Einthoven's triangle is defined as which of the following?

Einthoven's triangle is defined as which of the following?

• A. The triangle around the heart formed by the chest leads
• B. The triangle around the heart formed by the augmented limb leads
• C. The triangle around the heart formed by the bipolar limb leads
• D. The triangle around the heart formed by the precordial and limb leads

Answer: (C)

Einthoven's triangle is formed by the three standard limb leads, which are bipolar, arranged around the heart in the frontal plane. These leads—between the arms and between a leg and an arm—create a triangular frame that allows recording of electrical potentials in the frontal view. The augmented limb leads (aVR, aVL, aVF) are unipolar derivations from the same limb potentials, so they are not part of this triangle. The precordial chest leads lie on the chest and provide a horizontal view, also outside the triangle.

Einthoven's triangle is formed by the three standard limb leads, which are bipolar, arranged around the heart in the frontal plane. These leads—between the arms and between a leg and an arm—create a triangular frame that allows recording of electrical potentials in the frontal view. The augmented limb leads (aVR, aVL, aVF) are unipolar derivations from the same limb potentials, so they are not part of this triangle. The precordial chest leads lie on the chest and provide a horizontal view, also outside the triangle.