Artifacts And Troubleshooting

Overview

An electrocardiogram (EKG) records the heart's electrical activity. However, outside interference can create "noise" on the tracing, known as artifacts. As a Medical Assistant, you are the "signal detective." You must be able to recognize these artifacts, identify their source, and correct them to ensure a clean tracing.

1. Somatic Tremor (Patient Movement)

Cause: The patient's body (Soma) is moving. This creates erratic, jagged electrical spikes.

• Appearance: Fuzzy, erratic, irregular baseline.
• Common Culprits:
  • Shivering (cold).
  • Anxiety/Nervousness.
  • Parkinson's disease or other neurological tremors.
  • talking or chewing gum.
• Troubleshooting:
  1. Warmth: Offer a blanket.
  2. Calm: Reassure the patient to reduce anxiety.
  3. Stabilize: Ask the patient to place their hands, palms down, under their buttocks. This stabilizes the limb electrodes.

2. AC (Alternating Current) Interference

Cause: Electrical interference from the environment (not the patient).

• Appearance: A thick, uniform, fuzzy baseline. Looks like a "buzz" or a wide line made of consistent tiny spikes (60-cycle interference).
• Common Culprits:
  • Improper grounding of the EKG machine.
  • Other electrical devices (phones, IV pumps, lights).
  • Lead wires crossed over power cords.
• Troubleshooting:
  1. Check the Plug: Ensure the 3-prong plug is secure in the wall.
  2. Isolate: Unplug non-essential devices. Move the bed away from the wall.
  3. Untangle: Ensure lead wires are not draped over power cables.
  4. Remove Phones: Ask the patient to remove their cell phone.

3. Wandering Baseline

Cause: Poor connection between the electrode and the skin.

• Appearance: The tracing drifts slowly up and down (like a wave) across the paper.
• Common Culprits:
  • #1 Cause: Lotions, oils, or sweat on the skin.
  • Loose electrodes or dried-out gel.
  • Patient breathing heavily (chest wall movement).
• Troubleshooting:
  1. Skin Prep: Clean sites vigorously with alcohol. Shave hair if necessary.
  2. Secure: Press down on all electrodes.
  3. Relieve Tension: Ensure wires aren't pulling the electrodes off.

4. Interrupted Baseline

Cause: A complete break in the electrical circuit.

• Appearance: A flat line or the stylus shoots to the edge of the paper.
• Common Culprits:
  • Detached electrode.
  • Broken lead wire.
• Troubleshooting:
  1. Trace: Check connections from the patient to the machine.
  2. Replace: Reattach loose electrodes or replace broken wires.

5. Lead Reversal (Technical Error)

Cause: Electrodes are placed on the wrong limbs.

• Appearance (RA/LA Reversal): Lead I is completely inverted (upside down P-wave and QRS). This is the most common and tested reversal.
• Troubleshooting: Check your limb leads. Remember: White on the Right.

6. High-Yield Summary Table