title: Impaired heart rate variability in patients with dementia with Lewy bodies: Efficacy of electrocardiogram as a supporting diagnostic marker.
abstract: OBJECTIVE
  It has been suggested that impaired heart rate variability (HRV) may be an early sign of Parkinson's disease (PD). The aim of this study was to determine whether HRV can be employed in order to differentiate between dementia with Lewy bodies (DLB) and Alzheimer's disease (AD).
  
  
  METHODS
  We examined HRV in 30 probable DLB patients (16 men and 14 women; mean age, 79.9 years; SD, 4.7 years), and 30 probable AD patients (15 men and 15 women; mean age, 79.8 years; SD, 5.6 years), compared with that in 20 age- and sex-matched controls. Subjects with other causes of impaired HRV were excluded. HRV was determined using the RR intervals of a 5-min electrocardiogram recording. Measurements of beat-to-beat RR variability, including time domains [(RR-standard deviation (SDNN), percentage of consecutive RR intervals differing by more than 50 msec (pNN50), and root mean square difference of successive RR intervals (RMSSD)), and frequency domains [very low- (VLF), low- (LF), and high-frequency (HF) components, and total spectral power (Total power)], were assessed retrospectively. The association between these HRV parameters and cardiac iodine-123 metaiodobenzylguanidine ((123)I-MIBG) scintigraphy were investigated in 22 probable DLB patients.
  
  
  RESULTS
  DLB group showed significant decreases compared to AD group in almost all HRV parameters including SDNN, pNN50, RMSSD, VLF, LF, HF, and Total power. Among these, SDNN, VLF, and Total power were correlated with the (123)I-MIBG delayed heart to mediastinum ratio.
  
  
  CONCLUSIONS
  Impaired HRV was detected in patients with probable DLB. Non-invasive and routine electrocardiogram may have potential in differentiating DLB from AD.
authors.affiliation: PET/CT Dementia Research Center, Juntendo Tokyo Koto Geriatric Medical Center, Juntendo University School of Medicine, Tokyo, Japan; Department of Psychiatry, Juntendo University School of Medicine, Tokyo, Japan. Electronic address: ksnk1jobim@yahoo.co.jp.
authors.forename: Koji
authors.initials: K
authors.lastname: Kasanuki
authors.affiliation: PET/CT Dementia Research Center, Juntendo Tokyo Koto Geriatric Medical Center, Juntendo University School of Medicine, Tokyo, Japan; Department of Psychiatry, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Eizo
authors.initials: E
authors.lastname: Iseki
authors.affiliation: PET/CT Dementia Research Center, Juntendo Tokyo Koto Geriatric Medical Center, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Hiroshige
authors.initials: H
authors.lastname: Fujishiro
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Shuntaro
authors.initials: S
authors.lastname: Ando
authors.affiliation: Department of Psychiatry, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Sugiyama
authors.affiliation: Department of Psychiatry, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Kitazawa
authors.affiliation: PET/CT Dementia Research Center, Juntendo Tokyo Koto Geriatric Medical Center, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Chiba
authors.affiliation: PET/CT Dementia Research Center, Juntendo Tokyo Koto Geriatric Medical Center, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Sato
authors.affiliation: Department of Psychiatry, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Heii
authors.initials: H
authors.lastname: Arai
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004562:Electrocardiography / Q000592:standards*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D020961:Lewy Body Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D011877:Radionuclide Imaging / Q000592:standards; D012189:Retrospective Studies
keywords: Alzheimer's disease; Dementia with Lewy bodies; Heart rate variability; Iodine-123 metaiodobenzylguanidine ((123)I-MIBG) scintigraphy