Right Axis Deviation (RAD)

Right Axis Deviation RAD Overview

Right Axis Deviation = QRS axis greater than +90°

  • Normal Axis = QRS axis between -30° and +90°
  • Left Axis Deviation = QRS axis less than -30°
  • Extreme Axis Deviation = QRS axis between -90° and 180° (AKA “Northwest Axis”)

Hexaxial Reference System

Haxaxial ECG AXIS Reference

Hexaxial Reference System – relationship between QRS axis and frontal leads of the ECG.

How to recognise right axis deviation

Three Lead analysis

  • QRS is POSITIVE (dominant R wave) in Lead II, Lead III and aVF
  • QRS is NEGATIVE (dominant S wave) in Lead I
RAD Lead-I-II-aVF-Hexaxial-Evaluation-RAD 2

Example ECG of RAD

Left Posterior Fascicular Block (LPFB) Right axis deviation

RAD: leads II, III and aVF are POSITIVE; Leads I and aVL are NEGATIVE


Related Topics


  • Harrigan RA, Jones K. ABC of clinical electrocardiography. Conditions affecting the right side of the heart. BMJ. 2002 May 18;324(7347):1201-4. Review. [PMID: 12016190]

LITFL Further Reading

Advanced Reading




Emergency Physician in Prehospital and Retrieval Medicine in Sydney, Australia. He has a passion for ECG interpretation and medical education | ECG Library |

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