CCT Artifact Recognition and Troubleshooting 1 — Questions and Answers
Question 1: What is the most common cause of 60 Hz AC interference on an ECG tracing?
- Patient movement during recording
- Improper grounding or nearby electrical equipment (Correct answer)
- Respiratory variation
- Electrode gel drying out
Correct answer: Improper grounding or nearby electrical equipment
AC interference at 60 Hz is caused by improper grounding or electromagnetic interference from nearby electrical equipment in the room.
Question 2: Somatic tremor artifact on an ECG is most likely caused by:
- Loose electrode connections
- Patient muscle movement or shaking (Correct answer)
- Nearby electrical equipment
- Improper lead placement
Correct answer: Patient muscle movement or shaking
Somatic tremor artifact results from involuntary patient muscle movement or shaking, producing irregular baseline oscillations on the tracing.
Question 3: Wandering baseline artifact is most commonly caused by:
- 60 Hz electrical interference
- Patient talking during recording
- Respiratory movement or poor electrode-skin contact (Correct answer)
- Reversed limb lead placement
Correct answer: Respiratory movement or poor electrode-skin contact
Wandering baseline is typically caused by respiratory movement or poor electrode-skin contact, making the baseline drift rhythmically up and down.
Question 4: Which characteristic best distinguishes 60 Hz AC interference from somatic tremor artifact?
- AC interference is irregular and variable in amplitude
- AC interference appears as uniform, regular oscillations at 60 cycles per second (Correct answer)
- Somatic tremor produces a perfectly regular pattern
- AC interference only affects precordial leads
Correct answer: AC interference appears as uniform, regular oscillations at 60 cycles per second
AC interference appears as perfectly regular, uniform oscillations at exactly 60 Hz, distinguishing it from the irregular, variable pattern of somatic tremor.
Question 5: To minimize motion artifact during ECG recording, the technician should:
- Increase paper speed to 50 mm/sec
- Ask the patient to hold their breath throughout the entire recording
- Ensure the patient is relaxed, warm, and comfortably positioned (Correct answer)
- Reduce the gain setting on the ECG machine
Correct answer: Ensure the patient is relaxed, warm, and comfortably positioned
Ensuring the patient is relaxed, warm, and comfortable minimizes muscle tension and involuntary movement, which are primary sources of motion artifact.
Question 6: A detached or loose electrode is most likely to produce which type of artifact?
- 60 Hz AC interference throughout all leads
- Somatic tremor in the affected lead
- A flat line or intermittent signal loss in the affected lead (Correct answer)
- Wandering baseline only in limb leads
Correct answer: A flat line or intermittent signal loss in the affected lead
A loose or detached electrode interrupts the electrical circuit, producing a flat line or intermittent signal dropout in the lead(s) using that electrode.
Question 7: Which measure is MOST effective in reducing 60 Hz AC interference on an ECG?
- Asking the patient to breathe slowly and deeply
- Moving the ECG machine farther from electrical outlets
- Ensuring proper grounding and removing sources of electromagnetic interference (Correct answer)
- Using higher gain settings on the ECG machine
Correct answer: Ensuring proper grounding and removing sources of electromagnetic interference
Ensuring proper equipment grounding and removing electromagnetic interference sources (such as electric blankets or nearby devices) are the most effective methods to eliminate 60 Hz artifact.
CCT Artifact Recognition and Troubleshooting 1
What is the most common cause of 60 Hz AC interference on an ECG tracing?