CCT Artifact Recognition and Troubleshooting 2 — Questions and Answers
Question 1: Dried or insufficient electrode gel is most likely to cause:
- 60 Hz AC artifact from capacitive coupling
- Increased skin-electrode impedance and poor signal quality (Correct answer)
- Somatic tremor artifact in all leads
- Complete loss of precordial signals
Correct answer: Increased skin-electrode impedance and poor signal quality
Dried electrode gel increases skin-electrode impedance, leading to poor signal quality, increased artifact, and unreliable tracings.
Question 2: Reversal of the left arm (LA) and right arm (RA) electrodes would most likely produce:
- Inverted P wave and negative QRS in lead I with swapped leads II and III (Correct answer)
- A flat line in all limb leads
- Inverted QRS complexes in all precordial leads
- Widened QRS complexes in leads II and III only
Correct answer: Inverted P wave and negative QRS in lead I with swapped leads II and III
Swapping LA and RA reverses the polarity of lead I, causing inverted P waves and QRS in lead I, and effectively swaps leads II and III.
Question 3: Intermittent baseline wander that correlates with the respiratory cycle is best corrected by:
- Replacing the ECG machine
- Using a higher filter setting on the machine
- Checking and improving electrode-skin contact and adhesion (Correct answer)
- Asking the patient to breathe faster
Correct answer: Checking and improving electrode-skin contact and adhesion
Respiratory baseline wander is typically caused by poor electrode-skin contact; improving skin preparation and electrode adhesion resolves the artifact.
Question 4: A patient with Parkinson's disease undergoing an ECG is most likely to exhibit which type of artifact?
- 60 Hz AC artifact due to medication infusion pumps
- Somatic tremor artifact due to involuntary muscle movement (Correct answer)
- Wandering baseline due to diaphoresis
- Motion artifact from voluntary repetitive movements
Correct answer: Somatic tremor artifact due to involuntary muscle movement
Parkinson's disease causes involuntary resting tremors that appear as somatic tremor artifact on the ECG tracing.
Question 5: Which of the following BEST describes the appearance of somatic tremor artifact on an ECG?
- Regular, fine oscillations at exactly 60 Hz superimposed on the baseline
- Irregular, variable oscillations that can obscure the baseline and waveforms (Correct answer)
- A flat isoelectric line in one or more leads
- Slow, rhythmic baseline drift correlating with respiration
Correct answer: Irregular, variable oscillations that can obscure the baseline and waveforms
Somatic tremor produces irregular, variable oscillations arising from muscle electrical activity that can obscure and mimic cardiac waveforms.
Question 6: Which skin preparation technique is MOST effective in reducing ECG artifact?
- Applying extra electrode gel without cleaning the skin
- Lightly abrading the skin and wiping with alcohol to remove oils and dead cells (Correct answer)
- Using warming blankets before electrode placement only
- Increasing electrode pressure by taping more firmly
Correct answer: Lightly abrading the skin and wiping with alcohol to remove oils and dead cells
Lightly abrading the skin and wiping with alcohol removes dead skin cells and oils, significantly reducing impedance and improving electrode contact quality.
Question 7: To reduce somatic tremor artifact in an anxious or cold patient, the technician should FIRST:
- Apply additional electrodes in parallel to average the signal
- Immediately activate the artifact filter on the ECG machine
- Reassure the patient, ensure warmth, and allow time to relax before recording (Correct answer)
- Increase the recording speed to 50 mm/sec
Correct answer: Reassure the patient, ensure warmth, and allow time to relax before recording
Addressing patient comfort and anxiety through reassurance and warmth reduces muscle tension at its source before resorting to technical workarounds.
CCT Artifact Recognition and Troubleshooting 2
Dried or insufficient electrode gel is most likely to cause: