Tilt table procedure is a diagnostic procedure recommended to evaluate patients with unexplained fainting (syncope) and to confirm if the underlying cause is vasovagal syndrome.
Vasovagal syndrome, also called neurogenic syncope, results from a dysfunctioning of the nerves controlling the heart and the blood vessels. It leads to a sudden drop in blood pressure with or without a decrease in heart rate, causing episodes of fainting. These episodes usually occur while standing or sitting.
Tilt table procedure attempts to recreate a similar situation of change in posture, from lying to standing, by tilting the table from a horizontal position to vertical position while the patient is safely strapped to the special table. The cardiovascular response is monitored by evaluating change in both ECG and blood pressure, especially during the position change of the table. If fainting occurs, the table is immediately returned to the horizontal position. However, if no fainting occurs, the patient is administered a medication through an intravenous line to stimulate abnormal nervous system reflex that causes vasovagal syncope.
The medication lowers the diastolic blood pressure (lower reading of blood pressure) and peripheral vascular resistance while increasing the heart rate. The table is again tilted to the upright position and cardiovascular response is monitored. Once adequate data is obtained, the bed is lowered and the patient is allowed to leave after some rest.
A tilt table procedure is generally safe but may cause dizziness, headache, low blood pressure, high blood pressure, nausea, palpitation or change in heart rate, which usually resolves once the table is returned to the horizontal position.