A Nuclear Stress Test
To Determine Coronary Artery Disease

A nuclear stress test is given in two parts, the exercise part and the resting part.

Both tests are necessary as they determine the state of the heart during times of exertion, and during times of rest.

During times of exertion, when our heart rate increases, and our heart muscle pumps more quickly, the heart needs more oxygen, for it to pump efficiently.

If our coronary arteries are either blocked or narrowed significantly, the increased demand for oxygen by the heart causes angina and chest pain.

If the blockages erupt or the arteries continue to narrow, a heart attack can occur during those moments of exertion.

To detect if this is what is occurring, the test is given first while exercising, and then while resting, then the two tests results are compared with each other.

If the test results vary significantly it can show that atherosclerosis has formed on the arterial walls and an angiogram may be needed for further testing.

The Nuclear Stress Test Procedure

Tiny amounts of radioactive material are injected into our bloodstream, these bits of radiation can be detected by special cameras.

As the radioactive material enters the myocardium walls of the heart through the coronary arteries a picture of the heart is taken.

If any portion of the heart is recieving less blood then any other parts it shows up lighter in the picture

The doctor can verify, whether the blood flow to the heart muscle is suficient or there seems to be a blockage.

If the conclusion is that there may be blockages further invasive testing through an angiogram must be done to see the actual location, size and severity of the blockages.

The Nuclear Stress Test Phase One- Exercising

No Eating:

For several hours before the test no food or drink should be eaten; this is to avoid nausea. Therefore the best time to schedule the test is in the morning with the last meal being supper from the previous night.

Clothing:

Patients are asked to wear loose fitting clothing, and sneakers so that they can walk comfortably on the treadmill.

In The Room:

The patient gets undressed from the waist up, and electrodes are put on, to measure the heart rate and waves during the exercise.

An intravenous tube IV line is then inserted into a vein in the arm, a blood pressure monitor is wrapped around the upper arm, and you step on the treadmill.

The Nuclear Stress Test

You begin walking on the treadmill. The doctor increases the elevation and the speed of the treadmill gradually. The faster the treadmll gets, and the higher the elevation, the harder it gets to walk on it. The harder it gets to walk, the quicker the heart pumps and the heart rate increases.

When the doctor notices that you are reaching your heart limit, the nurse injects the radiocative material into the intravenous tube. You continue to exercise for an additional 60 to 90 seconds, then the elevation and speed is reduced, the treadmill is stopped and phase one of the exercise is concluded.

You are then requested to wait in the radioactive waiting room, for around an hour. During this hour you are supposed to drink around 12 cups of water.

After an hour or so you are taken to a room that has in it a nuclear scanning machine. You lie down on the table, and are asked to be very still. Your hands are placed above your head so that they do not move.

The camera which looks like a large tube begins to take images of your heart from many different angles. The camera detects the radiation that is being emmitted in your body and reconstructs it into a compuerized images.

You lie like this for around 25 minutes, then phase one of the test is done.

The Nuclear Stress Test Phase Two
The Resting Phase

The next day or several days later you return to the lab and the resting portion of the test is taken.

The procedure is the same, except for the exercise phase. A radioctive dye is injected, you are asked to wait 60 minutes drinking 12 cups of water until the radioactive material enters into the bloodstream.

After an hour or so, you are scanned again by the nuclear scanning machine, with that camera taking pictures from various angles. This part also takes around 25 minutes.

The Results

Getting back the test results can take several days. The doctor compares the two sets of images taken and verifies these three results.

No defects found during exercise and during rest, that means that your myocardium and heart muscle are functioning properly and there is no indication of atherosclerosis in your arteries.

Defects found after exercise and not after rest, means that some of the coronary arteries may be blocked or narrowed, sufficient blood flow doesn't reach the arteries during times of exertion.

During the rest period the blood does reach the heart , meaning the area does get blood flow but not enough, this may be causing the angina pains, and must be checked into further.

Defects found on both images during exercise and during rest, this means that an area of your heart has become scar tissue because of a previous heart attack, that part of the heart had a total blockage in the artery supplying it with oxygen.

How Can We Avoid The Need To Be Tested?

Having had this test done to me several times, my experiences of it are that it isn't painful, it isn't uncomfortable. But why should we have to take it? can't we avoid it? Fortunately the answer is yes.

We can avoid needing a nuclear stress test, by taking the necessary precautions to avoid heart disease in the first place. This can be done through, losing weight , proper nutrition, exercising, reducing our blood pressure, and lowering our cholesterol levels. Why wait till its too late, begin living a healthy active lifestyle now.

Disclaimer: The information that I am writing on these pages are for educational purposes only, and are intended to inspire us to learn more about heart disease. By doing so we can learn how to eliminate the leading cause of death, and create a better life for us and our children. I am only a heart patient, in no way should what I am writing, replace any medical advice given to you by your doctors.

Nuclear stress test