8/7/2019 Take5_ECG

1/2

12-lead electrocardiograms

SELECTING LEAD SITES Choose areas that are flat and fleshy, not muscular or

bony.

As needed, take steps to enhance electrode contact with

the skin:

Clip (dont shave) excessively hairy areas.

Remove excess oil and other substances from the skin.

To ensure an accurate recording, be sure to apply the

electrodes correctly.

Keep in mind that inaccurate placement of an electrode

may lead to inaccurate waveforms and incorrect ECG

interpretation.

PLACING THE LEADSLimb leads

Place electrodes on both of the patients arms and on hisleft leg.

Place an electrode on his right leg. (This is a ground

that doesnt contribute to the waveform.)

Precordial leads

Place the six unipolar precordial leads (V1 through V6)

in sequence across his chest.

Brought to you by Nursing2006

Precordial lead placementTo record a 12-lead ECG, place electrodes on the patients

arms and left leg and place a ground lead on the patients

right leg. The three standard limb leads (I, II, and III) and the

three augmented leads (aVR, aVL, and aVF) are recorded using

these electrodes. Then, to record the precordial chest leads,

place electrodes as follows:

V1 fourth intercostal

space (ICS), right sternal

border

V2 fourth ICS, left

sternal border

V3 midway between

V2 and V4

V4 fifth ICS, left

midclavicular line

V5 fifth ICS, left anterior

axillary line

V6 fifth ICS, leftmidaxillary line

_____________________________________________________________________

Source: ECG Interpretation: An Incredibly Easy! Pocket Guide, Lippincott

Williams & Wilkins, 2006.

Take5: Lippincott Williams & Wilkins, 2006

V1 V4

V2 V5

V3 V6

8/7/2019 Take5_ECG

2/2

Limb lead placement

Proper lead placement is crucial for accurate recording ofcardiac rhythms. These drawings show correct electrode

placement for the six limb leads. RA stands for right arm;

LA, left arm; RL, right leg; and LL, left leg. A plus sign (+)

indicates a positive pole; a minus sign (-), a negative pole; and

G indicates a ground. Below each drawing is a sample ECG

strip for that lead.

Lead I Lead II Lead III

Connects the rightarm (negative pole)with the left arm(positive pole).

Connects the rightarm (negative pole)with the left leg(positive pole).

Connects the leftarm (negative pole)with the left leg(positive pole).

Lead aVR Lead aVL Lead aVF

Connects the rightarm (positive pole)with the heart(negative pole).

Connects the leftarm (positive pole)with the heart(negative pole).

Connects the left leg(positive pole) withthe heart (negativepole).