title: Increased arterial wave reflection may predispose syncopal attacks.
abstract: BACKGROUND
  The incidence of syncope increases with age, while aging is also associated with increased arterial wave reflection.
  
  
  OBJECTIVE
  The study was undertaken to determine whether increased arterial wave reflection is a predisposing factor of syncope.
  
  
  METHODS
  We recruited 38 patients (28 men and 10 women, mean age 57.2 +/- 20.3 years, range 17-87 years) with a history of syncope within 6 months of entry. The etiology of syncope was documented for each patient by a complete assessment of vasomotor function and cerebral flow. All patients received a comprehensive echocardiographic evaluation of cardiac structure and function. Carotid augmentation index (AI) was estimated noninvasively with the tonometry technique. The results were compared with those from 54 age- and gender-matched controls.
  
  
  RESULTS
  The most frequent diagnoses of syncope were postural hypotension (13 patients) and cerebrovascular dysautoregulation (10 patients), and the cause could not be determined in 9 patients. Compared with the control group, the syncope group had a greater AI (20 +/- 21 vs. 10 +/- 15%, p = 0.013). Subgroup analysis of 20 patients aged > 50 years and with the aforementioned diagnoses showed even more striking results: AI, 29 +/- 10 vs. 11 +/- 15%, p < 0.001. The enhanced augmentation in the patients remained when age, systolic blood pressure, height, and heart rate were accounted for. Analysis of the carotid pulse wave suggested that both the timing and intensity of wave reflection were enhanced in patients with a history of syncope compared with controls.
  
  
  CONCLUSIONS
  Our results support the hypothesis that enhanced arterial wave reflection is associated with the occurrence of syncope, especially in the elderly.
authors.affiliation: Department of Medicine and Center of Neuroscience, Taipei Veterans General Hospital, Taiwan.
authors.forename: C H
authors.initials: CH
authors.lastname: Chen
authors.forename: H H
authors.initials: HH
authors.lastname: Hu
authors.forename: Y P
authors.initials: YP
authors.lastname: Lin
authors.forename: C M
authors.initials: CM
authors.lastname: Chern
authors.forename: T L
authors.initials: TL
authors.lastname: Hsu
authors.forename: P Y
authors.initials: PY
authors.lastname: Ding
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D001158:Arteries / Q000503:physiopathology*; D001794:Blood Pressure; D002339:Carotid Arteries / Q000503:physiopathology; D003627:Data Interpretation, Statistical; D004452:Echocardiography; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011674:Pulse; D013575:Syncope / Q000209:etiology / Q000503:physiopathology*; D018667:Tilt-Table Test; D017585:Ultrasonography, Doppler, Transcranial