Head-up tilt testing in children

The article by Kouakam et al. in issue 22/17 is a prospective observational study of syncope recurrence in 101 children (mean age 12·6 3; range 7–18 years) undergoing head-up tilt testing for investigation of recurrent unexplained syncope or presyncope. Data are presented for patients recruited between 1990 and 1998, and followed-up for an average of 4 years. Head-up tilt was initially positive in 67 patients, 58 of whom had a diagnosis of vasovagal pre-syncope or syncope and nine of psychogenic syncope. Forty-three of 67 tilt-positive patients were treated in a non-randomized manner with either beta-blockers, disopyramide, midodrine, dual-chamber pacemaker or psychotherapy. Treatment decisions were based on symptom severity. The only significant predictor of syncope recurrence was the number of pre-treatment syncopal events. Symptom recurrence during the follow-up period was independent of the head-up tilt test responses and of treatment decision. Fifteen per cent of children will have a syncopal episode before adulthood. The causes of syncope in children and adolescents are similar to those described for adults, although the relative frequency and prognosis of individual diagnoses vary. Fortunately, the majority of syncopal events in young persons are isolated and benign. Traditional investigations (including 12 lead ECG, 24 h Holter monitoring, EEG, glucose tolerance test, echocardiography and CT head scanning) have a diagnostic yield of less than 60% in adults. In children, the reported diagnostic rate of conventional testing is even less. The use of tilt testing as an investigative tool in children with unexplained or suspected vasovagal syncope was first reported in the early 1990s. Pongiglione et al. (1990), tilted 20 subjects (ages 7–22, mean 12·5 years), to 90 for 15 min and if symptoms (pre-syncope or syncope) did not develop a head-up tilt was repeated during isoproterenol infusion. A diagnosis was achieved in 16 (4 passive, 12 isoproterenol) patients. Thilenius et al. (1991) then reported a series of 35 patients with unexplained pre-syncope