title: Cardiovascular autonomic control in paraplegic and quadriplegic.
abstract: BACKGROUND
  Spinal cord injury (SCI) is commonly associated with devastating paralysis. This condition also results in cardiovascular autonomic dysfunction associated with increased mortality from cardiovascular disease. The purpose of this study was to explore the differences in cardiovascular autonomic modulation in individuals with and without SCI.
  
  
  METHODS
  The study included 60 individuals: 30 individuals without SCI, who formed the control group-CG and 30 individuals with SCI, who formed the SCI group-SCIG. The latter group was divided into two, one group of subjects with SCI above the spinal segment T6-SCIG (above T6) and a group of individuals with SCI below T6-SCIG (below T6). The subjects were evaluated by linear and nonlinear analysis of heart rate variability (HRV).
  
  
  RESULTS
  The SCIG showed significantly lower square root of the mean squares differences of successive NN intervals (rMSSD), number of pairs of adjacent NN intervals differing by more than 50 ms (pNN50), standard deviation of short-term HRV (SD1), and high frequency power (HF). Their low frequency power (LF) in absolute units (ms(2)) was significantly lower and their normalized units (n.u.) were significantly higher. Their LF/HF ratio was significantly higher, and sample entropy (SampEn), which indicates the complexity and irregularity of the NN intervals time series, was significantly lower compared to the CG. The differences between the SCIG and CG were derived mainly from the SCIG (above T6). The correlation test revealed very low values between each of the parameters evaluated for CG and SCIG.
  
  
  CONCLUSIONS
  The SCIG (above T6) showed greater cardiovascular autonomic impairment compared to SCIG (below T6) and CG. The SCIG (below T6) also presented some degree of autonomic dysfunction. All parameters, linear or nonlinear, are suitable to demonstrate the differences between the SCIG and CG.
authors.affiliation: Sensory Motor Rehabilitation Engineering Laboratory, Universidade do Vale do Paraíba (UNIVAP), Avenida: Shishima Hifumi, 2911, Urbanova, São José dos Campos, SP, 12244-000, Brazil. eliz_nasa@yahoo.com.br.
authors.forename: Elizângela Márcia
authors.initials: EM
authors.lastname: de Carvalho Abreu
authors.affiliation: Sensory Motor Rehabilitation Engineering Laboratory, Universidade do Vale do Paraíba (UNIVAP), Avenida: Shishima Hifumi, 2911, Urbanova, São José dos Campos, SP, 12244-000, Brazil.
authors.forename: Lucas Pinto Salles
authors.initials: LP
authors.lastname: Dias
authors.affiliation: Sensory Motor Rehabilitation Engineering Laboratory, Universidade do Vale do Paraíba (UNIVAP), Avenida: Shishima Hifumi, 2911, Urbanova, São José dos Campos, SP, 12244-000, Brazil.
authors.forename: Fernanda Pupio Silva
authors.initials: FP
authors.lastname: Lima
authors.affiliation: Instituto Nacional de Pesquisa Espacial (INPE), São José dos Campos, Brazil.
authors.forename: Alderico Rodrigues
authors.initials: AR
authors.lastname: de Paula Júnior
authors.affiliation: Sensory Motor Rehabilitation Engineering Laboratory, Universidade do Vale do Paraíba (UNIVAP), Avenida: Shishima Hifumi, 2911, Urbanova, São José dos Campos, SP, 12244-000, Brazil.
authors.forename: Mário Oliveira
authors.initials: MO
authors.lastname: Lima
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001342:Autonomic Nervous System Diseases / Q000503:physiopathology*; D002319:Cardiovascular System / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010264:Paraplegia / Q000209:etiology / Q000503:physiopathology; D011782:Quadriplegia / Q000209:etiology / Q000503:physiopathology; D013119:Spinal Cord Injuries / Q000150:complications / Q000503:physiopathology*
keywords: Autonomic nervous system; Heart rate variability; Spinal cord injury