AFAA Personal Trainer Certification Practice Exam

What causes a myocardial infarction?

1. Lack of oxygen in the bloodstream

2. Lack of blood flow through the coronary arteries

3. High blood pressure in the arteries

4. Excessive physical exertion

The correct answer is: Lack of blood flow through the coronary arteries

A myocardial infarction, commonly known as a heart attack, occurs primarily due to a lack of blood flow through the coronary arteries. The coronary arteries supply blood to the heart muscle, and if these arteries become blocked—often due to a buildup of plaque from cholesterol and other substances—oxygenated blood cannot reach the heart tissue. This blockage results in the heart cells becoming deprived of oxygen, leading to damage or death of that tissue. The interruption of blood flow is critical because it directly impacts the heart's ability to function effectively. While other factors such as high blood pressure can contribute to the overall risks associated with heart disease, they are not the immediate cause of a myocardial infarction. High blood pressure can lead to various cardiovascular complications, but the actual event of a heart attack is primarily triggered by the obstruction of blood flow. Lack of oxygen in the bloodstream can occur as a result of a myocardial infarction but is not the direct cause of the event itself. Excessive physical exertion may increase the risk of a heart attack in some individuals, particularly if they have pre-existing conditions, but it is the acute lack of blood flow that precipitates a myocardial infarction. Thus, the core reason behind a myocardial infarction centers around the obstruction of blood flow