📚 Series Article: This guide is part of our comprehensive 12 Lead ECG Placement: The Ultimate Guide. Proper preparation prevents most artifacts—see our ECG preparation guide for the foundation.
ECG artifact troubleshooting is a skill every clinician needs but few are formally taught. You've recorded what should be a clean ECG, but instead you're looking at a tracing full of noise, wandering baselines, or chaotic interference that makes interpretation impossible. Now what?
The key to ECG artifact management is pattern recognition. Each type of artifact has a distinctive appearance that points directly to its cause—and once you know the cause, the fix is usually straightforward. Baseline wander looks different from muscle tremor, which looks different from electrical interference. Learn to read these patterns, and you'll solve most artifact ECG problems in under 60 seconds.
This guide covers the 6 most common ECG artifacts you'll encounter, how to identify each one, and the specific steps to eliminate them.
⚡ Quick Reference: The 6 Common Artifacts
- Baseline wander: Slow, undulating movement — Fix: Better skin prep, secure electrodes
- Muscle tremor (somatic): Fine, irregular jaggedness — Fix: Relax patient, warm room
- 60 Hz (AC) interference: Regular, thick baseline — Fix: Eliminate electrical sources
- Motion artifact: Sudden, irregular spikes — Fix: Patient stays still
- Electrode pop: Sharp vertical deflections — Fix: Replace loose electrode
- Lead reversal: Inverted complexes — Fix: Check lead connections
In This Guide
- Why ECG Artifacts Matter Clinically
- Artifact #1: Baseline Wander
- Artifact #2: Muscle Tremor (Somatic Artifact)
- Artifact #3: 60 Hz (AC) Electrical Interference
- Artifact #4: Motion Artifact
- Artifact #5: Electrode Contact Problems
- Artifact #6: Lead Reversal Artifact
- Systematic ECG Artifact Troubleshooting Approach
- Prevention: The Best Troubleshooting
Why ECG Artifacts Matter Clinically
Artifacts aren't just technical annoyances—they're diagnostic hazards. According to American Heart Association literature, artifact-related misinterpretation contributes to both false-positive and false-negative cardiac diagnoses.
Artifacts That Mimic Pathology
| Artifact Type | Can Mimic | Clinical Risk |
|---|---|---|
| Muscle tremor | Atrial fibrillation, atrial flutter | Unnecessary anticoagulation |
| Baseline wander | ST elevation or depression | False STEMI diagnosis |
| Motion artifact | Ventricular tachycardia, PVCs | Inappropriate treatment |
| 60 Hz interference | Fine ventricular fibrillation | Unnecessary defibrillation |
I've personally witnessed muscle tremor artifact trigger a "new atrial fibrillation" diagnosis in a patient who was simply cold and shivering. The artifact disappeared completely when we gave her a warm blanket. Recognizing artifact patterns prevents these errors.
Artifacts That Obscure Pathology
Equally dangerous: artifacts can hide real abnormalities. A noisy baseline can mask:
- Subtle ST changes indicating ischemia
- Low-amplitude P waves
- Fine atrial fibrillation
- Small Q waves
When you can't see clearly, you can't diagnose accurately. That's why ECG artifact troubleshooting is a clinical skill, not just a technical one.
Artifact #1: Baseline Wander
Baseline wander is the most common artifact on ECG tracings—and the most commonly caused by poor technique.
What It Looks Like
The ECG baseline (the isoelectric line between complexes) slowly drifts up and down instead of staying flat. The wandering is:
- Slow: Moves over several complexes, not beat-to-beat
- Smooth: Gradual undulation, not sharp changes
- Often respiratory: May correlate with breathing cycle
Common Causes
- Poor electrode adhesion: Electrode lifting from skin with movement
- Inadequate skin preparation: Oil, lotion, or dead skin blocking contact
- Dried electrode gel: Expired or dried-out electrodes
- Patient movement: Especially respiratory movement
- Sweaty skin: Moisture lifting electrode edges
How to Fix It
✓ Baseline Wander Fix Protocol:
- Remove affected electrodes
- Clean skin with alcohol wipe, let dry completely
- Abrade skin gently with gauze until slightly pink
- Apply fresh electrodes with moist gel
- Press firmly for 10 seconds to ensure adhesion
- Ask patient to breathe normally (not deeply)
- Re-record
For complete skin preparation technique, see our ECG preparation guide.
