LEG 100 EXAM SCRIPT COMPREHENSIVE
STUDY GUIDE
●● Ratio of applied leads to recorded leads
Answer: 10:12
●● EKG vertical axis
Answer: Amplitude (gain)
Each small vertical square = 0.1 mV
Each large square = 0.5 mV
●● EKG horizontal axis
Answer: Time
Each small horizontal square = 0.04 s
Each large square = 0.2 s
●● Characteristics of EKG paper
Answer: Pressure and heat sensitive
●● Normal speed for EKG
,Answer: 25 mm/s
●● Normal amplitude of EKG
Answer: 10 mm (1 mV)
●● How to attach EKG limb leads (normal and amputation)
Answer: Place on fleshy areas of the skin and within the same general
vicinity on each limb
If one leg is amputated, place electrode on the abdomen, and the
electrode for the other limb should also be placed on the abdomen
●● Bipolar limb leads
Answer: I, II, and III
Impulses travel from negative to positive pole at specific positions in the
heart
●● Lead I
Answer: Records impulses btwn L and R arms
●● Lead II
Answer: Records impulses btwn R arm and L leg
, Clearest recording of heart rhythm on rhythm strip
●● Lead III
Answer: Records impulses btwn L arm and L leg
●● Unipolar limb leads
Answer: aVR, aVL, aVF
Record from one pole but due to poor illustration of waveforms, must be
augmented (requires assisting in enhancing the tracing by drawing from
2 other poles)
●● Lead aVL
Answer: L leg and R arm assist with L arm tracing
●● Lead aVR
Answer: L arm and L leg assist with R arm tracing
●● Lead aVF
Answer: R and L arms assist with L leg tracing
●● Precordial leads
STUDY GUIDE
●● Ratio of applied leads to recorded leads
Answer: 10:12
●● EKG vertical axis
Answer: Amplitude (gain)
Each small vertical square = 0.1 mV
Each large square = 0.5 mV
●● EKG horizontal axis
Answer: Time
Each small horizontal square = 0.04 s
Each large square = 0.2 s
●● Characteristics of EKG paper
Answer: Pressure and heat sensitive
●● Normal speed for EKG
,Answer: 25 mm/s
●● Normal amplitude of EKG
Answer: 10 mm (1 mV)
●● How to attach EKG limb leads (normal and amputation)
Answer: Place on fleshy areas of the skin and within the same general
vicinity on each limb
If one leg is amputated, place electrode on the abdomen, and the
electrode for the other limb should also be placed on the abdomen
●● Bipolar limb leads
Answer: I, II, and III
Impulses travel from negative to positive pole at specific positions in the
heart
●● Lead I
Answer: Records impulses btwn L and R arms
●● Lead II
Answer: Records impulses btwn R arm and L leg
, Clearest recording of heart rhythm on rhythm strip
●● Lead III
Answer: Records impulses btwn L arm and L leg
●● Unipolar limb leads
Answer: aVR, aVL, aVF
Record from one pole but due to poor illustration of waveforms, must be
augmented (requires assisting in enhancing the tracing by drawing from
2 other poles)
●● Lead aVL
Answer: L leg and R arm assist with L arm tracing
●● Lead aVR
Answer: L arm and L leg assist with R arm tracing
●● Lead aVF
Answer: R and L arms assist with L leg tracing
●● Precordial leads
