COMPARISON OF A SHORT- WITH A LONG-PASSIVE PHASE HEAD-UP TILT TEST
Introduction: Head-up tilt test (HUT) is widely used to investigate unexplained syncope. However, in clinical practice it is ime consuming and sometimes not well tolerated by the patient. The aim of this study was to compare the sensitivity of a short with a long- passive phase HUT.
Methods: Thirty –two patients with a history of vasovagal syncope (VVS) were randomized to a short-protocol passive phase HUT (group 1) consisting of 20 minutes passive tilt followed by 20 minutes after the administration of sulingual trinitrate of glicerol or a long-protocol passive phase HUT (group 2) where trinitrate was given 40-minutes after tilt and observed for 20 minutes.
Results: In 4/14 patients from group 1 and 7/12 patients from group 2, syncope occurred during the passive phase (28,6% versus 58,3%; p<0,001). Prolongation of the passive phase in the long-protocol group from 20 to 40 minutes positivated 6 more tests. Overall, after the finalization of the active phase in group 1: 14/16 patients had a positive HUT compared to 12/16 patients in group 2 (87,5% versus 75%; p=NS). Time to positivity was shorter in group 1 (18,07 minutes versus 33,4 minutes p<0,001).
Conclusions: HUT with a shorter passive phase was not inferior to the longer passive phase regarding positivity after finalization of both passive and active phase. Furthermore, the shortened HUT protocol allowed faster diagnosis.