Which Leads Are Affected?
Baseline wander usually affects specific leads, which tells you which electrode is the problem:
- Leads II, III, aVF wandering: Check LL (left leg) electrode
- Leads I, aVL wandering: Check LA (left arm) electrode
- Single precordial lead wandering: Check that specific V electrode
- All leads wandering: Usually RL (ground) electrode issue, or patient moving
Artifact #2: Muscle Tremor (Somatic Artifact)
Muscle tremor artifact—also called somatic artifact—comes from skeletal muscle electrical activity contaminating the ECG signal.
What It Looks Like
- Fine, irregular oscillations: Like a "fuzzy" baseline
- High frequency: Much faster than cardiac rhythm
- Variable amplitude: Irregular height of the noise
- Can obscure the baseline entirely in severe cases
The Atrial Fibrillation Mimicry Problem
This is the most clinically dangerous ECG artifact. Muscle tremor can look remarkably like atrial fibrillation:
- Both show irregular baseline activity
- Both can obscure P waves
- The difference: in true AF, the ventricular rhythm is irregularly irregular; in tremor artifact, if you can see the QRS complexes, the underlying rhythm may be regular
⚠️ Clinical Pearl
Before diagnosing new atrial fibrillation, always rule out muscle tremor artifact. Ask: Is the patient cold? Anxious? Tense? Eliminate the artifact and re-record before making the diagnosis.
Common Causes
- Patient shivering: Cold room or patient anxiety
- Muscle tension: Patient not relaxed, gripping bed rails
- Parkinson's disease: Baseline tremor condition
- Anxiety: Generalized muscle tension
- Pain: Causing muscle guarding
How to Fix It
✓ Muscle Tremor Fix Protocol:
- Warm the room or cover patient with blanket
- Ask patient to relax arms at sides (not gripping anything)
- Place pillows under arms for support
- Have patient close eyes and breathe slowly
- For Parkinson's patients: may need to use filter settings on ECG machine
- Wait 30-60 seconds for relaxation, then re-record
Which Leads Are Affected?
- Limb leads only: Arms or legs are tense
- All leads including precordial: Generalized tension (cold, anxiety)
- Specific limb leads: That limb is the source
Artifact #3: 60 Hz (AC) Electrical Interference
AC interference—also called 60 Hz artifact (50 Hz in some countries)—is electrical "noise" from nearby power sources.
What It Looks Like
- Extremely regular: Perfectly uniform oscillations
- High frequency: 60 cycles per second (very fast)
- "Thickened" baseline: Baseline looks fuzzy but regular
- Uniform across affected leads: Same pattern in multiple leads
According to LITFL ECG Library, the regularity of AC interference is its distinguishing feature—it's too perfect to be biological.
Common Sources
- IV pumps: Especially when touching patient or bed
- Bed motors: Electric bed controls
- Fluorescent lights: Overhead lighting
- Nearby electrical equipment: Monitors, computers
- Poor grounding: ECG machine or building electrical
- Cell phones: Patient's or clinician's phone
How to Fix It
✓ 60 Hz Interference Fix Protocol:
- Remove cell phones from patient and yourself—move them 6+ feet away
- Unplug unnecessary equipment near patient
- Move IV pumps away from ECG cables if possible
- Check ECG cable routing—don't run alongside power cords
- Ensure RL (ground) electrode has good skin contact
- Try different electrical outlet for ECG machine
- Use ECG machine's 60 Hz filter as last resort (may affect morphology)
The Ground Electrode's Role
The RL (right leg) electrode is your ground reference. If it has poor contact, AC interference affects all leads. Always ensure RL electrode:
- Has good skin preparation
- Uses fresh electrode with moist gel
- Is firmly adhered
- Is on the correct location
Artifact #4: Motion Artifact
Motion artifact results from patient movement during recording—often from talking, coughing, or repositioning.
What It Looks Like
- Sudden, irregular deflections: Sharp spikes or waves
- Unpredictable timing: Doesn't follow any pattern
- Variable morphology: Each artifact looks different
- May shift baseline suddenly: Baseline jumps then returns
The VT/VF Mimicry Danger
Severe motion artifact can mimic ventricular tachycardia or even ventricular fibrillation. Before treating a "lethal arrhythmia":
- Look at the patient: Are they awake and talking? Then it's not VF.
