An electrocardiogram (EKG or ECG) is a test that checks for problems with the electrical activity of your heart. An EKG shows the heart's electrical activity as line tracings on paper. The spikes and dips in the tracings are called waves.
The heart is a muscular pump made up of four chambers . The two upper chambers are called atria. The two lower chambers are called ventricles. A natural electrical system causes the heart muscle to contract. This pumps blood through the heart to the lungs and the rest of the body.
Why It Is Done
An EKG is done to:
- Check the heart's electrical activity.
- Find the cause of unexplained chest pain or pressure. This could be caused by a heart attack, inflammation of the sac surrounding the heart (pericarditis), or angina.
- Find the cause of symptoms of heart disease. Symptoms include shortness of breath, dizziness, fainting, and heartbeats that are rapid and irregular (palpitations).
- Find out if the walls of the heart chambers are too thick.
- Check how well medicines are working and see if they are causing side effects that affect the heart.
- Check how well mechanical devices that are implanted in the heart, such as pacemakers, are working. These devices help to control the heartbeat.
- Check the health of the heart when other diseases or conditions are present. These include high blood pressure, high cholesterol, cigarette smoking, diabetes, and a family history of early heart disease.
How To Prepare
Be sure to tell your doctor about all the medicines you take, even over-the-counter ones. Many medicines can change the results of this test.
If you take heart medicines, your doctor will tell you how to take your medicines before you have this test.
Remove all jewelry from your neck, arms, and wrists. Men are usually bare-chested during the test. Women may often wear a bra, T-shirt, or gown. You will be given a cloth or paper covering to use during the test.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).