Regulation Of Heart Rate Research Articles

Parametric analysis of an integrated cardio-respiratory model in preterm newborns during apnea

The analysis of the complex interactions involved in the acute physiological response to apnea-bradycardia events in preterm newborns remains a challenging task. This paper presents a novel integrated model of cardio-respiratory interactions, adapted to preterm newborns. A sensitivity analysis, based Morris’ screening method, was applied to study the effects of physiological parameters on heart rate and desaturation, during the simulation of a 15-seconds apnea-bradycardia episode. The most sensitive parameters are associated with fundamental, integrative physiological mechanisms involving: (i) respiratory mechanics (intermediate airways and lung compliance), (ii) fraction of inspired oxygen, (iii) metabolic rates (oxygen consumption rate), (iv) heart rate regulation and (v) chemoreflex (gain). Results highlight the relevant influence of physiological variables, involved in preterm apnea-bradycardia events.

Effect of Exercise on Heart Rate - Curiosity Turned into an Experiment

The heart pumps and circulates the blood throughout the system, contracting and relaxing in a rhythm with each beat. The autonomic nervous system (ANS) controls involuntary body function (heart rate, BP, breathing and more), the sympathetic nervous system (SNS), a branch of ANS, is activated in response to exercise and stress. SNS activation releases hormones like epinephrine and norepinephrine, which cause an increase in heart rate involving specific receptors on heart cells. It is very well known how the nervous system controls the heart function, this review article summarizes the findings on sympathetic regulation of heart rate. Of note, some pilot experiments were conducted in random groups of high school students to elucidate the effect of exercise on heart rate. A statistically significant increase in heart rate was observed after exercise.

Physical functional recovery in the early period after hospitalization for COVID-19: impact of hypertension and outcome prediction model

The aim – to study the influence of hypertension (HT) on the dynamics of natural recovery of physical functional status in the early period after hospitalization for COVID-19 and to develop a model for predicting recovery results at 1 month after discharge.Materials and methods. 221 hospitalized patients with COVID-19 (age 53.4±13.6 years, 53 % women) were included in the study, 176 of whom underwent the 6-minute walk test (6MWT) using an extended protocol within 1-2 days before discharge. A repeat visit to assess the dynamics of natural recovery was performed at 1 month after discharge.Results and discussion. Pre-discharge 6-minute walk distance was 378±57 m in patients with HT and 418±75 m without it, p=0.001, during the second visit – 440±52 versus 478±68, p=0.002; the achieved percentage of the individually predicted distance was 67.4±10.5 vs. 69.5±13.6 % and 81.6±9.9 vs. 81.9±15.7 %, respectively, p>0.05 for both visits. The increase in heart rate during the test at visit 1 was 18.5±8.3 versus 30.1±19.3 bpm, p<0.001, the percentage of chronotropic reserve utilizatoin was 21.3±9.6 % versus 29.2±11.4 %, p<0.001. During the second visit, residual manifestations of this trend were observed, with an increase in HR by 24.0±9.5 vs. 30.8±12.1, p=0.003 and the use of chronotropic reserve of 28.1±10.1 % vs. 33.4±12.4 %, respectively, p=0.029. The developed multivariate linear regression model explained 59 % of the variability in the achieved percentage of the individually predicted 6-minute walk distance at 1 month after discharge. The use of machine learning allowed to create an artificial neural network based regression model that used age, height, use of remdesivir in treatment, and SBP and DBP values at the time of discharge as predictors, and explained 90 % of observed variability.Conclusions. Hospitalized patients with COVID-19 were characterized by a decrease in the general physical functional status as assessed by 6MWT at the time of discharge and incomplete recovery after 1 month. Presence of hypertension was associated with more pronounced disturbances of the autonomic regulation of heart rate, but did not affect the reached percentage of the distance walked. The proposed artificial neural network based regression model allows for a high accuracy prediction of the 6MWT results at 1 month after discharge, which can be used in the selection of candidates for cardiopulmonary rehabilitation programs.

