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Dr. Alessandro Giardini
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Of all the investigations arranged for children with dizziness, fainting, or a racing heart on standing, the tilt table test is the one that generates the most parental anxiety in advance. The name itself suggest something technical and possibly alarming. What an explanation of test is provided it is immediately clear that the test is straightforward, entirely safe, and provides a significant amount of diagnostic clarity.
This post explains what the tilt table test is, how it differs from the active standing test, what your child will actually experience, and what the results mean in practice.
The head-up tilt table test, to give it its full name, is a controlled investigation of how the cardiovascular system responds to a sustained change in posture. The child lies flat on a motorised table. The table is then tilted to an angle of 60 to 70 degrees, which places the body in a position close to standing upright without requiring any physical effort or muscle activity from the child. The autonomic nervous system must then maintain the blood pressure and heart rate against the effect of gravity, while the team monitors both continuously.
The critical difference from the active standing test is that the child is passive. In the active standing test, the child stands up independently, which activates the leg muscles and the muscle pump that helps push blood back to the heart. The tilt table eliminates this muscle activity entirely, creating a purer and often more sustained orthostatic challenge. This makes it more sensitive for detecting subtle abnormalities in cardiovascular autonomic function, and more likely to reproduce symptoms in children who have them only intermittently.
The test is widely used in the investigation of postural tachycardia syndrome, vasovagal syncope, and other forms of orthostatic intolerance. It is also used to distinguish between these conditions, which can have similar symptoms but different physiological patterns and different management implications.
The active standing test is the first-line investigation for most children presenting with PoTS symptoms, and for the majority it is sufficient to make the diagnosis. The tilt table test is reserved for situations where the active standing test has not been conclusive, or where a more detailed characterisation of the autonomic response is needed.
Dr Giardini recommends the tilt table test when the active standing test is borderline despite a clinical history that is strongly consistent with PoTS, when there is a question about whether vasovagal syncope rather than PoTS is the predominant mechanism, or when a child has had recurrent unexplained blackouts and the full autonomic assessment needs to be comprehensive.
It is worth knowing that the tilt table test is not needed in every child. The vast majority of children with PoTS are diagnosed and treated successfully on the basis of the active standing test alone, combined with the clinical history and the results of the ECG and echocardiogram.
The test is performed in a specialist room, usually in a hospital or specialist clinic setting. The room is quiet and kept at a comfortable temperature. Bright lighting and noise are avoided because external stimulation can affect the autonomic response.
The child is asked to arrive fasted, meaning nothing to eat for at least four hours before the test. This is a different requirement from the active standing test and is important because food in the stomach activates the digestive circulation, drawing blood flow to the gut and making it more difficult to maintain blood pressure on standing. A full drink of water is typically permitted until two hours before the test.
The child lies flat on the table and electrodes for continuous ECG monitoring and a blood pressure cuff are attached. A period of ten to twenty minutes of complete rest in the lying position allows the baseline heart rate and blood pressure to fully stabilise. The table is then tilted upright, smoothly and over a few seconds, to an angle of 60 to 70 degrees. The child is secured with a footplate and a broad supportive strap so that they are held comfortably in position without any effort on their part. The team remains with the child throughout.
The upright phase lasts for up to 45 minutes, though in most children who are going to have a positive response, the diagnostic findings emerge within the first ten to fifteen minutes. If the child faints, the table is immediately returned to the horizontal position and recovery is rapid.
A positive tilt table test for PoTS shows a sustained rise in heart rate of 40 beats per minute or more within ten minutes of tilting, in the absence of a significant drop in blood pressure.
A positive vasovagal response shows a late drop in blood pressure, often accompanied by a slowing of the heart rate, occurring after a period of upright time during which readings may have appeared relatively normal. This pattern often culminates in a faint. It is the most common cause of fainting in otherwise healthy children and carries no structural cardiac risk.
A normal tilt test does not mean the symptoms are not real. It means that on this particular occasion and under these particular conditions, the cardiovascular response was within normal limits. Dr Giardini discusses the implications of a normal tilt result in the context of the full clinical picture.
Nothing to eat for four hours before the test, a normal drink of water up to two hours before, no caffeine or energy drinks on the morning of the test, and normal medications unless Dr Giardini has specifically asked for any to be held. Comfortable, loose clothing helps. The child can bring earphones and listen to music or a podcast during the lying and tilt phases. Parents are usually welcome to remain in the room throughout.
Yes. Most centres ask children to avoid food for four hours before the test. A normal drink of water is usually permitted until two hours before. This is different from the active standing test, which has no fasting requirement.
Not necessarily. Many children complete the full tilt test without fainting. A child who does not faint has not failed the test. The heart rate and blood pressure traces throughout the upright phase are the primary diagnostic output.
The test itself lasts between thirty and sixty minutes. Families should allow two hours for the full appointment, including preparation, the rest period, the tilt phase, and recovery time afterwards.
No. A parent or adult should accompany the child home after the test. Most children are well enough to go home within thirty minutes but should rest for the remainder of the day.
The active standing test asks the child to stand independently, activating the leg muscle pump. The tilt table tilts the child upright while they remain passive, eliminating muscle activity. This makes the tilt table more sensitive but also more complex. The active standing test is first-line; the tilt table is used when there are questions unanswered by the standing test.
Explaining the test clearly in advance helps considerably. A child who knows they will be safely secured, that fainting is possible but not dangerous, and that they can ask to stop at any point tends to manage much better.
Author: Dr. Alessandro Giardini, MD, PhD, Consultant Paediatric Cardiologist
Written: 02/07/2026
Last reviewed: 02/07/2026