Evaluation of the link between blood glucose levels and neurocardiogenic syncope in adults who experience fainting episodes.

The normal procedure for a heads-up tilt test is were the test is divided into two sections, Before the test commences the patient's blood pressure and heart rate are assessed. A small needle (like a blood test) will be placed in the arm (IV cannula) which medication will be given in the second part of the test. The patient lies flat on the tilt bed that has a footplate at the end to stand on when the bed has been tilted so that they are standing upright. Small straps are placed around the body, like seat belts that stabilize the patient in case they become dizzy or faint. After 10 minutes in this in the upright standing position, or sooner if they become dizzy or feel faint, the bed will be returned to the normal position so that they are lying flat. The heart rate and blood pressure will be taken frequently. If no blackouts or dizziness occurs, then the second part of the test begins. The tilt test is repeated with the addition of a medication (Isoprenaline) given via the small needle (IV cannula) in the arm The Isoprenaline stimulates the heart rate (making the heart beat stronger and faster), it makes you feel like you have gone for a brisk walk or run, similar to how you feel when you exercise. Similar to the first part of the tilt table test the second part of the test continues for 10 minutes or until the patient becomes dizzy or feels faint. As part of this project we will be checking the patient's venous blood glucose level at the following time points: -Before the test begins (Baseline) -After the first part of the tilt (after 10minutes) -2 minutes after the Isoprenaline infusion part of the test has commenced -After the end of the Isoprenaline phase of the test (End of test) The only change from a standard tilt table test is the blood sample collection and testing for blood glucose levels.