title: Alteration of Heart Rate Variability in Patients of Depression.
abstract: BACKGROUND
  Altered cardiac autonomic functions in form of reduced Heart Rate Variability (HRV) have been found to be associated with increased cardiovascular morbidity and mortality in depressive patients.
  
  
  OBJECTIVE
  To investigate the relationship between HRV measures, which is a non-invasive marker of autonomic nervous system and depression.
  
  
  METHODS
  The study included a convenient sample size of drug naive depressive patients (n=30) diagnosed on basis of ICD-10 and compared with age and gender matched healthy volunteers (n=30). Five minute ECG recording was done for HRV analysis and frequency domain measures like LF (Low Frequency), HF (High Frequency), LF/HF ratio as well as time domain measures like SDNN (Standard Deviation of all NN interval) and RMSSD (Root Mean Square of Successive differences of NN intervals) were obtained.
  
  
  RESULTS
  In the frequency domain parameters, values of LF (nu) and LF/HF Ratio were found to be significantly higher (p<0.001) whereas, that of HF (nu) was significantly lower (p<0.001) in depression group as compared to control group. However, in the time domain parameters, no significant difference was observed in SDNN and RMSSD values in between the two groups.
  
  
  CONCLUSIONS
  HRV recordings showed significant changes in frequency domain parameters in the patients suffering from depression. Thus, it could be said from our study that autonomic imbalance reflecting enhanced sympathetic activation relative to parasympathetic component is associated with depression.
authors.affiliation: Senior Resident, Department of Physiology, Lady Hardinge Medical College and Associated Hospitals , New Delhi, India .
authors.forename: Deepti
authors.initials: D
authors.lastname: Jangpangi
authors.affiliation: Director Professor and Head, Department of Physiology, Lady Hardinge Medical College and Associated Hospitals , New Delhi, India .
authors.forename: Sunita
authors.initials: S
authors.lastname: Mondal
authors.affiliation: Professor, Department of Physiology, Lady Hardinge Medical College and Associated Hospitals , New Delhi, India .
authors.forename: Rajiv
authors.initials: R
authors.lastname: Bandhu
authors.affiliation: Head of Department and Director Professor, Department of Psychiatry, Lady Hardinge Medical College and Associated Hospitals , New Delhi, India .
authors.forename: Dinesh
authors.initials: D
authors.lastname: Kataria
authors.affiliation: Director Professor, Department of Physiology, Lady Hardinge Medical College and Associated Hospitals , New Delhi, India .
authors.forename: Asha
authors.initials: A
authors.lastname: Gandhi
keywords: Autonomic nervous system; Cardiovascular disease; Major depressive disorder