Cardiac Medicine Certification (CMC) Practice Exam

The most significant change expected in the event of an anterior wall myocardial infarction is the significant ST elevation in leads V3 and V4. Anterior wall myocardial infarctions typically involve the left anterior descending artery, affecting the anterior region of the heart. This region is reflected in the anterior leads, particularly V2, V3, and V4, where ST elevation indicates acute ischemia.

ST elevation in these leads signifies that the heart muscle is receiving insufficient blood supply, which is characteristic of myocardial infarctions affecting the anterior wall. This pattern helps clinicians identify the location and extent of the myocardial damage.

While reciprocal changes in leads II, III, and aVF may occur with inferior wall infarctions, they are not the primary indicators for anterior wall events. Similarly, ST depression in lead II would not primarily signal an anterior wall infarction but could arise from other heart zone disturbances. R-wave progression is also a standard finding in healthy hearts and does not specifically indicate an anterior wall myocardial infarction, making significant ST elevation in the anterior leads the most crucial and relevant change.