The purpose of the tilt table test is to evaluate the patient for possible causes of loss of consciousness, dizziness, or tachycardia that may be affected by the autonomic nervous system.
The patient is without food for at least 6 to 8 hours
An intravenous line is inserted with the patient lying down (supine) on the tilt table
A baseline blood pressure and heart rate is obtained
Continuous ECG monitoring is performed.
The patient's legs and chest are supported with firms straps
The tilt table is slowly tilted to achieve the desired angle
Angles of tilt range from 60-80 degree
The duration of the tilt ranges from 20-60 minutes.
In some laboratories, an intravenous medication isoproterenol will be given and tilt will be again performed. In other laboratories, the procedure is considered complete or a sublingual nitroglycerin is given and tilting is continued.
The reproducibility of symptoms is noted and the patients heart rhythm, blood pressure, and pulse during symptoms are compared.
The pattern of change in blood pressure and heart rate are noted.
A drop in heart rate with a drop in blood pressure is most consistent with a neurocardiogenic mechanism of syncope (increase in the parasympathetic arm of the autonomic nervous system), which is the "common faint."
An increase in heart rate and drop in blood pressure is most consistent with orthostatic hypotension due to pooling of blood in the legs. A failure to increase heart rate and drop in blood pressure is most consistent with autonomic failure/dysautonomia.