Test Overview
An exercise electrocardiogram (EKG or ECG)
is a test that checks for changes in your heart while you exercise. Sometimes
EKG abnormalities can be seen only during exercise or while symptoms are
present. This test is sometimes called a "stress test" or a "treadmill test."
During an exercise EKG, you may either walk on a motor-driven treadmill or
pedal a stationary bicycle.
The
heart
is a muscular pump made up of
four
chambers
. The two upper chambers are called atria, and the two lower
chambers are called ventricles. A natural electrical system causes the heart
muscle to contract and pump blood through the heart to the lungs and the rest
of the body. See a picture of the
heart and
its electrical system
.
An exercise EKG translates the
heart's electrical activity into line tracings on paper. The spikes and dips in
the line tracings are called waves. See a picture of the
EKG
components and intervals
.
A resting EKG is always done
before an exercise EKG test, and results of the resting EKG are compared to the
results of the exercise EKG. A resting EKG may also show a heart problem that
would make an exercise EKG unsafe.