Furthermore, a variable number of normal individuals without any prior history of syncope will have a positive
HUT table test 3,
7,
8,
9. The percentage of false positive studies seems to be related to the age of the subjects
(10), duration and angle of tilt
11,
12, and use of provocative agents
(13). In fact, fainting may be considered one of the expected responses to this test as normal individuals left standing and dependent for a prolonged period of time will develop hypotension, cerebral hypoperfusion and finally syncope
(14). The time course of these events can be accelerated by exercise
(15), elevated body temperature
16,
17, and prolonged bed rest
(18). Because fainting does not occur in these individuals during normal circumstances, it is likely that a positive HUT in normal controls is due to the attendant gravitational stress overcoming some of the essential adjustments to orthostasis.
https://www.sciencedirect.com/scien...variable number of,of provocative agents (13).