- Mean direction of the QRS complex in the frontal plane towards which the QRS complex is predominately pointed.
- Since by definition it is calculated in frontal plane only, therefore MEAN ELECTRICAL AXIS is calculated only form the frontal or Limb leads.
Mean QRS Axis Calculation
- the mean QRS axis is oriented at right angles (90°) to any lead showing a bi-phasic complex
- the mean QRS axis points midway between any two leads that show tall R waves of equal height
This program demonstrates changes in the frontal surface leads with shifts in the cardiac axis .