CRAT ECG Troubleshooting and Artifacts 2

Question 1

Sixty-cycle (60 Hz) interference on an ECG most likely results from which cause?

Accepted Answer

Nearby electrical equipment or poor electrode grounding

Answer

60 Hz artifact appears as a thick, fuzzy baseline caused by electromagnetic interference from AC power sources including nearby electrical equipment or inadequate grounding.

Question 2

Baseline wander on an ECG is most commonly caused by which factor?

Accepted Answer

Patient breathing or movement causing electrode-skin interface changes

Answer

Baseline wander results from slow undulation of the baseline caused by patient movement, respiration, poor electrode contact, or electrode gel drying.

Question 3

A patient's ECG shows a completely flat line in lead II only, while other leads record normally. The most likely cause is which of the following?

Accepted Answer

Disconnected or failed lead II electrode

Answer

A flat line in one lead only, while other leads continue to show cardiac activity, indicates a technical failure specific to that lead — most likely a disconnected electrode.

Question 4

Which action is most appropriate when a patient's ECG shows muscle tremor artifact that obscures rhythm interpretation?

Accepted Answer

Reposition the electrodes away from muscle-heavy areas and ask the patient to relax

Answer

Muscle tremor creates irregular high-frequency artifact that can mimic arrhythmias. Repositioning electrodes to bony prominences and asking the patient to relax reduces this artifact.

Question 5

If limb leads show reversed arm electrode placement (right and left arm switched), which lead will appear inverted compared to a correct recording?

Accepted Answer

Lead I

Answer

Lead I measures the potential difference between the left arm (positive) and right arm (negative). Switching these electrodes inverts lead I and swaps leads II and III.

CRAT - Certified Rhythm Analysis Technician Practice Test

CRAT - Certified Rhythm Analysis Technician Practice Test

CRAT ECG Troubleshooting and Artifacts 2