EKG Week 1

Standard Limb Leads
• Leads I, II, & III
make up the
standard limb leads
• In the bipolar leads,
the R arm electrode
is always negative
& the L leg
electrode is always
positive
Lead I
• Records the
difference in
electrical potential
between the LA (+)
& RA (–) electrodes
• Views the lateral
wall of the LV
• Lead axis:
RA Ú LA
Lead II
• Records the difference
in electrical potential
between the LL (+) &
RA (–) electrodes
• Views the inferior
surface of the LV
• Lead Axis:
RA Ú LL
Lead III
• Records the
difference in
electrical potential
between the LL (+)
& LA (–) electrodes
• Views the inferior
surface of the LV
• Lead Axis:
LA Ú
LL