Stress Test


Catherine Spader, RN

What is a stress test?

A stress test, also called a cardiac stress test, shows how exercise affects your heart. A stress test determines how much exercise your heart can tolerate before having a problem. Doctors use stress tests to diagnose and monitor coronary artery disease, cardiac ischemia (not enough blood flow to the heart muscle), cardiac arrhythmias (abnormal heartbeats), and other types of heart disease.

A stress test is only one method to monitor and diagnose heart conditions. Discuss all of your testing options with your doctor to understand which options are right for you.  

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Types of stress tests

The types of stress tests include:

  • Standard or regular stress test (exercise stress test or treadmill test) involves walking on a treadmill or pedaling a stationary bicycle. If you cannot exercise due to a medical condition, your doctor may give you a medication called dobutamine to make you heart work as hard as it would during exercise. This is called a pharmacological or dobutamine stress test.

  • Nuclear stress test involves using an IV radioactive dye and taking pictures of your heart during a stress test. Nuclear stress tests include a thallium stress test, sestamibi (Cardiolite) stress test, and PET (positron emission tomography) stress test.

  • Stress echocardiogram uses sound waves to take moving pictures of your heart during a stress test.

Why is a stress test performed? 

Your doctor may recommend a stress test to determine how well your heart handles work. A stress test is not a routine screening test, and a stress test by itself cannot diagnose all types of heart conditions or predict future heart problems. It provides important information about your heart health in relation to your age, physical exam, medical history, and other tests. 

Doctors use stress tests to help diagnose or monitor the following conditions:

  • Cardiac arrhythmias including heartbeats that are too fast, too slow, or irregular, especially arrhythmias that occur during exercise

  • Cardiomyopathy, thickened or enlarged heart muscle

  • Congenital heart defects, birth defects of the heart

  • Coronary artery disease (CAD), a buildup of plaque on the walls of the coronary arteries that supply blood to the heart

  • Heart attack, death of a portion of the heart muscle usually due to coronary artery disease and a blood clot that blocks blood flow to the heart

  • Heart failure, an inability of a weakened heart to pump enough blood to the body

  • Heart valve disease including narrowed valves and leaky valves

  • Pericarditis, inflammation of the sac that surrounds the heart

Your doctor may also perform a stress test to:

  • Determine if certain symptoms are related to coronary artery disease (narrowing of the coronary arteries). Symptoms can include chest pain, dizziness, shortness of breath, fatigue, weakness, palpitations, passing out, or feeling a pounding, racing or irregular heartbeat.

  • Determine the kind of exercise and how much exercise is healthy and safe for you if you have heart disease or a high risk of heart disease due to diabetes, family history, obesity, and other conditions

  • Further evaluate abnormal heart test results such as changes on a standard, resting EKG (electrocardiogram)

  • Monitor your heart condition after a heart attack, angioplasty, heart transplant, or heart bypass surgery

Who performs a stress test?

The following specialists perform a stress test:

  • Cardiologists and pediatric cardiologists specialize in conditions and diseases of the heart and blood vessels. Pediatric cardiologists further specialize in treating infants, children and adolescents.

  • Clinical cardiac electrophysiologists specialize in diagnosing and treating abnormal heart rhythms (arrhythmias) using heart and blood vessel imaging and technical procedures.

  • Interventional cardiologists specialize in diagnosing and treating conditions and diseases of the heart and blood vessels using nonsurgical, catheter-based procedures and specialized imaging techniques.

  • Cardiac surgeons specialize in the surgical treatment of conditions of the heart and its blood vessels. Cardiac surgeons may also be known as cardiothoracic surgeons.

  • Advanced heart failure and transplant cardiologists care for people whose heart failure no longer responds to conventional therapies and symptom management.

How is a stress test performed?

Your stress test will be performed in a hospital or specialized clinic. The test takes about 30 minutes and generally includes these steps:

  1. You will undress from the waist up and wear a patient gown for modesty.

  2. Your provider will attach sticky, painless patches, or electrodes, to your chest, arms and legs. The electrodes are attached to an EKG (electrocardiogram) machine by wires. The EKG machine records your heart’s electrical activity during the test. If you have a hairy chest, your provider may shave small areas to apply the electrodes.

  3. Your provider will apply a blood pressure cuff to your arm to monitor blood pressure during the test.

  4. You will slowly walk on a treadmill or pedal a stationary bike. You will begin to pedal harder on the bike or exercise harder as the treadmill gradually moves more quickly and the incline increases.

  5. Your provider may have you breathe into a special tube to measure the amount of air you breathe out.

  6. When your heart reaches its target heart rate, you will slow down gradually. The test can be stopped at any time if you do not feel well or have symptoms, such as chest pain, fatigue, dizziness, or shortness of breath.

  7. For a nuclear stress test, you will receive a radioactive dye through an IV, and your care team will take pictures of your heart.

  8. For a stress echocardiogram, your care team will take pictures of your heart using sound waves before and during exercise.

  9. Your provider will watch your EKG and vital signs closely throughout the stress test and will stop the test if abnormalities occur.

  10. You will rest briefly after the test while your provider watches your vital signs for abnormalities.

  11. Your doctor will evaluate your stress test and discuss the results with you.

Your doctor may use a drug called dobutamine to simulate the effect of exercise on the heart if you aren't able to exercise due to a medical condition or illness. This is called a pharmacological or dobutamine stress test.

Will I feel pain?

Your comfort and relaxation is important to both you and your care team. A standard stress test should be painless. Tell your care team immediately if you have chest pain or any other discomfort during or after your test.

What are the risks and potential complications of a stress test? 

Any medical procedure involves risks and potential complications. Complications may become serious in some cases. A stress test carries a small risk of complications including:

  • Abnormal heartbeats, also called cardiac arrhythmia

  • Chest pain, also called angina

  • Heart attack (rare)

  • Low blood pressure and fainting

  • Shortness of breath and other breathing problems such as wheezing

Your care team will watch you closely during a stress test and will stop the test if you have any problems. Be assured that your team is trained and equipped to treat complications.

Reducing your risk of complications

You can reduce the risk of certain complications of a stress test by following your treatment plan and: 

  • Notifying your care team immediately of any concerns such as chest pain, palpitations, dizziness, or