocardialmapping of the asynergic area and coronary anatomy. Twenty-fivepatients with first inferior AMI (15 patients with anteriorST segment depression: group A and 10 patients without anteriorST segment shift: group B), all underwent: (1) electrocardiographicevaluation on admission to the Coronary Care Unit and at 24h intervals thereafter; (2) 2D-echocardiographic study within3 h of CCU admission: (3) dipyridamole echocardiographic test(DET) (doses of dipyridamole up to 0.84 mg.kg^–1 i.v. over10 min) 4 days after AMI; (4) coronary arteriography within14 days from AMI. To assess regional left ventricular wall motion,a 16 segment model was used and a wall motion score index (WMSI)was derived. The results of DET were correlated to the anatomyof the infarct-related vessel. Compared to group B, group Apatients showed a significantly greater maximal ST segment elevationin inferior limb leads (lead III: 3.9±1.9 mm vs 2.2±1.1mm, P<0.05; aVF: 3.5±13 mm vs 1.7±0.8 mm, P<0.001).Group A patients showed greater WMSI (1.35±0.22 vs 117±0.12,P<0.05), with more frequent postero-lateral wall involvement(72% vs 20%, P<0.05). No patient of either group showed asynergyof the anterior, anterolateral or anteroseptal segments. Nodifferences in the distribution of coronary artery disease wereobserved. Left anterior descending coronary artery disease waspresent in only three patients (20%) in group A and in one patientin group B. DET was positive in eight patients (53%) in groupA and in three (30%) in group B (P = statistically not significant).In all patients DET induced new wall motion abnormalities locatedin the territory of the infarct-related artery. None of thepatients developed new wall motion abnormalities remote fromthe infarct zone or adjacent to the infarct zone, but locatedin different vascular regions. In conclusion, anterior ST segmentdepression in inferior A MI appears to indicate a more extensivearea of asynergy, with frequent involvement of the posterolateralwall. The topography of DET-induced residual myocardial ischaemiadoes not support the hypothesis of concomitant anterior ischaemia.     

急性下壁心肌梗死心电图侧壁导联ST段下移的意义

目的 探讨急性下壁心肌梗死侧壁导联（I,aVL)ST段下移与梗死相关动脉（IRA）的关系。方法 分析98例急性下壁心肌梗死心电图及冠脉造影的结果。结果 Ⅰ导,aVL导ST段下移对判断急性下壁心肌梗死相关动脉为右冠（RCA）的敏感性分别为64．4％和95．9％,特异性分别为80．0％和56．0％,有显著性差异（P＜0．005）;aVL导ST段无明显下移对判断IRA为回旋支（LCX）的阳性预测值为82．4％,阴性预测值为86．4％。结论 I导,aVL导ST段下移是判断RCA为IRA的较敏感的指标;aVL导联ST段无明显下移是预测LCX为IRA较好的指标。     

急性广泛前壁心肌梗死并Ⅱ、Ⅲ、avF导联ST段压低的临床意义

目的　探讨急性前壁心肌梗死并心电图 、 、av F导联 ST段压低的临床意义。方法　随机选取 5 5例急性广泛前壁心肌梗死病人 ,根据入院时心电图 、 、av F ST段是否压低分为 ST段压低组 (n=35 )与 ST段无压低组 (n=2 0 )。 1月内作冠状动脉造影和心电图 ,比较两组病人合并其它冠状动脉病变的发生率、心功能及严重心律失常的发生率。结果　 ST段压低组合并其他冠状动脉病变的发生率为 77.14 % ,其中单支病变右冠状动脉 2 2 .86% ,左回旋支 17.14 % ,合并双支病变 37.14 % ,而无 ST段压低组合并其它冠状动脉病变的发生率为 15 .0 %。在广泛前壁加高侧壁心肌梗死 、 、av F ST段压低时合并其它冠状动脉病变的发生率为 12 .5 0 %。结论　急性广泛前壁心肌梗死伴 、 、av F ST段压低时多提示合并右冠状动脉和左回旋支病变 ,而广泛前壁加高侧壁心肌梗死并出现 、 、av F ST段压低更可能是一种对应性变化