EKG certification Certification EKG Equipment & Artifact Troubleshooting 2 — Questions and Answers
Question 1: What does the term 'lead reversal' mean in the context of a 12-lead EKG?
- The machine is printing leads in the wrong order
- Electrodes have been placed on incorrect body sites (Correct answer)
- The paper speed is reversed
- The sensitivity is inverted
Correct answer: Electrodes have been placed on incorrect body sites
Lead reversal occurs when electrodes are attached to the wrong limbs or precordial positions, producing inaccurate or mirror-image tracings.
Question 2: Which precordial lead is placed at the fourth intercostal space to the right of the sternum?
- V1 (Correct answer)
- V2
- V3
- V4
Correct answer: V1
V1 is placed at the fourth intercostal space just to the right of the sternum, making it one of the two septal leads.
Question 3: What color is the right arm electrode lead wire in the standard US (AHA) color coding system?
- Green
- Black
- White (Correct answer)
- Red
Correct answer: White
In the AHA color coding system used in the US, the right arm electrode is white, while the left arm is black, right leg is green, and left leg is red.
Question 4: When should an EKG technician replace disposable electrodes during a patient visit?
- Only if the patient requests it
- If the electrode loses adhesion or the gel dries out before recording (Correct answer)
- After every 30 minutes of monitoring
- Electrodes should never be replaced mid-session
Correct answer: If the electrode loses adhesion or the gel dries out before recording
Electrodes should be replaced if they lose adhesion or dry out, as poor electrode-skin contact leads to artifact and inaccurate recordings.
Question 5: Which EKG filter setting is used to reduce muscle artifact and motion noise while potentially affecting high-frequency components?
- 0.05 Hz high-pass filter
- 150 Hz low-pass filter
- 40 Hz low-pass filter (Correct answer)
- 60 Hz notch filter
Correct answer: 40 Hz low-pass filter
The 40 Hz low-pass filter reduces high-frequency muscle noise but may slightly reduce the amplitude of sharp waveform components like the QRS.
Question 6: What is the recommended action when somatic tremor artifact is identified on an EKG strip?
- Continue recording and note artifact in the report
- Ask the patient to hold their breath and relax muscles, then re-record (Correct answer)
- Increase the paper speed
- Switch to half sensitivity
Correct answer: Ask the patient to hold their breath and relax muscles, then re-record
Having the patient relax, warm the room, and ask them to hold their breath momentarily can eliminate somatic tremor artifact for a clean recording.
EKG certification Certification EKG Equipment & Artifact Troubleshooting 2
What does the term 'lead reversal' mean in the context of a 12-lead EKG?