How It Is Done continued...
The stress scan is done in two parts. In many hospitals, the
first images are taken while the person is at rest. Then a second set of images
is taken after the person is given a medicine such as adenosine,
which makes the heart respond like it would to exercise. Sometimes the stress scan is done first and the resting scan might be done the next day.
A stress test with
medicine is usually used when a person cannot exercise for some reason.
For this test, you will be asked to sit or lie on the examining
table and you will be given a routine electrocardiogram (EKG or ECG), which takes
about 5 to 10 minutes.
Then you will be given the medicine through your IV. You may get a
headache and feel dizzy, flushed, and nauseated from the medicine, but these
symptoms usually do not last long. Additional EKGs and blood pressure
measurements are often taken. After the medicine takes effect (about 4
minutes), a small amount of radioactive tracer is given through your IV.
You will wait about 30 to 60 minutes. You might be asked to eat or drink something. Then you will lie down
on a table for a set of scans. The camera records the tracer's signals as it
moves through your blood. The camera does not produce any radiation, so you are
not exposed to any more radiation while the scan is being done.
Sometimes more pictures are taken after you rest for 2 to 4
hours. Most people can resume their normal diet and activities after the final set of
Stress scan using exercise
For stress scans using exercise, your heart rate will be checked
electrocardiogram (EKG or ECG). Because EKG electrodes need
to be attached to the chest to check the heart, men are usually bare-chested
and women usually wear a bra, gown, or loose shirt. To learn more, see
the topic Electrocardiogram.
The exercise stress scan is done in two parts. First a set of
resting images is taken, then a set of stress images is taken immediately after
exercise. Sometimes the stress scan is done first and the resting scan might be done the next day.
In many hospitals, first resting pictures are taken using one type of
tracer. More pictures are taken using a different tracer after your heart has
been stressed by exercise.
In this stress test, you exercise on a treadmill or stationary
bike. Your heart rate will be checked during the test with standard
electrocardiography. Your blood pressure is checked using a blood pressure cuff
placed on your arm. To learn more, see the topic
You will begin by walking or pedaling slowly and easily. Every
few minutes, the speed or incline of the treadmill or resistance of the bike
may be increased. You will exercise until you need to stop or until you reach a
suitable heart rate. At that point, you will be given a different tracer medicine through your IV.
You will probably continue to exercise for an additional 1 to 2 minutes to
circulate the radioactive tracer.
You will then lie down on a table for scanning. Each scan takes 5
to 10 minutes. The camera does not produce any radiation, so you are not
exposed to any additional radiation while the scan is being done.
Sometimes more pictures are taken after you rest for 30 minutes
to 4 hours. In some hospitals, you are given more radioactive tracer several hours after exercise and before the final image.
Most people can resume their normal diet and activities after the
final set of scans.