What is an Electrocardiogram Test?

An electrocardiogram (ECG or EKG) is a test used to show the electrical activity of the heart muscle. This test is used on patients who have symptoms that point toward a heart problem, such as a heart attack or abnormal heart rhythm. The test tracks the hearts electrical activity and transfers the data to a computer and onto a printout sheet. This sheet is read by physicians and other health care providers to diagnose heart problems.

An EKG measures the underlying rate and rhythm mechanism of the heart, how the heart is positioned in the chest, and patterns of abnormal electric activity that may cause abnormal cardiac rhythm. In addition, and EKG can show evidence of increased thickness of the heart muscle, damage to various parts of the heart, and impaired blood flow.

During the EKG procedure, electrodes called leads are placed on designated areas of the patient’s body. The leads are often attached using a gel or paste that helps conduct the electrical pulses. A lead is attached to each of the patient’s four extremities and six more are attached to specific areas of the chest. The electrocardiogram is performed while the patient lies flat on a bed or examining table. The test usually takes between five and ten minutes, during which the patient is asked to breathe normally and refrain from speaking unless absolutely necessary.

Electrocardiogram tests are performed by medical personnel for many reasons. Often, an EKG is performed as part of a routine physical exam or as part of a cardiac exercise stress test. Test done on individuals who have no heart problems can be used for comparative purposes if a problem develops later in life. When a patient is experiencing symptoms of heart problem like chest pain, shortness of breath, dizziness, fainting, or heart palpitations, an EKG is typically performed as part of the diagnostic process. EKGs may also be performed to monitor and diagnose certain genetic heart conditions.

EKGs have many limitations. Since and EKG is a static picture from one point in time, it may not register health problems that are not constant. If a patient experiences intermittent chest pain, it may be difficult to conduct an EKG at a time when they are experiencing symptoms. Often, abnormalities seen on an EKG are non-specific, meaning they could be a symptom of many different diseases. Typically, further tests will be necessary before any diagnosis can be made.