**Question:** A 60 year old man presents with chest pain with last 6 hours and is diagnosed as acute myocardial infarction. Angiography showed involvement of anterior descending branch of left coronary artery. The most probable site of infarct is:

A. Apex
B. Anterior wall
C. Right coronary artery territory
D. Posterior wall

**Core Concept:** Acute myocardial infarction (AMI) is a medical emergency caused by a sudden loss of blood supply to a part of the heart muscle, leading to cellular death. In most cases, AMI involves one of the three coronary arteries: left anterior descending (LAD), right coronary artery (RCA), or circumflex artery (Cx). The infarct site is determined by the artery supplying the area in question.

**Why the Correct Answer is Right:** In this scenario, the anterior descending branch of the left coronary artery supplies the anterior wall of the heart. Therefore, the most probable site of infarct is the **B. Anterior wall**.

**Why Each Wrong Option is Incorrect:**

A. The apex is supplied by the right coronary artery, making it an unlikely site for infarction in this case.
C. The right coronary artery supplies the inferior wall, not the apex or anterior wall, making this option incorrect.
D. The posterior wall is supplied by the posterior descending branch of the left coronary artery, which is not involved in this case.

**Why the Correct Answer is Right:**

The involvement of the anterior descending branch of the left coronary artery indicates that the infarct took place in the territory it supplies, which is the **Anterior wall**. This artery is responsible for supplying blood to the anterior wall of the heart, leading to the infarction in this area.

**Why Each Wrong Option is Incorrect:**

A. The apex is supplied by the right coronary artery, making it an unlikely site for infarction in this case.
C. The right coronary artery supplies the inferior wall, not the anterior wall or the apex, making this option incorrect.
D. The posterior wall is supplied by the posterior descending branch of the left coronary artery, which is not involved in this case.

**Clinical Pearl:**

Understanding the coronary artery anatomy is crucial for diagnosing and treating patients with myocardial infarction. A correct anatomical knowledge helps in making accurate decisions regarding reperfusion therapy, such as primary percutaneous coronary intervention (PCI) or thrombolysis, to save the heart muscle and reduce complications and mortality.