What is a tilt-table test?
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.
Why do people have tilt-table tests?
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.
Are there risks with tilt-table tests?
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.
How do I prepare for a tilt-table test?
- Don’t eat or drink for at least two hours before the test.
- If you are having a morning test, you may be told not to eat or drink after midnight the night before.
- If you take medicine, ask your health care professional if you should keep taking it on your regular schedule before the test.
What happens during a tilt-table test?
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.
- You lie on your back on a table. Straps at your waist and knees help you stay in position. An IV (intravenous line) is put in your arm. Small pads with wires are attached to your chest and are connected to electrocardiograph (ECG or EKG) machine to track your heartbeat. A cuff on your arm measures your blood pressure.
- The table is tilted so your head is slightly higher (30 degrees) than the rest of your body while your blood pressure and heart rate are checked.
- After about five minutes, the table is tilted further, to a 60-degree angle or higher. You will remain in this position for up to 45 minutes while your blood pressure and heart rate are checked. You will be asked to stay still and quiet during this time, but you should tell someone if you feel uncomfortable.
- If your blood pressure drops during this time, the table will be lowered and the test will stop. You won’t need to take the second part of the test. If your blood pressure does not drop after the time is up, the table will be lowered again and the second part of the test will start.
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:
- You will be given medicine through your IV tube.
- Next, the table is tilted upwards to a 60-degree angle.
- You may feel your heartbeat increase because of the medicine.
- If your blood pressure drops, the table will be lowered to the flat position, the medicine will be stopped, and the test will end.
- If your blood pressure does not drop after about 15 minutes, the table will be lowered and the test will be over.
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.
What happens after a tilt-table test?
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.
How do I learn about my results?
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.”
- If your blood pressure does not fall during the test, and you have no other symptoms, the test results are negative (normal).
- If your blood pressure drops during the test and you feel faint or dizzy, the test is positive. Your health care professional may suggest changing your medicines or having more tests. If your fainting is due to a slow heart rate (bradycardia), a pacemaker may be recommended.