TY - CHAP M1 - Book, Section TI - Syncope A1 - Freeman, Roy A2 - Loscalzo, Joseph A2 - Fauci, Anthony A2 - Kasper, Dennis A2 - Hauser, Stephen A2 - Longo, Dan A2 - Jameson, J. Larry PY - 2022 T2 - Harrison's Principles of Internal Medicine, 21e AB - Syncope is a transient, self-limited loss of consciousness due to acute global impairment of cerebral blood flow. The onset is rapid, duration brief, and recovery spontaneous and complete. Other causes of transient loss of consciousness need to be distinguished from syncope; these include seizures, vertebrobasilar ischemia, hypoxemia, and hypoglycemia. A syncopal prodrome (presyncope) is common, although loss of consciousness may occur without any warning symptoms. Typical presyncopal symptoms include lightheadedness or faintness, dizziness, weakness, fatigue, and visual and auditory disturbances. The causes of syncope can be divided into three general categories: (1) neurally mediated syncope (also called reflex or vasovagal syncope), (2) orthostatic hypotension, and (3) cardiac syncope. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accessmedicine.mhmedical.com/content.aspx?aid=1197683182 ER -