title: Decreased cardiac vagal control in drug-naive patients with panic disorder: a case-control study in Taiwan.
abstract: BACKGROUND
  Cardiac autonomic dysregulation has been proposed in panic disorder (PD), but the results are mixed. Analyses with larger sample sizes and better methodology are needed.
  
  
  METHODS
  Forty-eight drug-naïve individuals with PD and 202 healthy volunteers were recruited for a case-control analysis. We used the Hamilton Anxiety Rating Scale and the Beck Anxiety Inventory to assess anxiety severity. Cardiac autonomic function was evaluated by measuring heart rate variability (HRV) parameters. Frequency-domain indices of HRV were obtained. The obtained results were evaluated in association with personality traits assessed by the Tridimensional Personality Questionnaire.
  
  
  RESULTS
  Patients exhibited reduced mean RR interval (816.94 ± 135.92 versus 873.47 ± 143.36 ms, P = 0.014) and HRV levels (Var 6.37 ± 1.32 versus 7.38 ± 0.95, LF 4.90 ± 1.63 versus5.82 ± 1.11 and HF 4.57 ± 1.53 versus 5.62 ± 1.24 [ln(ms2)], all P < 0.001) as compared to controls, which mainly suggested a reduction in cardiac vagal control in PD. The anxiety severity was negatively correlated with HRV levels (r = -0.29 for Var, r = -0.22 for LF and r = -0.28 for HF, all P < 0.001). The harm avoidance score (which has been suggested to be associated with serotonergic activity) was associated with decreased HRV levels (r = -0.22 for Var, P < 0.01, r = -0.14 for LF, P < 0.05 and r = -0.17 for HF, P < 0.01).
  
  
  CONCLUSIONS
  This study demonstrates that PD is associated with cardiac autonomic dysregulation, highlighting the importance of assessing HRV in PD patients.
authors.affiliation: Department of Psychiatry, Tri-Service General Hospital, National Defense Medical Center, 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: D000293:Adolescent; D000328:Adult; D001007:Anxiety / Q000503:physiopathology; D016022:Case-Control Studies; D003863:Depression / Q000503:physiopathology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016584:Panic Disorder / Q000503:physiopathology*; D010551:Personality / Q000502:physiology; D013624:Taiwan; D014630:Vagus Nerve / Q000502:physiology*; D055815:Young Adult
keywords: Taiwan; cardiac autonomic function; cardiac vagal control; heart rate variability; panic disorder