Anterior ST-segment deviation during inferior myocardial infarction: arteriographic correlations during the acute phase

Electrocardiographic changes in the anterior wall lead in inferior myocardial infarction were studied in coronary angiographic findings in the acute stage. The subjects were 40 patients with initial inferior myocardial infarction due to right coronary lesions. ST segments were elevated in 7 patients, remained unchanged in 11 and were depressed in 22. Two patients predominantly perfused in the left coronary artery showed ST elevation. All seven patients who showed elevation of the ST segments had occlusion of the ventricular branch proximal to right. However, another 15 (68%) of the patients with occlusion of the same lesion did not show elevation of any ST segment. There was no difference in left ventricular ejection fraction between the groups. The regional ejection fraction at the left ventricular inferior wall was significantly (p less than 0.01) higher in the ST elevated group than in the ST depressed group. Elevation of the ST segments in the anterior wall lead was observed only when the right ventricular free wall sustained injury, and no elevation of any ST segment was observed when the range of injury in the inferoposterior wall was wide, even in the presence of injury to the right ventricular free wall.     

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.     

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.     

Significance of exercise induced ST segment elevation in patients with previous myocardial infarction.

In order to determine the significance of exercise induced ST segment elevation in patients with previous myocardial infarction, we have studied 156 patients, 26 months (mean) after myocardial infarction. Each patient underwent 16 lead precordial electrocardiographic mapping before, during, and after exercise and in addition coronary arteriography was performed. There was no significant difference in the extent of coronary disease or abnormalities of left ventricular function between patients with exercise induced ST segment elevation that was noted to occur in leads with Q waves and those with ST segment elevation plus depression or those with ST segment depression alone. Patients without exercise induced ST segment changes had fewer coronary arteries involved than those who developed ST segment changes. Nineteen patients with exercise induced ST segment elevation alone underwent coronary artery bypass surgery; in 11 this resulted in complete abolition of the exercise induced ST segment elevation and was associated with symptomatic relief and patent grafts without alteration of left ventricular function. Thus, exercise induced ST segment elevation in patients with previous myocardial infarction should be considered as important as ST segment depression in terms of underlying myocardial ischaemia, coronary anatomy, and left ventricular function.     

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.     

Significance of exercise induced ST segment elevation in patients with previous myocardial infarction

In order to determine the significance of exercise induced ST segment elevation in patients with previous myocardial infarction, we have studied 156 patients, 26 months (mean) after myocardial infarction. Each patient underwent 16 lead precordial electrocardiographic mapping before, during, and after exercise and in addition coronary arteriography was performed. There was no significant difference in the extent of coronary disease or abnormalities of left ventricular function between patients with exercise induced ST segment elevation that was noted to occur in leads with Q waves and those with ST segment elevation plus depression or those with ST segment depression alone. Patients without exercise induced ST segment changes had fewer coronary arteries involved than those who developed ST segment changes. Nineteen patients with exercise induced ST segment elevation alone underwent coronary artery bypass surgery; in 11 this resulted in complete abolition of the exercise induced ST segment elevation and was associated with symptomatic relief and patent grafts without alteration of left ventricular function. Thus, exercise induced ST segment elevation in patients with previous myocardial infarction should be considered as important as ST segment depression in terms of underlying myocardial ischaemia, coronary anatomy, and left ventricular function.     

Incidence and prognostic significance of anterior precordial ST segment depression in acute inferior myocardial infarct

In order to evaluate the incidence and prognostic significance of anterior precordial ST segment depression (decreases ST) in acute inferior myocardial infarction (MI), 158 patients with inferior MI were selected. In 90 patients (56.9%) an anterior decreases ST was associated with inferior lesion wave (group A), and in 68 patients (43.1%) only an ecg pattern of inferior myocardial infarction (group B) was present. No significant statistical differences were observed in mortality (group A 10% vs group B 10.2%), in compliances (group A 54.4% vs group B 47.0%) and in higher peak serum ck-levels (group A 83.3% vs group B 69.1%) in two groups during hospitalization period. In conclusion the anterior decreases ST during inferior MI should not be considered a negative prognostic sign. These favourable results are probably related to stringent criteria for ecg diagnosis of inferior myocardial infarction used and to exclusion of all patients with non contemporary evolution of anterior decreases ST and inferior lesion wave.     

