An electrocardiogram (ECG or EKG) is a simple test to determine how the heart is beating. Sensors, called electrodes, are placed on the chest to record the heart's electrical signals. The signals are shown as waves on an attached computer monitor or printer.
Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission.
Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press.
Make a gift to our 2025 Drive to Cure Cancer and transform the way cancer is treated and defeated.