Which statement accurately describes the limb placement for Einthoven's triangle?

• A. Two shoulders and the pubis
• B. Two ankles and the wrists
• C. Chest leads V1-V6
• D. Head and neck

Answer: (A)

Einthoven's triangle is formed by placing three limb electrodes on the arms and a leg to create a triangle around the heart. The usual setup uses electrodes on the right arm, left arm, and left leg (often accessible at the wrists and ankles). The three limb leads measure differences between these points: Lead I is arm-to-arm, Lead II is right arm to left leg, and Lead III is left arm to left leg. This arrangement gives a frontal-plane view of the heart’s electrical activity. Chest leads V1-V6 are placed on the chest and provide a different perspective (the precordial view), not part of Einthoven’s triangle. The head and neck aren’t used in standard limb-lead placement. So the essential idea is three limb sites on the arms and legs forming the triangle around the heart.