ECG Electrode Placement Guide: Limb and Chest Leads (V1–V6)
Small placement errors can change ECG morphology and lead to wrong conclusions. Use anatomical landmarks every time.
Limb electrodes
| Electrode | Position |
|---|---|
| RA | Right arm (wrist or upper arm) |
| LA | Left arm |
| RL | Right leg (ground) |
| LL | Left leg |
Place them symmetrically and away from bony prominences.
Chest electrodes
- Find the sternal angle (angle of Louis). The 2nd rib attaches here. The space below is the 2nd intercostal space.
- Count down to the 4th intercostal space.
| Lead | Position |
|---|---|
| V1 | 4th intercostal space, right sternal border |
| V2 | 4th intercostal space, left sternal border |
| V3 | Midway between V2 and V4 |
| V4 | 5th intercostal space, left midclavicular line |
| V5 | Left anterior axillary line, same horizontal level as V4 |
| V6 | Left mid-axillary line, same level as V4 |
Special situations
- Women: place V4–V6 beneath the breast at the anatomical positions.
- Obese patients: palpate carefully and keep the horizontal alignment of V4–V6.
- Right-sided or posterior leads: used in specific clinical situations as requested.
Common errors
- V1/V2 placed too high (2nd or 3rd space).
- V4–V6 following the breast curve instead of a horizontal line.
- Limb lead reversal (check lead I and aVR).
Equipment tip
Colour-coded cables and lead-off detection on machines like the Maestros 12 Channel ECG and ECGSmart-3 help prevent errors.
12 Channel ECG Machine
12 channel interpretive ECG with 5" touch display and A4 printer. ₹60,000 – ₹1 lakh
Frequently Asked Questions
How do I find the 4th intercostal space?
Locate the angle of Louis (sternal angle) — the 2nd rib attaches there; count down to the 4th space.
Where do I place electrodes in women?
Place V4–V6 under the breast at the correct anatomical positions, not on breast tissue.
Can limb electrodes go on the upper arms?
Yes, if placed consistently and symmetrically.
This article is for general information for healthcare buyers and professionals and is not medical advice. Clinical decisions should be made by qualified practitioners.