OBJECTIVE To investigate the usefulness of head-upright tilt table testing for vasovagal episodes in the evaluation and management of elderly patients with recurrent idiopathic syncope. METHODS Prospective survey. METHODS Electrophysiology laboratory of a university hospital. METHODS Twenty-five patients (11 male, 14 female; mean age 73 +/- 6 years) with recurrent unexplained syncope and seven control subjects with other causes of syncope (4 male, 3 female; mean age 70 +/- 4 years). METHODS Each patient underwent head-upright tilt table testing for 30 minutes with or without an infusion of isoproterenol (1-3 micrograms/min given intravenously) in an attempt to provoke bradycardia, hypotension, or both. RESULTS Syncope occurred in nine patients (36%) during the baseline tilt and in seven patients (28%) during isoproterenol infusion (total positives 64%). None of the controls had syncope during the test. All of the patients who had positive test results eventually became tilt table negative with therapy, and over a mean follow-up period of 24 months, no further syncopal episodes have occurred. CONCLUSIONS Head-upright tilt table testing combined with isoproterenol infusion may be a useful tool in the diagnosis of vasovagal syncope in the elderly and in the evaluation of preventive therapy.