Постуральный баланс при выполнении теста Ромберга у футболистов с различными типами вегетативной регуляции

The study is relevant due to the importance of a high level of postural balance and optimal autonomic regulation in football players’ athletic activity, as well as due to the lack of such comprehensive research. The purpose of the article was to study postural balance maintenance during the Romberg test on a stabilometric platform in football players with different types of autonomic heart rate regulation. Materials and methods. The research involved 100 football players. Based on the cardiointervalograms recorded initially, the participants were divided into groups according to the types of autonomic regulation. Further, centre of pressure fluctuations on the platform were recorded while maintaining a vertical posture with eyes open (54 s) and closed (54 s). Results. Football players with the normotonic and vagotonic types of autonomic regulation are characterized by a higher level of postural balance maintenance in the position with eyes open. In the position with eyes closed, a higher level of postural balance maintenance was found in football players with the vagotonic type of autonomic regulation. The normotonic and vagotonic types of autonomic regulation in football players can be considered optimal for effective posture maintenance under simple conditions, as well as for a normal course of compensatory-adaptive rearrangements in the body and successful adaptation to complicated posture maintenance conditions. The results obtained in this study broaden the current understanding of the postural control system in football players, as well as of the role of the type of autonomic regulation in maintaining postural balance under complicated conditions.

The pancreas does not contribute to the non-adrenergic-non-cholinergic stimulation of heart rate in digesting pythons

Vertebrates elevate heart rate when metabolism increases during digestion. Part of this tachycardia is due to a non-adrenergic-non-cholinergic (NANC) stimulation of the cardiac pacemaker, and it has been suggested these NANC factors are circulating hormones that are released from either gastrointestinal or endocrine glands. The NANC stimulation is particularly pronounced in species with large metabolic responses to digestion, such as reptiles. To investigate the possibility that the pancreas may release hormones that exert positive chronotropic effects on the digesting Burmese python heart, a species with very large postprandial changes in heart rate and oxygen uptake, we evaluate how pancreatectomy affects postprandial heart rate before and after autonomic blockade of the muscarinic and the beta-adrenergic receptors. We also measured the rates of oxygen consumption and evaluated the short-term control of the heart using the spectral analysis of heart rate variability and the baroreflex sequence method. Digestion caused the ubiquitous tachycardia, but the intrinsic heart rate (revealed after the combination of atropine and propranolol) was not affected by pancreatectomy and therefore hormones, such as glucagon and insulin, do not appear to contribute to the regulation of heart rate during digestion in Burmese pythons.

Особливості психічного стану у кваліфікованих борців

Purpose: research of psychical state in qualified wrestlers in stage of special basic fitness. Material and methods. The study involved 31 skilled Greco-Roman wrestlers aged 14-16 years, pupils of the wrestling club in Kremenchuk. To assess the mental state of skilled wrestlers, the Luscher color test was used. According to the results of the study, the following indicators were obtained: performance, fatigue, anxiety, deviation from the autogenous norm, eccentricity, concentricity, vegetative coefficient, heteronomy and autonomy. Heart rate variability was studied as an indicator of mental stress. The cardiac monitor «Fazagraf» was used. Based on the results of the study, we obtained statistical processing indicators and spectral characteristics of cardiac intervals. Non-parametric statistics with the determination of the median, lower and upper quartiles were used to assess the differences between the studied parameters. Results: in wrestlers with high tension of the autonomic regulation system, a deterministic functional system aimed at ensuring the mental state is revealed. At the same time, an increase in the tension of autonomic regulation is accompanied by mental fatigue, anxiety, passivity and the presence of mental stress. Prevention of mental stress in skilled wrestlers may be associated with the activation of the athlete to external environmental stimuli, optimism and a mood for positive behavior. The relationship between the indicators of mental state and the parameters of mental functions in skilled wrestlers was revealed. The moderate tension of the heart rate regulation system in skilled wrestlers is accompanied by an increase in mental performance and a decrease in anxiety. In turn, the increase in the tension of autonomous regulation is reflected in the presence of internal psychological discomfort and independence in the formation of decision-making. However, there is an increase in anxiety and a decrease in mental performance. Conclusions. The relationship between indicators of mental state and parameters of psychical functions in qualified wrestlers was revealed. Moderate tension of the heart rhythm regulation system in qualified wrestlers is accompanied by an increase in mental capacity and a decrease in anxiety. The increase in the tension of autonomous regulation in qualified wrestlers is reflected in the presence of internal psychological discomfort and independence in decision-making. Keywords: mental state, qualified wrestlers, heart rate regulation, indicators, analysis.

Beta Blockers—Still the Best Option or an Obligation!

