Recommendations for tilt table testing and other provocative cardiovascular autonomic tests in conditions that may cause transient loss of consciousness : Consensus statement of the European Federation of Autonomic Societies (EFAS) endorsed by the American Autonomic Society (AAS) and the European Academy of Neurology (EAN)

Abstract

An expert committee was formed to reach consensus on the use of tilt table testing (TTT) in the diagnosis of disorders that may cause transient loss of consciousness (TLOC) and to outline when other provocative cardiovascular autonomic tests are needed. While TTT adds to history taking, it cannot be a substitute for it. An abnormal TTT result is most meaningful if the provoked event is recognised by patients or eyewitnesses as similar to spontaneous events. The minimum requirements to perform TTT are a tilt table, a continuous beat-to-beat blood pressure monitor, at least one ECG lead, protocols for the indications stated below and trained staff. This basic equipment lends itself to the performance of (1) additional provocation tests, such as the active standing test, carotid sinus massage and autonomic function tests; (2) additional measurements, such as video, EEG, transcranial Doppler, NIRS, end-tidal CO₂ or neuro-endocrine tests; and (3) tailor-made provocation procedures in those with a specific and consistent trigger of TLOC. TTT and other provocative cardiovascular autonomic tests are indicated if the initial evaluation does not yield a definite or highly likely diagnosis, but raises a suspicion of (1) reflex syncope, (2) the three forms of orthostatic hypotension (OH), i.e. initial, classic and delayed OH, as well as delayed orthostatic blood pressure recovery, (3) postural orthostatic tachycardia syndrome or (4) psychogenic pseudosyncope. A therapeutic indication for TTT is to teach patients with reflex syncope and OH to recognise hypotensive symptoms and to perform physical counter manoeuvres.

Keywords: Orthostatic hypotension; Psychogenic pseudosyncope; Reflex syncope; Syncope; Tilt table testing; Transient loss of consciousness; Vasovagal.

Fig. 1

Flow chart of the diagnostic work-up following the initial evaluation of transient loss of consciousness (TLOC), i.e. history taking, ECG and bedside supine and standing blood pressure measurements. AST active standing test with continuous blood pressure measurements, BP blood pressure, cOH classic orthostatic hypotension, CSM carotid sinus massage, TLOC transient loss of consciousness, TTT tilt table testing, VVS vasovagal syncope

Fig. 2

Flow chart of the diagnostic work-up of orthostatic intolerance, i.e. history taking and supine and standing blood pressure measurements. AST active standing test with continuous blood pressure measurements, classic OH classical orthostatic hypotension, POTS postural orthostatic tachycardia syndrome, TTT tilt table testing

Fig. 3

Choice of type of tilt table testing (TTT) protocol. ^#Pharmacological provocation with sublingual trinitroglycerin (TNG) may be considered to increase the sensitivity for VVS but should be avoided in those for whom delayed OH is suspected. AST active standing test with continuous blood pressure measurements, CSM carotid sinus massage, OH orthostatic hypotension, POTS postural orthostatic tachycardia syndrome, PPS psychogenic pseudosyncope, TTT tilt table testing