Limb leads:
(1) I
(2) II
(3) III
(4) aVL
(5) aVF
(6) aVR
Einthoven's Law and Augmented Lead Relationships
I + III = II
aVR + aVF + aVL = 0
aVR = - 1/2 * (I + II)
aVL = I - (1/2 * II)
aVF = II - (1/2 * I)
Combinations of 2 Limb Leads
All possible combinations for 2 limb leads known: 6 * 5 = 30
Combinations if 2 original or 2 augmented limb leads are known
(1) I and II
(2) I and III
(3) II and III
(4) aVF and aVL
(5) aVF and aVR
(6) aVL and aVR
I and II Known
III = II - I
aVR = - 1/2 * (I + II)
aVL = I - (1/2 * II)
aVF = II - (1/2 * I)
I and III Known
II = I + III
aVR = -1/2 * ((2 * I) + III)
aVL = 1/2 * (I - III)
aVF = III + (1/2 * I)
II and III Known
I = II - III
aVR = 1/2 * (III - (2 * II))
aVL = 1/2 * (II - (2 * III))
aVF = 1/2 * (II + III)
aVF and aVL Known
I = 2/3 * ((2 * aVL) + aVF)
II = 2/3 * (aVL + (2 * aVF))
III = 2/3 * (aVF - aVL)
aVR = -aVF - aVL
aVF and aVR Known
I = -2/3 * (aVF + (2 * aVR))
II = 2/3 * (aVF - aVR)
III = 2/3 * ((2 * aVF) + aVR)
aVL = -aVR - aVF
aVL and aVR Known
I = -2/3 * (aVR - aVL)
II = -2/3 * ((2 * aVR) + aVL)
III = -2/3 * (aVR + (2 * aVL))
aVF = -aVL - aVR
