An electrocardiogram (ECG or EKG) is a record of the electrical activity of the heart over a period of time. It was invented by Willem Einthoven. It is done by electrodes attached to the outer surface of the skin and recorded by a device outside the body.
An electrocardiogram is used to monitor your heart. Each beat of your heart is triggered by an electrical impulse normally generated from special cells in the upper right chamber of your heart. An electrocardiogram records these electrical signals as they travel through your heart. Doctors can use an electrocardiogram to look for patterns among these heartbeats and rhythms to diagnose various heart conditions.
ECG is used to measure the rate and regularity of heartbeats, the size and position of the chambers, the presence of any damage to the heart, and the effects of drugs or devices used to regulate the heart, such as an artificial pacemaker.
An electrocardiogram is a painless test. The results of your electrocardiogram will likely be reported the same day it is done.