Which lead is associated with the measurement between the right arm and left foot?

Which lead is associated with the measurement between the right arm and left foot?

• A. Lead II
• B. Lead III
• C. aVR
• D. aVL

Answer: (A)

The lead that measures the electrical activity between the right arm and left foot is Lead II. This lead provides a view of the heart's electrical impulses as they travel from the right arm to the left foot, which is a common orientation for assessing the overall cardiac axis.

Lead II is particularly useful because it typically shows a strong P wave, which corresponds to atrial depolarization, and a clear QRS complex, which reflects ventricular depolarization. The positive electrode in Lead II is on the left foot, while the negative electrode is on the right arm, making it well-suited to capture the heart's predominant electrical flow from the upper body down to the lower body, aligning well with the normal conduction path.

Understanding the orientation of each lead is crucial for accurately interpreting an EKG, as each lead provides a different perspective on the heart's electrical activity.