Electrocardiograms, also known as ECGs or EKGs, are used to record the heart's electrical activity. An ECG is used to determine a variety of things, including whether or not someone experiencing chest pain or heart palpitations has a normal heartbeat. It can also indicate whether or not a heart attack has occurred, and possibly when it took place.
An ECG is performed by placing electrodes at specific locations on the arms, legs and chest. This requires cleaning the site and, if necessary, shaving or clipping hair. The standard number of leads is 12 to 15 for a "diagnostic" ECG but may be as few as three to five for a "monitoring" ECG. Recording leads are attached to the electrodes.
This test usually takes place while the patient is lying down, but it is sometimes performed during exercise or while the patient is under minimal stress to monitor changes in the heart. The results are recorded on graph paper. ECGs do not produce any electricity of their own, and the test does not hurt or have any known side effects.
