title: Heart rate time irreversibility is impaired in adolescent major depression.
abstract: We aimed to study heart rate time irreversibility--a nonlinear qualitative characteristics of heart rate variability indicating complexity of cardiac autonomic control at rest and in response to physiological stress (orthostasis) in never-treated major depressive disorder (MDD) adolescent female patients.
  
  
  METHODS
  We studied 20 MDD girls and 20 healthy age-matched girls at the age of 15 to 18 years. The ECG was recorded in supine position and in response to position change from lying to standing (orthostasis). Time irreversibility analysis was performed using Porta's (P%), Guzik's (G%) and Ehlers' (E) index. The depressive disorder severity was evaluated using Montgomery-Asberg Depression Rating Scale (MADRS) and Children's Depression Inventory (CDI).
  
  
  RESULTS
  Resting heart rate time irreversibility indices (logG%, logP%, Ehlers' index) were significantly reduced in MDD female patients without significant differences in response to orthostasis in MDD girls compared to controls. No significant correlations between time irreversibility and MDD severity were observed.
  
  
  CONCLUSIONS
  This study revealed the impaired heart rate asymmetry pattern indicating an altered complexity of cardiac autonomic regulation in adolescent female patients suffering from MDD.
authors: Department of Physiology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovak Republic. tonhajzerova@jfmed.uniba.sk
authors: Ingrid
authors: I
authors: Tonhajzerova
authors: Igor
authors: I
authors: Ondrejka
authors: Lenka
authors: L
authors: Chladekova
authors: Ivan
authors: I
authors: Farsky
authors: Zuzana
authors: Z
authors: Visnovcova
authors: Andrea
authors: A
authors: Calkovska
authors: Alexander
authors: A
authors: Jurko
authors: Michal
authors: M
authors: Javorka
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000502:physiology*; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology*; D004562:Electrocardiography / Q000379:methods / Q000523:psychology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D017711:Nonlinear Dynamics; D011187:Posture / Q000502:physiology; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D063189:Symptom Assessment / Q000379:methods / Q000523:psychology*; D013997:Time Factors