Head-up tilt test

Head-upright tilt table testing has been used as a research tool over the past 50 years by physiologists and/or physicians to study the hemodynamic and endocrine adaptation to changes in position. Tilt test has become a widely accepted tool in the clinical evaluation of patients with syncope, since its first application to patients with syncope by Kenny et al. in 1986. There is substantial agreement that tilt table testing is an effective technique for providing direct diagnostic evidence indicating susceptibility to vasovagal syncope. Tilt test duration of 30 to 45 min at 60 to 80 degrees have become widely accepted in laboratories for evaluating adult patients. It exhibits a high level of diagnostic specificity of 80 to 100%. Its sensitivity, in contrast, remains to be 40 to 70%. Pharmacologic provocation during head-up tilt testing elicites susceptibility to vasovagal reactions. Isoproterenol is the most common agent applied for its use. Head-upright tilt testing is most warranted in following conditions; recurrent syncope or single episode of syncope in a high risk patient, evaluation of patients in whom demonstration of susceptibility to neurally mediated syncope would affect treatment plans, and exercise induced syncope.