Cardiac Axis
Cardiac Axis
Look at leads I, II, aVF
Look at leads I, II, aVF
Leads I, II, aVF "look" in the direction of the normal vector (down to the left)
Since the leads look in the direction of the vector... the inflection should be positive (most of the QRS going up)
The net directional movement of electricity is toward the LV (normally)
When things (ischemia, hypertrophy) affect conductivity... the vector can change
Lead II differentiates pathologic from physiologic LAD
(Isoelectric in lead II = physiologic)
Play with the Cardiac Axis Trainer
Two thumbs up = Normal
Left thumb up and Right thumb down = LAD
Left thumb down and R thumb up = RAD
Both thumbs down = extreme RAD