ECG Interpretation Part 1: Understanding Mean Electrical Axis

We have provided a concise overview of the knowledge required to interpret the mean electrical axis on the 12-lead ECG. In essence, the QRS electrical axis is useful because it helps determine the position of the heart in the chest, patency of electrical pathways, and integrity of muscle mass. By itself, it is not diagnostic, but it does lend support to the observant clinician's suspicions for each of these anomalies. The ability to determine the mean electrical axis provides the emergency nurse with an additional readily available clinical tool to assist in the early and rapid detection of potentially life-threatening changes in the patient's cardiovascular status.