Patients who use heart medications or who present with symptoms associated to a heart condition are likely to be attached to a heart monitor, according to the American Heart Association. A heart monitor is used to help doctors determine if a patient's medications are effective, or to establish the cause of symptoms such as dizziness, faintness or a slow heartbeat.
Cardiac monitors, known as an electrocardiograms or EKGs, allow doctors to observe electrical readings of a patient's cardiovascular system, explains the Encyclopedia of Surgery. Doctors often monitor additional properties that are relevant to heart health, such as the oxygen saturation of the patient's arterial blood and the output of the patient's respiratory system. The device is kept by the side of the patient's bed and is usually connected to the patient via electrodes that are placed on the surface of the skin.
When attaching the device to the patient's skin, doctors use a three-lead, five-lead or 12-lead electrode placement, meaning that there are three, five or 12 electrodes placed on the patient's skin, notes the Encyclopedia of Surgery. With a five-lead placement, one electrode is placed on each arm, one on each leg, and the final electrode is placed on the chest near the heart.