Study guide · concept · EKG & cardiovascular testing
EKG artifacts on the CCMA: how to tell them apart
Each EKG artifact has its own shape. Regular, even fuzz is AC (60-cycle) interference, irregular jagged spikes are somatic tremor, and a baseline that slowly rolls up and down is a wandering baseline.
- artifacts to tell apart
- 3
- cycles: AC interference
- 60
- standard paper speed
- 25 mm/s
§01
Read the shape before the label
Three adjectives decide it: regular, irregular, rolling.
Artifact questions describe a tracing in words and ask what caused it or what you should do. Start with the adjective. Uniform or regular points to electricity. Irregular or jagged points to muscle. Slow, rolling or drifting points to the electrodes or to breathing. The rest of the stem is supporting detail.
§02
Look, cause, fix
Learn each row as a unit: shape, source, remedy.
| Artifact | What you see | Usual causes | What the MA does |
|---|---|---|---|
| AC (60-cycle) interference | Uniform, regular, thick fuzz along the baseline | Nearby electrical equipment, poor grounding, lead wires crossing power cords | Unplug or move devices, check grounding, route lead wires away from cords |
| Somatic (muscle) tremor | Irregular, jagged spikes of varying size | Movement, cold, tremor disorders, tense muscles | Warm the patient, support the limbs, help them relax and lie still |
| Wandering baseline | The whole line slowly rolls up and down | Loose or dried electrodes, lotion or oil on the skin, breathing movement | Re-prep the skin, apply fresh electrodes firmly, coach slow, even breathing |
§03
Set up so artifact never starts
Most artifact is preventable before the first strip prints.
- A warm room and a covered patient, lying supine with the arms and legs supported.
- Clean, dry skin with no lotion or oil, and fresh electrodes pressed on firmly.
- Lead wires lying slack and away from power cords, with the machine properly grounded.
- A short explanation first, so the patient knows to lie still and breathe normally.
§04
When the chaos isn't noise
Check the patient before you check the machine.
Ventricular fibrillation is chaotic with no QRS complexes, and the patient has no pulse. That calls for a code and CPR. If the patient is talking to you while the line looks chaotic, you're looking at artifact. Asystole is confirmed in at least two leads before anyone acts on it, because a loose lead can also produce a flat line.
Rhythm recognition and what the MA does are covered on the EKG and cardiovascular testing page. Electrode errors that change the waveforms themselves are on the lead placement page.
§05
Details that come up
Why is AC interference called 60-cycle?
US mains current alternates 60 times a second (60 Hz). Equipment nearby can induce that rhythm into the lead wires, and it shows up as even fuzz.
Can artifact show up in only some leads?
Yes. A single loose electrode affects only the leads that use it, so noise in a few leads points to the electrodes those leads share.
Does a tracing with artifact go to the provider?
Correct the cause and record a clean tracing first. Then note anything unusual about the recording, such as a patient who couldn't lie flat.
§06
Artifact questions
6 questions. Pick an answer to see why it is right or wrong.
Find the adjective in each stem first: regular, irregular or rolling.
An EKG tracing shows uniform, regular, thick fuzz across the baseline in every lead. What is the most likely cause and fix?
Answer & explanation
Answer: C. AC interference; unplug nearby devices
Regular, evenly spaced fuzz is 60-cycle (AC) electrical interference, fixed by unplugging or moving nearby equipment, checking grounding, and keeping lead wires from crossing cords. Muscle tremor is the classic confusion, but somatic artifact is irregular and jagged, not uniform. A wandering baseline drifts slowly, and flutter waves appear as a sawtooth between QRS complexes.
- A wandering baseline drifts slowly up and down; it is not a uniform fuzz.
- Muscle tremor is irregular and jagged, not evenly spaced — the classic mix-up.
- Correct: regular, uniform fuzz is 60-cycle AC interference; unplug, ground, or move nearby cords.
- Flutter shows sawtooth waves between QRS complexes, not fuzz across every lead.
A patient with a resting tremor produces jagged, irregular artifact on the EKG. Which step best reduces it?
Answer & explanation
Answer: D. Support the limbs and help the patient relax
Somatic tremor artifact is reduced by supporting the limbs with pillows and helping the patient warm up and relax. Skipping leads, changing paper speed, or medicating the patient does not correct the underlying muscle movement and is outside the MA role.
- Paper speed changes complex width, not muscle movement, so the artifact remains.
- Skipping limb leads gives an incomplete 12-lead and does not address the tremor.
- Sedating a patient is outside MA scope and is not how tremor artifact is managed.
- Correct: supporting the limbs and helping the patient relax reduces the muscle activity causing the artifact.
An EKG tracing shows the baseline slowly rolling up and down. What is the most likely cause?
Answer & explanation
Answer: B. Loose electrodes or deep breathing
A slow, rolling baseline is a wandering baseline, caused by breathing movement or poorly attached, dried-out electrodes. Electrical (60-cycle) interference produces a regular, thick fuzzy line, not a drift. Muscle tremor produces irregular, jagged spikes, and a wrong paper speed changes the width of the complexes.
- Electrical interference produces regular, thick fuzz, not a slow rolling drift.
- Correct: a slow rolling baseline comes from breathing movement or loose, dried-out electrodes.
- Shivering causes irregular, jagged spikes, not a smooth drift.
- A wrong paper speed changes complex width and spacing, not baseline position.
Irregular, jagged spikes that vary in size appear on the tracing while the patient is shivering. This artifact is:
Answer & explanation
Answer: B. Somatic (muscle) tremor
Irregular, jagged, varying artifact caused by muscle activity such as shivering is somatic tremor, corrected by warming and relaxing the patient. AC interference is uniform and regular, and a wandering baseline slowly drifts rather than showing jagged spikes.
- Normal sinus rhythm shows a clean baseline with regular P-QRS-T complexes, not jagged spikes.
- Correct: irregular, varying spikes from shivering are somatic (muscle) tremor artifact.
- AC interference is uniform and regular — the key contrast with irregular somatic artifact.
- A wandering baseline drifts slowly rather than showing sharp jagged spikes.
The EKG baseline slowly drifts up and down across the tracing. What should the MA do?
Answer & explanation
Answer: C. Check for loose or dried electrodes
A slow, rolling drift is a wandering baseline, usually caused by loose or dried electrodes, lotion on the skin, or breathing movement, so the MA re-preps the skin and secures fresh electrodes. Unplugging equipment is the fix for regular 60-cycle interference, and warming the patient fixes irregular muscle-tremor artifact. Raising the gain enlarges the drift rather than fixing it.
- Warming the patient fixes jagged muscle-tremor artifact, not a slow drift.
- Raising the gain enlarges the drift instead of correcting it.
- Correct: slow drift points to poor electrode contact, so check, re-prep and resecure the electrodes.
- Unplugging equipment fixes regular 60-cycle fuzz, not a wandering baseline.
Sharp vertical spikes appear immediately before each QRS on a patient's tracing. What do these most likely represent?
Answer & explanation
Answer: D. Pacemaker (pacing) artifact spikes
Narrow vertical spikes just before each QRS are pacing spikes produced by an implanted pacemaker, and their presence should be noted on the tracing. AC interference and muscle tremor produce continuous fuzz rather than discrete spikes tied to each beat.
- A wandering baseline is a slow drift, not sharp spikes tied to each beat.
- Somatic tremor produces irregular, continuous jagged artifact, not one spike per beat.
- AC interference is a continuous regular fuzz across the baseline, not discrete spikes.
- Correct: a narrow spike before each QRS is a pacemaker firing; note it on the tracing.
That is the whole set. Open any card to re-read its explanation, or start over.