Nuclear Stress Test: Uses, Risks, and Results

A nuclear stress test measures the blood flow that goes into your heart. The goal of the test is to measure the normalcy level of the said blood flow.

Nuclear stress test

What is Nuclear Stress Test?

Not the nuclear nor stress is the subject of the nuclear stress test, but the blood flow that goes to your heart. The goal of the test is to measure the normalcy level of the said blood flow.

To conduct the test, conductors use a radioactive tracer that produces an image on how the blood reaches your heart muscle. They do it both during physical activity and while you rest. If you cannot do physical activity because of a certain circumstance, the test can still be performed by simply supplying you with a medication that will give your cardiovascular system the same experience when you exercise.

Most often, experts use a nuclear stress test to assess the severity of obstruction that is due to coronary artery disease. The study is considered non-evasive and accurate when spotting coronary artery obstruction. By doing the stress test, cardiac catheterization became unnecessary to perform among patients.

What is the Purpose of the Test?

To identify a coronary artery disease, a nuclear stress test is a common procedure that health professionals do.  Sometimes, what causing unexplained symptoms such as chest pain and dyspnea cannot fully identify. But by doing the nuclear stress test, the health professionals can confirm if the source of the said symptoms is from coronary artery disease.

For those who are already diagnosed with coronary artery disease, the test is helpful among health professionals to come up with a better treatment plan.

If a patient who has coronary artery disease is being treated either with a stent or a medication, a nuclear stress test is still needed to check if the chosen treatment is taking effect. The test gives some information that can help health professionals to give objective advice about physical activities as well as other activities.

What Does the Test Assess?

Providing an image of how the blood is distributed to the heart is the responsibility of a nuclear stress test. Either while you are exercising or resting, the test will draw an image on how your blood flows to your heart muscle. The typical image of blood distribution should be equal whether you are resting or exercising.

So, let’s say the image resulted in a similar blotch of poor blood flow both while you are exercising and resting. It means that a heart attack occurs prior to the test. However, if the blotch of poor blood flow is recognized during exercise, but not in rest, then it means that a blockage is present in one of your coronary arteries.

Thus the test is very helpful among doctors to identify and determine the location, presence, and even the size of a prior heart attack. Similarly, the location, presence, and size of a coronary artery blockage will be determined by doctors.

What is the Test Procedure?

The test is usually performed two days in a row. In the first day, you have to perform an exercise. The second day will serve as the resting image, on the other hand.

It is a typical method to do the exercise first before proceeding to rest. If you do not exercise, the exercise image will most probably be normal. Thus, doing a rest image is no longer necessary.

Nevertheless, some labs are hitting two birds in one stone. Meaning to say, they did the test on the same day. They do this by performing the resting image first. They will inject you with a Tc-99 tracer intravenously in a small dose. A few hours later, stress imaging will be done by giving you a much higher Tc-99 dosage. The aim of these labs is to avoid practical challenges in 2-day testing among patient.

The image will be captured using a gamma scan. This is normally performed between 15 and 60 minutes after being injected with the tracer.


Some people cannot exercise for certain reasons. For instance, their doctor thinks that exercising is not a good idea. Thus, their physical activities are limited to exercise stress testing, such as exercising in a stationary bicycle or treadmill, to make the nuclear stress test possible.

However, there are people that are totally banned from doing exercise because of physical limitations. In cases like this, patients are given drugs that can induce physiological cardiac stress. The stress is enough to perform the test.

How is the Test Performed?

Before the test, one of the healthcare team will conduct an interview to check for any change in your medical condition or symptoms. The healthcare professional may also do a quick physical examination. He/she will also instruct you on what to expect during the test. Your questions are also welcome during the interview.

Throughout the testing process, it will be supervised by a doctor. If you are having one-day testing, expect that the resting image will be done first. Your vein will be inserted with an intravenous line, then you will be injected with a small dose of radioactive tracer. After 20 minutes, you will be asked to lie down under a gamma camera to do the imaging. You will lie still as your arms will be kept above your head.

Then a few hours later, stress imaging will be done.

What are the Risks Associated with Nuclear Stress Test?

A nuclear stress test is usually performed by trained and skilled personnel, thus, it is safe. However, there are still some risks that are associated with it.

  • Cardiac Arrhythmias – the condition occurs when exercise is performed. However, it is not dangerous and usually gone after the exercise. Moreover, detecting it has diagnostic value.
  • Symptoms that are not limited to dizziness and chest pain – patients with coronary artery disease oftentimes trigger their symptoms because of exercising. However, the same with cardiac arrhythmias, detecting it has a diagnostic value since health professionals can identify if the symptoms are produced by coronary artery disease or not.
  • Allergic reaction – the radioactive tracer sometimes cause an allergic reaction to patients. But this rarely occurs.
  • Heart attack – this complication rarely occurs. However, the exercise performed by a patient may cause a heart attack.

Nuclear stress test

Leave a Reply

Your email address will not be published. Required fields are marked *