Tilt table testing is usually recommended for people who experience fainting Fainting Light-headedness (near syncope) is a sense that one is about to faint. Fainting (syncope) is a sudden, brief loss of consciousness during which the person falls to the ground or slumps in a... read more (syncope) for an unknown reason and who do not have a structural heart disorder (such as narrowing of an aortic valve Aortic Stenosis Aortic stenosis is a narrowing of the aortic valve opening that blocks (obstructs) blood flow from the left ventricle to the aorta. The most common cause in people younger than 70 is a birth... read more ).
Typically, people are strapped to a motorized table and remain lying flat for 15 minutes. Then they are tilted head up at a 60° to 80° angle for 45 minutes to see whether they feel faint or their blood pressure and heart rate decrease. If blood pressure does not decrease, isoproterenol (a drug that stimulates the heart) is injected into the person's vein in a dose large enough to accelerate the heart rate by 20 beats per minute, and the test is repeated.