#456: Nurse’s Guide to Cardiac Stress Tests

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Cardiac stress testing is a noninvasive way to evaluate cardiac health. In simple terms, the test stresses the heart and measures how well it performs under pressure. With this test, cardiologists can assess things like cardiac function, coronary perfusion, exercise tolerance, and viability of the myocardium. 

Indications for a cardiac stress test

Cardiac stress tests are utilized in patients with a range of cardiac conditions or symptoms. Common indications include detection of coronary artery disease or wall motion abnormalities, angina, and shortness of breath. Stress tests are also utilized to evaluate risk in patients who are undergoing cardiovascular surgery or who have cardiac symptoms prior to undergoing surgery of any type. Some patients who are significantly deconditioned may undergo cardiac stress testing to determine their exercise tolerance. In addition, cardiac stress testing may also be used to monitor patients with known cardiac disease.

Two types of cardiac stress tests

There are two ways to conduct a cardiac stress test – pharmacologically or through exercise. The least invasive method is through physical activity, so this is used when possible. However, not all individuals are capable of exercising and would undergo pharmacologic testing instead. 

Exercise stress test

Also called a “treadmill stress test” this procedure monitors the patient’s symptoms, blood pressure, heart rate and EKG tracing while they are walking (or jogging) on a treadmill. In most cases, the Bruce protocol is utilized. This involves utilizing 3-minute stages of increasingly faster and steeper treadmill settings for a total of 6 to 12 minutes. Mild symptoms without hemodynamic compromise do not generally necessitate ending the test. However, if the patient experiences more significant manifestations of cardiac dysfunction, the test should be terminated. These include: 

• Moderate to severe angina
• Sustained ventricular tachycardia
• ST elevation of more than 1 mm
• Decrease in systolic blood pressure > 10 mmHg from baseline when other signs of cardiac ischemia are present (such as angina, near-syncope or poor skin signs)
• Signs of poor perfusion such as pallor or cyanosis
• Neurological manifestations such as dizziness, ataxia or feeling faint.

Potential indications for terminating the test include: 

• QRS or ST changes
• Any cardiac arrhythmia such as PVCs, SVT, or conduction deficits
• Significant shortness of breath or wheezing
• Increasing chest pain
• Hypertension beyond what is expected (> 250 mmHg systolic and/or > 115 mmHg diastolic)
• Decrease in systolic blood pressure > 10 mmHg from baseline without signs of ischemia

A normal response to exercise stress testing is for the heart rate and blood pressure to increase appropriately in response to the exercise. In addition, the patient should have no changes on the EKG and no signs of ischemia (angina, pallor, etc…). Specifically, ST-segment changes are indicative of a positive stress test result.

Note that a treadmill isn’t the only way to perform an exercise stress test as bicycles may also be utilized.

Pharmacologic stress test

For patients that cannot (or should not) exercise, stress on the heart is induced with medication. This includes individuals with mobility issues, blood pressure > 200 mmHg, unstable angina, poorly controlled heart failure, aortic stenosis, recent myocardial infarction, severe pulmonary hypertension, and acute respiratory or cardiac issues such as pulmonary embolism or pericarditis.

In addition, pharmacologic testing is more beneficial in patients with certain cardiac conditions that involve an abnormal EKG at baseline. Examples include Wolff Parkinson White syndrome, left bundle branch block, and left ventricular hypertrophy. 

During the procedure, the patient’s heart rate, blood pressure, and EKG tracing are closely monitored. To induce stress on the heart, a pharmacologic agent is injected via a peripheral IV. This is followed by the injection of a small amount of radioactive material which allows for visualization of blood flow through the coronary vasculature. 

Medications used for cardiac stress testing include those that dilate coronary blood vessels (adenosine, regadenoson, dipyridamole) and the inotrope, dobutamine. Vasodilating agents work by inducing something called “coronary steal.” This occurs when blood flow to non-diseased coronary vessels is temporarily increased while flow to diseased vessels is reduced, making them easier to visualize. Dobutamine is an inotropic agent that may also be utilized in cardiac stress testing, though it is not common. 

Adenosine – For cardiac stress testing, adenosine is a weight-based medication typically administered continuously for six minutes with the radioactive agent given at the three minute mark. Patients can expect a mild increase in heart rate and a slight decrease in blood pressure with adenosine administration. Side effects are generally minor and include flushing, shortness of breath and chest pain. However, more serious adverse effects such as bronchospasm and AV block can occur. 

