Syncope During Cycling

Syncope during exertion often heralds cardiac disease.

We evaluated 2 cyclists with syncope during bicycling without identifiable cause, then identified 23 additional cyclists (mean age: 68 ± 8 years; 84% male) who had experienced 32 syncopal episodes during cycling to develop a clinical profile. Only 1 cyclist was aged <50. There were no reports of prodrome and 23 episodes of postsyncope confusion. Most episodes occurred on road bicycles with cyclists leaning forward (n = 19). Four cyclists recalled turning their head immediately before the event. No cardiac or neurological etiology was identified in the 23 cyclists.

We conclude that cycling may be associated with syncope without an identifiable cause.

The etiology of this syndrome is unclear, but the age of the cyclists, the high rate of postevent confusion, and associated head turning in some participants raise the speculative possibility that this is a form of carotid sinus sensitivity.