EKG Procedures

Why EKG Recording Matters in Patient Care

An electrocardiogram (EKG or ECG) is a non-invasive diagnostic test that records the electrical activity of the heart over time. For the medical assistant, performing a high-quality EKG is a common and critical skill.^[1] Electrodes placed on the patient’s chest and limbs detect the heart’s electrical impulses, which are then displayed as waveforms. This study guide covers the key steps, lead placement, patient preparation, common artifacts, and the role of the medical assistant in obtaining a diagnostic-quality tracing. Mastery of EKG procedures ensures accurate interpretation by the provider and directly impacts patient care, especially in screening for arrhythmias, ischemia, and conduction abnormalities.^[2]

Waveform Components and Lead Configurations

• Electrocardiogram (EKG/ECG): A graphic representation of the heart’s electrical activity; used to detect rhythm disturbances, myocardial infarction, and electrolyte imbalances.^[3]
• Electrode: A conductive pad that adheres to the skin and transmits electrical signals to the EKG machine.
• Lead: A specific view of the heart’s electrical activity created by a combination of two electrodes (bipolar) or an electrode and a reference point (unipolar). Standard 12-lead EKG uses 10 electrodes to produce 12 leads.^[2]
• P Wave: Represents atrial depolarization (contraction).
• QRS Complex: Represents ventricular depolarization; the largest waveform.
• T Wave: Represents ventricular repolarization (recovery).
• Artifact: Unwanted signals on the EKG tracing caused by muscle movement, loose electrodes, electrical interference, or poor skin preparation.
• Isoelectric Line: The baseline of the EKG tracing; any deviation indicates electrical activity.

Stepwise Approach to Performing a 12-Lead EKG

Patient Preparation

1. Identify the patient using two identifiers per facility policy.^[1]
2. Explain the procedure: painless, takes 5–10 minutes, requires lying still and breathing normally.
3. Ask the patient to remove all jewelry, watches, and clothing from the waist up; provide a gown for privacy.
4. Shave or clip excessive hair at electrode sites if necessary for good adhesion.
5. Cleanse the skin with alcohol or a mild abrasive to remove oils and dead skin cells; allow to dry completely.^[4]
6. Ensure the patient is relaxed, warm, and lying supine (or semi-Fowler’s if unable to lie flat).

Electrode Placement (Standard 12-Lead EKG)

Correct lead placement is essential for accurate interpretation. Use the mnemonic “White on right, clouds over grass, smoke over fire” for limb leads.^[2]

Note: Limb electrodes should be placed on fleshy areas, not over bone. Chest electrodes are placed over intercostal spaces, not on ribs.^[4]

Performing the EKG

1. Connect the patient cable to the EKG machine and ensure power is on (or battery charged).
2. Enter patient demographics (name, date of birth, ID) into the machine if required.
3. Instruct the patient to remain still, breathe normally, and not talk during the recording.
4. Press the “Record” or “Auto” button to acquire the tracing. Most machines capture 10 seconds of data for a 12-lead rhythm strip.
5. Check the quality of the tracing: look for a clean baseline, clear P waves, and no artifact.
6. If artifact is present, troubleshoot causes (see “Safety Precautions and Complications” below) and repeat the recording if necessary.
7. Discard or decontaminate disposable electrodes if used. Clean the patient’s skin with alcohol or a wipe to remove gel residue.
8. Label the EKG with patient ID, date, and time; attach to the patient’s chart or send electronically per facility protocol.^[1]

Normal and Abnormal EKG Patterns to Recognize

The medical assistant does not formally interpret the EKG, but should be able to recognize gross abnormalities that require immediate attention (e.g., no visible complexes, very fast/slow rate). Common findings that may be noted:^[5]

• Normal sinus rhythm: Regular rate 60–100 bpm, upright P waves in leads II and V1, normal PR interval (0.12–0.20 sec) and QRS duration (<0.12 sec).
• Sinus bradycardia: Rate <60 bpm, regular rhythm, normal P wave axis.
• Sinus tachycardia: Rate >100 bpm, regular rhythm.
• Atrial fibrillation: Irregularly irregular rhythm, no distinct P waves (fibrillatory baseline).
• ST-elevation or depression may indicate ischemia or infarction; requires urgent provider notification.
• Wide QRS (>0.12 sec) can indicate ventricular conduction delay or ventricular rhythm.

