Stress tests, also known as exercise stress tests, demonstrate how your heart responds to any activity that enables the heart to pump faster and harder. This test can detect abnormalities in the heart’s blood flow.

A stress test consists of walking or riding a stationary bike on a treadmill to monitor the blood pressure, respiration rate, and heart rhythm. It may include a drug used to simulate the effects of exercise during tests. An abnormal heart rhythm (arrhythmia) or signs of coronary artery disease may warrant a stress test. A stress test is found helpful to:

  • Ensure the effectiveness of heart treatments
  • Diagnosing the severity of existing heart conditions
  • Make decisions about treatment

Types of Stress Test

Depending on the health condition of an individual, a stress test can be performed in a variety of ways;

1. Exercise stress test

The doctor will determine how the patient feels and responds to different physical activities during a stress test by measuring heart rate, blood pressure, breathing, and fatigue. For example, during a treadmill stress test following procedure will be followed;

  • The doctor will initially take particular readings on the treadmill by attaching a specific device to monitor the heart.
  • Once the person stands on the treadmill, the doctor will take further readings.
  • The patient will start strolling as the treadmill moves.
  • As the treadmill speed increases, the patient will walk faster.
  • It is possible to incline the treadmill.
  • An individual may be required to breathe through a mouthpiece at the end to measure their exhalation.
  • A doctor will take blood pressure and other patient measurements while lying down.
  • The person will do 10–15 minutes of exercise. They can, however, stop at any time if they feel uncomfortable.
  • A doctor might stop the test if a patient experiences any of the following:
  • Dizziness
  • Hypertension
  • Hypotension
  • An irregular heartbeat or arrhythmia
  • An uncomfortable feeling in the chest
  • An inability to breathe 
  • Tiredness

The electrocardiogram device can also detect any unusual changes, which may cause the test to be stopped. Moreover, qualified medical professionals should always be on hand to deal with the adverse effects.

2. Stress test without exercise

Doctors can use medications to trigger the same process if a person cannot exercise. By attaching electrodes to the chest, the doctor can deliver the medication through an IV line in the patient’s arm that requires at least 15–20 minutes to provide medication.

The medicine provides heart stimulation. Likewise, exercise stress tests, flushing, or shortness of breath may cause similar effects that require immediate medical attention.

3. Nuclear stress test

Doctors may recommend nuclear stress tests, also named Radionuclide scans, to get a more detailed diagnosis of the heart. An injection of tracer dye was injected into the arm to visualize the heart, and blood flow was highlighted on an image. Any blocked heart area where blood does not flow properly will also be visible with the dye. 

Moreover, medication may be prescribed if a person cannot exercise. In this situation, an imaging test named single-photon emission computer tomography or a cardiac PET will be performed that does not involve much radiation. It will provide the doctor with two images, each lasting 15 to 30 minutes.

The first pill will be taken immediately after the person has exercised, and the second pill will be swallowed after the body has recovered, either later that day or the next day. The doctor will compare the heart’s functioning and effectiveness before and after the test.

Furthermore, this test is not suitable for pregnant women who may become pregnant as its radiation can harm the fetus. 

Why are Stress Tests Performed?

1. Diagnose coronary artery disease

The coronary arteries supply blood, oxygen, and nutrients are supplied to your heart by the coronary arteries. Atherosclerosis occurs when the arteries become damaged or diseased – usually due to a buildup of cholesterol-containing deposits (plaques).

2. Diagnose an irregular heartbeat (arrhythmia)

A heart arrhythmia occurs when your heart’s electrical signals are not functioning correctly. An arrhythmia is a condition of irregular heartbeat that poses life-threatening symptoms for an individual. 

3. Provides tips for treating heart conditions:

A doctor can use an exercise stress test to determine the effectiveness of the current heart treatment you get due to existing heart disease. The doctor will also use the test results to decide the treatment, its relevancy, intensity, and level. 

4. Get your heart checked before surgery

When you’re ready for surgery, such as a valve replacement or heart transplant, a stress test will be helpful to check your heart condition.

Note: A stress test with imaging, such as a nuclear stress test or stress test with an echocardiogram, may be recommended if your exercise stress test does not pinpoint the cause and its symptoms.

Risks of Stress Tests

There is generally no risk associated with stress tests, having rare complications. But overall, the possible complications are mentioned below; 

  • Hypotension: You may feel dizzy or faint if your blood pressure drops during or after exercise. It should subside once you stop working out.
  • A heartbeat disorder (arrhythmia): If you experience an arrhythmia during an exercise stress test, they usually go away soon after you stop exercising.
  • Myocardial infarction (heart attack): However, a heart attack can occur during an exercise stress test, although it is infrequent.

Summary:

Heart stress tests can diagnose various heart conditions and evaluate how well the heart functions. This test also measures a person’s heart’s ability to withstand the strain. An exercise program or planning for heart surgery can benefit from this information.

In most cases, a doctor monitors the heart’s activity while you walk on a treadmill. However, some medication may be necessary to produce a similar effect in people with reduced mobility. Stress tests can provide insights into a person’s heart health and suggest exercises and other treatment options.

References:

  • https://www.medicalnewstoday.com/articles/265503#what-to-expect retrieved on 13th December 2021.
  • https://www.webmd.com/heart-disease/stress-test retrieved on 13th December 2021.
  • https://medlineplus.gov/lab-tests/stress-tests/ retrieved on 13th December 2021.
  • https://www.healthline.com/health/exercise-stress-test#follow-up retrieved on 13th December 2021.