The clinical significance of exercise-induced ST segment changes in patients with previous inferior myocardial infarction

To investigate the clinical significance of exercise-induced ST changes, we performed exercise body surface mapping (87 leads) in 52 patients (one-vessel disease [1 VD] n = 12, multivessel disease [MVD] n = 40) with previous inferior myocardial infarction (MI). ST isointegral maps were constructed and the locations of ST changes were compared with the findings of exercise thallium-201 (TI-201) myocardial scanning. Exercise-induced ST elevation was observed in 14 patients (27%) on the lower chest and on the back, corresponding to the infarcted area. Exercise-induced ST depression was observed more frequently in the MVD group (n = 30, 75%) than in the 1VD group (n = 2, 17%). Seventeen (77%) of 22 patients with ST depression had thallium-201 redistribution. There was a significant association between ST depression and TI-201 redistribution (chi2 = 13.1, p less than 0.001), but no association between ST depression and ST elevation. The body surface distribution of ST depression was shifted upward and rightward compared with its appearance in angina pectoris without MI. These findings suggest that exercise-induced ST depression reflects myocardial ischemia in patients with previous inferior MI.     

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     

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。     

Electrocardiographic and coronary arteriographic correlations during acute myocardial infarction

One hundred fifty-two patients underwent cardiac catheterization and coronary arteriography within 6.3 ± 6.0 hours from the onset of acute myocardial infarction (AMI). All had standard 12-lead electrocardiograms recorded within 1 hour of cardiac catheterization. The electrocardiographic abnormalities present were correlated with the infarctrelated artery as determined by coronary arteriography. ST-segment elevation was the most common finding in patients with the left anterior descending (LAD) or right coronary artery as the infarct-related artery. ST-segment depression was the most common abnormality in patients with the left circumflex (LC), artery as the infarct-related artery. A classic pattern of anteroseptal AMI was seen in 93% of all patients with the LAD as the infarct-related artery. A classic pattern of inferior AMI was seen in 53% of patients with right or LC narrowing taken as 1 group. The pattern of true posterior and isolated lateral wall AMI in the absence of classic changes in the inferior leads was highly specific and predictive of LC narrowing. In contrast, the pattern of an inferior wall AMI, in the absence of true posterior or lateral wall changes, was highly specific and predictive of right coronary artery narrowing. Fifty-six percent of patients with LC artery as the infarct-related artery presented with non-classic electrocardiographic abnormalities. The electrocardiographic patterns in patients with subtotal occlusions were similar to those of patients with total occlusions. Thus, the electrocardiogram obtained in the first few hours of AMI is reliable in localizing the LAD as the infarct-related artery. Certain patterns are specific but not sensitive in localizing the right coronary artery as opposed to the LC artery as the infarct-related artery. Presentation with signs and symptoms of AMI and a nonclassic electrocardiogram is suggestive of LC narrowing.     

The significance of stress-induced ST segment depression in patients with inferior Q wave myocardial infarction

OBJECTIVES

This study was conducted to evaluate the relationship between ST segment depression (STD) during dobutamine stress tests in different electrocardiogram (ECG) leads and myocardial ischemia assessed by simultaneous single photon emission computed tomography (SPECT) imaging in patients with inferior Q wave myocardial infarction.

BACKGROUND

STD is a standard electrocardiographic sign of myocardial ischemia. Although STD may represent reciprocal changes in patients with previous myocardial infarction, studies of reciprocal changes during stress tests are scarce.