- Check the pulse: Palpable pulse rules out VF.
- Correlate with symptoms: VT/VF patients are unconscious or symptomatic.
Common Causes
- Patient talking: Especially during "hold still" moment
- Coughing or sneezing: Sudden large movements
- Repositioning: Patient adjusting position
- Clinician touching patient: During recording
- Cable movement: Cables being moved or pulled
How to Fix It
✓ Motion Artifact Fix Protocol:
- Clearly instruct patient: "Please lie very still and don't talk for 10 seconds"
- Wait for movement to stop before hitting record
- Ensure cables are not pulling on electrodes
- Step back from patient during recording
- If patient cannot stay still (respiratory distress, altered mental status): document, do your best, note on ECG
Artifact #5: Electrode Contact Problems (Electrode Pop)
Electrode contact artifacts—often called "electrode pop"—occur when an electrode intermittently loses contact with the skin.
What It Looks Like
- Sharp vertical deflections: Sudden spikes up or down
- Rectangular shape: Vertical lines with flat tops
- Intermittent: Random occurrence
- Affects specific leads: Only leads connected to the problem electrode
Common Causes
- Loose electrode: Edge lifting from skin
- Dried gel: Old or expired electrode
- Hairy skin: Hair preventing adhesion
- Sweaty skin: Moisture breaking seal
- Cable clip loose: Clip not fully attached to electrode
How to Fix It
✓ Electrode Pop Fix Protocol:
- Identify the problem lead(s) from the tracing pattern
- Check that electrode—is it lifting? Is gel dry?
- Check cable connection—is clip fully attached?
- Replace the electrode with a fresh one
- If hairy: shave the area
- Re-prep skin and apply fresh electrode
Identifying Which Electrode Is the Problem
The pattern of affected leads tells you which electrode to fix:
| Leads Affected | Problem Electrode |
|---|---|
| I, II, all precordial | RA (right arm) |
| I, III, aVL, aVF | LA (left arm) |
| II, III, aVF | LL (left leg) |
| All leads noisy | RL (ground) |
| Single V lead only | That specific V electrode |
Artifact #6: Lead Reversal Artifact
Lead reversal isn't "noise" in the traditional sense—it's an artifact of incorrect electrode placement that produces a technically clean but diagnostically wrong ECG.
What It Looks Like
The ECG appears clean, but the morphology is wrong:
- LA-RA reversal: Inverted P wave and QRS in Lead I; upright in aVR
- Precordial reversal: Unexpected R-wave progression (suddenly smaller or reversed)
- May look like axis deviation that doesn't match clinical picture
For detailed lead reversal patterns and recognition, see our 10 common ECG placement mistakes guide.
The Classic Pattern: LA-RA Reversal
The most common reversal. Recognition keys:
- Lead I: Inverted P wave, inverted QRS (should normally be upright)
- aVR: Upright P wave, upright QRS (should normally be inverted)
- Lead II = Lead III (they swap when arms are reversed)
How to Fix It
✓ Lead Reversal Fix Protocol:
- Recognize the pattern (inverted Lead I + upright aVR = arm reversal)
- Trace each cable from electrode to machine
-
Verify colors match positions:
- White/RA = Right arm
- Black/LA = Left arm
- Green/RL = Right leg
- Red/LL = Left leg
- Correct any misconnections
- Re-record the ECG
Prevention is Key
Lead reversal is entirely preventable with systematic technique:
- Always attach leads in the same sequence
- Verify colors before recording
- Check Lead I and aVR for expected pattern before accepting ECG
Systematic ECG Artifact Troubleshooting Approach
When you see a noisy ECG, don't panic. Follow this systematic ECG artifact troubleshooting protocol:
Step 1: Characterize the Artifact (10 seconds)
| Ask Yourself | If Yes, Likely Cause |
|---|---|
| Is it slow and undulating? | Baseline wander |
| Is it fine and irregular? | Muscle tremor |
| Is it perfectly regular and fast? | 60 Hz interference |
| Are there sudden spikes? | Motion or electrode pop |
| Is Lead I inverted with upright aVR? | Lead reversal |
Step 2: Identify Which Leads Are Affected (10 seconds)
- All leads: Check ground electrode (RL), or generalized problem (cold patient, electrical interference)
- Limb leads only: Check limb electrodes
- Specific leads: Check the electrode that connects those leads (use the table above)
Step 3: Apply the Specific Fix (30-60 seconds)
Use the fix protocol for the identified artifact type. Most fixes take under 60 seconds.
