About Cardiac Stress Test
A cardiac stress test is a test done by cardiologists to measure heart’s response towards external stress. The test is carried out in controlled environment, and stress is induced by either exercise or drug. In this test, doctors observe and compare patient’s blood flow during rest and the blood flow during physical exercise.
How does it work?
When we exercise, our body needs more blood and oxygen. Therefore, heart works faster and pumps more blood during heavy physical activities. In order to meet these requirements, arteries dilate to allow more blood flow. Healthy arteries show more dilation than blocked ones.
The blocked arteries provide less blood because of which patient can experience chest pain and lightheadedness during physical exertion. Presence of these signs helps doctors to detect patient’s heart conditions. This test also helps physicians to locate areas where blocked arteries are present.
Reasons to Carry Out Stress Test
Doctors carry out this test to find:
– An irregular heartbeat
– Possible symptoms of coronary artery disease
– Whether treatments taken for any heart disease are working or not
– Determine the right level of physical activity
– Whether or not other cardiac tests are required for detection of blocked or narrowed arteries
What is done during the Test?
– First of all, you’re connected to the equipment that monitors your heart.
– The physician measures your ECG, blood pressure and heart rate at rest.
– After that, you’re asked to walk slowly on a treadmill.
– The treadmill is tilted a bit to make you feel like you’re walking up a small hill.
– Treadmill’s speed changes to make you walk faster. You will be asked to walk till you feel exhausted.
– During this, your physician may ask you to breathe into a tube for few minutes.
– You can stop the test if you feel dizziness or unusual breathing problems. However, you should not stop immediately. Walk on slow speed for few minutes and then stop.
– After that, you’re allowed to sit or lie down for few minutes.
The physician once again measures your breathing, electrocardiogram and heart rate and compares this result with the one taken during rest.
Preparations of Stress Test
You will need to do the following things prior to the test:
– Inform your doctor about any medicines you’re taking including any herb or vitamin supplement. You might need to discontinue your medicines before the test. But, don’t do so before your doctor says so.
– You are not allowed to consume alcohol, smoke or eat for two to four hours prior to the test. However, you are allowed to drink water.
– Do not eat or drink anything that contains caffeine for almost 12 hours prior to the test. This is because caffeine can interfere with test results.
– Since you’ll be doing physical activity, it is essential that you wear comfortable clothes and proper, soft-soled shoes as improper clothing can make you feel uncomfortable during the test.
Type of Stress Tests
There are four types of stress tests which are described below.
1) Treadmill Test: This is the most common and the first stress test for heart check. In this, you walk on a treadmill while the physician observes how much you can walk and whether you develop chest pain, dizziness or other unusual symptoms.
2) Adenosine Test: This test is taken by people who are unable to walk or do heavy exercise. A drug is induced in the patient’s body that makes the heart respond in the same way like it does during exercise. The measurements are taken when the heart starts responding to the drug.
3) Stress Echocardiogram: In this test, an echocardiogram is used which gives a graphic outline of the heart’s movement. This test shows accurate visualization of motions of heart’s walls under stressed conditions and helps in revealing lack of blood flow.
4) Nuclear Test: In this test, a radioactive substance is injected into the patient. A special camera is used to identify rays emitted by the substance. The camera produces clear pictures of heart tissues on a monitor. This test is extremely useful in detecting heart areas where the blood supply is poor.
Is there any risk involved?
There is no major risk involved in stress test and not at all if you’re used to fast walking or jogging. In fact, for a healthy person, a stress test works as both heart and health check. Also, the tests are carried out under medical supervision. So you will always get immediate help in case anything goes wrong.