Epidemiology and prognostic implications of syncope in young competing athletes.

Aims: This study was undertaken to evaluate the epidemiological features and the prognostic implications of syncope in young athletes.
Methods and Results: A cohort of 7568 young athletes (5132 males, 2436 females, aged 16.2 +/- 2.4) underwent a pre-participation evaluation. A syncopal spell in the last 5 years was reported by 474 athletes (6.2%). Syncope was unrelated with exercise in 411 athletes (86.7%), post-exertional in 57 (12.0%) and exertional in 6 (1.3%). All episodes of non-exertional or post-exertional syncope had the typical features of neurally-mediated fainting. The 6 athletes with exertional syncope underwent further testing allowing the diagnosis of hypertrophic cardiomyopathy in one case, and of right ventricular outflow tract tachycardia in another. The remaining 4 athletes only showed a positive response to tilt-testing. All athletes were followed for 6.4 +/- 3.1 years, during 48,066.6 person-years of follow-up. The recurrence rate was 20.3 per 1000 subject-years in athletes with non-exertional, and 19.2 per 1000 subject-years in athletes with post-exertional syncope. The incidence of first report of syncope was 2.2 per 1000 subject-years for non-exertional and 0.26 per 1000 subjects-years for post-exertional spells. No other adverse event was noted during follow-up.
Conclusions: In young athletes, syncope occurring before the initial pre-participation screening has a neurally-mediated origin in most cases and shows a low recurrence rate. Exercise-related syncope is infrequent and is not associated with an adverse outcome in subjects without cardiovascular abnormalities. The incidence of new syncope during competitive activity is particularly low.