hyperventilation syncopes 《英文msh词典》Hyperventilation Syncopes ; [入口词] Hyperventilation Syncopes ; [主题词] Syncope ; [英文释义] A transient loss of consciousness and postural tone caused by diminished blood flow to the brain (i.e.,BRAIN ISCHEMIA). Presyncope refers to the sensation of lightheadedness and loss of strength that precedes a syncopal event or accompanies an incomplete syncope. (From Adams et al.,Principles of Neurology,6th ed,pp367-9)