If the heart has an infarction that affects its vectors, where is the mean QRS vector displaced?

If the heart has an infarction that affects its vectors, where is the mean QRS vector displaced?

• A. Toward the infarcted area
• B. Away from the infarcted area
• C. Directly upward
• D. It does not change

Answer: (B)

When an infarction occurs in the heart, it typically leads to damage in that area which results in a reduction of electrical activity. The mean QRS vector represents the overall direction of electrical impulses as they spread through the ventricles.

In the case of an infarction, the areas of the heart that are damaged lose some of their electrical activity, leading to decreased depolarization in that region. As a result, the mean QRS vector is influenced by the remaining healthy myocardium, which can cause the vector to shift away from the infarcted area. This shift occurs because the electrical forces from the damaged myocardium are weaker compared to those from the healthy tissue, thus resulting in a net movement of the electrical vector toward areas that are still viable.

In clinical practice, this principle is useful for diagnosing the presence and extent of myocardial infarction through analysis of EKG patterns, contributing to better patient management.