An electrocardiogram (ECG) tracing is a graphical representation of electrical activity of the heart. An ECG is generally performed by a cardiologist or ECG technician. This particular method of viewing or monitoring movement of the heart has been used for the greater part of the past century and is a common, noninvasive method of examining heart activity.
An ECG, also called an EKG, from the German elektrokardiogramm, is able to easily map the rhythm and electrical activity produced by each heart beat. The graphing of an ECG maps heart rhythm and heart rate. The output of an ECG — an ECG tracing — is a useful diagnostic tool and can be used to detect and diagnose abnormal patterns or rhythms in heart rate and electrical impulses.
Through the examination of an ECG tracing, it is possible to see evidence of coronary artery disease, locate damaged heart tissue, and detect other cardiovascular disorders. An ECG tracing can provide a baseline examination of the tissues of the heart and can show whether a heart attack, or myocardial infarction, has occurred. Following a heart attack, an ECG can be used to examine the electrical activity in various areas and tissues of the heart and to help find damaged areas.
There are a number of reasons for an electrocardiogram to be recommended. If a patient has recently had symptoms of a heart attack, an ECG tracing may be made. An electrocardiogram is also performed if a patient has dysrhythmias, murmurs, or other irregular heart rhythms. Loss of consciousness, blackouts, seizures, or evidence of syncope or collapse could also be cause for an ECG tracing.
The electrocardiogram process is a fairly straightforward method of recording heart activity. As the heart functions, it polarizes. The depolarizing and repolarizing of each heart beat can be monitored through measuring electrical activity on the skin. The electrical activity can then be graphed to better visually examine the heart’s activity.
The electrical current is measured using a number of electrodes placed on the skin in specific positions on the chest, arms, and legs. Normally, 10 cables are used while creating a standard ECG tracing. The ECG tracing consists of several components, including a P wave, a T wave, the QRS complex, and an ST segment.
Each component of an ECG can be recorded, measured, and used to observe and inspect a specific aspect of the heart's activity. The P wave reveals electrical activity of the upper heart chambers. The QRS complex measures the electrical activity of the lower heart chambers. The T wave can measure the rest period of the lower heart chambers. Examining the height of the ST segment can expose damage to the heart muscles or tissues.