title: Heart rate variability in patients with atrial septal defect and healthy children.
abstract: OBJECTIVE
  Heart rate variability (HRV) measures are altered in various cardiac and non-cardiac situations in children. The autonomic nervous system is assumed to have a role in the pathophysiology of atrial septal defect (ASD). In this study, we evaluated the autonomic system by measuring HRV in children with ASD.
  
  
  METHODS
  Twenty-eight patients with ASD and 32 healthy children (mean ages: 6.6±2.1 years and 6.4±2.2 years, respectively) were enrolled in the study. Twenty-four-hour ambulatory electrocardiographic recordings were obtained and the seven time-domain (SDNN, SDANN, rMSSD, SD, SDNN index, PNN50, and mean RR) and four frequency-domain (VLF, LF, HF, and LF/HF ratio) indices of HRV were analyzed.
  
  
  RESULTS
  A significant decrease in calculated HRV variables was observed in children with ASD as compared to controls. The HRV alteration was found in both time-domain and frequency-domain parameters.
  
  
  CONCLUSIONS
  Our results indicate that HRV is decreased in children with ASD, which implies parasympathetic withdrawal and sympathetic predominance.
authors.affiliation: The Karen Hospital, Department of Pediatric Cardiology, Nairobi, Kenya.
authors.forename: Süleyman
authors.initials: S
authors.lastname: Bakari
authors.forename: Bülent
authors.initials: B
authors.lastname: Koca
authors.forename: Funda
authors.initials: F
authors.lastname: Oztunç
authors.forename: Mahmut
authors.initials: M
authors.lastname: Abuhandan
mesh_terms: D001341:Autonomic Nervous System / Q000502:physiology* / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D015716:Electrocardiography, Ambulatory; D005260:Female; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D006344:Heart Septal Defects, Atrial / Q000209:etiology* / Q000503:physiopathology*; D006801:Humans; D008297:Male