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Bedside procedures

How to place the leads for a 12-lead ECG

Other platforms explain it with text and video. In Making Synapses you practice it on the patient.

Nursing (NCLEX)EMS (NREMT)MD / DOPA
Practice it in VR with Blocky

A wrong lead position can change the ECG enough to mimic a heart attack. Counting the rib spaces carefully is the whole skill.

Step by step

  1. Prepare

    Clean your hands, introduce yourself, explain, get consent, privacy, patient lying flat or slightly raised. [1]

  2. Skin

    Clean and dry the skin; clip hair where needed. [1]

  3. Limb leads

    Right arm, left arm, right leg and left leg on the limbs, not on the chest. [1]

  4. V1 and V2

    Fourth intercostal space just right (V1) and just left (V2) of the breastbone. Find the angle of Louis to locate the second rib, then count down. [2]

  5. V4, then V3

    V4 in the fifth intercostal space on the midclavicular line; V3 halfway between V2 and V4. [2]

  6. V5 and V6

    Same level as V4: V5 on the front of the armpit line, V6 on the middle of the armpit line. Place under breast tissue, not on top. [2]

  7. Record

    Patient still and quiet, check for a clean tracing, label with time and symptoms, show it to the clinician right away if there is chest pain. [1]

Common errors

Practice it in Making Synapses

In Making Synapses you do this on the patient, not on paper: every step goes on the checklist with a score, and in Teach mode Blocky tells you what comes next.

Making Synapses cases that train this skill

58 Making Synapses cases train this skill: open the case library

Sources

  1. OpenStax, Clinical Nursing Skills (reference)
  2. National EMS Education Standards (2021)

Facts and steps follow National EMS Education Standards (2021); OpenStax, Clinical Nursing Skills (reference). Making Synapses is not affiliated with these organizations. Updated: 2026-10-11.