Your physician has ordered a cardiac nuclear stress test. This test is performed for many reasons. It is done to identify the cause of chest pain or chest discomfort which can occur with blockages in blood flow to the heart, to monitor heart function in people with known heart disease, and to determine the response to medications or after angioplasty or bypass surgery. The nuclear stress test involves taking pictures, also known as images, of your heart. A radioactive substance, known as a tracer, is injected into a vein in your arm and travels in the bloodstream to the heart. Areas of the heart receiving adequate blood flow pick up the tracer more completely.
Your physician has determined that you would not be able to perform an exercise test, such as walking on a treadmill or pedaling a bicycle, well enough to stress your heart adequately. As a result, a pharmacological or medicated stress test must be performed. The drug, Dobutamine, is used to stress the heart. Dobutamine has the effect of increasing the force of contraction of the heart, the heart rate and blood pressure. This stresses the heart muscle, which simulates exercise. When combined with the administration of Dobutamine, the pictures can detect areas of the heart that are not receiving enough blood flow. This enables your physician to determine your heart’s response to stress. The results assist the physician in managing you cardiac condition.
A 24 HOUR NOTICE OF CANCELLATION IS REQUIRED. THE RADIOACTIVE TRACER MATERIAL FOR YOUR TEST IS ORDERED IN ADVANCE, AND IS DELIVERED DAILY. IT IS NOT REUSABLE. YOU MAY BE RESPONSIBLE FOR THE COST OF THE MATERIAL IF YOU FAIL TO CANCEL.
How do I prepare for the Dobutamine nuclear stress test?
Do not eat 2 hours prior to your test.
Withhold caffeinated beverages, decaffeinated coffee and colas, and chocolate for 24 hours prior to your test. You may have water, juice or milk—these beverages are not restricted.
Do not smoke or use any form of nicotine 24 hours prior to your test.
Take your medications on the day of the test unless instructed otherwise.
Do not apply lotions or powders to the chest.
Wear loose, comfortable clothing; ladies may want to wear a front-buttoning, short sleeve shirt.
What happens during the Dobutamine nuclear stress test?
Rest Portion
You will be given an explanation of the test and asked to sign a consent form.
A registered nuclear medicine technologist inserts an intravenous catheter into your hand or arm.
A small amount of radioactive material, called a tracer, is injected through the intravenous catheter.
You lie flat on a special table under a large scanning camera.
The camera takes pictures, called images, of your heart from several angles.
Stress Portion
Electrodes are placed on your chest and connected to an electrocardiogram (ECG) machine, which permits continuous monitoring of your heart rhythm.
A nurse supervises the stress portion of the test.
Your blood pressure is checked frequently, and your ECG is continuously monitored
Dobutamine is administered through the intravenous catheter in increasing doses over a 15 minute period.
Near the end of the infusion of the Dobutamine a second tracer is injected into the intravenous catheter.
It is common to experience sensation of heart pounding or racing with Dobutamine.
Report any symptoms, such as chest pain, shortness of breath, or dizziness.
When the stress portion is completed, your blood pressure and ECG will be monitored for several more minutes.
You lie under the camera again for a second set of images.
Please allow 2 –2 ½ hours for the entire test to be completed.
When will I know the results of the stress test?
Final interpretation of the test results is completed by a cardiologist with a specialty in nuclear medicine.
The physician ordering your test and family doctor will receive a report within 3 days.