Understanding the ECG. Part 6: QRS axis

This document is the Accepted Manuscript version of a Published Work that appeared in final form in British Journal of Cardiac Nursing, copyright © MA Healthcare, after peer review and technical editing by the publisher. To access the final edited and published work see 10.12968/bjca.2016.11.4.180 In this sixth article of the British Journal of Cardiac Nursing ECG Interpretation series, we hope to shed some light on these issues, and to describe the QRS axis in terms that readers can understand. We will present the currently accepted definitions of both normal and abnormal axis, as defined by internationally agreed practice guidelines. We will also explain how to evaluate axis on the 12-lead ECG, using simple methods that are appropriate to the clinical setting. Finally, we will examine the most common cause of axis deviation, the fascicular blocks.