Measuring the Mean QRS Electrical Axis in an ECG




Garrison, Ryan, Osteopathic Medical Student
Dang, Kim Chi, Osteopathic Medical Student
Carter, Reagan, Osteopathic Medical Student
Loomis, Mario, Associate Professor Clinical Anatomy
Alvarez, Diego F, Professor Physiology and Pharmacology

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In this episode of the Loomis-Alvarez Medical Video Series, we unlock the electrocardiogram (ECG) mastery in deciphering the Mean Electrical Axis of the heart by using different approaches. In this educational video, we dive into the intricacies of electrocardiography (ECG) to determine the mean electrical axis of the heart. Led by our medical students, this tutorial aims to equip students, residents, and enthusiasts alike with the knowledge and skills needed to accurately interpret ECGs. Throughout the video, viewers will be guided step-by-step through different approaches for calculating the mean electrical axis, a crucial aspect of ECG interpretation that provides valuable insights into cardiac health and function. Starting with a brief overview of the vectorcardiogram principle, the tutorial gradually progresses to analyze the information generated in an ECG and apply it to interpret waveforms and their relation with the vectorial movement of electrical cardiac depolarization defining in its path a mean electrical axis. Detailed instructions on how to determine an electrical axis are laid out and clinical implications from real-life examples are presented. Featuring clear explanations and illustrative diagrams this video offers a guide to mastering the calculation of the mean electrical axis. Whether you are a medical student or a medical resident, this tutorial is sure to enhance your ability in ECG interpretation and contribute to better patient care.


Welcome to this crucial component of the ECG analysis for understanding heart health and disease with this Loomis-Alvarez Video Series episode! Ready to elevate your ECG expertise? Join us in this comprehensive video tutorial, led by our medical trainees, where we unravel the complexities of calculating and interpreting the Mean Electrical Axis. Designed by and for medical students, this video guides viewers through different approaches on how to measure the mean electrical vector on an ECG. This work has been crafted with the support of Jacob Rivas for video editing. 2024 CC-BY-NC-ND


ECG main electrical axis, QRS axis measurement, cardiac electrophysiology, cardiac axis determination, EKG vectocardiogram


Garrison R, Dang KC, Carter R, Loomis M, Alvarez D. Measuring the mean QRS electrical axis in an ECG. Scholarly Works @ SHSU. 2024.