ECG Leads

The 12 Conventional ECG Leads

  • Electrode
    Electrode
  • AVL
    AVL
  • AVF
    AVF

These 12 leads are divided into two groups:

  • six extremity (limb) leads; they are recording electrical potentials transmitted into the frontal plane;
  • six chest (precordial) leads, they are recording electrical potential transmitted into horizontal plane.[1]

There are the leads with their location and polarity[2]:

limb location of the lead
bipolar extremity leads

-Einthoven's leads-

I + left upper limb - right upper limb
II left lower limb right upper limb
III left lower limb left upper limb
unipolar extremity leads

-Goldberg's leads-

aVR right upper limb lead
aVL left upper limb lead
aVF left lower limb lead
unipolar chest leads

-Wilson's leads-

V1 fourth intercostal space, just to the right of the sternum
V2 fourth intercostal space, just to the left of the sternum
V3 midway between V2 and V4, fifth intercostal space
V4 fifth intercostal space, midclavicular line on the left
V5 fifth intercostal space, anterior axillary line
V6 fifth intercostal space, midaxillary line

Additional ECG Leads

These leads are used in special situations, when conventional 12-leads ECG cannot reliably show the myocardial defect.[1]

Below are some examples of additional ECG leads[2]:

lead location of the lead
unipolar chest leads V7 posterior axillary line, on the same level as V6, on the left
V8 scapulary line, in the same level as V6, on the left
V9 paravertebral line on the left, on the same level as V6
VE just to the left of processus xiphoideus
V3R - V6R on the right, same location as V3–V6
unipolar chest leads V1´– V6´ about 1 intercostal space above the V1–V6
V1´´– V6´´ about 2 intercostal space above the V1–V6
esophageal leads E/Oe for example 37.5 cm (left atrium)


References

  1. ↑ a b KASPER, Dennis L – FAUCI, Anthony S – LONGO, Dan L, et al. Harrison's principles of Internal Medicine. 16th edition. New York : McGraw-Hill Companies, Inc, 2005. 2607 pp. pp. 1312-1313. ISBN 0-07-139140-1.
  2. ↑ a b WikiSkripta. Elektrokardiografie [online]. ©2011. The last revision 2011-07-2, [cit. 2011-07-03]. <http://www.wikiskripta.eu/index.php/Elektrokardiografie>.

Bibliography

  • KASPER, Dennis L – FAUCI, Anthony S – LONGO, Dan L, et al. Harrison's principles of Internal Medicine. 16th edition. New York : McGraw-Hill Companies, Inc, 2005. 2607 pp. pp. 1311-1319. ISBN 0-07-139140-1.