Adenosine Stress Test
Adenosine (Dobutomine) Stress Test
What is it?
An adenosine stress test is a diagnostic test used to evaluate blood flow to the heart. It is used in people who are unable to exercise or cannot walk for very long.
How does it work?
Adenosine is a drug that is given to make the heart respond as if the patient were exercising so the doctor can determine how the heart responds to stress. The medication does not increase the heart rate. The medication dilates blood vessels leading into the heart, increasing blood flow, therefore simulating exercise for patients unable to exercise on a treadmill. Pictures are taken before and after the adenosine is given.
Dobutamine may be used as the drug versus adenosine for patients with a history of asthma, COPD or use inhalers regularly. The diagnostic test is done the same way regardless of whether adenosine or dobutamine is the drug used.
Reasons for an Adenosine Stress Test
This test can help determine if there is adequate blood flow to the heart during activity versus at rest. It is a diagnostic test for coronary artery disease.
What to expect
The entire test takes about three to four hours in total. First, an intravenous (IV) line will be inserted into the arm. The adenosine and isotope (an imaging agent) will be given through an IV during the stress part of the test. The patient will lie on an examination table, which has a gamma-ray camera above it which is used to take pictures of the heart. The camera moves non-stop for about 20 minutes and can pick up traces of the radioactive substance in the body and then send a picture to a television monitor.
After the pictures are taken, the patient will be connected to an electrocardiogram (EKG) machine which will monitor the heart rate during the test. The adenosine will be given though the IV, which is called an infusion. Additional isotope will be given so additional pictures can be made. During the infusion, symptoms may occur such as chest pain, flushing or nausea which will all cease once the medicine is stopped.
This adenosine (or dobutamine) and isotope are not harmful to your body or your organs. After the test is over the patient may resume normal activities.