Does Lead Electrode Placement Matter?

Your EMS instructor told you to put the limb-lead electrodes on the limbs. The manufacturer of your cardiac monitor says to put the electrode on the limbs...the electrodes are marked RA, LA, RL, LL. But every time you show up in the hospital, the electrodes are on the torso...and that "super educated" guy on your fire department...he puts them on the torso too. Who's right? And why does it make a difference?

[@adamcaul]

Good info!

[@91nikolai91]

But do we know what causes this difference in readout of a 12-lead core vs limb placements? I mean... the electrical values shouldn't change, as long as they are done with correct placement and symmetry.

[@GhostPants16]

When the LL are placed on the limbs. It allows for the electrical signals to be detected from a midline point of view relevant to the heart. The abdominal placement changes the view because the Limb leads are now anterior to the heart and mess with how the Limb leads algorithm detects electrical impulse.