Vasovagal syncope (vvs) is a hyper reflex and once triggered a person is likely to have a run of episodes and then it subsides. Adequate hydration, salt intake help to decrease frequency and there are maneuvers to slow the heart rate when it occurs such as rubbing one side of the neck or putting hands in icy water. It is a heart response to low circulating volume sensed by the vagal nerve. Getting you to lie flat(faint)is the body s way to preserve blood flow to the brain. While nausea is not uncommon with VVS, and also common with motion sickness, that is where the connection ends. Motion sickness has to do with the brain processing movement, a miscue between info from the eye and equilibrium info from the ear. It has nothing to do with vagal nerve, heart, or circulating volume. People who get migraines are more prone to motion sickness, but I am not aware of the association with VVS