An electrocardiogram (eh-lec-troe-CAR-dee-oh-gram,) or EKG, (E-K-G) measures changes in the heart's electrical activity. The test itself is painless and takes only a few minutes. When combined with a stress test, EKG's are helpful in diagnosing coronary artery disease resulting from the hardening of the arteries. During this procedure, electrodes are attached to the arms, legs, and front of the chest, and the patient begins to exercise, usually on a treadmill. The heart's electrical activity, communciated via the electrodes, is either displayed on a screen or recorded as a trace on paper. EKG's from a normal, healthy heart have a characteristic shape. Any irregularity in the heart's rate, rhythm, or structure, as well as damage from previous heart attacks, can alter its electrical activity, and may show up on the screen or print-out. EKG's are also used in intensive care, major surgery, and sometimes during childbirth to constantly monitor a patient's heart. For more information about electrocardiograms, contact a health care professional.