Regadenoson – Ragadenoson produces maximal blood flow in the coronary arteries quickly and maintains it for an optimal duration. Other key benefits of regadenoson is that it is a simple injection rather than a slower infusion and it is not weight based like the other vasodilating medications. Once administered, the radiotracer is injected 10 to 20 seconds later. Studies show that it is as effective as adenosine for diagnostic purposes and is safer and better tolerated. However, patients can experience side effects. The most common are pain (arm, back, or jaw), nausea, sweating, chest tightness, and chest discomfort.

Dipyridamole – This weight-based medication also dilates the coronary vessels and it works by increasing levels of adenosine in the body. It is administered over four minutes and the radioactive tracer is injected three to five minutes after the infusion is complete. Note that because dipyridamole has a longer half life than other medications, the effects can linger for up to 25 minutes. Minor side effects of dipyridamole include dizziness, nausea, headache, flushing, and hypotension. More significant adverse effects include chest pain and AV block (though the incidence of heart block is less than it is with adenosine). 

Dubutamine – Dobutamine is an inotrope, meaning it increases the contractile force of the heart though it is important to note that it also increases heart rate. By increasing myocardial workload, dobutamine increases myocardial oxygen demand. This leads to ischemia in areas of the heart that don’t receive adequate blood flow due to coronary artery disease. Dobutamine is administered as a weight-based infusion for three minutes and then increased in dosage at three-minute intervals to a max of 12 minutes or until the desired heart rate is achieved. The radiotracer is injected when the heart rate is at its peak and the dobutamine is stopped one minute later. Dobutamine is not commonly used, and is generally only utilized in patients who aren’t able to take vasodilating medications, such as those with COPD, asthma, or high-degree AV blocks.

Patient education prior to testing

Key things to teach patients prior to cardiac stress testing include: 

• If undergoing a pharmacologic test, avoid caffeine for 24 hours prior to the test – including decaffeinated beverages.
• Do not eat, drink, or smoke for three hours prior to the procedure. If the patient has diabetes, they should speak to their cardiologist for specific instructions.
• If using a treadmill, wear athletic shoes and clothing appropriate for exercise – no dresses, skirts, one-piece outfits, shapewear, etc…
• Shirts should be loose fitting, short-sleeved and free of metal.
• Avoid use of creams, oils, powders, and lotions on the chest and arms for the 24 hours prior to the test.
• Some medications may need to be avoided the day of the test and these should be discussed with your physician – especially beta blockers, nitrates, diuretics, and diabetic medications.

For more cardiac topics, start exploring here.

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References:

Cleveland Clinic. (2023). Adenosine Stress Test. Cleveland Clinic. https://my.clevelandclinic.org/health/diagnostics/16839-cardiac-mri-adenosine-stress-test

DrugBank. (2025). Adenosine. DrugBank. https://go.drugbank.com/drugs/DB00640

Garner, K. K., Pomeroy, W., & Arnold, J. J. (2017). Exercise Stress Testing: Indications and Common Questions | AAFP. American Family Physician. https://www.aafp.org/pubs/afp/issues/2017/0901/p293.html

Lak, H. M., Ranka, S., & Goyal, A. (2025). Pharmacologic Stress Testing. In StatPearls. StatPearls Publishing. http://www.ncbi.nlm.nih.gov/books/NBK555963/

Lak, H., Ranka, S., & Goyal, A. (2023). Pharmacologic Stress Testing. In StatPearls [Internet]. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK555963/

Mayo Clinic. (2025a). Dipyridamole (oral route, intravenous route) – Side effects & dosage. Mayo Clinic. https://www.mayoclinic.org/drugs-supplements/dipyridamole-oral-route-intravenous-route/description/drg-20063475

Mayo Clinic. (2025b). Regadenoson (intravenous route) – Side effects & uses. Mayo Clinic. https://www.mayoclinic.org/drugs-supplements/regadenoson-intravenous-route/description/drg-20071632

Vilcant, V., & Zeltser, R. (2025). Treadmill Stress Testing. In StatPearls. StatPearls Publishing. http://www.ncbi.nlm.nih.gov/books/NBK499903/

Last Updated on January 6, 2026 by Maureen Osuna, MSN, RN