Cardiac Medicine Certification (CMC) Practice Exam

In a myocardial infarction, which of the following leads would you expect to show ST elevations for a septal MI?

1. II, III, and aVF

2. V4-V5

3. V1-V4

4. V5-V6

The correct answer is: V1-V4

In the context of a myocardial infarction, a septal MI primarily affects the septal region of the heart, which is supplied by the left anterior descending artery. This type of infarction typically results in ST-segment elevation in the anterior leads, particularly in the precordial leads. When looking for ST elevations that indicate a septal MI, the precordial leads V1 and V2 are most sensitive as they are positioned directly over the heart's septum. In a septal MI, the changes would also extend into V3, possibly affecting V4, but the primary focus is on V1 and V2. Thus, the correct choice indicating ST elevations in the leads that would display this pattern is the group that includes V1 through V4. The other options either represent areas of the heart that do not correspond to the septal wall specifically (as seen in the inferior or lateral leads) or lack the necessary lead placements that encompass the septal region adequately. Therefore, the leads that would show ST elevations during a septal myocardial infarction are indeed V1 through V4.