A tilt table test is a diagnostic test used to help physicians determine the cause of unexplained fainting (syncope) or severe lightheadedness in a patient. There are a number of reasons a patient might faint, including low blood sugar (hypoglycemia), abnormal heart rhythms (e.g., tachycardia or bradycardia) or low blood pressure (hypotension).

The tilt table test assesses whether the patient is fainting as a result of a sudden drop in blood pressure. The change may be to a hyperactive reflex that causes the blood vessels to suddenly widen (dilate), which may be due to dehydration, emotional stress or standing upright for a prolonged period of time. This type of fainting is now known as neurocardiogenic syncope, although many physicians and patients still refer to it as vasovagal syncope.

The tilt table test is conducted on a pivoting table. By securing the patient on his or her back to the tilt table, and then tilting the table upright (head up and feet down), the factors leading to neurocardiogenic syncope may be simulated. This test is designed to detect orthostatic hypotension, one of the most common causes of fainting.  

Medications may also be given to the patient to try to re-create the abnormal reflex. The patient's heart rate and blood pressure are monitored carefully throughout the test. Results from the test are available immediately, and a specific course of treatment can be prescribed at that time. There are very few risks associated with this test and it provides valuable information to help physicians diagnose a number of heart-related conditions.  

A tilt table test is a diagnostic test used to help a physician determine why a patient has been experiencing dizziness, lightheadedness or fainting spells (syncope). There are a number of different factors that may cause fainting spells, and the tilt table test is used to assess one in particular – a sudden drop in blood pressure (due to a widening of the blood vessels), often with a drop in heart rate as well. Fainting that results from this change in blood pressure and blood vessels is now called neurocardiogenic syncope, although many people still refer to the syndrome as vasovagal syncope.

Neurocardiogenic syncope often occurs after an event that causes emotional stress. It may also be provoked by dehydration or by standing upright for a prolonged period of time. Normally, stress increases the amount of adrenaline released by the body and causes the heart rate to speed up. However, stress may trigger a reflex in certain people that causes a sudden slowing of the heartbeat and a dangerous drop in blood pressure, leading to fainting.

Fainting may also result from other causes of low blood pressure, such as orthostatic hypotension or neurogenic orthostatic hypotension. These conditions are characterized by the body's inability to quickly regulate blood pressure, especially when standing up quickly or after other abrupt changes in position. When a person stands, gravity causes blood to pool in the leg vein, reducing the amount of blood that returns to the heart. Normally, the autonomic nervous system adapts by constricting the blood vessels and increasing the heart rate. If this process does not work properly, blood pressure can drop causing a feeling of lightheadedness and possible fainting.

A tilt table test may also be recommended to individuals who do not experience fainting, but who have the need to lie down as a result of feeling lightheaded.

To prepare for the tilt table test, patients may be asked to stop eating and drinking for at least six hours prior to the test. By completing the test on an empty stomach, patients are at less risk of side effects, such as nausea and vomiting. Most medications can be taken with only a sip of water, but the physician may ask a patient to suspend beta blockers, vasodilators and/or diuretics shortly before testing. Patients should always consult their physicians before changing their medication schedule.

At the test site, the procedure will be explained, and the patient will have the opportunity to ask questions. There may be some paperwork to complete, including a medical history and/or a test consent form. The patient may be required to change into a hospital gown.

To begin, the patient is strapped to a special table on his or her back. Electrodes are typically attached to the chest and back to provide information about the heart’s activity in an electrocardiogram (EKG) read-out. The patient’s symptoms, blood pressure, pulse and possibly blood oxygen saturation will be recorded during the test. In some cases, an intravenous (I.V.) line may be started in the patient's arm to provide medication, if necessary, that simulates the effect of adrenaline.

After the patient is secured to the table, blood pressure and heart monitoring may last for 10 minutes, in a normal reclined position, to establish a baseline. After the baseline is established, the table is moved into an almost upright position, with the patient's head above his or her feet, in a series of progressively steeper angles up to as much as 70 degrees. This portion of the test may last up to 45 minutes. There may be observable signs of fainting (syncope) but the spells will only last a short time before recovery.

If no signs of fainting emerge during the test, the table is reclined again and the patient may be given medication through the I.V. The medication is designed to provoke fainting in susceptible patients, which can help the physician determine the cause of the fainting.The test is performed again and the patient’s responses are recorded.

Patients are monitored by healthcare professionals throughout the test. Patients who do not feel well at any point during the test should tell a medical professional immediately. Depending on the protocol, the test usually takes 30 to 45 minutes but may take more than an hour in some cases.

After the test, the intravenous (I.V.) line and monitoring equipment are removed. Patients may be required to stay for 30 to 60 minutes to monitor their blood pressure and pulse. In some cases, patients may feel some nausea, dizziness or fatigue. For this reason, driving is not recommended and a friend or relative should accompany the patient to and from the testing location. In most cases, people can return to their routine activities shortly after the test is completed. However, if the patient loses consciousness during the test, he or she may need to undergo extended hospital observation and further testing.

The test results will likely be provided on the same day and, depending on the diagnosis, appropriate medications may be prescribed at that time. If an abnormally slow heartbeat (bradycardia) was revealed, the patient may be referred to cardiologist for further testing. A pacemaker may be necessary to correct the heart condition.  

If medication is required, the physician may suggest a second tilt table test to make sure that the prescribed medication is working. The second test will be scheduled approximately seven days after the patient starts to take the medication.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor or healthcare professional the following questions related to tilt table tests:

1. Why are you recommending tilt table testing for me?
   
   
2. What type of condition do you expect to find?
   
   
3. How should I prepare for the test?
   
   
4. About how long will this test take?
   
   
5. Where will the test be administered?
   
   
6. Will I be given medications during the test?
   
   
7. What are the risks associated with a tilt table test?
   
   
8. When will I learn the results of the test?
   
   
9. Can I drive immediately after the test?
   
   
10. What happens if the test does not determine the cause of my fainting?
    
    
11. Will I need to undergo additional tests?
    
    
12. Will I need to have the tilt table test repeated in the future?