EKG and Electrode Position
Limb electrodes
l RA (right arm) - between the right shoulder and right wrist
l RL (right leg) - below the right torso and above the rightankle
l LA (left arm) - between the left shoulder and the left wrist
l LL (left leg) - below the left torso and above the left ankle
The positions of the upper limb electrodes can vary from wristto shoulder, but they should be uniformly distributed. For instance, if oneelectrode is attached to the right wrist, the other one should be on leftwrist, not shoulder. The same rule applies to the positions of the lower limbelectrodes.
Chest electrodes
l V1 - 4th intercostal space tothe right of the sternum
l V2 - 4th intercostal space tothe left of the sternum
l V3 - midway between V2 and V4
l V4 - 5th intercostal space atthe midclavicular line
l V5 - anterior axillary lineat the same horizontal level as V4
l V6 - midaxillary line at thesame horizontal level as V4 and V5
When placingelectrodes on female patients, electrodes V3- V6 should be placed under the breasts rather than on.Also, patient’s nipples shouldn’t be used as reference points for locating theelectrode position, because their locations vary from patient to patient. Up to50% of ECGs have V1 and V2 electrodes in a more superior location, which can causeT wave inversion; and up to 33 % have chest electrodes inferiorly or laterallymisplaced, which can alter the amplitudes.