Objective: To investigate the predictive value of an intravenous fluid bolus during tilt table testing on clinical outcome and to evaluate of oral therapy is an effective treatment for patients with vasodepressor syncope.
Design: Retrospective cohort.
Setting: Regional pediatric cardiology outpatient clinic.
Patients: Patients (N = 58) with a positive baseline tilt table testing result who were treated with oral fluid therapy between February 1991 and March 1996.
Interventions and main outcome measures: Patients with a positive tilt table test result were given an intravenous bolus of isotonic saline solution. Responders were identified as having a negative tilt table test result after the bolus. Patients were prescribed a protocol of oral fluid therapy. Data were obtained from the medical record and a mailed survey.
Results: Of the 58 subjects, 90% had no recurrent syncope while receiving oral fluid therapy. During tilt table testing, the mean decrease in mean arterial pressure seen with symptomatic events was lower after the intravenous fluid. The heart rate, which dropped during the initial test, increased during the rests after the intravenous bolus. In the nonresponders, symptomatic episodes occurred significantly later in the tilt table test when given fluids. The response to intravenous fluid bolus had positive predictive value of 92% and negative predictive value of 11% of clinical outcome.
Conclusions: Our data suggest that oral fluid therapy is an effective treatment for vasodepressor syncope in our population. Fluid bolus response during tilt table testing has a high positive but a low negative predictive value of response to oral fluid therapy. We now recommend oral fluid therapy as a primary intervention and reserve tilt table testing for oral fluid therapy failures.