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

Abstract

IntrOductIOnIt has been reported in prior research that autonomic nervous system (ANS) is significantly compromised in depression/phobic anxiety patients [1]. Carmilla MM Licht et al., hypothesized that depression is associated with lower heart rate variability (HRV) and decreased cardiac vagal control [2]. In the last 2 decades, various studies have shown a significant relationship between the ANS and cardiovascular mortality, including death [3,4]. HRV is one of the most promising markers in evaluating the ANS. Being an easy derivation, HRV has popularized its use and many commercial devices are now available which provide an automated measurement of HRV. An accurate view of the ANS as well as the variability of the heart is tested by HRV. The analysis is based on measuring variability in heart rate; specifically variability in the intervals between R waves -"RR intervals." Heart Rate Variability (HRV) as a whole monitors the mean heart rate and autonomic nervous system function [5]. Two subjects can have exactly or nearly the same average heart beat, but when the time period between each heartbeat is calculated specifically, the variation of time between each beat is different for different subject.The main advantage of HRV test is its ability to detect the early signs and symptoms of pathological processes or any functional disorder which may not be detected by the ordinary physical examination. Diminished HRV detects both arrhythmic events and death with higher sensitivity and specificity than conventional methods. It has been shown to be a reliable indicator of overall health but also be a predictor of sudden death [6].Prior studies suggested that individuals suffering from depression often show decreased vagal tone, increased heart rate, fatigue, sleep disturbance, and sympathetic arousal. Maria Karavidas in her study of Biofeedback for HRV has proved that improving LF component of HRV and SDNN values is a useful adjunctive treatment for major depressives [1]. A study of HRV in patients of depression with history of chemical irritants can go a long way in effective treatment of depression. As we know there is a close link between autonomic nervous function and function of SA node, heart rate and its fluctuations reflect changes in cardiac autonomic control.The sympathetic and parasympathetic (vagal) activity of ANS on the sinus node can be very easily accessed by a noninvasive technique i.e. HRV. Increased sympathetic stimulation increases the heart rate and decreases the variability of the heart rate. The efferent vagal activity is a major contributor to the HF component the LF component, which is considered as marker of both sympathetic and vagal influences [5]. Important and debilitating feature of multiple chemical sensitivity (MCS) is its ability to augment the effects of other problems like Depression and Asthma. The augmentation of this kind is reported by 50% of all multiple chemical sensitivity syndrome sufferers [7][8][9].Terri Perry reported that many people were adversely affected by chemical ...

Correlative study on the effect of toxic paint chemicals on the hepatorenal of paint factory workers in Enugu, Nigeria

“…These symptoms may manifest as transient symptoms of the CNS (e.g. euphoria, headache and dizziness) at low or moderate concentrations and serious symptoms such as fainting, respiratory and circulatory failure at high concentrations [8][9][10]. Solvents such as benzene, toluene, and xylenes (BTXs) are reported to be carcinogenic and therefore need effective control [11,12].…”