Usefulness of the admission electrocardiogram for identifying the infarct-related artery in inferior wall acute myocardial infarction

Abnormalities in the electrocardiogram (ECG) are frequently used to predict the infarct-related artery (IRA) in patients with acute myocardial infarction (AMI). Whereas inferior ST-segment elevation occurring during AMI usually indicates occlusion of the right coronary artery, less often the left coronary artery (LC) or rarely the left anterior descending (LAD) artery may be the cause. Because of the limitations of the ECG and the posterior distribution of the LC, occlusion of this artery infrequently results in diagnostic ST-segment elevation,(1,2) and inferior ST-segment elevation occurs <50% of the time.(3) Criteria for determining the IRA based on the initial ECG in patients with inferior wall AMI have not been well described. This study compares the initial ECG with coronary angiographic findings in patients having electrocardiographic criteria for inferior wall AMI in order to determine whether the initial ECG can predict the IRA and whether the extent of coronary artery disease alters the ability to predict the culprit artery.