Autonomic Stress Test (The expanded head-up tilt test) Artur Fedorowski Syncope Unit Skåne University Hospital, Malmö, Sweden NordSync 2011, Malmö
Disclosure None
The expanded head-up tilt test When? Why? How? And what is the diagnosis?
Single syncope in high risk settings Recurrent syncope episodes To evaluate susceptibility to reflex syncope To discriminate between reflex and OH syncope To discriminate between syncope and epilepsy In unexplained falls
The expanded head-up tilt test When? Syncopal attacks of uncertain etiology without clinical signs of underlying heart disease (ECG? Positive history or signs of structural heart disease?) Suspected orthostatic blood pressure instability Presyncopal attacks/vertigo if haemodynamic etiology is suspected or needs to be excluded Elderly patients who present with falls and amnesia
The expanded head-up tilt test Why? If you cannot catch it (syncopal attack), provoke it! Even if diagnosis is benign it can be important for patient s reassurance and coping skills. It is the best way to evaluate circulatory response to standing and autonomic reflexes. Some diseases can only be diagnosed using this method. It is a non-invasive and safe procedure.
The original stress test
It all started in 1986 Kenny et al,1986
HUT protocol Continuous BP and ECG monitoring Supine, cannulation, blood sample nr 1 after 15 min, Carotid sinus massage (CSM) in supine position (pos/neg) Head-up tilt and CSM if needed Tilt back, 5 min rest and head-up tilt nr 2 Blood sample nr 2 after 3 min Observation for 20±5 min (orthostatic response?/ vasovagal reflex?) GTN (glyceryl trinitrate) challenge if needed and observation for 15 min Initial (rapid) orthostatic response (under active rising) if needed
Valsalva maneuver Goldstein et al. 2009
Initial orthostatic response to active standing Wieling et al, 2007
What is the HUT diagnosis?
Carotid sinus reflex: how does it work?
Carotid sinus hypersensitivity
Classical orthostatic hypotension
Delayed OH and vasovagal syncope
Neurocardiogenic (reflex) syncope 7 + 6 sec
Postural (orthostatic) tachycardia syndrome
Syncope Unit, Malmö 2008-2011 ~10 % No Dx
Take-home message By applying the expanded head-up tilt test with additional autonomic tests you will be able to effectively diagnose up to 80% of non-cardiac syncopal attacks (Fedorowski et al, 2010) Most frequently, you will find some variant of neurocardiogenic reflex such as vasovagal syncope or carotid sinus hypersensitivity among elderly patients (Brignole et al, 2006) Orthostatic blood pressure instability (hypotension or POTS) can be adequately diagnosed using this diagnostic tool (Gibbons et al, 2006; Grubb et al, 1997)
Thank you for your attention!