What is the proper procedure and preparation for an electrocardiogram (ECG) test?

Proper Procedure and Preparation for an Electrocardiogram (ECG) Test

The proper procedure for an electrocardiogram (ECG) requires proper patient positioning, electrode placement on clean skin, and documentation of relevant clinical information, while avoiding common technical errors that may affect interpretation. 1, 2

Patient Preparation

• Patient positioning: Patient should be lying supine in a comfortable position
• Skin preparation:
  • Clean electrode sites with alcohol if skin is oily or dirty
  • Shave excessive hair if necessary to ensure proper electrode contact
  • Gently abrade skin to remove dead skin cells for better electrical contact
• Environment:
  • Ensure room is at comfortable temperature (cold can cause muscle tremors)
  • Minimize electrical interference by turning off nearby electrical devices
  • Provide privacy and explain the procedure to reduce patient anxiety

Electrode Placement

• Standard 12-lead ECG requires 10 electrodes:
  • 4 limb electrodes (right arm, left arm, right leg, left leg)
  • 6 precordial (chest) electrodes (V1-V6)
• Ensure proper anatomical placement according to American Heart Association standards:
  • V1: Fourth intercostal space at right sternal border
  • V2: Fourth intercostal space at left sternal border
  • V4: Fifth intercostal space at midclavicular line
  • V3: Halfway between V2 and V4
  • V5: Anterior axillary line at same horizontal level as V4
  • V6: Mid-axillary line at same horizontal level as V4 and V5

During the Recording

• Instruct patient to:
  • Lie still and relax
  • Breathe normally
  • Avoid talking during the recording
• Document relevant information:
  • Patient demographics
  • Current medications (especially cardiac medications)
  • Reason for ECG
  • Presence of symptoms during recording
  • Time and date of recording

Special Considerations

• For patients with cardiac devices:
  • Document presence of pacemakers or implantable cardioverter-defibrillators 1, 2
  • Consider recording rhythm strip to evaluate pacemaker function
• For post-surgical patients:
  • Serial ECGs are recommended until condition stabilizes 1
  • Additional ECG before discharge is recommended

Common Pitfalls to Avoid

• Technical errors:
  • Improper electrode placement
  • Poor skin contact
  • Limb lead reversal
  • Electrical interference
• Procedural errors:
  • Failure to document relevant clinical information
  • Not comparing with previous ECGs when available
  • Relying solely on computer interpretation without clinical correlation 2

Indications for ECG Testing

According to the American College of Cardiology/American Heart Association guidelines, ECGs are indicated in the following situations 1, 2:

• Patients with cardiovascular symptoms (chest pain, dyspnea, palpitations, syncope)
• Patients with known cardiovascular disease with change in symptoms
• Patients receiving medications that may affect cardiac conduction
• Preoperative evaluation for patients with known cardiovascular disease
• Patients over 40 years of age as a baseline assessment
• Patients with systemic conditions that may affect the heart

Post-Procedure

• Label the ECG with patient information and date/time
• Compare with previous ECGs if available
• Ensure proper storage in patient's medical record
• Communicate significant findings to the healthcare provider

By following these standardized procedures, healthcare providers can ensure high-quality ECG recordings that provide accurate diagnostic information for clinical decision-making.