As the name suggests, a tilt table test is conducted on a motorized table that tilts to position the patient at various angles for observation. These changes in position provoke pre-existing symptoms and changes in blood pressure and heart rate.
Why is This Test Used?
In a healthy person, changes in position signal the cardiovascular system to adjust to changes in the force of gravity. This results in the constriction (narrowing) of blood vessels in the legs and feet, with a slight increase in heart rate. This ensures that blood continues to be pumped throughout the body—despite the gravitational force that would otherwise cause it to pool in the legs and feet.
However, certain conditions prevent this automatic adjustment and instead cause significant changes in heart rate or blood pressure, as well as the onset of many other symptoms including (but not limited to) dizziness, lightheadedness, nausea, and fainting (syncope).
Therefore, a tilt table test is often recommended for patients experiencing repeated, unexplained syncope, lightheadedness, or dizziness. Some conditions that can be identified with this test include:
Dysautonomia—a malfunctioning autonomic nervous system (the system that controls “automatic” functions throughout the body)
Orthostatic hypotension—a decrease in blood pressure with changes in position
Postural Orthostatic Tachycardia Syndrome (POTS)—a type of dysautonomia characterized by a dramatic increase in heart rate (tachycardia) with changes in position.
Vasovagal Syncope—a nervous system response characterized by a decrease in heart rate and blood pressure and the dilation (widening) of blood vessels.
What to Expect During a Tilt Table Test
The test is designed to provoke symptoms such as fainting. Therefore, the tilt table has safety belts and a footrest to prevent injury. Additionally, a health professional will assist if symptoms are triggered. The procedure is typically conducted as follows:
Preparation:
Plastic patches (electrodes) are placed on the patient’s chest, arms, and legs with a sticky gel. They monitor heart rate with an ECG (electrocardiogram).
A blood pressure cuff is placed on the patient’s arm so that blood pressure can be monitored during the test.
A pulse oximeter is placed on the tip of the patient’s finger to measure oxygen levels.
An IV (intravenous) line is placed in a vein in the patient’s arm or hand if necessary.
Test
The test starts with the tilt table in a horizontal position. The patient lies flat on their back for 5-10 minutes.
Then, the table tilts the patient upright for 5-60 minutes. During this time, the patient is monitored for fainting, changes in heart rate and blood pressure, and the onset or worsening of other symptoms.
The table may tilt to several different angles throughout the test.
If the patient faints, the table is immediately returned to a horizontal position for recovery.
If this period of upright positioning fails to provoke symptoms, medication may be administered through an IV line to make symptoms more noticeable. Typically, Isuprel (isoproterenol) or nitroglycerin are used.
Recovery
After the test, the patient is monitored during a recovery period. Depending on the severity of their symptoms and the effects of the medications given during the test, this period can last from a few minutes to a few hours.
Test Results
A positive result would be indicated by abnormal changes in blood pressure or heart rate. Typically, these changes are accompanied by fainting or the worsening of other symptoms.
No significant changes in blood pressure, heart rate, or symptoms could indicate a negative result.
These results, positive or negative, can help rule out conditions and help providers diagnose patients who suffer from unexplained cardiovascular or neurological symptoms. Although test results—positive or negative, can be discouraging, remember that the information they provide will make the next steps in the diagnostic or treatment process more productive.
References:
Clinic, Cleveland. “What a Tilt Table Test Can Show.” Cleveland Clinic, 2023,
my.clevelandclinic.org/health/diagnostics/17043-tilt-table-test. Accessed 21 July 2024.
Fogoros, Richard. “A Test to Get to the Bottom of Fainting Spells and Dizziness.”
Verywell Health, 4 June 2023, www.verywellhealth.com/tilt-table-testing-1745418. Accessed 21 July 2024.
“Tilt Table Test - Mayo Clinic.” Mayoclinic.org, 2024,
www.mayoclinic.org/tests-procedures/tilt-table-test/about/pac-20395124. Accessed 21 July 2024.
“Tilt Table Testing.” Www.hopkinsmedicine.org, 2024,
www.hopkinsmedicine.org/health/treatment-tests-and-therapies/tilt-table-testing. Accessed 15 July 2024.
Assessed and Endorsed by the MedReport Medical Review Board