Beta blockers (BBs) are widely acknowledged as a standard care for numerous cardiovascular conditions. They have a long-established history in treating angina, regulating heart rate in atrial fibrillation and ventricular tachycardia, and managing heart failure with reduced ejection fraction (HFREF). The effectiveness of BBs in treating acute coronary syndrome was established during a time when reperfusion therapies were not readily available. However, with the recent advancements in coronary revascularization techniques, the role of BB therapy in managing patients after a myocardial infarction and in those with stable angina has become a subject of debate. Likewise, there are uncertainties about the efficacy of BBs in individuals with HFREF who also suffer from atrial fibrillation, as well as in patients with heart failure with preserved ejection fraction (HFPEF). Furthermore, there are numerous concerns about using BBs as the initial therapy, as was customary in hypertension management in the past, and safety concerns regarding their use in patients undergoing non-cardiac surgery. This comprehensive review aims to thoroughly examine all existing recent evidence concerning BB therapy in various cardiovascular scenarios and to provide a valuable guidance to the clinicians in the field of cardiology.

Dlg1 gene expression and sexual dimorphism in regulation of heart rate and its variability in a murine model

Dlg1 gene expression and sexual dimorphism in regulation of heart rate and its variability in a murine model

Sympathetic transduction of cardiac sympathetic nerve activity in healthy, conscious sheep.

Sympathetic transduction is the study of how impulses of sympathetic nerve activity (SNA) affect end-organ function. Recently, the transduction of resting bursts of muscle SNA (MSNA) has been investigated and shown to have a role in the maintenance of blood pressure through changes in vascular tone in humans. In the present study, we investigate whether directly recorded resting cardiac SNA (CSNA) regulates heart rate (HR), coronary blood flow (CoBF), coronary vascular conductance (CVC), cardiac output (CO) and mean arterial pressure. Instrumentation was undertaken to record CSNA and relevant vascular variables in conscious sheep. Recordings were performed at baseline, as well as after the infusion of a β-adrenoceptor blocker (propranolol) to determine the role of β-adrenergic signalling in sympathetic transduction in the heart. The results show that after every burst of CSNA, there was a significant effect of time on HR (n=10, ∆: +2.1±1.4 beatsmin-1 , P=0.002) and CO (n=8, ∆: +100±150mLmin-1 , P=0.002) was elevated, followed by an increase in CoBF (n=9, ∆: +0.76mLmin-1 , P=0.001) and CVC (n=8, ∆: +0.0038mLmin-1 mmHg-1 , P=0.0028). The changes in HR were graded depending on the size and pattern of CSNA bursts. The HR response was significantly attenuated after the infusion of propranolol. Our study is the first to explore resting sympathetic transduction in the heart, suggesting that CSNA can dynamically change HR mediated by an action on β-adrenoceptors. KEY POINTS: Sympathetic transduction is the study of how impulses of sympathetic nerve activity (SNA) affect end-organ function. Previous studies have examined sympathetic transduction primarily in the skeletal muscle and shown that bursts of muscle SNA alter blood flow to skeletal muscle and mean arterial pressure, although this has not been examined in the heart. We investigated sympathetic transduction in the heart and show that, in the conscious condition, the size of bursts of SNA to the heart can result in incremental increases in heart rate and coronary blood flow mediated by β-adrenoceptors. The pattern of bursts of SNA to the heart also resulted in incremental increases in heart rate mediated by β-adrenoceptors. This is the first study to explore the transduction of bursts of SNA to the heart.

Individual typological approach to the analysis of the body function of medical students

Aim. Rationale of the individual typological approach in the analysis of the body function of medical students.Material and methods. In students with moderate (Group I) and high (II Group) dominance of central regulation, with moderate (III Group) and high (IV Group) predominance of autonomous regulation, a comparative analysis of heart rate variability parameters, the functional state of the myocardium and the central nervous system was carried out.Results. We found that 53,3% of group III students had no deviations in myocardial function. There were the maximum values of nervous response stability (2,0 [1,5-2,3] units) and functional capability of the nervous system (3,3, [2,7-3,5] units) relative to students of other groups, as well as the formation of normal and slightly reduced mental performance (93,6%), satisfactory biological adaptation (33,3%). In group II students, relative to group III students, there were an increase in the "myocardium" index by 1,2 times, "rhythm" index by 1,8-1,9 times, T wave alternans by 1,3 times and myocardial electrical instability by 2 times, as well as a decrease in nervous system stability by 2,5 times, its functionality by 1,7 times, the formation of reduced performance (55,6%) and unsatisfactory biological adaptation (35,2%). In group IV students, the functional state was characterized by heart rhythm dysregulation (94,1%), borderline myocardial function deviations (76,5%), and a 1,7-fold decrease in nervous reaction stability and 1,3-fold decrease functional capability of the nervous system relative to group III students, reduced performance (38,5%) and unsatisfactory biological adaptation (58,8%).Conclusion. Differentiation of students depending on the individual typological characteristics of the autonomic heart rate regulation makes it possible to identify students at risk with a pronounced dominance of autonomous and central heart rate regulation, which becomes the starting point for the implementation of differentiated methods of wellness education.

