Question

Remember that a positive deflection indicates electrical activity moving toward the green EKG lead. What accounts for the difference in appearance between lead 2 and lead AVR on an EKG? Explain the answer referencing the hexaxial limb lead reference system.

Answer 1

• A diagram which is used to determine the hearts electrical axis in the frontal plane is known as hexaxial reference system, its better known as Cabrera system. Way of using this is extremity leads according to Cabrera system,reversing polarity of lead aVR and in order of ( aVR,I,aVR, II ,aVF, III)
• Another alternative use is to locate the most isoelectric lead (I,II,III,aVR, aVF,aVL).
• If the most isoelectric lead is AVR ,the perpendicular lead on the hexaxial reference system is lead III. if lead iii positively deflected on EKG , the hearts electrical axis in the frontal plane will be approximately +90-120 right axis.