What Are Stress Tests?

Stress tests measure how your heart functions when it is stimulated by exercise. If you can’t exercise, physical stress can be created by taking certain medications.

Some heart problems are easier to diagnose when your heart is working hard. Stress testing can also help your health care provider understand the impact of health issues on your heart and guide medical treatment choices.

The Role of Stress Tests

Stress tests may be ordered for the following purposes:

  • To assist in the diagnosis of coronary heart disease, a common condition where a buildup of cholesterol plaque narrows the arteries, which are the vessels that move blood away from the heart. Stress testing is also used in the diagnosis of abnormal heart rhythms, called arrhythmias, and heart valve problems. It is common for people to undergo more than one test if their health care provider suspects they have a heart problem.
  • To evaluate the risk level of a known heart disorder. This helps your health care provider better understand the prognosis, or the likely outcome, of your disease.
  • To assist in treatment planning for your heart condition. Testing can help doctors to monitor how effective a surgical procedure or other treatment has been. Additionally, stress testing is used to provide medical clearance for exercise or surgery in some patients with chronic conditions like diabetes or heart disease.

Stress testing may also be used to screen patients without symptoms of heart disease to detect heart problems before they cause symptoms. The use of stress testing for screening is controversial. Most doctors use stress testing only in patients whose occupation involves public safety, like pilots and bus drivers, as well as competitive athletes.

Who should get testing?

There are a number of situations which may prompt stress testing. Experts may recommend stress testing to investigate the following symptoms, which are associated with common heart conditions:

  • Angina, which is chest pain caused by poor blood flow to the heart
  • Shortness of breath
  • Fatigue or weakness
  • Abnormal heart rhythms, which may feel like your heart is racing or skipping beats
  • New or worsening symptoms in patients with known coronary heart disease

Stress testing is also used to monitor patients with diagnosed heart disease, to plan and evaluate treatments for heart disease, to clear patients for surgery or exercise, and for other purposes. Your health care team can tell you what they are hoping to learn from your stress test.

Getting test results

Your doctor may be involved with the administration of your stress test. If your test is supervised by another health care professional, a report will be provided to your doctor. Your doctor may call you or schedule an appointment to discuss your test results. You may also be able to access your test report through an online health record.

Types of Stress Tests

Stress tests can be performed in several different ways. Stress testing varies both in how the heart is put under stress and how the impact of stress on the heart is measured.

Although exercising on a treadmill or an exercise bicycle is the preferred method of stressing the heart for a stress test, it is not right for everyone. Health care providers may choose to stress your heart using medication if you:

  • Cannot exercise due to arthritis, obesity, lung disease, or other disorders
  • Have certain conditions that could make exercise unsafe, like unstable angina, uncontrolled heart failure, poorly controlled high blood pressure, recent heart attack, or another serious medical problem
  • Have certain abnormalities on your baseline electrocardiogram (ECG), when you are at rest, that would interfere with interpreting exercise changes

Methods of creating stress

Stress for a stress test can be induced in three different ways:

  • Exercise: Stressing the heart using exercise produces the most informative results for your health care provider. In exercise stress testing, you either walk on a treadmill or pedal a stationary bicycle to make your heart work harder.
  • Medication: Some patients have health conditions that interfere with exercise stress test results, or make exercise impossible or unsafe. Depending on the test type being used and what your doctor thinks is best for you, one of the following types of medication may be given to induce stress on the heart during testing:
    • A drug which widen the arteries of your heart
    • A drug which makes your heart beat faster and harder, simulating the changes caused by exercise
  • Combined approach: In a combined approach patients are given medication and then asked to perform low-level exercise.

Methods of measuring stress

There are also different ways of measuring the impact of stress on the heart. Different methods include:

  • Electrocardiogram (ECG): An ECG records the electrical activity of the heart. It measures how fast your heart is beating and whether its rhythm is normal.
  • Nuclear imaging: This test uses radioactive material to show the blood flow in the heart. After the radioactive substance is injected, scans will be taken when your heart is at rest, then after it is stressed by exercise or medication.
  • Stress echocardiogram: An echocardiogram uses sound waves to create images of the heart. It allows observation of the heart valves and heart structures while it is beating.

Typically, your blood pressure will be monitored throughout the stress test in addition to the methods listed above. If you are having a nuclear stress test or a stress echocardiogram, you will usually also have an ECG performed at the same time.

Getting a Stress Test

Stress tests are ordered by a primary care provider or a doctor who specializes in heart problems, called a cardiologist. Stress tests may be done at a medical center, a clinic, or in the health care provider’s office.

At-home testing

Stress tests are performed in medical settings where the necessary experts and equipment are available. They cannot be conducted in an at-home environment.

Comparing Tests

A doctor will take several factors into account when deciding on the best method of measuring the impact of stress on your heart. Most often, you will have an exercise stress test and ECG first if you are able to exercise.

If you are unable to exercise, medication combined with imaging will be used. Electrocardiograms are not as sensitive at detecting abnormalities when stress is induced with medication instead of exercise, so additional imaging tests may be necessary.

The table below provides information about the advantages and disadvantages of different forms of stress testing:

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