Neurocardiogenic syncope in selected pediatric patients - Natural history during long-term follow-up and effect of prophylactic pharmacological therapy

Objective: The natural history of pediatric patients with severely symptomatic neurocardiogenic syncope is poorly defined respect to the likelihood of remission or symptomatic recurrence along time. We undertook this study to investigate the likelihood of clinical relapse, and to assess the effect of prophylactic pharmacological treatment in the most symptomatic patients. Methods: Twenty-nine patients with neurocardiogenic syncope were studied at our Institution: 14 (12 +/- 3.6 years) highly symptomatic received prophylactic therapy with beta -blockers guided by head up tilt (HUT), whereas 15 (12.2 +/- 2.7 years) moderately symptomatic received only education to avoid triggering of the vasovagal reflex and to abort forthcoming syncope. Patients were then followed respectively for 33.7 +/- 9.0 and 33.3 +/- 8.7 months (p = NS). Results: The average duration of symptoms before HUT was 9.0 +/- 4.3 months (range 3-17) for treated patients, and 6.2 +/- 2.5 months (range 2-11) for those untreated (p < 0.05). Treated patients had also a greater number of symptomatic events: 6 +/- 2 vs. 2 +/- 1 (p < 0.001). During follow up, 9/15 untreated and 6/14 treated patients had at least I recurrence, with an odds ratio of 2 (95% Cl 0.72-5.49). Clinical events were greatly reduced in both groups at follow up, but treated patients had a significantly greater reduction either of syncopal (p < 0.001) or near syncopal events (p < 0.02). Time to the first recurrence, syncope or near syncope, was shorter for untreated vs treated patients: 5 +/- 2 vs. 25 +/- 12 months (p < 0.001). Looking at the time course of all clinical recurrences, 23/26 occurred in untreated patients, whereas 7/10 occurred in treated patients within 24 months. An attempt to therapy discontinuation was made after 30 months in 4 patients, and resulted in half of them being asymptomatic, and half with a single minor recurrence. Conclusions: Spontaneous reduction of symptoms occurs along time in pediatric patients with neurocardiogenic syncope, so that recurrences are very unlikely after 24 months from first diagnosis. Tiered prophylactic therapy may be guided by HUT in selected highly symptomatic patients; -blockers appear a very effective intervention. Larger, prospective controlled studies are required to investigate the role of any intervention in moderately symptomatic patients.