Right Axis Deviation RAD Overview
- QRS axis between +90° and + 180°
Hexaxial Reference System
The Hexaxial Reference System illustrates the relationship between QRS axis and the frontal leads of the ECG.
- Normal Axis = QRS axis between -30° and +90°.
- Left Axis Deviation = QRS axis less than -30°.
- Right Axis Deviation = QRS axis greater than +90°.
- Extreme Axis Deviation = QRS axis between -90° and 180° (AKA “Northwest Axis”).
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
Example ECG of RAD
- Left posterior fascicular block
- Lateral myocardial infarction
- Right ventricular hypertrophy
- Acute lung disease (e.g. Pulmonary Embolus)
- Chronic lung disease (e.g. COPD)
- Ventricular ectopy
- Sodium-channel blocker toxicity
- WPW syndrome
- Normal in children or thin adults with a horizontally positioned heart
- 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]
- Brady WJ, Truwit JD. Critical Decisions in Emergency and Acute Care Electrocardiography
- Hampton, JR. The ECG In Practice, 6e
- Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice: Adult and Pediatric, 6e
- Wagner, GS. Marriott’s Practical Electrocardiography 12e
- Chan, TC. ECG in Emergency Medicine and Acute Care
- Wang, K. Atlas of Electrocardiography
- Mattu, A. ECG’s for the Emergency Physician
LITFL Further Reading
- ECG BASICS — Waves, Intervals, Segments and Clinical Interpretation
- ECG A to Z by diagnosis –alphabetical diagnostic approach to the ECG
- ECG CLINICAL CASES — ECG’s placed in clinical context with a challenging Q&A approach
- 100 ECG Quiz — Self-assessment tool for examination practice
- ECG Reference SITES and BOOKS — the best of the rest
- LITFL ECG IMAGE Database — Searchable database of LITFL ECG’s
- ECG and Cardiology Eponymous Syndromes — Cheats guide to eponymous emancipation
- ECG Exam Template — a framework for answering ECG exam questions.