## Core Concept
Subendocardial infarction, also known as non-transmural infarction, occurs when there is a blockage in one of the coronary arteries that only partially occludes the artery, leading to damage to the inner layer of the heart muscle (endocardium) but not extending through the entire thickness of the heart wall.

## Why the Correct Answer is Right
Subendocardial infarctions are characterized by their location in the inner layer of the myocardium and are often the result of severe coronary artery stenosis. They do not extend through the full thickness of the heart wall, which differentiates them from transmural infarctions. This type of infarction can lead to significant morbidity and mortality, particularly if not promptly and effectively treated.

## Why Each Wrong Option is Incorrect
To accurately address this question, the specific details of options A, B, C, and D are required. However, given the structure of the query and the standard information about subendocardial infarctions:

- **Option A:** Typically, without specifics, we can't directly refute or confirm, but generally, if a statement about subendocardial infarction being associated with Q-waves is incorrect, it would be because subendocardial infarctions often do not produce Q-waves on an ECG; instead, they may show ST-segment depression or T-wave inversion.
- **Option B:** If a statement regarding the involvement of the inner layer of the myocardium is made, it would be correct and not the answer we're looking for.
- **Option C:** Similarly, without specifics, if a statement about coronary artery disease being a cause is made, it would be true, as coronary artery disease is a primary cause of subendocardial infarctions.
- **Option D:** This option would be evaluated based on its accuracy in relation to subendocardial infarctions.

## Clinical Pearl / High-Yield Fact
A key point to remember is that subendocardial infarctions are more likely to lead to heart failure than transmural infarctions because they often involve a larger volume of the left ventricle. Additionally, the ECG in subendocardial infarction may show ST-segment depression or T-wave inversion rather than the Q-waves seen in transmural infarctions.

## Correct Answer: D.