Right axis deviation (RAD)
Also calledRAD · right axis deviation · right QRS axis deviation
Definition
A mean frontal-plane QRS axis more positive than +90 degrees (that is, +90 to +180 degrees in adults). It is recognized when the QRS is net negative in lead I and positive in aVF. Causes include right ventricular hypertrophy, left posterior fascicular block and chronic lung disease, and it can also be a normal variant.
Sources
- Surawicz B, Childers R, Deal BJ, Gettes LS. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part III: intraventricular conduction disturbances. Circulation. 2009;119(10):e235-e240. doi.org/10.1161/CIRCULATIONAHA.108.191095
- Hancock EW, Deal BJ, Mirvis DM, et al. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part V: electrocardiogram changes associated with cardiac chamber hypertrophy. Circulation. 2009;119(10):e251-e261. doi.org/10.1161/CIRCULATIONAHA.108.191097
- Meek S, Morris F. ABC of clinical electrocardiography. Introduction. I: Leads, rate, rhythm, and cardiac axis. BMJ. 2002;324(7334):415-418. doi.org/10.1136/bmj.324.7334.415
- Gao Q, Dai Z, Hu Y, et al. A new method to determine the QRS axis: QRS axis determination. Clin Cardiol. 2020;43(12):1534-1538. doi.org/10.1002/clc.23477
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.