Perioperative reflex bradycardia and cardiac arrest.

vasovagal syncope or neurocardiogenic syncope refers to the loss of consciousness that occurs secondary to hypotension resulting in reduced blood supply to the brain. it is the most common form of unexplained syncope (50-60%) in the outpatient setting. Bradycardia and vasodilation are the primary causes of this hypotension. fear, pain, dehydration, alcohol consumption, anxiety, tight clothing and hot climate may be its triggering agents1,2. although it is benign, it can result in significant morbidity (falls, accidents); mortality is 5-10%. Treatment varies from drugs to pacing2.