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 2021
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
Lead-I-II-aVF-Hexaxial-Evaluation-RAD-2021 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


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LITFL Further Reading


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

MBBS (UWA) CCPU (RCE, Biliary, DVT, E-FAST, AAA) Adult/Paediatric Emergency Medicine Advanced Trainee in Melbourne, Australia. Special interests in diagnostic and procedural ultrasound, medical education, and ECG interpretation. Editor-in-chief of the LITFL ECG Library. Twitter: @rob_buttner

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