Page 16 - Rapid Review of ECG Interpretation in Small Animal Practice, 2nd Edition

Principles of Electrocardiography

VetBooks.ir Table 1.1 The positive and negative terminals of the six ECG limb leads
Augmented
Bipolar
leads
limb leads unipolar limb
I R arm (–) to L arm (+) aVR R arm (+) to common terminal (–)
II R arm (–) to L foot (+) aVL L arm (+) to common terminal (–)
III L arm (–) to L foot (+) aVF L foot (+) to common terminal (–)

Fig. 1.4 The augmented
(unipolar) limb leads RA LA
use the same electrodes
as leads I, II, III, but the
recording electrode is
always positive and
the negative terminal is
made up of the sum of
the electrodes attached
to the right arm, left arm,
and left leg.
aVR: (+)RA, (–)LA+LL
RL LL Augmented
limb aVL: (+)LA, (–)RA+LL
leads
aVF: (+)LL, (–)RA+LA

Fig. 1.5 The augmented
limb leads are named
after their positive
electrode, located on the
left arm (aVL), the right RA LA
arm (aVR), and the left + 0 +
foot (aVF), where the “a” aVR aVL
stands for augmented,
and “V” stands for vector.
0 0

+ aVF
LL

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