title: Cardiac autonomic regulation is impaired in girls with major depression.
abstract: We aimed to study short-term heart rate variability (HRV) as an index of cardiac autonomic control in never-treated major depressive disorder (MDD) adolescent patients using linear and nonlinear analysis.
  
  
  METHODS
  We have examined 20 MDD girls and 20 healthy age-matched girls at the age of 15 to 18yr. The ECG was recorded in three positions: the 1st supine rest, orthostasis, the 2nd supine position. HRV magnitude was quantified by time and frequency-domain analysis (mean RR interval, SDRR, RMSSD, spectral powers in low [LF] and high frequency [HF] bands). In addition to linear measures, HRV complexity was assessed by nonlinear (symbolic dynamics) indices: normalized complexity index (NCI), normalized unpredictability index (NUPI), and pattern classification measures (0V%, 1V%, 2LV%, 2UV%).
  
  
  RESULTS
  HRV magnitude (RMSSD, SDRR, LF and HF powers) was significantly decreased in MDD group in a supine rest and after posture change. HRV complexity was significantly reduced (lower NCI) in the standing position. Pattern classification analysis revealed significantly higher 0V% and lower 2LV% in MDD group in supine position and orthostasis.
  
  
  CONCLUSIONS
  The HRV linear and nonlinear analysis revealed decreased magnitude and complexity of heart rate time series indicating altered neurocardiac regulation in girls with major depression without pharmacotherapy.
authors.affiliation: Department of Physiology and Center of Excellence for Perinatology Research, Jessenius Faculty of Medicine, Comenius University, 036 01 Martin, Slovak Republic. tonhajzerova@jfmed.uniba.s
authors.forename: Ingrid
authors.initials: I
authors.lastname: Tonhajzerova
authors.forename: Igor
authors.initials: I
authors.lastname: Ondrejka
authors.forename: Kamil
authors.initials: K
authors.lastname: Javorka
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Turianikova
authors.forename: Ivan
authors.initials: I
authors.lastname: Farsky
authors.forename: Michal
authors.initials: M
authors.lastname: Javorka
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001341:Autonomic Nervous System / Q000503:physiopathology*; D003865:Major Depressive Disorder / Q000503:physiopathology*; D004244:Dizziness / Q000503:physiopathology; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D007297:Inpatients; D018579:Patient Selection; D018709:Statistics, Nonparametric; D016683:Supine Position; D018667:Tilt-Table Test