Certified Emergency Nurse (CEN) Practice Test

What area of the heart is affected by a circumflex myocardial infarction?

1. Lateral wall

2. Inferior wall

3. Posterior wall

4. Anteroseptal wall

The correct answer is: Lateral wall

The lateral wall of the heart is primarily supplied by the circumflex artery, which branches off the left coronary artery. In the case of a circumflex myocardial infarction, the area of the heart that is directly impacted is the lateral wall, as this region relies on the circulation provided by the circumflex artery. An injury or blockage in this artery can lead to ischemia and subsequent damage in the lateral wall, which includes segments such as the left atrium and the outer parts of the left ventricle. The other options pertain to different areas of the heart supplied by other arteries. The inferior wall is primarily supplied by the right coronary artery, while the posterior wall can also receive blood supply from branches of the right coronary artery in most individuals. The anteroseptal wall is predominantly supplied by the left anterior descending artery. Understanding these vascular territories is crucial for interpreting the implications of myocardial infarctions in clinical practice.