Exercise-related syncope in young competitive athletes without evidence of structural heart disease. Clinical presentation and long-term outcome.

Abstract

Exercise-related syncopal spells in athletes receive great attention and are a source of anxiety in the sporting world. The aim of the present study is to describe the clinical presentation, the yield of the initial diagnostic work-up and the long-term outcome of a series of consecutive competitive athletes with recurrent exercise-related syncopal spells. The study cohort included 33 athletes (20 females, mean age 21.4+/-3.2 years) referred for recurrent unexplained episodes of exercise-related syncope (mean number of spells before evaluation 4.66+/-1.97). All athletes underwent an extensive evaluation, including echocardiography, 24-h electrocardiographic monitoring, exercise testing, cardiac electrophysiological study and head-up tilt testing. The echocardiographic examination revealed the presence of a mitral valve prolapse in two cases (6.0%). During maximal exercise testing, four athletes (12.1%) developed hypotension associated with pre-syncope. Twenty-two subjects (66.6%) showed a positive response to head-up tilt testing. During follow-up (33.5+/-17.2 months) 11/33 athletes (33.3%) showed at least one recurrence of exercise-related syncope (mean time to first recurrence 20.4+/-14.5 months). No other adverse event of any kind was noted during follow-up. The Kaplan-Meier estimates of first recurrence of exercise-related syncope after 12, 36 and 60 months were 9.1%, 24.4% and 42.9%. The number and frequency of exercise-related syncopal spells before evaluation were found to be univariate predictors of syncope recurrence (P<0.001). However, in the multivariate analysis, the number of exercise-related syncopal spells before evaluation was found to be the only independent predictor of syncope recurrence (P<0.05). These findings support the idea that recurrent exercise related-syncope is not associated with an adverse outcome in athletes without cardiac disease.