Inferoposterior wall myocardial infarction will show changes in the following leads except –
**Core Concept**
Inferoposterior wall myocardial infarction (MI) involves the inferior and posterior walls of the left ventricle, which are typically supplied by the right coronary artery. The electrocardiographic (ECG) changes in this type of MI are reflective of the affected myocardial segments.
**Why the Correct Answer is Right**
Inferoposterior wall MI often presents with ST-segment elevation in leads II, III, and aVF, reflecting the involvement of the inferior wall. Additionally, ST-segment depression or elevation in leads V1-V4 may be seen, indicating posterior wall involvement. These changes are due to the altered repolarization and depolarization patterns in the affected myocardium.
**Why Each Wrong Option is Incorrect**
**Option A:** This lead is not typically affected by inferoposterior wall MI, as it reflects the anterior wall of the left ventricle.
**Option B:** This lead may show ST-segment elevation or depression in inferoposterior wall MI, reflecting the involvement of the inferior or posterior wall.
**Option C:** This lead may show ST-segment elevation or depression in inferoposterior wall MI, reflecting the involvement of the inferior or posterior wall.
**Clinical Pearl / High-Yield Fact**
Inferoposterior wall MI often presents with atypical ECG changes, and a high index of suspicion is required for diagnosis. The ECG changes may be subtle, and additional diagnostic tools, such as echocardiography or cardiac biomarkers, may be necessary for confirmation.
**Correct Answer: A. Lead V5**