If you often feel faint or lightheaded, your health care team may use a tilt-table test to find out why. During the test, you lie on a table that is slowly tilted upward. The test measures how your blood pressure and heart rate respond to the force of gravity. A nurse or technician keeps track of your blood pressure and your heart rate (pulse) to see how they change during the test.
This test is used to trigger your symptoms while your health care team is watching you. They measure your blood pressure and heart rate during the test to find out what’s causing your symptoms. The test is normal if your average blood pressure stays stable as the table tilts upward and your heart rate increases by a normal amount.
If your blood pressure drops and stays low during the test, you may faint or feel lightheaded. This can happen either with an abnormally slow heart rate or with a fast heart rate. That’s because your brain isn’t getting enough blood for the moment. (This is corrected as soon as you are tilted back to the flat position.) Your heart rate may not be adapting as the table tilts upward, or your blood vessels may not be squeezing hard enough to support your blood pressure.
Feeling lightheaded or fainting (syncope) may be caused by taking certain medicines, severe dehydration, abnormal heart rhythms (arrhythmias), low blood sugar (hypoglycemia), prolonged bed rest and certain nervous system disorders that cause low blood pressure.
The tilt-table test is generally a safe procedure. People rarely faint during the test. And, even if they do, medical staff will be present and it’s safer than fainting on your own in an uncontrolled situation. If a person does faint, usually they feel well again within a short time after the table returns to a flat position.
A specially-trained nurse or technician performs the tilt-table test in a hospital or clinic electrophysiology lab. The test has two parts.
The first part of the test shows how your body responds when you change positions.
The second part of the test shows how your body responds to a medicine (isoproterenol) that causes your heart to beat faster and stronger. This medicine is like the hormone adrenaline that your body releases when you are under stress. This medicine may make you feel like you are exercising. It may make you more sensitive to the tilt-table test if your blood pressure didn’t change during the first part of the test. For this part of the test:
The tilt-table test lasts about an hour if you do both parts. If you only do the first part, you may be done in 20 to 45 minutes.
You may feel tired and a little sick to your stomach right after the test. After recovery, most people can drive home and return to their normal activities. However, if you lose consciousness during the test, you may need to have more observation and testing. Don’t drive yourself home if you fainted.
You may get your results as soon as the test is over. Sometimes your health care professional will give you the results a few days later. The results are either “negative” or “positive.”
Last Reviewed: Aug 18, 2023