TILT-TABLE TESTING OF YOUNG-ADULT PATIENTS - IMPROVED SPEED AND SENSITIVITY USING AN ISOPROTERENOL BOLUS AND A CONTINUOUS 60-DEGREES TILT

The tilt table is a diagnostic device used to induce vagal syncope and determine etiology. Sensitivity enhancing techniques, such as the adm inistration of isoproterenol, can be applied to children and young adu lts to compensate for the otherwise low sensitivity (20%-30%) observed in that population. This study describes an improved test that offers a simplified approach while decreasing the amount of time involved by up to 50%, without compromising sensitivity. This 45-minute procedure relies on sensitization with isoproterenol administered as a 2- to 8- mu g bolus instead of a continuous infusion. The isoproterenol is inje cted at the 30th minute of a 45-minute 60 degrees tilt test without re turning the patient to the supine position. In this study, the isoprot erenol bolus tilt test was found to be ''positive'' in 24 of 30 patien ts reporting unexplained syncope: 10 cases before the 30th minute (11. 2 +/- 8.4 min) and 14 cases after administration of 5.1 +/- 1.9 mu g o f isoproterenol.