EKG (Electrocardiography)

Print this page Bookmark and Share
Parents

Electrocardiography (EKG) measures the heart's electrical activity to help evaluate its function and identify any problems that might exist. The EKG can help determine the rate and regularity of heartbeats, the size and position of the heart's chambers, and whether there is any damage present.

How Is an EKG Done?

There is nothing painful about getting an EKG. The patient is asked to lie down, and a series of small metal tabs (called electrodes) are fixed to the skin with sticky papers. These electrodes are placed in a standard pattern on the shoulders, the chest, the wrists, and the ankles. After the electrodes are in place, the person is asked to hold still and, perhaps, to hold his or her breath briefly while the heartbeats are recorded for a short period. The patient also might be asked to get up and exercise for a while.

The information is interpreted by a machine and drawn as a graph. The graph consists of multiple waves, which reflect the activity of the heart. The height, length, and frequency of the waves are read in the following way:

  • The number of waves per minute on the graph is the heart rate.
  • The distances between these waves is the heart rhythm.
  • The shapes of the waves show how well the heart's electrical impulses are working, the size of the heart, and how well the individual components of the heart are working together.
  • The consistency of the waves provides relatively specific information about any heart damage present.

A person's heartbeat should be consistent and even. EKGs look for abnormally slow and fast heart rates, abnormal rhythm patterns, conduction blocks (short-circuits of the heart's electrical impulses that cause rhythm inconsistencies between the upper and lower chambers) — and four types of heart damage:

  1. ventricular hypertrophy — an abnormal thickening of the heart muscle
  2. ischemia — caused by an abnormally decreased blood supply
  3. cardiomyopathies — abnormalities in the heart muscle itself
  4. electrolyte and drug disturbances — these can alter the heart's electrochemical environment

Computerized EKGs can be combined with other tests to provide a multimedia account of the heart. These additional tests include echocardiograms (which are basically "ultrasound" tests that bounce sound off the heart and use the echoes to produce an image) and thallium scans (which are kind of like X-rays and use a radioactive tracer, injected into the bloodstream, to help draw a picture of the heart).

In the past, the EKG was recorded on a machine that drew on long strips of paper, with records from each electrode presented in a standard sequence. Now the EKG tracings are stored as computer files that can be called up and printed.

How Long Will it Take to Get Results?

Results of the EKG are available immediately. In fact, the EKG machine's computer even provides an instant interpretation of the findings as it makes the report. However, the doctor also might ask an expert, usually a cardiologist, to help analyze and interpret the EKG.

Reference ranges for heart rate and the relative lengths and sizes of the various components of the heartbeat figures vary, and diagnostic differences may be subtle, requiring an expert eye to detect them.

Reviewed by: Steven Dowshen, MD
Date reviewed: September 2010



Related Resources

OrganizationNational Heart, Lung, and Blood Institute (NHLBI) The NHLBI provides the public with educational resources relating to the treatment of heart, blood vessel, lung, and blood diseases as well as sleep disorders.
OrganizationAmerican Heart Association This group is dedicated to providing education and information on fighting heart disease and stroke. Contact the American Heart Association at: American Heart Association
7272 Greenville Ave.
Dallas, TX 75231
(800) AHA-USA1


Related Articles

Heart Murmurs and Your Child A heart murmur diagnosis is extremely common. Most murmurs are not a cause for concern and do not affect a child's health.
If Your Child Has a Heart Defect Congenital heart defects are relatively common, affecting almost 1 in every 100 newborns in the United States.
A Directory of Medical Tests Sometimes, doctors need to order tests to evaluate a child's health or to understand what's causing an illness. Here are some common ones.
Congenital Heart Defects Congenital heart defects involve abnormal or incomplete development of the heart. Learn about the different types of congenital heart defects.
Arrhythmias Arrhythmias are abnormal heart rhythms usually caused by an electrical "short circuit" in the heart. This can lead to a variety of symptoms including fatigue, dizziness, and chest pain.




Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.

© 1995-2012 The Nemours Foundation/KidsHealth. All rights reserved.



 

Upcoming Events

Free bike helmets will be given out as part of the Monroe Bike Rodeo this year.

The 1st Annual Logan X. Hess Stop Child Abuse Poker Run and Car Show will take place August 3. The ride begins at the Piqua American Legion and ends at Edison Community College. The car show will be at Edison Community College.

West Carrollton Police will be on hand to insure proper fit for all bike helmets.

Sample the distinctive flavors of the many cultures of Old North Dayton while enjoying entertainment, children's activities and a bicycle decoration competition for ages 9-16. All bike entries MUST be registered with the Dayton Police in advance at go.cityofdayton.org or at the Festival at 5:30 PM.

View full event calendarView full event calendar

Health and Safety

Your child's health and safety is our top priority

Accreditations

The Children's Medical Center of Dayton Dayton Children's
The Right Care for the Right Reasons

One Children's Plaza - Dayton, Ohio - 45404-1815
937-641-3000
www.childrensdayton.org