- QRS axis between -30 and -90 degrees
How to recognise left axis deviation
- QRS is positive (dominant R wave) in leads I and aVL
- QRS is negative (dominant S wave) in leads II and aVF
- Axis diagram reproduced from David C Chung’s ‘ECG: A Pictorial Primer’.
- Mattu A, Brady W. ECGs for the Emergency Physician 2, BMJ Books 2008.
- Wagner, GS. Marriott’s Practical Electrocardiography (11th edition), Lippincott Williams & Wilkins 2007.