Perhaps one of the most useful 20th century technologies for the diagnosis of heart disease is the electrocardiogram (EKG) machine. Although much more bulky and heavy than the modern EKG machines in use today, the first device was built at the turn of the century and was considered a huge advancement in medicine. Unlike its bulky ancestors, the modern EKG machine is lightweight and portable; most clinics have them on rolling tables that can be easily transported from room to room.

The use of electrodes for an EKG reading is a relatively new procedure. In the beginning phases of EKG technology, patients were required to place their hands and feet into sodium chloride baths, a conductive method for the faint electric impulses found in the heart. Later, electrical wires were used to transmit heart signals to the machine; eventually the electrodes we use now replaced these wires. If you look at photographs from the late 1800s, the patients look as though they are strapped into an electric chair. Modern methods have made the procedure much more simple, safe, comfortable and accurate.

Today many patients lie on an examination table, although some doctors prefer the electrodes to be attached while the patient is performing moderate exercise. Some patients may be asked to ride a stationary bike or walk on a treadmill. Exercising while attached to the EKG machine may often give the technician or your doctor a better understanding of your heart-function pattern during physical strain.

The electrodes are attached to the EKG machine through cables that produce a graph of your heart