Overview
An exercise stress test aims to detect hidden heart problems that are not noticed at rest but emerge with exertion. During the test, while you exercise on a treadmill or bicycle, your heart rate, blood pressure, and ECG are closely monitored to evaluate your heart’s performance under stress.
What is a exercise stress test?
An exercise stress test is a test that evaluates your heart’s performance and electrical activity during physical activity. During this test, while you walk on a treadmill or pedal a bicycle, a specialist continuously monitors your heart rate, blood pressure, and your heart’s electrical signals (ECG).
The main purpose of the test is to detect hidden heart problems that do not cause problems at rest but may emerge when your heart needs more oxygen during exertion. This way, problems affecting the heart such as coronary artery disease can be diagnosed, or the severity of an existing condition can be evaluated.
When and why might you need a stress test?
Your doctor may recommend an exercise stress test to evaluate some conditions related to your heart and vascular health. Common situations where this test is used include:
- Suspected Coronary Artery Disease (CAD): If you have symptoms such as chest pain, shortness of breath, or palpitations, this test investigates possible narrowing and blockages in your coronary arteries.
- Assessment After Heart Attack or Surgery: Used to see how the heart responds to exercise in patients who have previously had a heart attack or undergone angioplasty/bypass surgery.
- Exercise-Induced Arrhythmias: Useful for detecting arrhythmias that are normal at rest but emerge with exertion.
- Measuring Exercise Capacity: Can be used to determine the physical capacity and exercise tolerance of patients with heart failure.
- Monitoring Treatment Effectiveness: Performed to see how well medications or treatments used for heart disease are working.
Before the Test
Who should or shouldn’t take a cardiac stress test?
The exercise stress test is a safe method for most patients who are at risk for heart disease or have symptoms related to this condition. However, some conditions may prevent or restrict the test from being performed:
Who Is It Suitable For?
- Those with symptoms such as chest pain and shortness of breath
- Those with high risk factors for heart disease (high blood pressure, cholesterol, smoking, etc.)
- Those who want to evaluate their condition after heart surgery or treatment
Who Should Avoid It?
- Unstable Angina (Chest Pain at Rest): The test is not performed in this condition because the risk of heart attack is high.
- Uncontrolled High Blood Pressure: If your blood pressure is very high (for example, 200/110 mmHg and above), the test may create risk by further elevating your blood pressure.
- Acute Myocarditis or Pericarditis: If there is inflammation of the heart muscle or membrane.
- Severe Aortic Stenosis: In case of severe narrowing of the main vessel leaving the heart, it may place excessive load on the heart.
- Recently Experienced Heart Attack: The test may be risky for patients who have recently (usually within the first 48 hours) had a heart attack.
How to prepare for an exercise stress test?
Some preparations are necessary for the stress test to give accurate results and be performed safely:
- Fast: Stop eating at least 2-3 hours before the test. Having a full stomach during the test may cause nausea.
- Don’t Forget to Ask About Your Medications: Ask your doctor which medications you should or shouldn’t take. Especially heart medications (such as beta blockers) may affect test results.
- Dress Comfortably: Since you will be exercising, wear comfortable sports shoes and loose, comfortable clothing.
- Avoid Caffeine: Do not consume caffeinated beverages (coffee, tea, energy drinks) 12-24 hours before the test.
- Don’t Smoke: Stop smoking at least a few hours before the test.
Test Procedure
How is a exercise stress test performed?
The test is usually performed in a cardiology clinic or hospital, accompanied by a cardiologist and nurse. The test continues until 85% of the maximum heart rate is reached. Maximum heart rate is calculated using the formula 220 minus age. For a 50-year-old person, the maximum heart rate is 220 minus 50, which equals 170 beats per minute. During the test, heart rate, blood pressure, and ECG are continuously monitored. ECG is a test that shows the electrical activity of the heart.
- Preparation: ECG electrodes are attached to your chest, shoulders, and waist. A cuff is placed on your arm to measure your blood pressure.
- Resting Measurements: Before the test begins, your resting heart rate, blood pressure, and ECG are recorded.
