The Assessment of the Autonomic Response to Acute Stress Using Electrodermal Activity

The response of autonomic nervous system to mental stress is currently studied as a key role factor in the pathophysiology of stress related diseases. Altered autonomic regulation can result in increased morbidity, potentially affecting (directly or indirectly) any of the organs. Cardiovascular system (CVS) is one of the most sensitive systems to the effect of autonomic outputs. The predictive value of the laboratory stress tests was proved in several studies with CVS pathology. In this study we aimed to assess the autonomic reactivity to different mental stressors (cognitive and emotional) in healthy subjects using electrodermal activity (EDA) as a sensitive psychophysiological marker of sympathetic activity. We found significantly increased EDA in response to all the mental tasks with decrease of the values during recovery periods. However, EDA did not return to the baseline values during recovery periods, potentially indicating the sympathetic arousal during complete stress profile protocol. We suggest EDA presents a well applicable marker of the sympathetic activation, offering a different information about central regulation processes regarding the sympathetic activity compared to cardiac autonomic indices

Potential Effect of Pharmacotherapy on Sympathetic Arousal in Autism

Background: Autism spectrum disorder (ASD) is a serious neurodevelopmental disorder associated with autonomic nervous system (ANS) abnormalities. Moreover, at least 50% of children with ASD suffer from other comorbid diseases such as anxiety, depression, and attention deficit hyperactivity disorder (ADHD) associated with receiving psychotropic medication. From this context we aimed to evaluate changes in sympathetic arousal using analysis of electrodermal activity (EDA) as an index of sympathetic cholinergic activity in treated and non-treated autistic children under resting conditions

Therapeutic Drug Monitoring of Venlafaxine and Impact of Age, Gender, BMI, and Diagnosis

Depression is a common mental disorder affecting more than 264 million people in the world and 5.1% of the Slovak population. Although various antidepressant approaches have been used; still, about 40% of patients do not respond to a first-choice drug administration and one third of patients do not achieve total remission. Therapeutic drug monitoring (TDM) is a method used for quantification and interpreting the drug concentrations in plasma in order to optimize the pharmacotherapy. The aim of this study was to measure the plasma concentrations of venlafaxine, the fourth most prescribed antidepressant in Slovakia, as well as its active metabolite and interpret them with the relevant patients’ characteristics

Biofeedback – A Promising Non Pharmacological Tool of Stress – Related Disorders

Biofeedback is a therapeutic method of obtaining better awareness of physiological functions based on principles of operant conditioning and learning in general. While patient observes changes in physiological parameters in real-time (e.g. blood pressure, heart rate variability, temperature, electrodermal activity, etc.), he/she learns how to manipulate them at will. By means of this technique, individuals can improve their mental, emotional, and physical health. Clinical biofeedback training becomes popular for treating a variety of medical conditions, manage ment of disease symptoms, and improvement of overall health through training of stress management. There is no center or group to systematically deal with biofeedback methods in Slovakia, except the Slovak Institute of CBT (cognitive-behavioral therapy) that teaches biofeedback as a therapeutic method. However, biofeedback and its opportunities have a relatively long history of exploration and practice, which is the best precondition for positive changes in this area. The review article aims to provide an insight to biofeedback training as a non-pharmacological therapeutic tool in stress management and stress-related diseases and disorders. The article also describes biofeedback modalities and efficacy on various medical conditions

Blood Cell Counts and Blood Cell Ratios as Non-Specific Major Depressive Disorder Biomarkers

Introduction: With an increasing prevalence of major depressive disorder (MDD) in population there is a particular interest in finding a suitable biomarker for diagnosis and prognosis of the disease. Many studies have shown that MDD is linked to a systemic inflammatory process, so blood elements counts and ratios have been suggested to be promising indicators in the management and effectiveness of the disease therapy. The aim of this retrospective study was to compare absolute and relative white blood cells counts and to search for any changes in their ratios before and after the therapy of the patients

Sympathetic nervous system and cardiovascular risk in mitral valve prolapse

Mitral valve prolapse (MVP) represents a frequent cardiovascular condition associated with increased cardiovascular risk, which may have progressive course and become malignant. Dysregulation of autonomic nervous system - especially sympathetic overdrive – is one of the factors considered to play a key role in its aetiology and development. There is a growing evidence of a large impact of sympathetic system on the development of MVP. Exaggerated sympathetic activity may lead to morphologic changes in valves tissue such as thickening and redundancy. Nowadays, few investigative methods are known for evaluation of the regulatory state of sympathetic nervous system, which could be, theoretically, used to identify the subjects with sympathetic overactivity associated with an increased cardiovascular risk. Electrodermal activity or blood pressure variability represent promising non-invasive methods for evaluation of the regulatory outputs of sympathetic nervous system. There is a possibility to extend a set of investigative methods in MVP and include the monitoring of sympathetic activity in the assessment of cardiovascular risk. This article summarizes knowledge about pathogenesis, diagnostic and therapeutical approaches of MVP, and brings some novel insights on the parameters of autonomic nervous regulation, which haven’t yet been used in cardiovascular risk assessment in MVP

Multiscale time irreversibility of heart rate and blood pressure variability during orthostasis

Time irreversibility is a characteristic feature of non-equilibrium, complex systems such as the cardiovascular control mediated by the autonomic nervous system (ANS). Time irreversibility analysis of heart rate variability (HRV) and blood pressure variability (BPV) represents a new approach to assess cardiovascular regulatory mechanisms. The aim of this paper was to assess the changes in HRV and BPV irreversibility during the active orthostatic test (a balance of ANS shifted towards sympathetic predominance) in 28 healthy young subjects.We used three different time irreversibility indices— Porta’s, Guzik’s and Ehler’s indices (P%, G%and E, respectively) derived from data segments containing 1000 beat-to-beat intervals on four timescales. We observed an increase in the HRV and a decrease in the BPV irreversibility during standing compared to the supine position. The postural change in irreversibility was confirmed by surrogate data analysis. The differences were more evident in G% and E than P% and for higher scale factors. Statistical analysis showed a close relationship between G% and E. Contrary to this, the association between P% and G% and P% and E was not proven. We conclude that time irreversibility of beat-to-beat HRV and BPV is significantly altered during orthostasis, implicating involvement of the autonomous nervous system in its generation.L. Chladekova, B. Czippelova, Z. Turianikova, I. Tonhajzerova, A. Calkovska, M. Baumert and M. Javork