A tilt-table study is used to check for changes in heart rate and blood pressure when your body's position is changed. This test is most commonly done when a person has periods of losing consciousness or nearly fainting.

When the table is upright, blood collects in the legs and lower part of the body. Less blood returns to the heart to be pumped. This may cause the blood pressure to drop. Normally the nerves that control the heart and blood vessels keep your blood pressure at a steady level. A tilt table study will show the heart slowing as the blood pressure falls.

A nurse prepares you before the procedure by inserting an intravenous (IV) line in your arm. He or she will also connect you to an electrocardiogram and a blood pressure cuff.

At first, you will be lying flat for 20 to 30 minutes. Then, the tilt bed will be changed to a nearly vertical (80 degrees) position for 30 to 45 minutes. In this position, you might feel lightheaded, dizzy or as if you might faint. It is important that you tell the doctor or nurse of any symptoms you may be feeling. Finally, the tilt bed will be put in a horizontal position and you will be observed for another 20 to 30 minutes.

You may also be given a drug to increase you heart rate through your IV as part of this test. The drug may make your heart feel like it is pounding. The doctor will decide if this is needed at the time of the study. During this portion of the test, your position will be changed from vertical to flat several times. Depending on your body's response, the test may last up to three hours.

The For Patients section has specific instructions for preparing for a stress test.