Tilt Table Study

        The previous section describes the most common type of electrophysiology study. Another type of study that is used to test for a specific problem is called the tilt table study. While this test is performed using a completely different technique than a standard EP study, it still falls under the area covered by the electrophysiologist. The tilt table study is used to test patients that may have neurocardiogenic syncope. This is a complex condition that occurs when patient's have an abnormal response to stimulation of the nervous system. Whenever your body receives any form of stimulation, the brain tells your heart to respond with an increase in heart rate and blood pressure. When this happens, the body reacts to the elevated heart rate and blood pressure with an opposing response that prevents the pulse and BP from going to high. In patients with neurocardiogenic syncope, this opposing response may be so strong that the stimulation is completely suppressed. Instead of increasing, the heart rate and/or the blood pressure decrease, sometimes going so low that the patient passes out.

          This test is performed by placing the patient on a flat table and hooking them up to heart rate and blood pressure monitors. Once everything is ready, the table is raised up to a 70 degree angle. This elevation causes blood to flow down to the lower portion of the body. As this happens, the brain senses that there is less blood in the center regions of the body. To compensate for the decreased volume of blood, the brain sends a signal to the heart to increase the number of heart beats per minute. The blood vessels will also constrict a little causing an increase in blood pressure. The table is held at this angle for around 20 minutes. During this time, the patient is monitored closely for indications of a strong opposing reaction to the bodies stimulation. If, after 20 minutes, the patient's heart rate and blood pressure have not changed, a medicine called isuprel may be given. Isuprel is a medication that is used to increase stimulation of the heart. After the isuprel is given, the patient is monitored for another 10 to 20 minutes. If nothing has happened by that point, the results of the test are considered negative and the test is stopped. A tilt table study can be considered positive with just a decrease in heart rate, a decrease in blood pressure or both. It is possible that a patient who has a positive tilt table study may pass out completely. For this reason, all patients who have a tilt table study will be securely strapped on to the exam table before the test is started.

          The images below were taken from a tilt table study that turned out to be very positive. This series of rhythm strips should demonstrate why it is important to pay close attention during this type of procedure. Many times, nothing will happen. When something does happen, it can be sudden and extreme. In this procedure, there were immediate indications that the study would be positive. It was less than four minutes before a near code situation occurred. Fortunately, recovery was as quick as the onset of symptoms.

Tilt Table Images