Revaluation Of Electrocardiogram On Positioning Of Infarct-related Artery Of Acute Myocardial Infarction

Objective:Through comparative analysis of electrocardiographic changes and coronary angiography.re-evaluation of the surface ECG in patients with acute myocardial infarction predict the diagnosis of infarct-related artery.Methods:Collect patients of the teda international cardiovascular disease hospital from January2005to june2010for acute myocardial infraction in the parallet emergency diagnosis and treatment of patients in415cases.the detailed record admission with immediate and the subsequent ECG,CAG,UCG,general clinical situation and the related laboratory examination index results.Analysis the electrocardiogram change in all leads and predict infarct-related artery (IRA), and by comparing coronary angiography (CAG) test results,evaluate the ECG in predicting acute myocardial infarction patients.IRA.Results:Study of the ECG changes of acute inferior wall myocardial infarction caused by Single coronary artery lesions show:1. ECG STⅢ↑/STⅡ↑>1, STaVL↓/STⅠ↓>1to judge related artery infarction in RCA sensitivity were87.5%,96.4%. specificity were85.0%,85.0%. STV3↓/STⅢ↑>1.2to judge related artery infarction in LCX specificity was94.6%.2. ECG ST3VF↑+STV2↓>0to determine the infarct-related artery in RCA specificity, positive predictive values respectively were90.0%,95.8%.3. ECG ST (V1-V3)↓/ST (inf)↑≤0.5to determine the infarct-related artery in RCA sensitivity andpositive predictive values respectively were78.6%,91.7%.4. ECG ST V3↓/STⅢ↑≤0and ECG STV1↑predict infarct-related artery in the and proximal RCA sensitivity were54.5%and86.4%, specificity were29.4%and88.2%.Study of the ECG changes of acute anterior myocardial infarction caused by simple anterior descending artery lesions show: 1. Among of67acute anterior myocardial infarction caused by simple anterior descending artery lesions had51(76.1%) patients showed inferior wall ST-segment depression,13(19.4%) patients had inferior wall T-segment elevation, and3cases without ST-segment changes;45patients that Lesions positioning in the anterior descending branch proximal had43(95.6%) patients showed inferior wall ST-segment depression,2(4.4%) patients showed inferior wall ST-segment elevation; while17cases that lesions in the distal of the anterior descending branch had11(64.7%) cases show inferior wall ST-segment elevation,5(29.4%) patients show inferior wall ST-segment depression,1(5.9%) patients with inferior wall ST-segment without change.2. Among of67acute anterior myocardial infarction caused by simple anterior descending artery lesions had44patients (65.7%) show ST-segment elevation in lead aVR;36patients (75.0%) in48cases of proximal lesions showed lead aVR ST-segment elevation, and11patients (57.9%) patients in19cases of the distal lesions did not show ST-segment elevation in lead aVR;23cases that lead aVR ST-segment without elevation showed lesions in the proximal and distal were12cases and11cases.3. The number of48cases that lesions in proximal anterior descending artery showing STV2↑≥3mm, STV3↑≥2mm, STⅡ,Ⅲ.aVF↓≥1mm respectively31.37,19; the positive rate were64.6%,77.1%and39.6%:while19cases of lesions in distal anterior descending artery were16,19,10; positive rate were84.2%,100%. and52.6%:the statistical comparison showed STV2↑≥3mm, STV3↑≥2mm. STⅡ,Ⅲ.aVF↓≥1mm predict lesion in proximal left anterior descending artery the sensitivity are64.6%,77.1%,39.6%, positive predictive values are66.0%,66.1%and65.5%.4.67cases of acute anterior myocardial infarction caused by simple anterior descending artery lesions were divided into proximal lesion group and distal lesion group by CAG results.comparesion showed the difference between the two groups in STⅠ↑≥0.05mv, STⅡ↓≥0.1mv were statistically significant, these two indicators in acute anterior myocardial infarction caused by simple anterior descending artery lesions positioning valuable. Simple LAD lesions group combined with LAD and LCX double-vessel lesions but IRA for LAD group, the12-lead ECG ST-segment changes in the statistical calculations had no significant difference.Simple LAD lesions group combined with LAD and RCA double-vessel lesions but IRA for LAD group, the statistical calculations showed ST-segment elevation in lead aVR was statistically significant (P=0.005) between the two groups was.Simple LAD lesions group combined with three-vessel lesions but IRA for LAD group, ST-segment elevation in lead V3between the two groups was statistically significant (P=0.046); ST-segment down in V6lead. ST-segment elevation in III lead and ST-segment elevation in aVF lead three indexs compared between the two groups was statistically difference (P value were0.041.0.046,0.010)Conclusions:1. Acute inferior wall myocardial infarction caused by single coronary artery lesions, using of ECG indicators of STⅢ↑/STⅡ↑>1,STaVL↓/STⅠ↓>1, STv3↓/ST Ⅲ↑>1.2, STaVF↑+STV2↓>0,ST(V1-V3)↓/ST(inf)>0.5to predict the IRA have higher sensitivity, specificity; the use of ECG-related leads ST-segment change can accurately determine the IRA:Acute inferior wall myocardial infarction caused by proximal coronary artery lesions.95.6%of the cases cases appear inferior wallST-segment depression,4.4%appear ST-segment elevation; distal anterior descending artery lesion group64.7%of cases appear inferior wall ST-segment elevation,29.4%appear ST-segment depression,5.9%of the cases ST-segment without change.2. Acute anterior myocardial infarction caused by proximal anterior descending artery lesion more accompanied by inferior wall leads ST-segment depression,but the feature in distal lesion is not obvious:in the acute anterior myocardial infarction caused by simple anterior descending artery lesions group65.7%(44/67) cases showed aVR lead ST-segment elevation, in which lesions located in the proximal anterior descending cases nearly75.0%(36/48) showed aVR lead ST-segment elevation; The use of anterior and inferior leads ECG changes to predict proximal left anterior descending artery lesion sensitivity, positive predictive value are acceptable but not ideal:STⅠ↑≥0.05mv and STⅡ↓≥0.1mv to predict the IRA was anterior descending artery which caused acute anterior myocardial infarction valuable.3. Simple LAD lesions group compared with LAD and LCX double-vessel lesions but IRA for LAD group, the12-lead ECG ST-segment changes in the statistical calculations had no significant difference, this study showed in a certain extent, this group can use simply left anterior descending artery lesions to determine the characteristics of the infarct-related artery and lesion location;4. Simple LAD lesions group compared with LAD and RCA double-vessel lesions but IRA for LAD group, found that STaVR↑showed statistically significant difference between the two groups (P=0.005), the use of lead aVR ST-segment elevation in some extent could know the coronary lesions situation;5. Simple LAD lesions group combined with three-vessel lesions but IRA for LAD group, STV3↑between the two groups was statistically significant (P=0.046); STV6↓,STⅢ↑, STaVF↑three indexs compared between the two groups was statistically difference,Though this study we know that when the coronary artery three system are exist different degree lesions at the same time, the change in this kind of ECG compare with those just exist simple coronary artery, more changes exist.At this time we use the characteristic of simple lesion to determine the IRA is difficult and unaccurate, so in the daily work we should strengthen understanding of this ECG, fully aware of the seriousness of this kind of patient and timely, accurateiy to take corresponding treatment to them.