Significance of ST segment depression in the precordial leads during the acute phase of inferior myocardial infarction

Reciprocal changes of the ST segment in the acute phase of inferior myocardial infarction are common but their significance remain controversial. We studied this problem by comparing the ECG on admission of 83 patients with acute inferior myocardial infarction, with the clinical outcome and haemodynamic and angiographic data obtained on average 3 weeks after the onset of symptoms. Fifty nine patients (Group I) had ST depression greater than or equal to 1 mm in at least one of the leads V1 to V4; 24 patients (Group II) had no ST depression in this territory. The patients in Group I were older (59.6 +/- 6.4 vs 54 +/- 5.3 years, p less than 0.01), had higher total CPK (1 835 +/- 940 vs 875 +/- 305, p less than 0.01) and MB fractions (269 +/- 102 vs 95 +/- 35), more complications during the hospital period (80%, mainly haemodynamic vs 38%, p less than 0.01) and more severe left ventricular dysfunction: ejection fraction 52.2 +/- 6% vs 59.2 +/- 7%, p less than 0.05; cardiac index 2.75 +/- 0.4 l/min/m2 vs 3.25 +/- 0.3 l/min/m2, p less than 0.005). There was no difference in left ventricular wall motion between the groups on biplane angiography. However, coronary angiography showed left coronary disease to be more common in Group I (84%) than in Group II (37%), p less than 0.005. Left anterior descending and left circumflex disease was equally common. Patients with persistent ST depression after 48 hours had lower ejection fractions than those in whom it regressed within 48 hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Significance of reciprocal S-T segment depression in anterior precordial leads in acute inferior myocardial infarction: Concomitant left anterior descending coronary artery disease?

The reciprocal changes of S-T segment depression in the anterior precordial leads of the electrocardiogram in acute inferior myocardial infarction may be due to left anterior descending coronary artery disease and anterior wall ischemia. The electrocardiograms of 45 patients with acute inferior infarction who had subsequent cardiac catheterization (41 patients) or necropsy (4 patients) were examined to test this hypothesis.

Significant left anterior descending coronary artery disease (greater than 70 percent stenosis of luminal diameter) was observed in 31 (69 percent) of the 45 patients. The sensitivity, specificity and predictive value of S-T depression (1 mm or greater) in various anterior precordial leads singly or in combination was determined for this lesion. Left anterior descending coronary artery disease was present in 23 of 24 patients with S-T depression in one or more leads from V₁ to V₄ (predictive value 95 percent), and this index had the best combination of sensitivity (74 percent), specificity (93 percent) and predictive value in this group. Seven of 13 patients with left anterior descending coronary artery disease had S-T depression only in lead I or aVL, or both (sensitivity 100 percent, specificity 53 percent and predictive value 54 percent). S-T depression in any of leads I, aVL and V₁ to V₆ occurred in 37 patients, and 31 of these had left anterior descending coronary artery disease (sensitivity 100 percent, specificity 57 percent and predictive value 84 percent). The eight patients without anterior precordial lead S-T depression did not have left anterior descending coronary artery disease. Complications of infarction developed in 13 patients;S-T depression in at least one of leads V₁ to V₄ occurred in 12 (92 percent) of these 13 but in only 12 (38 percent) of 32 patients without complications.

Thus the predictive value of S-T depression in leads V₁ to V₄ (95 percent) for left anterior descending coronary artery disease is greater than the occurrence of the latter (69 percent) in all cases of acute inferior myocardial infarction (p < 0.05). S-T depression in these leads may be due not to reciprocal changes but rather to left anterior descending coronary artery disease with anterior wall ischemia. Such S-T depression is a sensitive marker for complications in these patients.     

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.     

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。     

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   

ST segment depression in right-sided electrocardiographic leads in patients with acute myocardial infarction.

The presence of ST segment depression in right-sided electrocardiographic leads has been infrequently reported in the literature. We report the cases of two patients with anterolateral and posterior myocardial infarctions with ST segment depression in right-sided electrocardiographic leads. We hypothesize that this electrocardiographic change is a reciprocal expression of ST segment elevation of the opposing left ventricular wall.     

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     

Implications of precordial ST segment depression during acute inferior myocardial infarction. Arteriographic and ventriculographic correlations during the acute phase.

Thirty two patients presenting with acute transmural inferior wall myocardial infarction underwent cardiac catheterisation and angiography within 12 hours of the onset symptoms. Twelve lead electrocardiograms performed within one hour of catheterisation showed ST segment depression in the anterior precordial leads in addition to inferior wall changes in 17 patients and no ST segment changes in the anterior leads in 15. When the clinical, arteriographic, and ventriculographic variables were compared between the two groups no significant differences were noted with regard to age, sex, risk factors for coronary disease, duration of symptoms before angiography, Killip class, number of inferior leads with ST segment elevation, or initial serum creatine kinase activity. The extent of coronary artery disease as well as the prevalence of severe disease in the left anterior descending artery were similar for both groups. Biplane left ventriculography showed no significant differences between the two groups with regard to global ejection fraction or to the prevalence of posterolateral or anterior segmental wall motion abnormalities.     

Clinical implications of anterior S-T segment depression in patients with acute inferior myocardial infarction

To assess various factors associated with anterior S-T segment depression during acute inferior myocardial infarction, 47 consecutive patients with electrocardiographic evidence of a first transmural inferior infarction were studied prospectively with radionuclide ventriculography an average of 7.3 hours (range 2.9 to 15.3) after the onset of symptoms. Thirty-nine patients (Group I) had anterior S-T depression in the initial electrocardiogram and 8 (Group II) did not have such “reciprocal” changes. There was no difference between the two groups in left ventricular end-diastolic or end-systolic volume index or left ventricular ejection fraction. Stroke volume index was greater in Group I than in Group II. There were no group differences in left ventricular total or regional wall motion scores. A weak correlation existed between the quantities (mV) of inferior S-T segment elevation and reciprocal S-T depression. No relation between anterior S-T segment depression and the left ventricular end-diastolic volume index could be demonstrated; the extent of left ventricular apical and right ventricular wall motion abnormalities, both frequently associated with inferior infarction, did not correlate with the quantity of anterior S-T depression.These data show that anterior S-T segment depression occurs commonly during the early evolution of transmural inferior infarction, is not generally a marker of functionally significant anterior ischemia and cannot be used to predict left ventricular function in individual patients. Anterior S-T segment depression may be determined by reciprocal mechanisms.     

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。     

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。     

Prognostic significance of precordial ST-segment depression during inferior acute myocardial infarction

To study the mechanism and prognostic importance of precordial ST-segment depression during inferior acute myocardial infarction, 162 patients admitted during 1969 through 1982 were identified. Patients with ST depression in leads V1, V2 and V3 had significantly larger infarctions as assessed by a QRS scoring system. Hospital mortality was 4% (3 of 75) among patients without ST depression, and 13% (11 of 87) in patients with ST depression. The relation between the amount of ST depression and hospital mortality was significant (p less than 0.001 by logistic regression), and remained significant (p less than 0.003) after adjusting for other potentially prognostic factors. Among patients discharged from the hospital, the 5-year survival was 92% in those without precordial ST depression and 80% in those with precordial ST depression (p = 0.058 by the Cox model). Precordial ST-segment depression on the admission electrocardiogram during an inferior acute myocardial infarction indicates a larger infarction, predicts a higher hospital mortality and suggests a worse long-term prognosis after discharge.     

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.