nt: 0pt; line-height: 52pt;">Axis Determination & Deviation

Why Axis Determination?
Definitions
Axis Quadrants
Axis Determination
Axis Deviation

Physiologic vs Pathologic

Axis Determination & Deviation

Why Axis Determination?

Paramedics dont need to know this

The ability to identify hemiblocks (fascicular blocks)
is the main reason you need to be able to determine axis

But paramedics dont need to know this either

Should they know this?

Axis Determination & Deviation

It is my opinion that the inability to determine
the presence of a hemiblock has often been the cause of complete heart
block when well-intentioned caregivers have improperly administered
lidocaine

Mike Taigman, Taigmans Advanced Cardiology, 

Brady, 1995, p. 71

Axis Determination & Deviation

What is Axis?

the general (mean vector) direction of electrical
impulses as they travel through the heart
the sum total of all electrical currents generated
by the ventricular myocardium during depolarization
normally  from upper right to lower left

Axis Determination & Deviation

What do you need to determine the axis of an ECG?

The 12 Lead ECG
Leads CORRECTLY placed on the patient

RA on the right arm
LA on the left arm
LL on the left leg
Not on the chest or abdomen

Knowledge of axis deviation

Axis Reference

Hexaxi