title: Correlation among Poincaré plot indexes and time and frequency domain measures of heart rate variability.
abstract: OBJECTIVE
  In order to corroborate the rported performance advantage of Poincaré plot indexes as autonomic activity markers, the correlation among these indexes and those computed from the time and frequency domains were obtained.
  
  
  METHODS
  Starting from the RR series derived from the ECG of 21 healthy volunteers during five manoeuvres, longitudinal (L), transverse (T) axis, and autocorrelation (r) from Poincaré plots, rMSSD and standard deviation (SD) in the temporal domain, and frequency domain indexes were computed.
  
  
  RESULTS
  Poincaré plot indexes were correlated in a better way with the time indexes, rather than the spectral measures. A strong correlation (0.997) between L and SD was observed, while an underlying mathematical relationship was established for T vs rMSSD.
  
  
  CONCLUSIONS
  Poincaré plot indexes may be considered as equivalent or surrogates of the temporal ones, and they do not have a better performance as autonomic markers.
authors.affiliation: Departmento de Canarias de la Salud, Universidad Autónoma Metropolitana Iztapalapa, México, DF. scas@xanum.uam.mx
authors.forename: S
authors.initials: S
authors.lastname: Carrasco
authors.forename: M J
authors.initials: MJ
authors.lastname: Gaitán
authors.forename: R
authors.initials: R
authors.lastname: González
authors.forename: O
authors.initials: O
authors.lastname: Yánez
mesh_terms: D000328:Adult; D016000:Cluster Analysis; D004562:Electrocardiography; D015444:Exercise / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D015233:Models, Statistical; D017711:Nonlinear Dynamics; D012016:Reference Values; D012146:Rest / Q000502:physiology; D012815:Signal Processing, Computer-Assisted