METHODS

Dobutamine (up to 40 μg/kg/min) stress and rest myocardial perfusion scintigraphy using technetium SPECT imaging was performed in 125 patients >3 months after Q wave inferior myocardial infarction. The location of STD at the ECG was defined as anterior (V_1–4), high lateral (I, aVL) and lateral (V_5,6). Ischemia was defined as reversible perfusion abnormalities.

RESULTS

STD occurred in the high lateral leads in 20 patients, in the anterior leads in 12 patients and in the lateral leads in 2 patients. ST segment elevation occurred in 25 patients in the inferior leads. High lateral STD was associated with inferior ST elevation in 16 patients (80%). There was a significant inverse linear correlation between the magnitude of ST segment shift from rest to peak stress in the inferior and the high lateral leads (r = −0.8, p < 0.0005), whereas no significant correlation was found between ST segment shift in the inferior and the anterior leads (r = −0.1, p = NS) or between the inferior and the lateral leads (r = 0.15, p = NS). Ischemia was detected in 45% of patients with and in 42% of patients without high lateral STD (p = NS). Patients with high lateral STD had a higher prevalence of fixed perfusion defects in the inferior wall (100% vs. 70%) and in the posterolateral wall (55% vs. 29%) compared with other patients (both p < 0.05). Ischemia was more prevalent in patients with anterior STD than without (75% vs. 39%, p < 0.05).

CONCLUSIONS

In patients with inferior Q wave myocardial infarction, stress-induced STD in high lateral leads should be recognized as a reciprocal change for ST elevation in the inferior leads, and therefore, should be interpreted with the consideration of the significance of ST elevation if present, rather than being indicative of myocardial ischemia on its own. The STD found in the anterior leads appears to be a sign of myocardial ischemia. These findings should be considered in the definition of a positive ECG stress test and in establishing the criteria for the termination of stress test.     

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.     

急性下壁心肌梗死胸前导联ST段压低与冠状动脉病变的关系及临床意义探讨

目的 :探讨急性下壁心肌梗死胸前导联ST段压低与冠状动脉病变的关系及临床意义。方法 :回顾分析 2 0 0 0年 7月至 2 0 0 2年 5月住院的首次急性下壁心肌梗死患者 6 0例。按胸前导联ST段压低范围将患者分为 4组 :无胸前导联ST段压低组 (Ⅰ组 ,n =2 2 ) ;胸前导联V1～ 3ST段压低组 (Ⅱ组 ,n =12 ) ;胸前导联V4～ 6 ST段压低组 (Ⅲ组 ,n =12 ) ;胸前导联V1～ 6 ST段压低组 (Ⅳ组 ,n =14 )。分析内容包括冠心病危险因素、心电图、心肌酶谱、心脏彩超、冠状动脉造影以及心肌梗死的并发症。结果 :左前降支 (LAD)病变发生率在Ⅰ与Ⅲ、Ⅳ各组分别为 4 7 1%、6 0 %、72 7% (P >0 0 5 ) ,而在Ⅱ组仅为 9 1% ,与Ⅰ组比较 ,Ⅱ组的LAD病变发生率低 (P <0 0 5 ) ,但Ⅰ组LAD病变程度较轻 ,>90 %狭窄者仅占 12 5 % ,而Ⅲ、Ⅳ组分别占 83 3%、87 5 % (P <0 0 5 ) ;回旋支 (LCX)病变在Ⅰ、Ⅱ、Ⅲ、Ⅳ组分别占 17 6 %、4 5 5 %、6 0 %、6 3 6 % ,与Ⅰ组比较 ,Ⅲ、Ⅳ各组的LCX病变发生率较高 (P <0 0 5 ) ,且Ⅳ组多支病变比例较高 (P <0 0 5 ) ;左室射血分数 (LVEF)在Ⅰ、Ⅱ、Ⅲ、Ⅳ组分别为 0 6 3± 0 0 5、0 6 2± 0 0 6、0 5 5± 0 10、0 5 1± 0 13,与Ⅰ组相比 ,Ⅳ组的LVEF较低 (P <0 0 5 ) ;低血压状?