A cardiac stress test is a test performed to evaluate how your heart responds to stress and exercise while in a controlled environment. This test may be suggested by your physician because of recent complaints of chest pain, or may be advised as part of a routine physical due to your age, health history, or family past medical history.
What is a Stress Test?
A stress test looks at the circulation of blood through your heart and circulatory system while you are at rest, and while being exerted. The exertion can be through exercise on a treadmill, or chemically stressed through medication for patients that are unable to run on a treadmill. The blood flow through the heart is studied for any interruption or abnormal flow, which can determine if there is partial blockages in the coronary arteries. This can help diagnose coronary artery disease (CAD). However, a person with CAD can pass a stress test, so it is a limited test for diagnosing.
Types of Stress TestThere are two types of stress test, described below:
Treadmill Cardiac Stress Test: The American Heart Association recommended the treadmill stress test for all patients that are physically capable and have minimal risk factors such as smoking and high cholesterol. The test is performed by having the patient run on the treadmill while connected to an electrocardiogram (ECG). The ECG is studied for any cardiac changes with the heart rhythm. The test does progressively get more difficult by inclining the slope on the treadmill, and increasing the speed.
Chemically Induced Stress Test: This is a stress test when chemicals are given to stimulate the heart, rather than running on the treadmill. Two types of medications are used: one to stress the heart and the other that contains a small amount of radioactive medicine. The radioactive medicine is given in order to see the blood flow while using a nuclear camera. This is primarily for patients that are physically incapable of running on the treadmill, or unable to increase their heart rate, such as those with a pacemaker. As with the treadmill stress test, patients are connected to an ECG and the blood flow through the heart is evaluated while are rest, and while stressed. The nuclear camera can also evaluate for any blockages in coronary arteries.
Pass or Fail: What Comes After the Stress Test?
Passing a stress test means that you completed the test without developing any cardiac symptoms, such as chest pain or shortness of breath. There also can be no changes on your ECG, such as damage to cardiac muscle or decrease in blood flow to any part of the heart. After passing a stress test, you can feel pretty confident that your heart is healthy. However, the value of the stress test is limited in assessing for heart disease. It is important to make healthy lifestyle and food choices in order to maintain a healthy heart. It is also important to not ignore any future chest pain just because you had a good stress test. Again, stress tests are not 100% effective in diagnosing heart disease, they are simply an indicator as to how the heart performs under stress. It is possible to have CAD and still pass a stress test. You may need further testing, such as an angiogram or cardiac catheterization if chest pain or coronary symptoms persist.
Failing a stress test will require further examination of the heart. Failing a stress test means that you became symptomatic while the heart was being stressed, or you had ECG changes during the test. There is typically a blockage in an artery that causes ischemia, or lack of oxygen and blood flow to part of the heart muscle. This probably required the test to be stopped before completion in order to prevent any further cardiac symptoms or damage. You cardiologist will review the information with you, but a cardiac catheterization will probably be suggested if the blockage is significant and requires more intervention. A cardiac cath is a more invasive procedure that involves going up through the groin with a catheter and visually inspecting the coronary arteries. There may be some intervention required, such as a stent placement or angioplasty.
A stress test provides a limited amount of information regarding cardiac function. It is a starting point when looking at the heart, to determine if more invasive procedures need to be performed. Passing a stress test is good news, but it is not a guarantee for a clean bill of health. If the reason for your stress test was because of chest pain, then these symptoms should not be ignored in the future because you passed a stress test. Periodic stress test may be ordered to evaluate your continued heart function, and to determine if there is any progression in your cardiac health. Continue to maintain a healthy lifestyle and make proper food choices in order to achieve good cardiac health.
heart.org- American Heart Association- "Invasive Tests and Procedures" (accessed 10-20-10)
Diane Middleton - I have been a registered nurse in the Emergency Department for the past 15 years. I love to write about my ER experiences, and use this ...
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