Cardiac Medicine Certification (CMC) Practice Exam

During an anteroseptal wall myocardial infarction, which ECG changes are most commonly observed?

1. ST elevation in V1-V3

2. ST depression in V5-V6

3. ST elevation in II, III, and aVF

4. No significant ECG changes

The correct answer is: ST elevation in V1-V3

During an anteroseptal wall myocardial infarction, the most commonly observed ECG changes are characterized by ST elevation in the precordial leads, particularly in leads V1-V3. These leads are positioned over the anterior part of the heart, where the left anterior descending artery (LAD) supplies blood. Anteroseptal infarctions usually occur due to occlusion of this artery, leading to ischemia and subsequent elevation of the ST segment in the affected leads. In detail, the presence of ST elevation in V1-V3 indicates that myocardial injury is occurring in the anterior and septal portions of the left ventricle. This finding is critical in diagnosing the specific type of myocardial infarction and guiding treatment. Medically, recognizing these changes can prompt immediate interventions, such as coronary angioplasty or thrombolysis, to restore blood flow and minimize damage to the heart muscle. The other options do not correspond to the typical ECG changes observed in an anteroseptal myocardial infarction. ST depression in leads V5-V6 is typically associated with lateral wall ischemia rather than anteroseptal involvement. ST elevation in II, III, and aVF indicates an inferior wall MI, usually due to right coronary artery oc