Electrocardiography (ECG) is a simple and non-invasive test for measuring and recording electrical activity of the heart. It's used to diagnose cardiac arrhythmias, heart attacks and other heart conditions.
An ECG uses electrodes placed on the skin to detect the tiny electrical changes that occur when the heart beats. These changes are recorded using pens on paper, or transmitted electronically to a computer for analysis.
Discover the ECG basics with our tutorials on the electrocardiogram with interactive animations and diagrams below, or learn more about the heart.