The tilt table test is done as part of a workup for dizziness and falls to observe the effect of position changes on heart rate and blood pressure, which can trigger symptoms like weakness or dizziness.
The test is typically considered positive when syncope (fainting) or symptoms like dizziness or weakness occur due to a drop in heart rate and blood pressure related to the change in position, and could indicate conditions like orthostatic hypotension or vasovagal syncope.
Even if the result is negative, other tests like an electrocardiogram (ECG) or electrocardiogram (echo) may be necessary to complete the workup.
The tilt table test is easy to do and does not require admission to the hospital, however it is important to follow the instructions given to you by your healthcare provider about how to prepare for the test. This includes not eating for at least 4 hours prior to the test in order to prevent nausea and malaise during the test.
Indications for testing
The tilt table test may be used in the following situations:
- Suspected vasovagal syncope;
- Fainting episodes;
- Seizures that do not improve despite adequate treatment;
- Suspected orthostatic hypotension;
- Recurrent falls;
- Dysautonomia;
- Suspected postural orthostatic tachycardia syndrome (POTS).
Vasovagal syncope is usually the main cause of fainting in people without heart problems, and can be triggered by changes in body position. The tilt table test can therefore be helpful in identifying this condition.
The tilt table test is typically ordered by a cardiologist or primary care provider, along with additional tests to rule out other conditions like heart conditions. These additional tests may include blood work, ambulatory blood pressure monitoring (ABPM), or exams like an electrocardiogram (ECG), an echocardiogram (echo), or a 24-hour Holter monitor.
How to prepare
It is important not to eat or drink anything (including water) for at least 4 hours prior to the test. This is because position changes during the test can cause nausea and malaise on a full stomach. It is also recommended to use the bathroom right before the test to avoid interruptions.
Before the test begins, the doctor will ask about any daily medications you are taking. They will also ask questions about when the symptoms started and if there is anything that makes them worse.
Test procedure
The tilt table test is usually performed in an electrophysiology lab at a clinic or hospital and should be done under the supervision of a cardiologist and a nurse or tech.
Duration of the test may vary based on the indication, but generally lasts between 5 minutes and 1 hour. The test is done using a special table that can be tilted upward at an incline, with the patient typically strapped to the table to prevent them from falling off as the table tilts forward.
Monitors are also connected to the patient before the exam starts in order to measure blood pressure and heart rate during the test. The patient is typically observed for 5 to 20 minutes in a horizontal position, and then in a vertical position for 20 to 45 minutes.
The test may sometimes need to be repeated using medications like nitroglycerin or isoproterenol to increase the chances of identifying alterations during the test, however this is not always indicated.
It is important to let the doctor or tech know how you are feeling throughout the test. The doctor can interrupt the test at any point if blood pressure is very low or the patient feels very unwell.
Post-test precautions
After the test, people may feel tired and a bit nauseated. It is therefore recommended for the patient to remain lying down for 30 minutes after the test and to be observed by a nurse or tech during this time.
After this period, the patient is free to return to their regular activities, however it is recommended to avoid driving for at least 2 hours after the test. People who feel unwell or have very low blood pressure after the test, or who fainted during the test, may need to remain for longer under observation.
Contraindications to testing
The tilt table test should not be done during pregnancy. It is contraindicated in people with narrowing or a blockage of the carotid arteries and those with orthopedic conditions that prevent them from standing up.
Interpreting the results
The results of a tilt table test are typically either positive or negative, and are based on changes in heart rate and blood pressure observed during the test as well as the presence of symptoms like dizziness or nausea.
Positive result
The tilt table test is generally considered to be positive if a change in position from horizontal to vertical results in symptoms like dizziness, nausea, weakness, or sweating as a result of a drop in blood pressure and heart rate.
While a positive result may happen in otherwise healthy individuals, it may be a sign of conditions like orthostatic hypotension or vasovagal syncope.
Negative result
A negative result typically means that there was no change in blood pressure or heart rate noted during the test.
In these cases, other exams, like a 24-hour Holter monitor or an echo, may be indicated to complete the evaluation.