What is a Stress Test, and Should I Have One?

You already know you’re stressed. In fact, the stressors in your personal life, work life, and the world at large may even have been what sent you to the doctor. Maybe you have chest pain or heart palpitations. Or you feel so fatigued that you have to drag yourself through your day.

When your doctor orders a stress test, you wonder what exactly that entails. What kinds of stress does a stress test measure, and why do those measurements matter? 

At Lone Star Heart and Vascular Center, our expert cardiologists — Waqar Khan, MD, MPH, FACC, FSCAI; Alexander Trujillo, MD; and Steven Napierkowski, MD — administer a nuclear stress test to patients in need. Like a conventional exercise stress test, a nuclear stress test is easily and safely performed at our office in Tomball, Texas. 

The results from a nuclear stress test can literally save your life.  Do you need one, and if so, what is a nuclear stress test, and how does it help you?

What is a nuclear stress test? 

A nuclear stress test is designed to evaluate the strength, health, and function of your heart while it’s under stress. 

Unlike a conventional exercise stress test — which uses only an electrocardiogram (EKG) to monitor the electrical activity in your heart — a nuclear stress test lets your doctor look inside your heart and blood vessels, too.

They monitor your heart and circulation in two phases. First, they watch your heart when it’s at rest. Then, they have you perform a set of exercises that force your heart and circulation to work harder. They monitor your heart after the exercise, too. 

The nuclear stress test evaluates how efficiently or inefficiently your heart pumps blood through your body. 

How a nuclear stress test is performed

In the first part of a nuclear stress test,  your provider injects a radioactive tracer, such as thallium or sestamibi,  directly into your veins through an intravenous (IV) line. You then lie down and relax for 15-45 minutes, while your blood vessels and your heart take up the tracer so they’re visible to a specialized camera. 

While you’re in the positron emission tomography (PET) scanning machine, the camera takes a series of photos while your heart is at rest. These serve as your baseline cardiovascular function.

Next, they attach adhesive electrodes to your chest, legs, and arms. You then walk or run on a treadmill or exercise bike. Your doctors may increase the intensity of the exercise gradually until your heart is working at a target rate.

After you reach your target rate, your doctor injects more tracer. You wait another 15-45 minutes. They scan your heart again to evaluate how your blood flows during a period of stress.

If you’re not able to exercise,  you can still have a nuclear stress test. Instead of putting you on a treadmill, your doctor injects a drug that raises your heart rate to mimic the stress of exercise.

What a nuclear stress test feels like

During a nuclear stress test, you may feel stressed. You may have symptoms, such as:

• Chest pain
• Shortness of breath
• Palpitations
• Rapid heart rate
• Dizziness
• Muscle cramps

Your doctor closely monitors your condition to ensure that you’re safe. However, be sure to tell the technician or your doctor if you feel dizzy, in pain, or have difficulty breathing. 

A nuclear stress test diagnoses heart disease

After the stress test is complete, your doctor analyzes both sets of images as well as the EKG.  The metrics shed light on how well your heart works under pressure. Heart disease, such as heart rhythm issues (aka, arrhythmias), can be diagnosed through a nuclear stress test. 

The test also detects any blockage in your arteries. It’s especially good at identifying blockages that narrow the arteries by 70% or more. 

A stress test is a snapshot that provides just one part of the story about why you have symptoms such as chest pain or difficulty breathing. While a stress test can’t definitively predict a heart attack, it can reveal your risk. 

If your stress test shows evidence of arterial blockage or heart dysfunction, we may order more tests to thoroughly evaluate your condition.

A nuclear stress test monitors heart treatments  

A nuclear stress test isn’t just a diagnostic tool. If you’re already being treated for heart disease, we may order periodic stress tests to monitor the progress of your therapy. If you’re undergoing treatment for your heart, a stress test also helps determine the safest exercise program for you.

If you need a nuclear stress test, don’t delay: Book your stress test today by contacting our knowledgeable office staff by phone or by requesting an appointment online.