Correlation between Abnormal Q Wave in Leads I or aVL and First Diagonal Branch Stenosis in Patients with Acute Myocardial Infarction

BACKGROUND: Twelve lead electrocardiagram is often used to localize the site of myocardial infarction and coronary artery stenosis. There are many studies to correlate the electrocardiographic abnormalities and the site of coronary artery stenosis in patients with ischemic heart disease. In patients with acute myocardial infarction, however, a few studies that correlate the site of coronary artery stenosis and abnormal Q wave in leads I or aVL have been reported. METHOD: In 60 patients with acute myocardial infarction(Male : Female=48 : 12), the author investigated the development of abnormal Q wave in leads I or aVL and the presence, severity and location of stenosis in left anterior descending coronary artery and its first diagonal branch, and correlated abnormal Q wave and the presence of first diagonal branch stenosis with the progression of myocardial infarction. RESULTS: The presence of first diagonal branch stenosis can be predicted in patients with acute myocardial infarction who had abnormal Q wave in leads I of aVL with sensitivity and specificity of 70% and 85% during the early stage respectively and 88% and 96% after stabilization of infarction respectively. CONCLUSION: With the presence of abnormal Q wave in leads I or aVL in patients with acute myocardial infarction, it can be predicted that there is stenosis in the first diagonal branch. Howeve, there should be more experineces and further and metriculous studies.

Changes of Abnormal Q Wave Progression after Reperfusion in Patients with Anterior Acute Myocardiac Infarction

Abnormal Q wave which suggest myocardial necrosis frequently develope after successful reperfusion in acute myocardial infarction(AMI). To investigate patterns of abnormal Q wave development and the significance of the rapid progression of Q wave after reperfusion therapy, sixty patients with first attack of anterior AMI were studied. All patients showed complete occlusion of proximal or mid left anterior desending artery and received intracoronary thrombolysis therapy(ICT) with urokinase. ICT was completed within 6 hours of chest pain. Fourty for patients were reperfused. There were significant correlation between the number of leads with Q waves before ICT(PRE-nQ) and after ICT(POST-nQ) both in patients with reperfused and failed reperfusion(r=0.68, 0.96). Three patterns of abnormal Q wave progression were identified by the first correlationship of PRE-nQ and POST-Nq. Abnormal Q waves were rapidly progressed in 14 patients(Group I : 31.8%), regressed in 10 patients(Group II : 22.7%) and natureally progressed in 20 patients(45.5%). Patients in Group I had greater creatine kinease release(6133+/-2536mIU) and higher QRS score(immidiate ICT : 7.9+/-3.0, 7th day : 8.7+/-3.0) than those of patients in Group II(2135+/-1701mIU, 3.6+/-3.0, 4.6+/-3.3, respectively, P<0.01, all). A significant decreased wall motion of infarcted area was observed in Group I patients(% area change, area 26.1+/-14.0%) compared with Group II patients(46.5+/-10.7%, P<0.05). The followings can be concluded : Three patterns of abnormal Q wave progression were noted after reperfusion therapy in patients with anterior AMI. Rapid progression of abnormal Q wave may indicate accelerated ischemic injury or reperfusion injury rather than salvaging myocardium.