Usefulness of ambulatory blood pressure monitoring and head-up tilt test in the evaluation of paediatric syncope

OBJECTIVES: The aim of this study was to investigate the usefulness of ambulatory blood pressure monitoring versus head-up tilt test in the evaluation of children with a history of syncope. STUDY DESIGN: We considered 146 consecutive children with more than one episode of syncope. All patients had a normal electrocardiogram at rest and were otherwise considered to be healthy. Forty-six patients,19 male, with a mean age of 13.6 plus or minus 5.6 years, were studied with a head-up tilt test and 100 patients, 41 male with a mean age of 9.4 plus or minus 5.6 years, were studied with ambulatory blood pressure monitoring. Twelve patients underwent both procedures. Hypotension during ambulatory blood pressure monitoring was defined when mean blood pressure values were lower than the 50th centile and the head-up tilt test was positive when syncope occurred. All patients were followed for 10 plus or minus 2 months. RESULTS: Ambulatory blood pressure monitoring showed postural hypotension in 91% children, while head-up tilt test was positive for 54%. In the group of children having both tests, two of them were negative for both, 10 of 12 children had a positive ambulatory blood pressure monitoring while only five of 10 children had a positive response to head-up tilt test. CONCLUSIONS: When a child with a normal resting electrocardiogram is referred with a typical history of syncope, the use of ambulatory blood pressure monitoring as a non-invasive first step for diagnosis of postural hypotension may be more sensitive than the head-up tilt test. Behavioural adjustments resolved the continued syncope in most cases. If episodes persist then the head-up tilt test is indicated.