What Is Tilt Table Testing?

A tilt table test is used to evaluate the cause of unexplained syncope (fainting, loss of consciousness). It is a non-invasive procedure that involves moving you from a lying to a standing position while your symptoms and vital signs are monitored. You might also receive a medication, Isuprel (isoproterenol), that can trigger a response to help in the assessment of your fainting spells.

Purpose of the Test

The main utility of the tilt table study is to help your healthcare provider diagnose the cause of unexplained dizziness, lightheadedness, fainting spells, and falls. It does this by replicating your symptoms so your physician can get a better sense of the circumstances under which you have these experiences.

However, a tilt test is not considered a highly reliable test, and it is normally done only when common causes of syncope, such as heart disease and cerebrovascular disease, are ruled out. Often, a tilt table test is only done after your healthcare provider has excluded these serious causes of syncope with tests such as brain magnetic resonance imaging (MRI), brain magnetic resonance angiography (MRA), electrocardiogram (EKG), or echocardiogram.

What the Test Looks For

When you normally stand, your cardiovascular system has to adjust itself in order to prevent too much of your blood from pooling into your legs. These adjustments consist of a mild increase in heart rate and a constriction (narrowing) of the blood vessels in your legs. Normally, these cardiovascular adjustments occur very quickly, and you shouldn't have a significant drop in your blood pressure.

This, however, is not the case if you have orthostatic hypotension or vasovagal syncope—the primary conditions the tilt table test can help identify. Orthostatic hypotension is an excessive drop in blood pressure that occurs when you stand up. Vasovagal syncope is caused by a dramatic fall in blood pressure due to a reflex that causes sudden dilation of the blood vessels in the legs and a slowing of the heart rate. Numerous triggering events can initiate this vasomotor reflex, including physical stress, sudden anxiety, or fatigue.

Because your body does not adjust to the standing position normally if you have either one of these conditions, you will likely experience loss of consciousness or substantial changes in physical measures when you are moved from a lying down to an upright position during a tilt test. Any major response to the tilt table test is considered suggestive of orthostatic hypotension or a vasovagal episode.

The tilt table test can also be useful in distinguishing epilepsy from syncope, as seizures are not always associated with physical movements, and sometimes syncope is associated with jerking movements.

Similar Tests

Many people confuse a tilt table test with a stress test because both monitor heart function under modified conditions. However, a stress test is normally done for evaluation of chest pain, while a tilt table test is done for evaluation of fainting or dizziness.

Limitations

The main limitation of the test is that it does not provide a diagnosis, but rather information that is used along with your medical history to help your healthcare providers determine that a diagnosis is more likely or less likely. Even for people who have definite vasovagal syncope based on symptoms, the tilt table study reproduces the symptoms only about 70% to 75% of the time. In other words, 25% to 30% of people with vasovagal syncope have false-negative studies.

The tilt test, therefore, is not considered a gold standard in the diagnosis of vasovagal syncope; results need to be interpreted along with your medical history and your physician's examination.

Risks and Contraindications

A tilt table test can induce dizziness, nausea, vomiting, or loss of consciousness. It is done under monitored conditions and therefore, these risks, while not uncommon outcomes of the test, can be managed safely.

If you have a serious heart condition or severely low blood pressure, you should not have a tilt table test. Not only will these conditions predispose you to a high chance of fainting, there is little chance that the test could provide your healthcare providers with additional useful information if you already know that you have these conditions.

Before the Test

If you are scheduled for a tilt table test, you should ask your healthcare provider if you need to stop taking any of your usual medications. Your practitioner might ask you to stop taking those that alter your heart rate or blood pressure for a day or so before the test, but, because the evaluation of unexplained syncope is so complex and individualized, there is no hard and fast rule about this.

Timing

You should expect that the test and recovery time should take about half a day. There will be a check-in and wait time, which can range from half an hour to several hours. The test itself should take about an hour.

After the test, some people may feel dizzy or lightheaded, while others may recover right away. It is almost impossible to predict how long the positional changes or medications will affect you, so it is best to anticipate a two- to three-hour recovery time when the test is done.

You won't receive your results the day of the test and may need to wait several days for them.

Location

Your tilt table test will most likely be done in an outpatient suite, although some healthcare providers have this capability in their offices.

What to Wear

You can wear whatever is comfortable for your test, and you will likely be asked to change into an examination gown.

Food and Drink

You should not eat or drink for three to four hours before your test, mainly because the test can induce nausea.

