Sign in  |  Register

Illustrated Health Encyclopedia
[an error occurred while processing this directive]

Ency. home > Test > E > ECG

ECG    See images

Overview | Risks | Results

Alternative names:

Electrocardiogram; EKG

Definition:

A test that records the electrical activity of the heart.

The ECG is used to measure the rate and regularity of beats as well as the size and position of the chambers, any damage to the heart, and effects of drugs or devices to regulate the heart (pacemaker). See also exercise treadmill ECG, Holter monitor (24h).

How the Test is Performed

You are asked to lie down, and electrodes are affixed to each arm, leg, and the chest. This requires cleaning the site and, if necessary, shaving or clipping the hair. The standard number of leads attached is 12 to 15 for a "diagnostic" ECG, but may be as few as 3 to 5 for a "monitoring" ECG.

You are usually required to remain still and may be asked to hold your breath for short periods during the procedure. Sometimes this test is performed while you are exercising or under minimal stress to monitor changes in the heart (see exercise treadmill ECG). The results are recorded on graph paper.

How to Prepare for the Test

Adults:

  • Tell the health care provider if you are taking any medications.
  • There are no restrictions for food or fluids. However, ingestion of cold water immediately before an ECG may produce changes in one of the waveforms recorded (the T wave).
  • Exercise (such as climbing stairs) immediately before an ECG may significantly increase your heart rate.
  • Remove all jewelry.
  • You may be asked to wear a hospital gown.

Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:

How the Test will Feel

An ECG is painless. When first applied, the disks may be cold and in rare circumstances, a person may develop a localized rash or irritation where the patches are placed.

Why the Test is Performed

An ECG is very useful in determining whether a person has heart disease. If a person has chest pain or palpitations, an ECG is helpful in determining if the heart is beating normally. If a person is on medications that may affect the heart or if the patient is on a pacemaker, an ECG can readily determine the immediate effects of changes in activity or medication levels. An ECG may be included as part of a routine examination in patients over 40 years old.

Ency. home > Test > E > ECG

[an error occurred while processing this directive]