Electrocardiogram (ECG or EKG)

An electrocardiogram is a test that checks for problems with the electrical activity of your heart.

The electrocardiogram (ECG or EKG) records the heart's electrical activity. Small patches called electrodes are placed on your chest, arms and legs, and are connected by wires to the ECG machine. An EKG translates the heart's electrical activity into line tracings on paper. The spikes and dips in the line tracings are called waves.

Sometimes EKG abnormalities can be seen only during exercise or while symptoms are present. An exercise electrocardiogram (EKG or ECG) is a test that checks for changes in your heart while you exercise.. This test is sometimes called a "stress test" or a "treadmill test," because it’s performed as you walk on a motor-driven treadmill.