ECG Motion Artefacts

ECG Motion Artefacts Overview
  • Motion artefact due to tremor or shivering can obscure the waveforms of the ECG or simulate pathology, making ECG interpretation difficult
  • In certain circumstances (e.g. hypothermia), the presence of shivering artefact may actually aid diagnosis

Causes of Tremor
  • Benign Essential Tremor (physiological tremor)
  • Parkinson’s Disease (resting tremor)
  • Cerebellar disease (intention tremor)
  • Alcohol / Benzodiazepine withdrawal
  • Anxiety
  • Thyrotoxicosis
  • Multiple sclerosis
  • Drugs: Amphetamines, cocaine, beta-agonists (adrenaline, salbutamol), theophylline, caffeine, lithium.
Other types of motion artefact
  • Fever (rigors)
  • Hypothermia (shivering)
  • Cardiopulmonary resuscitation (chest compressions)
  • A non-compliant, mobile, talkative patient (= the most common cause)!

ECG Examples
Example 1
ECG hypothermia shiver artefact bradycardia long QT

Hypothermia:


Example 2
tremor-artefact-parkinsons 2

Parkinsonian tremor:

  • The irregular baseline in this ECG gives the appearance of atrial fibrillation
  • The slow regular rhythm even suggests the possibility of atrial fibrillation with complete heart block and a junctional escape rhythm
  • However, on closer inspection there are visible P waves in V3 (circled)
  • This patient had sinus bradycardia and a resting tremor due to Parkinson’s disease

Example 3
chest-compressions 2

Chest compressions during CPR:

  • The high amplitude oscillations at the start of the rhythm strip are produced by movement artefact due to chest compressions during cardiopulmonary resuscitation
  • The second half of the rhythm strip shows ventricular fibrillation – presumably at this point the resuscitating team have stopped CPR to reassess the rhythm!

Example 4
Precordial thump

Precordial thump:


Advanced Reading

Online

Textbooks


LITFL Further Reading

ECG LIBRARY 700

ECG LIBRARY

Electrocardiogram

Emergency Physician in Prehospital and Retrieval Medicine in Sydney, Australia. He has a passion for ECG interpretation and medical education | ECG Library |

MBBS (UWA) CCPU (RCE, Biliary, DVT, E-FAST, AAA) Emergency Medicine Advanced Trainee in Melbourne, Australia. Special interests in diagnostic and procedural ultrasound, medical education, and ECG interpretation. Editor-in-chief of the LITFL ECG Library. Twitter: @rob_buttner

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