Assesment of Heart Rate Variability As A Measure of Cardiac Autonomic Status in Psychiatric Patients Exposed to Chemical Irritants.

BACKGROUND AND PURPOSE: However, little is known about the cardiac autonomic activity due to chemicals in psychiatric patients. Therefore, the objective of this study was to assess the effect of chemical irritants on the ANS of the person and measure that in the form of Heart Rate Variability (HRV), a noninvasive method to estimate the cardiac autonomic activity. The autonomic nervous system can significantly compromised by use of chemical irritants.

MATERIALS AND METHODS: A cross-sectional hospital based study was conducted in which 33 patients (mean age: 29.94 years) of depression/anxiety were compared with 37 age matched controls (mean age: 28.10). The patients who were diagnosed as either depressed or anxious by the psychiatry were included in the study group by random sampling. Out of these 8 patients gave positive history of odour use. Thirty seven age matched healthy persons were taken as controls. Grading of patients was done according to DSMV-IV criteria and short- term HRV was recorded. Five minute HRV recording was done and time domain and frequency domain indices of HRV were assessed using RMS Polyearite D. The result in case and control groups was compared.

RESULTS: We have reported a poor HRV compared to control group in patients of depression/anxiety as reflected by NN50 values (p< 0.05). Although not significant the trend shows a better HRV control in almost all the time domain and frequency domain parameters in controls compared to cases. Regarding the history of use of chemical irritants the trend showed a poor HRV control in these cases compared to the patients who did not give any such history.

CONCLUSION: Our results suggest that impaired cardiac autonomic nerve function characterized by sympathetic over activity may occur in depression/phobic patients. The study also proves a poor HRV in psychiatric subjects with history of use of odoriferous substances.