- This ECG demonstrates a normal axis (0° to +90°) (1)
- The most efficient way to estimate axis is to look at Lead I and Lead aVF (1)
- The addition of Lead II can help determine pathological LAD from normal axis/physiological LAD
Lead I
Lead II
Lead aVF
Axis
Positive
Positive
Positive
Normal: 0° to +90
Positive
Equiphasic
Negative
Normal (Physiological LAD): 0° to -30°
Positive
Negative
Negative
Left axis deviation (LAD): -30° to -90°
Negative
Positive
Positive
Right axis deviation (RAD): +90° to 180°
Negative
Negative
Negative
Extreme axis deviation: 180°° to -90