Ground vasovagal presyncopes and fighter pilot fitness: aeromedical concerns

Vasovagal episodes are common events but may have consequences for flight safety, particularly in high-performance aircrafts, where the autonomic nervous system is impacted during +G(z) accelerations. However, the risk is difficult to assess in the case of ground presyncopes.

A 27-yr-old fighter pilot experienced a feeling of faintness at a daily briefing. He had previously shown no medical history except for a single episode. The initial physical examination was normal. During vagal maneuvers, the pilot developed a cardiac pause and a tilt-table test was positive. Other investigations were normal.The pilot lost consciousness twice in centrifuge testing while previous tests had shown a good cardiovascular tolerance. He was declared unfit to fly fast jets but fit as a multicrew transport pilot with a waiver.

The epidemiology of vasovagal reactions is difficult to estimate in aircrew. A late occurrence in the career can be explained by either a newly acquired hypervagotonia, or an old predisposition with specific triggering factors in which psychosocial aspects are important. In such circumstances three steps are necessary to assess fitness: 1) to check for other etiologies; 2) to look for vasovagal predisposition; and 3) to check psychiatric condition. The studies about the predictive value of the tilt-test must be taken into account.

In the case of vasovagal presyncope in a fighter pilot, the aeromedical decision should consider the medical history of the pilot, the results of investigations, and the experience and motivation of the individual under review. Centrifuge testing may be useful in difficult situations.