A stress test is a special type of test that is performed to evaluate the tolerance of your heart when the body is exposed to exercise. This test is also used to detect various types of heart diseases as well. The exercise stress test is the most common diagnostic test that combines certain types of mild exercise with an electrocardiogram. This test is performed to measure the activities of your heart both while performing an activity and even while you are at rest. Generally, this test is noninvasive, safe and harmless. This test may be performed in numerous settings, such as physician's office, hospitals or clinics.
If the patient is unable to do exercise, then another form of stress test is performed that uses drugs in spite of physical activity in order to generate the effects of exercise during the check up. Although the EKG exercise stress test is performed most commonly, there are a number of other stress tests also, including a:
* Nuclear stress test
* Stress echocardiogram
* Pharmacological stress test
An echocardiogram is performed when the patient does exercises in a limited manner on a stationary bicycle or treadmill at different elevations and speeds. During this test, the response of your heart under exertion, as well as the working and structure of your heart can be evaluated. If the patient is unable to exercise, then this test is performed with the help of specific medicines.
The Pharmacological stress test is also known as the Chemical stress test. This type of test is used for patients who cannot perform physical activities. During this test, a medicine like adenosine or dobutamine is given to the patient that causes the heart to respond as if the patient was exercising, although the person is actually resting. Some drugs increase the heart rate of the patient, while other medicines improve blood flow by causing the coronary arteries to expand. In the Nuclear stress test, a radionuclide tracer is introduced into the blood flow and the rate of uptake is screened. This type of test is performed with the combination of a nuclear imaging test, like PET scan SPECT scan. In the SPECT test, a special gamma camera measures how fast the radionuclide tracer is accepted into heart muscle on a blood cell. Where as, in the PET scan test some special sensors evaluate how rapidly a carrier molecule, generally glucose is taken into the heart muscle. These tests are mostly advised after a heart attack in order to help physicians finds out how much part of the heart tissue has been damaged. These tests also help doctors determine if the damaged areas are really undergoing necrosis or they are recuperating.
Patients preparing for this test are suggested to stay away from drinking or eating anything other than water at least four hours before the test. Only a small amount of water can be taken if needed. This is because, it is simpler to evaluate the performance of your heart when your stomach is empty. Your physician will also advise you to stop taking specific drugs before taking such tests.