|Other encyclopedia topics:||A-Ag Ah-Ap Aq-Az B-Bk Bl-Bz C-Cg Ch-Co Cp-Cz D-Di Dj-Dz E-Ep Eq-Ez F G H-Hf Hg-Hz I-In Io-Iz J K L-Ln Lo-Lz M-Mf Mg-Mz N O P-Pl Pm-Pz Q R S-Sh Si-Sp Sq-Sz T-Tn To-Tz U V W X Y Z 0-9|
|Contents of this page:|
Alternative Names Return to topECG; EKG
Definition Return to top
An electrocardiogram (ECG) is a test that records the electrical activity of the heart.
How the Test is Performed Return to top
You will be asked to lie down. The health care provider will clean several areas on your arms, legs, and chest, and then attach small patches called electrodes to the areas. It may be necessary to shave or clip some hair so the electrodes stick to the skin.
The number of patches used may vary.
You usually need to remain still, and you may be asked to hold your breath for short periods during the procedure. It is important to be relaxed and relatively warm during ECG recording. Any movement, including muscle tremors such as shivering, can alter the results.
The electrodes are connected by wires to a machine that converts the electrical signals from the heart into wavy lines, which are printed on paper and reviewed by the doctor.
Sometimes this test is done while you are exercising or under minimal stress to monitor changes in the heart. This type of ECG is often called a stress test.
How to Prepare for the Test Return to top
Make sure your health care provider knows about all the medications you are taking, as some can interfere with test results.
Exercising or drinking cold water immediately before an ECG may cause false results.
How the Test Will Feel Return to top
An ECG is painless. No electricity is sent through the body. The electrodes may feel cold when first applied. In rare cases, some people may develop a rash or irritation where the patches were placed.
Why the Test is Performed Return to top
An ECG is used to measure:
An ECG is a very useful tool for determining whether a person has heart disease. Your doctor may order this test if you have chest pain or palpitations.
An ECG may be included as part of a routine examination in patients over age 40.
Normal Results Return to top
What Abnormal Results Mean Return to top
Abnormal ECG results may be a sign of
Additional conditions under which the test may be performed include the following:
Risks Return to top
There are generally no risks. An ECG only monitors the heart's electrical activity. No electricity is sent through the body, so there is no risk of shock.
Considerations Return to top
The accuracy of the ECG depends on the condition being tested. Some heart conditions are not detectable all the time, and others may never produce any specific ECG changes.
A person who has had a heart attack or who may have heart disease may need more than one ECG. There is no reason for healthy people to undergo annual testing unless they have a family history of heart disease or another medical condition.Update Date: 9/3/2008 Updated by: Larry A. Weinrauch MD, Assistant Professor of Medicine, Harvard Medical School, Cardiovascular Disease and Clinical Outcomes Research, Watertown, MA.. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.