The electrocardiogram, also referred to as ECG, 12-lead ECG, or EKG, is a non-invasive diagnostic test that evaluates your heart’s electrical system to assess for heart disease. It uses flat metal electrodes placed on your chest to detect the electrical charges generated by your heart as it beats, which are then graphed. Your doctor can analyze the patterns to get a better understanding of your heart rate and heart rhythm, identify some types of structural heart disease, and evaluate cardiac efficiency.
In a conventional 12-lead ECG, ten electrodes are placed on the patient’s limbs and on the surface of the chest. The overall magnitude of the heart’s electrical potential is then measured from twelve different angles (“leads”) and is recorded over a period of time (usually ten seconds).