What is tilt table testing?

From the Guidelines

Tilt table testing is a diagnostic procedure used to evaluate patients with unexplained fainting (syncope) or near-fainting episodes, particularly useful for patients with suspected vasovagal syncope, orthostatic hypotension, or postural orthostatic tachycardia syndrome (POTS) 1.

Overview of Tilt Table Testing

Tilt table testing involves a patient lying on a table that tilts from a horizontal to a vertical position while their heart rate, blood pressure, and symptoms are continuously monitored. The test typically lasts 30-45 minutes and aims to reproduce symptoms by challenging the body's blood pressure regulation mechanisms. As the table tilts upright (usually to about 60-80 degrees), blood pools in the lower extremities, which may trigger an abnormal cardiovascular response in susceptible individuals.

Key Points About Tilt Table Testing

• The test is used to diagnose conditions such as vasovagal syncope, orthostatic hypotension, or postural orthostatic tachycardia syndrome (POTS) 1.
• Sometimes medications like isoproterenol or nitroglycerin are administered during the test to increase sensitivity 1.
• Patients should fast for 4 hours before the test, wear comfortable clothing, and inform their doctor about all medications they're taking, as some may need to be temporarily discontinued.
• The test is generally safe, though patients may experience lightheadedness, nausea, or fainting during the procedure, which is actually the intended diagnostic outcome in positive cases.

Recommendations for Tilt Table Testing

• Tilt-table testing can be useful for patients with suspected VVS, particularly when the diagnosis is unclear after initial evaluation 1.
• Tilt-table testing is reasonable to distinguish convulsive syncope from epilepsy in selected patients 1.
• Tilt-table testing is reasonable to establish a diagnosis of pseudosyncope 1.
• Tilt-table testing is not recommended to predict a response to medical treatments for VVS 1.

Important Considerations

• The test should be reserved for patients with suspected vasovagal syncope who have recurrent episodes that adversely affect their quality of life or represent a high risk for injury 1.
• Correlation of tilt-table–induced findings to patients’ clinical presentation is critically important to prevent consequences of false-positive results from tilt-table testing 1.

From the Research

Tilt Table Testing Overview

• Tilt table testing (TTT) is a diagnostic tool used to study short-term blood pressure and heart rate regulation during orthostatic challenges 2.
• It has been used for decades to diagnose and evaluate syncope, particularly in patients with unexplained syncope or recurrent syncope 3, 4.
• The test involves tilting a patient upright on a table to provoke a vasovagal reflex, which can help diagnose conditions such as reflex syncope, orthostatic hypotension, and postural orthostatic tachycardia syndrome 2, 5.

Indications and Uses

• TTT is indicated when the initial syncope evaluation does not yield a certain, highly likely, or possible diagnosis, but raises clinical suspicion of reflex syncope, orthostatic hypotension, or other conditions 2.
• It can be used to educate patients on prodromes and to recognize hypotensive symptoms causing near-syncope, allowing for physical countermeasures to prevent syncope 2.
• TTT can also be used to assess autonomic function in patients with conditions such as Parkinson's disease and to differentiate it from multiple system atrophy 5.

Methodology and Interpretation

• The minimum requirements for performing TTT include a tilt table, a continuous beat-to-beat blood pressure monitor, and trained staff 2.
• The test results should be interpreted using the Vasovagal Syncope International Study classification, and acknowledgement by the patient or eyewitness of the reproducibility of the induced attack is mandatory for concluding a diagnosis 2.
• The timing and response to the orthostatic challenge can help differentiate between various forms of neurocardiogenic syncope, orthostatic hypotension, and non-cardiovascular conditions 5.

Limitations and Variability

• There is significant lack of standardization in TTT protocols, including tilt angle, tilt duration, use of pharmacologic agents, and duration of fasting prior to the test 6.
• The usefulness of TTT in children with syncope is unclear, and pediatric electrophysiologists have reported limited utility and decreasing use of the test 6.
• TTT is not useful for assessing the response to treatment, and other diagnostic tools such as implantable loop recorders may be more beneficial in certain cases 5.