Discover the ins and outs of a nuclear stress test, its procedure, benefits, and how it helps diagnose heart conditions. Visit Meri Sehat for more information.

Nuclear Stress Test Explained

Introduction

Nuclear stress test (also known as cardiac PET study or cardiac SPECT study or myocardial perfusion imaging (MPI) study) is a nuclear imaging test that measures the amount of blood flow in your heart while you are exercising and resting.&nbsp;

During the procedure, a liquid containing a trace amount of radioisotope is injected into one of your veins. It travels through your bloodstream and eventually reaches your heart. Once the radiation has entered your heart, a gamma camera (a special camera) is used to detect the radiation and reveal any problems with your heart (function or blood flow)<a href="#accordion">[1]</a>. 
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Understanding The Nuclear Stress Test

The test results determine whether or not your heart muscle receives adequate blood flow and oxygen when working hard.

&nbsp;

<ul>
	<li>
	<h5>Symptoms Of Heart Disease</h5>
	</li>
</ul>

If you experience heart disease symptoms, such as chest pain or shortness of breath, you may have to undergo a nuclear stress test.&nbsp;

&nbsp;

<ul>
	<li>
	<h5>Determining <a href="https://merisehat.pk/disease/coronary-artery-disease">Coronary Artery Disease</a></h5>
	</li>
</ul>

Coronary arteries are the main blood channels that carry oxygen, nutrients, and blood to your heart. Fatty deposits or plaques present in these arteries reduce the flow of oxygenated blood to your heart muscle.

If you are experiencing symptoms like shortness of breath or chest pain, your doctor will order a nuclear stress test because it will help diagnose whether you have coronary artery disease. The test results will also help identify how severe or advanced the condition is<a href="#accordion">[4]</a>.&nbsp;

&nbsp;

<ul>
	<li>
	<h5>Making A Treatment Strategy</h5>
	</li>
</ul>

Since a nuclear stress test measures how much activity your heart is able to withstand, your doctor will use it to select the best course of treatment for you and, later again, to check the efficacy of that treatment. 
&nbsp;

The nuclear stress test is performed at a medical facility.

<ul>
	<li>A technician inserts an intravenous line into your arm and injects a radioactive substance, such as thallium or sestamibi, before the test begins<a href="#accordion">[5]</a>.</li>
	<li>After a few minutes, you need to lie down for 15-45 minutes.&nbsp;</li>
	<li>A special camera scans your heart and takes pictures to show how the substance moved through your blood and into your heart while you were resting.</li>
	<li>During this period, electrodes are also placed on your arms, chest, and legs. These electrodes are connected to an ECG machine. Your heart rhythm will be monitored throughout the test.</li>
	<li>At the same time, the technician or the nurse ensures you wear the BP cuff correctly on your arm. Your blood pressure will be monitored throughout the test, too.</li>
	<li>Next, if the doctor asks to combine the nuclear test with the traditional exercise stress test, you have to walk on a treadmill or pedal on an exercise machine. The technique is to start walking slowly and slowly increase the speed for the length of the test.</li>
	<li>If you are unable to exercise, a vasodilator, such as adenosine or persantine, is prescribed to dilate the arteries in your heart. In other cases, you may be given a drug such as dobutamine that causes your heart to beat faster and harder.</li>
	<li>When your heart is functioning as hard as it possibly can, a radioactive substance is injected into one of your veins one more time and you have to wait 15-45 minutes again.</li>
	<li>Again, the specialized camera scans your heart and produces images.</li>
	<li>At this stage, you&rsquo;re permitted to get up from your seat or table and have a snack or beverage.</li>
	<li>You have to continue exercising till you reach the target heart rate or till you start to feel distressed or have other symptoms.</li>
	<li>At the end of the test, your doctor compares the first and second sets of images on their computer, i.e., compare how your heart functions at rest and under stress, whether you have heart disease, or whether your heart condition is worsening.</li>
</ul>

&nbsp;

<h5>1. Pre-Test Preparation</h5>

The point to remember is that the test is of no use if you&rsquo;re uncomfortable or in any undue physical stress. So, prioritize your comfort and your health:

