The clinical relevance of the duration of loss of consciousness provoked by tilt testing

Abstract

Objective — The authors assessed the relationships between the duration of loss of consciousness (dLOC) during tilt testing-induced syncope (TTS) and demographics, medical history as well as tilt testing results. Previous research focused on the relevance of the type of neurocardiogenic reaction during TTS. The importance of dLOC has not been assessed so far. The study was carried out in 274 patients with suspected neurally mediated syncope and total loss of consciousness during tilt testing.

Results — The syncope burden, demographics, and data regarding spontaneous syncope or TTS were compared between group 1 with dLOC ≥ 47 seconds and group 2 with dLOC < 47 seconds. Medical history revealed that patients in group 1 had more syncopal spells, more frequent syncope-related traumatic injuries, urine incontinence, jerking movements and typical vasovagal history than in group 2. Moreover, group 1 patients had more frequently a cardioinhibitory type of reaction and a shorter active phase duration. In addition, they manifested more frequent accompanying cerebral hypoperfusion signs and reproduction of symptoms during TTS than patients in group 2.

Conclusions — The loss of consciousness during tilt testing-induced syncope differs in terms of duration among patients with neurally mediated syncope.The dLOC during TTS is associated with medical history and tilt-testing data which confirm the vasovagal aetiology of spontaneous events. The longer dLOC suggests deeper cerebral haemodynamic disturbances during either spontaneous or provoked syncope.

Key Words:

• Neurally mediated syncope
• tilt testing
• syncope duration