Step 4: Re-record and Verify (30 seconds)
Record a new ECG and confirm the artifact is eliminated. If it persists, return to Step 1 and reconsider the cause.
✓ Pro Tip: If you've tried everything and artifact persists, try a different ECG machine. Occasionally the machine itself is the problem (damaged cables, faulty filters).
Prevention: The Best ECG Artifact Troubleshooting
The fastest way to fix artifacts is to prevent them in the first place. According to clinical research, proper preparation reduces artifact rates by approximately 40%.
Pre-Recording Checklist
Artifact Prevention Checklist
- ☐ Environment: Room warm, cell phones away, unnecessary equipment off
- ☐ Skin prep: Clean, dry, abraded (pink skin rule)
- ☐ Electrodes: Fresh, gel moist, pressed firmly 10 seconds
- ☐ Patient: Supine, arms relaxed at sides, pillows for support
- ☐ Cables: Not pulling on electrodes, not near power cords
- ☐ Communication: Patient understands to stay still and quiet
For the complete preparation protocol, see our ECG preparation guide.
Equipment Maintenance
- Check electrode expiration dates monthly
- Inspect cables for damage weekly
- Clean patient cable connections regularly
- Service ECG machine per manufacturer schedule
Build Artifact Recognition Skills
Like any skill, artifact recognition improves with deliberate practice. Our ECG quality control system guide includes training protocols for building these competencies.
Frequently Asked Questions
Q: How do I tell the difference between muscle tremor artifact and atrial fibrillation?
A: Look at the QRS rhythm. In true atrial fibrillation, the ventricular rhythm is irregularly irregular—the RR intervals vary randomly. In muscle tremor artifact with underlying sinus rhythm, if you can measure the RR intervals, they'll be regular (or regularly irregular if there's sinus arrhythmia). Also, warm up the patient and see if the "AF" disappears—true AF won't change with a blanket.
Q: When should I use the ECG machine's filter settings?
A: Filters should be a last resort because they can alter the ECG morphology and affect diagnosis. Try to eliminate artifact at the source first. Use the muscle (high-frequency) filter only for tremor you cannot control (Parkinson's disease). Use the 60 Hz filter only when you've eliminated all electrical interference sources and artifact persists.
Q: What if the patient simply cannot stay still?
A: Do your best and document the limitation. Write "Patient unable to remain still due to [respiratory distress/altered mental status/pain]" on the ECG. Obtain the cleanest tracing possible and interpret with the understanding that artifact may be present. Serial ECGs when the patient is more stable may help.
Q: How often should electrodes be replaced during monitoring?
A: For continuous monitoring, electrodes should be replaced every 24 hours, or sooner if they show signs of lifting, dried gel, or artifact. For one-time ECGs, always use fresh electrodes.
Mastering ECG Artifact Troubleshooting
ECG artifact troubleshooting is a fundamental clinical skill that improves with practice. The key is pattern recognition: each artifact type has a distinctive appearance that points to its cause, and once you identify the cause, the fix is usually straightforward.
What are these on my ECG? They are not "Artifacts".
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Remember the core principles of managing artifacts on ECG tracings:
- Characterize first: Slow/fast? Regular/irregular? Which leads?
- Fix at the source: Don't just use filters—address the underlying cause
- Prevention beats correction: Proper preparation eliminates most artifacts before they occur
- Correlate clinically: Always look at the patient, not just the screen
Master these ECG artifact patterns and you'll spend less time wrestling with noisy tracings and more time making accurate diagnoses. That's the ultimate goal of ECG artifact troubleshooting—clean data that you can trust.
📚 Get the Complete Picture
Return to the main guide: 12 Lead ECG Placement: The Ultimate Guide
Related quality and technique guides:
Clinical Education Team
Our clinical team has collectively performed thousands of ECGs and trained hundreds of clinicians in artifact recognition and troubleshooting. This guide reflects real-world experience combined with evidence-based best practices.