<ul>
	<li>Wear loose-fitting clothing and shoes with non-slip soles.&nbsp;</li>
	<li>Avoid eating or drinking a couple of hours before the test is scheduled to take place. If you need to take medications, you will be permitted to take them with a few sips of water.</li>
	<li>However, a lot of medicines affect blood test results. Inform your doctor of any medicine you&rsquo;re taking; they&rsquo;ll tell you if you need to change their dose or entirely stop taking them before this test.</li>
	<li>Coffee, tea, chocolates, and caffeine-containing pain relievers should be avoided at all costs at least 24 hours before the test.</li>
</ul>

&nbsp;

<h5>2. During the Test</h5>

Some people experience the following symptoms during the test:&nbsp;

<ul>
	<li>Chest pain</li>
	<li>Fatigue and weariness</li>
	<li>Cramps in the legs or feet</li>
	<li>Breathing difficulty</li>
	<li>Nausea</li>
	<li>Headache</li>
	<li>A sting followed by a warm sensation when the vasodilator medicine is injected</li>
</ul>

Generally, it&rsquo;s nothing serious. However, you need to immediately notify the person performing the test if you feel any of these symptoms. 
&nbsp;

That feeling of stress on your heart may be an indicator of something serious, but let&rsquo;s not jump to any conclusions, okay? You&rsquo;ve had your test and you&rsquo;re nervous already; read on to find out what the test results mean and whether you require additional testing.

&nbsp;

<ul>
	<li>
	<h5>Normal&nbsp;</h5>
	</li>
</ul>

Stress tests categorize the majority of patients evaluated for stable CAD as low risk<a href="#accordion">[3]</a>.&nbsp;A normal result is an indicator that you were able to exercise for the same amount of time as or longer than most people your age and gender. The reason for your test and your family history of heart or other medical issues are also factored into this result.

The result also shows that you did not experience any significant changes in your blood pressure and ECG and that there are no blockages or ruptures in the coronary artery.

&nbsp;

<ul>
	<li>
	<h5>Abnormal</h5>
	</li>
</ul>

This implies that the blood flow to a portion of your heart has decreased due to some narrowing in one or more arteries supplying blood to that muscle. Additionally, the blood flow may be affected due to scarring of the heart muscle caused by a previous heart attack.

An abnormal result means you require either an angiography/angioplasty or a bypass surgery to open the blocked arteries<a href="#accordion">[6]</a>. It&rsquo;s highly probable that your doctor changes your medications or their dosage following this result. 
&nbsp;

Generally, the thallium stress test has no side effects. Yes, the medicine stings when it&rsquo;s first injected, but that feeling quickly goes away.&nbsp;

The test may cause headache, nausea, and a racing heart. And while the radioactive material is eliminated via urine or feces, it does not cause any complication at the time of injection.

In rare instances, the test may involve the following complications:&nbsp;

<ul>
	<li>Abnormal heartbeat or arrhythmia.&nbsp;</li>
	<li>Elevated angina or discomfort&nbsp;</li>
	<li>Breathing difficulty</li>
	<li>Asthmatic symptoms</li>
	<li>Large fluctuations in blood pressure</li>
	<li>Rashes on the skin</li>
</ul>

If you have any of these signs and symptoms at any point during or after your test, you should notify the test administrator and/or your doctor.

<div>&nbsp;</div>

Conclusion

A stress test reveals how well your heart works and how much strain it&rsquo;s able to withstand. It assists in the diagnosis of several heart diseases and also assesses how well the treatment plan is working.&nbsp;Typically, the test consists of walking on a treadmill while a medical professional will monitor your heart activity. If need be, you may be given a specific medicine to achieve a similar effect. 
&nbsp;

Key Points

<ul><li>A heart stress test reveals how effectively your heart functions.</li><li>You'll use a treadmill or receive drugs during the stress test to put your heart under stress. During the test, your ECG, heart rate, and blood pressure will be monitored by a doctor or technician.</li><li>You may be at risk of having a heart attack if your heart stress test results are abnormal. In that case, more tests will be required to confirm the diagnosis.</li></ul>

[1] Gopal S, Murphy C. Nuclear Medicine Stress Test. In: StatPearls [Internet]. StatPearls Publishing; 2022.

[2] Sabharwal NK, Stoykova B, Taneja AK, Lahiri A. A randomized trial of exercise treadmill ECG versus stress SPECT myocardial perfusion imaging as an initial diagnostic strategy in stable patients with chest pain and suspected CAD: cost analysis. J Nucl Cardiol. 2007;14(2):174–86.

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