Axis & Deviation - Course # 322-5


  • Axis is the general flow of electricity as it passes through the heart from the SA node al the way to the Purkinje fibers.
  • It is typically obtained from the limb or frontal plane leads.
  • The axis of the heart can change for a number of different reasons from birth defects which affect the physical location of the heart i.e. Dextrocardia, to obesity to pregnancy among others.
  • If you can envision a circle with a centered vertical and horizontal line superimposed over the chest, you would note that the normal heart is located in the lower left quadrant of this circle.
  • You will be provided an example of this image in a few slides.

Electrical Axis Determination

Axis determination can be determined a number of different ways. From complex to simple. The following steps are the easiest I know to obtain this important information.

Electrical Axis Determination

Imagine a large circle, divided into four equal quadrants superimposed over the patient’s chest.

12lead ecg image 2

322 Axis & Deviation - Course # 322-5