title: Transcranial Doppler assessment of the cerebral circulation during postprandial hypotension in the elderly.
abstract: OBJECTIVE
  The aim of the present study was to evaluate whether alterations in postprandial hemodynamics in the elderly were associated with changes in cerebral perfusion assessed by transcranial Doppler ultrasonography.
  
  
  METHODS
  Time series, ie, post-intervention compared to pre-intervention with no-intervention controls.
  
  
  METHODS
  Ten elderly institutionalized subjects (4 women, 6 men, mean age 84.9 years). Three subjects had a history of syncope.
  
  
  METHODS
  A 725-bed academic long-term care facility.
  
  
  METHODS
  A 400-kcal mixed meal.
  
  
  METHODS
  Heart rate, blood pressure, and blood flow velocity in the middle cerebral artery by transcranial Doppler recording, before the test meal and at 5-minute intervals for 60 minutes afterwards.
  
  
  RESULTS
  Systolic, diastolic, and mean arterial blood pressure declined significantly from baseline between 30 and 55 minutes after the meal (P < 0.05, ANOVA); however, maximum and mean blood flow velocity did not change. The pulsatility index (end diastolic to peak systolic amplitude divided by mean velocity) increased significantly (P < 0.05, ANOVA) between 30 and 55 minutes after the meal, suggesting increased arteriolar resistance. There were no significant changes in blood pressure, blood flow velocity, and pulsatility index during a control study conducted with four subjects under identical conditions but without a meal.
  
  
  CONCLUSIONS
  The results of this study suggest a small, unexpected increase in resistance of the intracranial circulation following a meal in elderly people with postprandial hypotension. Although the clinical significance of this finding is not known, the occurrence of postprandial arteriolar vasoconstriction may lead to cerebral ischemia during periods of marked blood pressure decline.
authors.affiliation: University of Toronto, Ontario, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Krajewski
authors.forename: R
authors.initials: R
authors.lastname: Freeman
authors.forename: R
authors.initials: R
authors.lastname: Ruthazer
authors.forename: M
authors.initials: M
authors.lastname: Kelley
authors.forename: L A
authors.initials: LA
authors.lastname: Lipsitz
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001783:Blood Flow Velocity; D002536:Cerebral Arteries / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D004435:Eating; D005069:Evaluation Studies as Topic; D005260:Female; D015577:Geriatric Assessment; D006439:Hemodynamics; D006706:Homeostasis; D006801:Humans; D007022:Hypotension / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D008297:Male; D009735:Nursing Homes; D011673:Pulsatile Flow; D014463:Ultrasonography; D014655:Vascular Resistance