title: QT dispersion and heart rate variability abnormalities in Alzheimer's disease and in mild cognitive impairment.
abstract: OBJECTIVE
  To investigate the effect of cardiovascular changes (i.e., QT interval, QT dispersion (QTD), heart rate variability (HRV), and other cardiovascular measures) in subjects with Alzheimer's disease (AD) and mild cognitive impairment (MCI).
  
  
  METHODS
  Each subject underwent clinical and cognitive examination, a structural brain imaging study, echocardioDoppler, electrocardiogram (ECG), HRV analysis using 24-hour ECG monitoring, and 24-hour blood pressure monitoring.
  
  
  METHODS
  Community population-based sample of patients admitted to an AD center for investigation of cognitive disturbances.
  
  
  METHODS
  Thirty-three subjects with AD, 39 subjects with MCI, and 29 cognitive healthy subjects (controls) matched for demographic characteristics, hypertensive condition, smoking habits, and laboratory parameters were enrolled consecutively.
  
  
  METHODS
  Clinical and cognitive examination, structural brain imaging study, echocardioDoppler, ECG, HRV analysis using 24-hour ECG monitoring, and 24-hour blood pressure monitoring.
  
  
  RESULTS
  QTD and QT corrected dispersion mean values were significantly higher in patients with AD than in patients with MCI and controls and higher in patients with MCI than in controls. HRV time and domain parameters were lower in patients with AD than in patients with MCI and controls. No difference in other cardiovascular measures was found. QTD and HRV were found to be significantly correlated with the degree of cognitive impairment.
  
  
  CONCLUSIONS
  These findings support the presence of a peculiar neuroanatomic dysfunction in patients with AD and MCI that parallels the disease progression. These noninvasive parameters might prove to be powerful predictive tools in the worsening of cognitive function and mortality risk.
authors.affiliation: Institute of Internal Medicine, Department of Medical Sciences, University of Brescia, Brescia, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Zulli
authors.forename: Franco
authors.initials: F
authors.lastname: Nicosia
authors.forename: Barbara
authors.initials: B
authors.lastname: Borroni
authors.forename: Chiara
authors.initials: C
authors.lastname: Agosti
authors.forename: Paola
authors.initials: P
authors.lastname: Prometti
authors.forename: Paolo
authors.initials: P
authors.lastname: Donati
authors.forename: Massimiliano
authors.initials: M
authors.lastname: De Vecchi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Romanelli
authors.forename: Vittorio
authors.initials: V
authors.lastname: Grassi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Padovani
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology / Q000503:physiopathology*; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D006329:Heart Conduction System; D006339:Heart Rate; D006801:Humans; D007558:Italy / Q000453:epidemiology; D016014:Linear Models; D008297:Male; D016555:Matched-Pair Analysis; D015999:Multivariate Analysis