Cost and Health Insurance

As with many diagnostic tests, you may need insurance pre-authorization. The facility where your test is scheduled should be able to tell you if your health insurance requires this and how long the process should take. You may also need to pay a co-pay, and the facility can provide you with this information as well.

If you are going to pay for the test yourself, you should expect the test to cost several hundred dollars, but you should ask about the total cost, because the price can be highly variable.

What to Bring

You should bring your test order form, your insurance information, a form of identification, and a form of payment. You should also be sure to have someone with you who can drive you home in case you become dizzy during the test.

During the Test

Your own healthcare provider may be performing your test, or it may be performed by another physician. You will also have one or more technicians assisting the practitioner with the test.

Pre-Test

Before the test, you will have to check in and sign a consent form, as well as patient privacy forms. Right before your test, you may be asked to change into an examination gown.

You will then lie down on a table and be secured to it so that you can maintain your position when it is moved. You will have a blood pressure cuff placed on your arm, as well as EKG leads placed on your chest. Your pulse and oxygen saturation will be monitored by a pulse oximeter, which is a small clip that is placed on the tip of your finger.

Throughout the Test

Initially, the team will assess your vital signs while you are lying down, and then the table will be mechanically tilted to an upright position. Because you are secured, this requires no effort from you. Your team will monitor your symptoms and physiological signs, such as blood pressure, heart rate, and possibly oxygen levels, while you are in a motionless standing position for 10 to 60 minutes.

In some instances, you may receive a medication such as nitroglycerin or Isuprel (isoproterenol), which speeds the heart rate, making symptoms more noticeable. During this test, you may experience dizziness, lightheadedness, or syncope, but not pain. If this occurs, tell the team, who will then likely move the table so that you can lie down. They may administer treatment to reverse your symptoms and physiological changes if necessary. Resolution of symptoms can take seconds or hours.

After the test is completed, all monitoring and straps will be removed.

Post-Test

After the test, your team will make sure that you have recovered from any dizziness or nausea and will provide you with instructions regarding eating, drinking, and resting based on your symptoms, clinical signs, and how well you are recovering. You will then be permitted to be driven home.

After the Test

You should expect to recover within a few hours, even if you experience dizziness or loss of consciousness during the test.

Managing Side Effects

If you experience mild dizziness within the first 24 hours after your test, it is fine to lie down.

If you experience persistent symptoms that last longer than one day after the test, you should call your healthcare provider. If you feel more lightheaded than usual, or have vision changes, chest pain, or seizures, these are not expected outcomes of a tilt table test, and you should seek urgent medical attention.

Interpreting Results

The test itself does not provide a definitive diagnosis of any medical condition. It provides information that your healthcare providers can use along with your medical history. In fact, it is important to know that the results are not based in any clear positive or negatives.

For example, almost everyone has a minor drop in blood pressure and a slight increase in heart rate when moving from sitting to standing, but the rate at which these changes occur, as well as the degree to which they occur and their association with symptoms, are all evaluated together to come to a conclusion.

The healthcare provider who does your tilt table test will probably need some time to evaluate the outcomes of your test to compile a report. If your healthcare provider is not the same person who did your tilt table test, then your practitioner will need to review that report and assess it in combination with your symptoms and medical history to be able to discuss a diagnosis and plan with you. It may take several days for the team to be able to combine all of this information to determine the next steps.

To give you a sense of what certain observations during the test can indicate:

• If you have orthostatic hypotension, your pulse would have increased markedly and your blood pressure would have dropped precipitously during the shift to the upright position.
• If you have vasovagal syncope and are among those who experience symptoms during the test, you would have adjusted normally to an upright tilt, but possibly experienced a sudden and marked change in your vital signs (with a dramatic drop in blood pressure and pulse) within 20 to 30 minutes after the position change. You might have even passed out. Recovery would have been observed within seconds after the table was brought back down.

Follow-Up

In general, a tilt table test is not usually repeated. If the results point to orthostatic hypotension as the cause of your symptoms, then you will likely be treated with medications that raise your blood pressure or increase the fluid in your body. Vasovagal syncope is somewhat difficult to treat, and there is a chance that you may also need to take medication to raise your blood pressure.

A Word From Verywell

A tilt table test is a non-invasive procedure that is used in combination with your medical history and physical examination to assess the cause of your syncopal episodes. Syncope is a stressful symptom, and the medical workup is often prolonged and complex. Treatment, similarly, is not straightforward. As you are dealing with this process, be sure to maintain your safety. Simple strategies include getting up slowly from lying or seated positions, avoiding prolonged drives, not climbing on ladders, and making sure that you have handrails while showering.