How to read it

Lead I

positive

aVF

positive

Narrows to

Normal quadrant → 0° to +90°

Measured

59.0°

Normal, and what moves it

• Nearer +90° in children and tall, thin adults
• Nearer 0° with age, obesity and pregnancy
• A normal axis does not rule out disease: right bundle branch block alone leaves it normal

The leads

The leads sit as a printed ECG shows them: I, II and III, then aVR, aVL and aVF. aVR is drawn as recorded, looking along -150°, up and to the right and away from the heart, which is why it is negative on almost every normal ECG.

Only the QRS turns. The P and T stay where a normal heart puts them, because axis means the QRS axis.