CET ECG Artifact Troubleshooting 3 — Questions and Answers
Question 1: A patient with Parkinson's disease produces a continuous tremor artifact on the ECG that closely mimics atrial flutter waves. Which feature best distinguishes true atrial flutter from tremor artifact?
- Flutter waves are faster than 300 bpm
- Tremor artifact is absent in lead aVR
- Flutter waves maintain a consistent morphology and rate across all leads (Correct answer)
- Tremor artifact always causes QRS widening
Correct answer: Flutter waves maintain a consistent morphology and rate across all leads
True atrial flutter produces sawtooth waves of uniform morphology at a consistent rate (typically 250–350 bpm) in all leads, whereas tremor artifact varies in amplitude and regularity.
Question 2: During electrode application, the technician notices the patient has very oily skin. Which preparation step is MOST important to reduce motion artifact?
- Apply a larger electrode pad
- Cleanse the skin with an alcohol wipe and allow it to dry completely (Correct answer)
- Press harder on the electrode after application
- Use a conductive spray instead of gel
Correct answer: Cleanse the skin with an alcohol wipe and allow it to dry completely
Oil creates a barrier between the electrode and skin; cleansing removes it, and allowing the alcohol to dry prevents impedance changes from solvent residue.
Question 3: What is the primary reason limb lead cables should not be draped over the patient's body during recording?
- The cable weight pulls electrodes off the skin
- Cable movement generates motion artifact via triboelectric effect (Correct answer)
- Body heat degrades the cable insulation
- It violates standard infection-control protocol
Correct answer: Cable movement generates motion artifact via triboelectric effect
The triboelectric effect causes charge generation when cables rub against the patient's skin or gown, introducing motion artifact into the signal.
Question 4: An ECG recorded in the ICU shows 60 Hz interference only when a specific IV infusion pump is running. The best corrective action is:
- Turn off the infusion pump for the duration of the ECG
- Temporarily disconnect the pump's power cord during recording
- Reposition the ECG lead wires away from the pump and its power cable (Correct answer)
- Replace the ECG electrodes with silver-silver chloride type
Correct answer: Reposition the ECG lead wires away from the pump and its power cable
Routing ECG lead wires away from the power cable of the infusion pump reduces electromagnetic coupling that causes 60 Hz artifact.
Question 5: A flat line appears in lead V5 while all other leads record normally. After checking the lead wire connection, the technician should next:
- Reposition the V5 electrode to V4 location
- Check the central terminal connection on the ECG machine
- Inspect the V5 electrode for adequate gel and skin contact (Correct answer)
- Increase the gain setting for lead V5
Correct answer: Inspect the V5 electrode for adequate gel and skin contact
A flat line in a single precordial lead most often indicates the electrode has lost contact with the skin, making adequate gel and adhesion the next check.
Question 6: Which filter setting is most appropriate for a standard diagnostic resting 12-lead ECG recording to preserve accurate ST-segment morphology?
- 0.05–150 Hz bandwidth (Correct answer)
- 0.5–40 Hz bandwidth
- 0.5–100 Hz with 60 Hz notch enabled
- 1–30 Hz bandwidth
Correct answer: 0.05–150 Hz bandwidth
The AHA recommends a 0.05–150 Hz bandwidth for diagnostic ECGs to preserve low-frequency ST changes and high-frequency QRS detail without distortion.
Question 7: A pediatric patient cannot remain still, producing continuous motion artifact. Which strategy is appropriate to minimize artifact while maintaining diagnostic quality?
- Record during natural sleep or a quiet moment and lengthen the recording duration (Correct answer)
- Increase paper speed to 50 mm/s to separate complexes
- Apply sedation medication before recording
- Use only a 3-lead configuration to reduce setup time
Correct answer: Record during natural sleep or a quiet moment and lengthen the recording duration
Recording during a calm or sleeping period captures the clearest signal without altering the ECG with pharmacological intervention or reducing diagnostic leads.
CET ECG Artifact Troubleshooting 3
A patient with Parkinson's disease produces a continuous tremor artifact on the ECG that closely mimics atrial flutter waves.
Which feature best distinguishes true atrial flutter from tremor artifact?