Anatomic Landmarks III - Performing 12-Lead ECG.
Another common reason for adjusting sensor placement are large breasts or patients with breast implants.
In instances where the sensor will not lay flat (cleavage), you may need to move the V1 and V2 sensor as high as the second intercostal space
You may have to elevate the head of the bed as well to allow gravity and natural movement of the breasts downward to make your job easier.
Either way, if this is necessary, it is important to document the new location for V1 and V2 and the elevated head of bed and why you made those modifications to placement and position.