Ensuring Tracing Quality and Patient Well-Being

The medical assistant’s assessment focuses on the quality of the tracing and patient tolerance. Evaluate:

• Skin integrity: Check for redness or irritation after electrode removal; report allergies to adhesive or gel.
• Patient anxiety or pain: Some patients may feel clammy or anxious; provide reassurance.
• Tracing quality: Acceptable tracing shows a flat isoelectric line, no 60-cycle interference, no wandering baseline, and minimal muscle tremor.^[4]
• Identification errors: Confirm patient identity and correct labeling to prevent misdiagnosis.

Comfort Measures, Education, and Documentation Steps

• Provide privacy and comfort: Keep the patient warm; a warm blanket reduces shivering artifact.
• Educate the patient: Explain that the test records the heart’s electrical activity, not “electricity” going into the body.
• Document: Note the date, time, technician, any difficulties (e.g., patient anxiety, tremor), and any abnormal findings reported to the provider.
• Prepare for additional tests: If the EKG is abnormal, the medical assistant may assist with a stress test or Holter monitor setup as ordered.
• Clean and maintain equipment: Recharge or replace cables as needed; clean leads per manufacturer’s instructions to prevent cross-contamination.

Risk Prevention and Common Artifact Solutions

• Skin breakdown: Do not place electrodes over open wounds, rashes, or surgical incisions. Rotate sites if performing serial EKGs.
• Allergic reactions: Use hypoallergenic electrodes if patient reports adhesive sensitivity; some patients are allergic to latex or gel.
• Electrical safety: Ensure the EKG machine is properly grounded (three-prong plug). Do not use near water or with frayed cables.^[6]
• Artifact troubleshooting:
  • Somatic tremor (muscle artifact): Ask patient to relax arms and legs; provide a warm environment.
  • Wandering baseline: Check electrode adhesion; clean and dry skin; replace old electrodes.
  • AC interference (60-cycle artifact): Move electrical devices away; check plug polarity; ensure cables are not crossed or touching metal.
  • Broken or loose lead wires: Inspect and replace as needed.^[4]
• Patient fall risk: Do not leave the patient unattended on an exam table; assist with getting on/off the bed.
• Infection control: Perform hand hygiene before and after; clean reusable electrodes with approved disinfectant; dispose of single-use electrodes in ordinary waste (unless contaminated with blood).

Memory Devices and Lead Placement Checks

• Memory aid for chest lead placement: “Yes, I Want More Fun in the Bedroom” → V1: 4th R sternal border, V2: 4th L sternal border, V3: between V2 and V4, V4: 5th L MCL, V5: 5th L AAL, V6: 5th L MAL.^[2]
• Limb electrodes can be placed on the wrists/ankles or on the proximal arms/legs if the patient has amputations or burns. Do not place them over bone.
• Systematic lead placement check: Use the “Einsten” mnemonic: V1-V6 placement locations.
• Always apply electrodes in the same order to avoid confusion: limb leads first, then chest leads.
• The P wave should be positive in lead II; if inverted, suspect electrode reversal (e.g., left and right arm swapped).
• Common exam question: “What do you do if the EKG shows artifact?” — Answer: Check electrode adhesion, ask patient to be still, ensure skin is clean and dry, and reposition leads.
• Know the difference between a 12-lead EKG (diagnostic) and a rhythm strip (single lead, often lead II).
• The medical assistant is responsible for the technical quality of the tracing; do not attempt to interpret unless specifically trained and ordered.
• HIPAA reminder: Keep EKG results confidential; attach to patient chart only after verifying ID.

References & Sources

1. Saunders Comprehensive Review for the NCLEX-RN® Examination. 8th ed. Elsevier; 2019: 830-833. https://evolve.elsevier.com/cs/product/9780323358415?role=student
2. American Heart Association. ECG Electrode Placement: A Guide for Clinicians. AHA; 2022. https://www.heart.org/en/health-topics/arrhythmia/conduction-disorders/ecg-electrode-placement
3. “Electrocardiography (ECG/EKG).” StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. https://www.ncbi.nlm.nih.gov/books/NBK470595/
4. Phlebotomy: A Competency-Based Approach. 4th ed. McGraw-Hill Education; 2020: 211-218. https://www.mheducation.com/highered/product/phlebotomy-competency-based-approach-booth/M9781260027002.html
5. “12-Lead ECG Interpretation: A Primer for the Non-Cardiologist.” American Family Physician. 2019; 100(12): 771-778. https://www.aafp.org/pubs/afp/issues/2019/1215/p771.html
6. Association for the Advancement of Medical Instrumentation (AAMI). EC57: Standard for Cardiac Monitors, Electrocardiographs, and Accessories. AAMI; 2021. https://www.aami.org/standards/standardslisting/ec57