CET Lead Placement & Recording Procedures 2 — Questions and Answers
Question 1: Which anatomical landmark is used to locate the fourth intercostal space for V1 and V2 placement?
- Xiphoid process
- Sternal angle (angle of Louis) (Correct answer)
- Clavicle midpoint
- Suprasternal notch
Correct answer: Sternal angle (angle of Louis)
The sternal angle (angle of Louis) marks the junction of the manubrium and sternal body, which aligns with the second rib, allowing the technician to count down to the fourth intercostal space.
Question 2: When applying limb electrodes to a patient with bilateral lower-limb amputations, where should the leg electrodes be placed?
- Skipped entirely; only chest leads are recorded
- On the lower torso or upper thighs bilaterally (Correct answer)
- On the upper arms instead
- On the shoulders to balance the signal
Correct answer: On the lower torso or upper thighs bilaterally
When limbs are absent, electrodes are repositioned to the most distal portion of the remaining limb or the corresponding torso area, maintaining left-right symmetry.
Question 3: What does a 'wandering baseline' on an ECG most commonly indicate?
- Atrial fibrillation
- Patient movement or improper skin preparation (Correct answer)
- Lead reversal
- Ventricular hypertrophy
Correct answer: Patient movement or improper skin preparation
A wandering baseline is typically caused by poor electrode contact, patient breathing, movement, or inadequate skin preparation preventing stable electrical conduction.
Question 4: Which precordial lead is placed at the right side of the sternum at the fourth intercostal space?
- V2
- V1 (Correct answer)
- V3R
- V4
Correct answer: V1
V1 is positioned at the right sternal border in the fourth intercostal space, while V2 mirrors it on the left sternal border.
Question 5: The standard paper speed for a resting 12-lead ECG in the United States is:
- 10 mm/sec
- 50 mm/sec
- 25 mm/sec (Correct answer)
- 12.5 mm/sec
Correct answer: 25 mm/sec
25 mm/sec is the standard paper speed in the US, making each small square represent 0.04 seconds and each large square 0.20 seconds.
Question 6: A patient has excessive chest hair that prevents adequate electrode adhesion. What is the correct course of action?
- Apply more conductive gel over the hair
- Place the electrode on an adjacent hairless area
- Shave or clip the hair before placing the electrode (Correct answer)
- Skip those leads and note it on the report
Correct answer: Shave or clip the hair before placing the electrode
Shaving or clipping chest hair at the electrode site is the accepted procedure to ensure skin contact and artifact-free recording.
Question 7: How many seconds of rhythm strip is the minimum typically required on a standard 12-lead ECG printout?
- 5 seconds
- 10 seconds (Correct answer)
- 30 seconds
- 60 seconds
Correct answer: 10 seconds
A minimum 10-second recording is standard, long enough to capture at least one full cardiac cycle in most heart rates and assess rhythm.
CET Lead Placement & Recording Procedures 2
Which anatomical landmark is used to locate the fourth intercostal space for V1 and V2 placement?