Tilt Table Testing Protocol

05 November 2004

Preparation

A peripheral intravenous catheter is inserted and fluids administered at 10 mL/h to allow isoprenaline hydrochloride infusion in stage 2 if needed.

4 hours of fasting

Preferably in the morning & 22°C room temperature.

Setup

Positioned supine on the tilt table, loosely restrained by safety straps, with a footboard for weight bearing, and remain supine for 15 minutes before the tilt test begins.

During the test, visual stimulation and other conversation kept to a minimum, and asked to remain motionless.

Blood pressure was measured using an automated blood pressure cuff with the arm resting at the subject's side.

Heart rate monitored continuously.

Stage 1

Upright tilt to 70° for up to 45 minutes.

Blood pressure, heart rate, heart rhythm, and symptoms recorded every 5 minutes while supine, 1 minute after upright tilt, and every 5 minutes thereafter.

When symptoms become severe, when heart rate drops, or when heart rhythm changes, blood pressure is recorded each minute.

Stage 2

If stage 1 of the test is tolerated and hypotension is not provoked, the subject is returned to the supine position and received by infusion 2 µg/min of isoprenaline hydrochloride for 10 minutes. The table was then brought to the upright 70° position for a maximum of 15 minutes more

Indications to terminate test

The test is terminated at the request of the subject, if the heart rate exceeds 180/min for 2 minutes despite reduction in the rate of isoprenaline infusion to 1 µg/min, or if hypotension or syncope occurs.

After the tilt test, all subjects receive at least 1 L of normal saline solution intravenously for 30 to 60 minutes.

Working definitions

The baseline heart rate and blood pressure values for the tilt test are the mean of the 10- and 15-minute supine readings.

Neurally mediated hypotension is defined as a 25-mm Hg reduction in systolic blood pressure from the baseline supine values, sustained for at least 1 minute, with no associated increase in heart rate, and accompanied by symptoms of presyncope.

Presyncope is defined by the presence of premonitory symptoms and signs of imminent syncope such as severe weakness, lightheadedness, nausea, or diaphoresis

It is not necessary for syncope to occur for the test to be considered abnormal.

Postural tachycardia syndrome is defined as the occurrence of orthostatic symptoms in association with either a 30/min increase in heart rate from baseline within 10 minutes of being tilted upright, sustained for 1 minute or more or a heart rate of higher than 120/min in the same period.