To determine the Mean Electrical Axis in ECG

Electrical axis...

• 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 .