An electrocardiogram (ECG or EKG) is a test that checks how your heart is functioning by measuring the electrical activity of the heart. An electrocardiogram records the electrical signals in your heart. Your doctor may suggest you get an electrocardiogram -- also called an EKG or ECG -- to check for signs of heart disease. An electrocardiogram (EKG) is a test that measures electrical signals in your heart. An electrocardiogram — abbreviated as EKG or ECG — is a test that measures the electrical activity of the heartbeat. An electrocardiogram is a painless test that measures your heart's electrical activity.