Neuroscience Journal / 2016 / Article / Tab 3

Research Article

Cerebral Blood Flow, Heart Rate, and Blood Pressure Patterns during the Tilt Test in Common Orthostatic Syndromes

Table 3

The characteristics of the patterns associated with the tilt test.


Orthostatic hypotension (OH), compensated, with stable orthostatic CBFvOH with stable orthostatic CBFv indicating preserved cerebral autoregulation. OH can have any pattern: early, late, sustained, intermittent, progressive, stable. Patients are typically not dizzy during the tilting

OH, uncompensated, with reduced orthostatic CBFvOH with reduced orthostatic CBFv indicating either autoregulatory failure or BP below the autoregulatory range. Patients are typically dizzy during the tilting

Orthostatic cerebral hypoperfusion syndrome (OCHOs)Orthostatic CBFv is low without OH or arrhythmia. Patients are typically dizzy during the tilting

Orthostatic hypertension syndrome (OHTN)If HR increases ≥30 BPM during the tilt then it is POTS. If HR increases <30 BPM and CBFv decreases during the tilt then it is OCHOs

Postural tachycardia syndrome (POTS) or HVHR increase during the tilt is usually sustained. HR ≥ 120 BPM during the tilt is also required. If maximal HR < 120 BPM during the tilt then it is called “mild orthostatic intolerance”

Inappropriate sinus tachycardia (IST)HR during the supine may fluctuate but mean HR > 100 BPM during supine. HR is increased during the tilt and the increase is usually fluctuating

Paroxysmal sinus tachycardia (PST) or HV or HVHR increase which may happen during both supine and the tilt is usually intermittent and associated with anxiety and may respond to reassurance

Syncope, cardiovagalHR < 40 BPM

Syncope, vasodepressorMinimal HR slowing (<10%)

Syncope, mixedBoth HR and BP decrease

Primary cerebral autoregulatory failure (pCAF)Hyperventilation should be ruled out

Psychogenic pseudosyncopePseudosyncope can occur in both supine and upright position

Comments: CBFv = cerebral blood flow velocity; = end tidal CO2; HR = heart rate; BP = blood pressure; BPM = beats per minute; supine = absolute values of respective variables in supine position; tilt = absolute values of respective variables during the tilt (upright position); HV = hyperventilation defined as < 35 mmHg in supine position and < 30 mmHg during the tilt; CAF = cerebral autoregulatory failure; ↑ = increased; ↓ = decreased; ↕ = any; normal; ↑ = normal or increased; ↓ = normal or decreased. indicates the primary abnormality.