- Exercise Phase: You begin walking slowly on the treadmill. Every few minutes (usually 3 minutes), the speed and incline of the treadmill are increased. This gradually increases the load on your heart.
- End of Test: The test is terminated when symptoms such as fatigue, chest pain, or shortness of breath begin, or when your target heart rate is reached.
What is monitored during a exercise stress test?
The healthcare team closely monitors you throughout the test. The main parameters monitored include:
- ECG Monitoring: Your heart’s electrical activity is continuously recorded. In cases where blood flow to the heart muscle is insufficient, some changes (such as ST segment depression) may be seen on the ECG.
- Blood Pressure: Your blood pressure is measured at each stage of exertion. Normally, blood pressure rises with exercise, but in some cases, it may give an abnormal response.
- Heart Rate: Your heart rate is continuously monitored to see how your heart responds to exertion.
- Your Symptoms: You are regularly asked whether you have symptoms such as chest pain, shortness of breath, or dizziness.
How is the exercise stress test progressed or stopped?
In exercise stress testing, protocols for loading the heart are standardized. The most commonly used is the Bruce Protocol.
Bruce Protocol: The test increases the speed and incline of the treadmill every 3 minutes. Starting with a slow pace walk, it progresses to a pace close to running in the final stages.
Points Where the Test Is Terminated:
- Onset of symptoms such as chest pain or shortness of breath in the patient
- Seeing findings of ischemia (insufficient blood flow) on ECG
- Drop or excessive rise in blood pressure
- Patient reaching maximum heart rate and becoming unable to exert further
Safety and Recovery
Are there any risks or side effects of stress testing?
Exercise stress testing is generally a safe test. However, like any medical procedure, it has some risks and limitations:
Risks: The risk of heart attack or dangerous rhythm disorder is very low (usually 1 in 10,000). All precautions are taken against emergencies.
Limitations:
- False Positive or Negative Results: Some findings seen on ECG may occur even without coronary artery disease (false positive), or the test may be normal despite the presence of disease (false negative).
- Inability to Perform the Test: Some patients may not be able to show sufficient exertion due to joint disorders, neurological problems, or general weakness.
What to expect after an exercise stress test?
After the test ends, instead of stopping suddenly, you will be asked to continue walking slowly for a few minutes. This allows your heart rate and blood pressure to return to normal. The ECG electrodes are then removed. You may feel a bit tired immediately after the test, which is normal. Test results are usually evaluated immediately, and your doctor may share initial findings with you after the test.
Results and Evaluation
Will I need more tests after my stress test?
Depending on the results of the stress test, your doctor may request additional tests for further evaluation.
- Echo-stress Test: This test is an echocardiography combined with a stress test. Heart muscle movements are examined with ultrasound immediately after exercise.
- Nuclear Stress Test: A radioactive substance is used to visualize blood flow to the heart muscle.
- Coronary Angiography: If there are serious findings in the stress test, angiography may be necessary to directly visualize blocked vessels for definitive diagnosis.
What do my exercise stress test results mean?
The results of the stress test show how your heart responds to exercise.
- Negative (Normal) Result: Typical ECG changes for heart attack or CAD are not seen, and complaints such as chest pain or shortness of breath do not occur. This means there is no serious narrowing in your coronary arteries.
- Positive (Abnormal) Result: Chest pain develops during exertion and/or findings of ischemia (insufficient blood flow) are seen on ECG. This condition indicates that there may be a blockage in your coronary arteries and requires further diagnostic tests.
- Suspicious Result: This is when there are unclear changes on ECG or symptoms cannot be clearly associated with CAD. In this case, additional tests may be needed.
Frequently Asked Questions
How long does the stress test take?
The stress test, including preparation and recovery time, usually takes 30-45 minutes. The exercise portion is typically completed in 8-12 minutes.
Is the exercise stress test painful?
An exercise stress test is normally not painful. You may feel slight discomfort during electrode placement. During exercise, you may experience fatigue and shortness of breath that you would feel in a normal exercise routine.
Should i take my medications?
Follow your doctor’s instructions regarding medication use. Some medications (especially beta blockers) may affect test results, so your doctor may ask you to temporarily stop taking certain medications before the test.
Reference: Stress Testing
