title: R-R interval variation in Parkinson's disease and multiple system atrophy.
abstract: OBJECTIVE
  To investigate whether the cardiac R-R interval variation (RRIV) is of value in differentiating patients with Parkinson's disease (PD) from multiple system atrophy (MSA).
  
  
  BACKGROUND
  RRIV assessment is a simple procedure, reflecting mainly vagal efferent activity. Reduced RRIV was reported in MSA.
  
  
  METHODS
  RRIV at rest and after 120 s of deep breathing was assessed blindly to clinical diagnosis in 22 PD and 20 MSA patients. The results were compared with data from 23 age-matched healthy subjects.
  
  
  RESULTS
  RRIV at rest was 7.1 +/- 2.7% in PD and 9.7 +/- 7.2% in MSA, increasing after deep breathing to 11.2 +/- 6.3 and 12.3 +/- 6.6% correspondingly. The frequency of the RRIV abnormalities in the PD group (4/22, 18.2%) and MSA (6/20, 30%) were higher than among controls (P < 0.004).
  
  
  CONCLUSIONS
  RRIV, either at rest or after deep breathing, may be abnormal both in PD and MSA, but does not distinguish between these disorders.
authors.affiliation: Department of Neurology, Tel-Aviv Sourasky Medical Center, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: T Yu
authors.initials: TY
authors.lastname: Gurevich
authors.forename: G B
authors.initials: GB
authors.lastname: Groozman
authors.forename: N
authors.initials: N
authors.lastname: Giladi
authors.forename: V E
authors.initials: VE
authors.lastname: Drory
authors.forename: J M
authors.initials: JM
authors.lastname: Hausdorff
authors.forename: A D
authors.initials: AD
authors.lastname: Korczyn
mesh_terms: D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis* / Q000503:physiopathology; D010300:Parkinson Disease / Q000175:diagnosis* / Q000503:physiopathology; D012119:Respiration; D012146:Rest / Q000502:physiology