Electrocardiography

Electrocardiography (pronounced: e-lek-tro-kar-dee-og-rah-fee) is a medical diagnostic procedure used to record the electrical activity of the heart over a period of time. This non-invasive procedure is performed using an instrument called an Electrocardiograph, which produces an Electrocardiogram (ECG or EKG).

Etymology

The term "Electrocardiography" is derived from the Greek words Elektron meaning amber (a reference to electric charge), Kardia meaning heart, and Graphien meaning to write.

Procedure

During an Electrocardiography, electrodes are placed on the patient's skin around the heart area. These electrodes detect the tiny electrical changes on the skin that arise from the heart muscle's electrophysiologic pattern of depolarizing and repolarizing during each heartbeat. The electrodes are connected to the Electrocardiograph, which amplifies the electrical activity and records it in a graphical form.

Interpretation

The Electrocardiogram (ECG) produced by the Electrocardiograph is interpreted by medical professionals to assess the heart's rate and rhythm, the size and position of the heart chambers, the presence of any damage to the heart's muscle cells or conduction system, the effects of cardiac drugs, and the function of implanted pacemakers.

Related Terms

Electrode: A conductor through which electricity enters or leaves an object, substance, or region.
Heart Rate: The speed of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm).
Pacemaker: A small device that's placed in the chest or abdomen to help control abnormal heart rhythms.
Cardiac Conduction System: A group of specialized cardiac muscle cells in the walls of the heart that send signals to the heart muscle causing it to contract.