Anatomic Landmarks II - Performing 12-Lead ECGs

Chest V1 & V2

V1 and V2 are placed on the right and left side of sternum at the fourth intercostal space.

People use different techniques to make this determination, but I have found one that works consistently well.

I palpate at the suprasternal notch at the top of the sternum (base of the throat). From this location, I gently palpate down the sternum until I feel a horizontal ridge (about 1 ½ inches down). This is called the Angle of Louis. This ridge is where the body of the sternum joins with the manubrium (upper portion of the sternum).

The anatomic landmark is important because it articulates with the second rib. Below the second rib is the second intercostal space. Distal to this space is the third rib and space and so on.

Chest V1 & V2 (continued)

Once you have located the fourth intercostal space, this is the location that should be prepped for placement of the sensor. The V1 (right side) and V2 (left side) locations straddle the sternum. One on each side. When the sternum stops and the intercostal space begins, this is where you place each sensor.

People who just “eyeball” and put the sensors any old place will never have consistency of sensor placement and diagnostic tracing quality.

Chest V3 & V4

V3 is skipped and placed between V2 and V4 after V4 is placed.

V4 is placed in the fifth intercostal space in the mid-clavicular line.

Chest V5 & V6

V5 is placed in a direct line with V4 at the anterior axillary line (front of the armpit).

V6 is placed in alignment with V4 & V5 at the mid-axillary line (middle of the armpit).

If the sensors cannot be placed in the usual locations, be sure to document the alternate location and why they were moved i.e. burns, surgical dressings, chest tube etc.