Cardiac Stress Test
(Exercise Tolerance Test)
Definition |
Body Parts Involved |
Reasons for Procedure |
Complications |
What to Expect |
Outcome |
Call Doctor If
Definition
The recording of the heart's electrical activity while it is under the stress of increased physical demand. This is also known as an exercise tolerance test.
Parts of the Body Involved
Reasons for Procedure
A cardiac stress test is used to assess the heart muscle's response to the need for additional oxygen, which occurs during increased physical activity. This procedure is most often performed for the following reasons:
- To evaluate if complaints of chest pain are related to the heart
- To determine if blockages exist in a coronary artery or arteries supplying the heart with oxygen-rich blood (coronary heart disease or CHD)
- To identify an irregular heart rhythm that only occurs during activity
- To monitor the heart's response to cardiac treatment or a procedure to open a coronary artery
- To determine a safe level of participation before the start of an exercise regimen
- To plan the pace and intensity of rehabilitation after a heart attack
- To screen for the presence of asymptomatic CHD in certain high risk people
Risk Factors for Complications during the Procedure
Pre-existing heart condition
What to Expect
Prior to Procedure
Your doctor will likely do the following:
- Physical exam
- Resting electrocardiogram (ECG, EKG) – a test that records the heart's activity by measuring electrical currents through the heart muscle
- Review of medications; some should not be taken before testing
In the time leading up to your procedure:
- Do not eat or drink products with caffeine for 12-24 hours before testing
- Do not eat or drink anything except water for 4 hours before testing
- Do not smoke for several hours before testing
- Wear comfortable clothing and walking shoes
- Bring a list of your current medications to the test
- If you have diabetes, bring your glucose monitor to the test
During Procedure - Continuous ECG and intermittent blood pressure monitoring
Anesthesia - None
Description of the Procedure - The technician checks your blood pressure, attaches electrocardiogram electrodes (small adhesive patches with wires that connect to an ECG machine) to your chest and arms, and performs a resting ECG.
The cardiac stress test is done either on a treadmill (most common) or a stationary bike. You slowly start walking or riding. At 2- or 3-minute intervals, the technician increases the speed and elevation or resistance, in order to make the exercise more strenuous. The technician closely monitors the ECG and your symptoms to assess the status or your heart. Try to exercise until you are exhausted or you have reached the target heart rate.
Report any discomfort, dizziness, lightheadedness, pounding in your chest, extreme shortness of breath, or other symptoms to the technician. The test may be stopped early if you complain of excessive fatigue, pain, or any symptoms that suggest heart problems, or if the technician observes significant changes in the ECG. After exercising is complete, blood pressure, heart rate, and ECG monitoring continues until levels return to normal.
In conjunction with a cardiac stress test, a doctor will sometimes order a blood-flow imaging exam, called a thallium stress test. A small amount of thallium, which is a radioactive material, is injected into a vein during maximal heart rate. Exercise continues for about another minute, to allow the substance to circulate and enter cardiac cells. Scans are taken while you lie in different positions under a special camera. The images help identify areas of the heart muscle that may not be receiving enough oxygen. A second set of images is taken about an hour later, after you have rested.
After Procedure - Plan on eating and resuming normal activities
How Long Will It Take? The exercise portion of the test generally takes less than 15 minutes, but with monitoring before and after the test, expect your appointment to last an hour. A thallium test may take up to 2 or 3 hours.
Will It Hurt? Exercise testing normally causes no pain
Possible Complications:
- Chest pain (angina)
- Irregular heart rhythm
- Heart attack (rare)
A cardiac stress test presents minimal risk and is not considered any more dangerous than walking quickly uphill. Technicians are alert for any signs of cardiac problems, such as chest pain or irregular heartbeats, and are prepared to take immediate action if complications develop. A doctor (usually a cardiologist) will be readily available during the stress test as well.
Average Hospital Stay - None
Postoperative Care - None
Outcome
A cardiologist will review the test results and send a report to the referring doctor.
One or more of the following may constitute a positive stress test, which may indicate CHD:
- ECG changes characteristic of low oxygen supply to the heart muscle
- Angina (chest pain produced by low oxygen supply to the heart muscle) or severe shortness of breath, especially if associated with characteristic ECG changes
- Failure to adequately increase heart rate and/or blood pressure during exercise
Generally, the earlier these changes occur during the test, the more severe the CHD. Not all patients who test positive have CHD. Similarly, not all patients who test negative do not have CHD.
Call Your Doctor If Any of the Following Occurs
- Chest pain
- Pounding in the chest
- Dizziness or lightheadedness
- Excessive fatigue or shortness of breath
SOURCE:
American Heart Association
Last reviewed February 2001 by Medical Review Board
