title: Heart rate variability in unmedicated patients with bipolar disorder in the manic phase.
abstract: OBJECTIVE
  Decreased heart rate variability (HRV) has been proposed in bipolar disorder. To date, there has been no adequate study that has investigated resting HRV in unmedicated patients with bipolar disorder in the manic state.
  
  
  METHODS
  To examine whether bipolar mania is associated with decreased HRV, 61 unmedicated patients with bipolar mania and 183 healthy volunteers aged 20-65 years were recruited for this case-control analysis. The Young Mania Rating Scale (YMRS), Clinical Global Impression-Severity, Hamilton Depression Rating Scale (HAM-D), and Hamilton Anxiety Rating Scale (HAM-A) were used for the clinical ratings. Cardiac autonomic function was evaluated by measuring HRV parameters and the frequency-domain indices of HRV were obtained.
  
  
  RESULTS
  Patients with bipolar mania exhibited significantly lower mean RR interval, variance, low-frequency (LF)-HRV, and high-frequency (HF)-HRV but higher LF/HF compared to controls. Decreased HRV (variance) was associated with the YMRS total scores. Both the YMRS total scores and the Clinical Global Impression-Severity scores were positively correlated with the LH/HF ratio and inversely correlated with the HF-HRV. There was no significant correlation between the HAM-D/HAM-A scores and any HRV parameter.
  
  
  CONCLUSIONS
  Bipolar mania is associated with cardiac autonomic dysregulation, highlighting the importance of assessing HRV in manic patients. Further studies examining the influence of anti-manic psychotropic drugs on cardiac autonomic regulation in bipolar mania are needed.
authors.affiliation: Department of Psychiatry, Tri-Service General Hospital, Taipei, Taiwan.
authors.forename: Hsin-An
authors.initials: HA
authors.lastname: Chang
authors.forename: Chuan-Chia
authors.initials: CC
authors.lastname: Chang
authors.forename: Nian-Sheng
authors.initials: NS
authors.lastname: Tzeng
authors.forename: Terry B J
authors.initials: TB
authors.lastname: Kuo
authors.forename: Ru-Band
authors.initials: RB
authors.lastname: Lu
authors.forename: San-Yuan
authors.initials: SY
authors.lastname: Huang
mesh_terms: D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D011569:Psychiatric Status Rating Scales; D055815:Young Adult
keywords: bipolar disorder; cardiac autonomic function; heart rate variability; mania; vagal control