Impaired Cardiac Vagal Tone in Patients with Major Depressive Disorder

Abstract

Background: Altered cardiovascular autonomic nerve function with impaired autonomicl balance is found in Major Depressive Disorder(MDD).Objective: To assess some time domain measures of Heart Rate Variability (HRV) in MDD patients to observe their autonomic nerve function status.Methods: This cross sectional study was conducted in the Department of Physiology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, during 2011on 60 patients of both sexes with Major Depressive disorder (MDD) aged 20-50 years. They were further subdivided into 30 drug naïve and 30 patients treated with anti depressive drug. Age, sex and BMI matched 30 apparently healthy subjects were control. The HRV parameters were recorded by 4 active channels, Polyrite-D. For statistical analysis ANOVA, independent sample t-test, were performed.Result: Mean R-R interval, SDNN,RMSSD ,PNN50%, NN50% were found significanty lower but heart rate was significantly higher in all MDD patients of both group compared to control.No significant differences were found in these parameters between treated and recently diagnosed patient.Conclusion: Cardiac autonomic nerve function was impaired in MDD patient which was characterized by reduced vagal tone. Antidepressive medication may not have any effect on impaired autonomic function in MDD.Bangladesh Soc Physiol. 2015, December; 10(2): 41-45