1. A temporary loss of consciousness which sometimes causes provoked convulsive seizures as a result of the intensity of the carotid sinus reflex when pressure increases in one or both carotid sinuses.
2. Intense hypotension (low blood pressure) and bradycardia (abnormally slow heartbeat) following carotid sinus stimulation, resulting in dizziness, fainting or convulsions, and occasionally other neurologic symptoms.