Essential Fatty Acid Associated with Heart Rate Variability in Highly Trained Male Cross-Country Skiers: A Pilot Study

Polyunsaturated fatty acid (PUFA) metabolites play important roles in the modulation of vascular tone, heart rate variability (HRV), and cardiovascular diseases. This study was undertaken to examine the relationship between HRV and the plasma levels of essential acids. Methods: Highly trained cross-country skiers participated in the study (n = 19). Time-domain and frequency-domain HRV analyses were performed. The plasma levels of fatty acids were determined using gas–liquid chromatography. Results: Plasma eicosapentaenoic acid and docosahexaenoic acid were found to be negatively correlated with resting heart rate (HR) (p = 0.026). The plasma levels of alpha-linolenic acid (ALA) were positively associated with the relative value of high-frequency power (rs = 0.465, p = 0.045) and negatively correlated with the sympathovagal balance ratio (rs = −0.493, p = 0.032) and the absolute and relative values of low-frequency power (rs = −0.490, p = 0.028). The plasma levels of arachidonic acid (ARA) were positively associated with the relative value of high-frequency power (rs = 0.59, p = 0.006) and negatively correlated with the sympathovagal balance ratio (rs = −0.54, p = 0.017) and the relative values of low-frequency power (rs = −0.52, p = 0.022). No correlation was found between n6/n3 and HRV parameters except for HR and pNN50. Conclusions: n-3 PUFAs and ARA play an important role in the autonomic regulation of heart rate in highly trained skiers. Athletes with substantial deficiencies in plasma ALA and excess levels of ARA had increased sympathetic and decreased parasympathetic activity.

Model-based estimation of AV-nodal refractory period and conduction delay trends from ECG.

Introduction: Atrial fibrillation (AF) is the most common arrhythmia, associated with significant burdens to patients and the healthcare system. The atrioventricular (AV) node plays a vital role in regulating heart rate during AF by filtering electrical impulses from the atria. However, it is often insufficient in regards to maintaining a healthy heart rate, thus the AV node properties are modified using rate-control drugs. Moreover, treatment selection during permanent AF is currently done empirically. Quantifying individual differences in diurnal and short-term variability of AV-nodal function could aid in personalized treatment selection. Methods: This study presents a novel methodology for estimating the refractory period (RP) and conduction delay (CD) trends, and their uncertainty in the two pathways of the AV node during 24 h using non-invasive data. This was achieved by utilizing a network model together with a problem-specific genetic algorithm and an approximate Bayesian computation algorithm. Diurnal variability in the estimated RP and CD was quantified by the difference between the daytime and nighttime estimates, and short-term variability was quantified by the Kolmogorov-Smirnov distance between adjacent 10-min segments in the 24-h trends. Additionally, the predictive value of the derived parameter trends regarding drug outcome was investigated using several machine learning tools. Results: Holter electrocardiograms from 51 patients with permanent AF during baseline were analyzed, and the predictive power of variations in RP and CD on the resulting heart rate reduction after treatment with four rate control drugs was investigated. Diurnal variability yielded no correlation to treatment outcome, and no prediction of drug outcome was possible using the machine learning tools. However, a correlation between the short-term variability for the RP and CD in the fast pathway and resulting heart rate reduction during treatment with metoprolol (ρ = 0.48, p < 0.005 in RP, ρ = 0.35, p < 0.05 in CD) were found. Discussion: The proposed methodology enables non-invasive estimation of the AV node properties during 24 h, which-indicated by the correlation between the short-term variability and heart rate reduction-may have the potential to assist in treatment selection.

Typical everyday movements cause specific patterns in heart rate.

Physical inactivity and sedentary behaviour are important risk factors for cardiovascular disease. Knowledge about the impact of everyday movements on cardiac autonomic regulation is sparse. This study aims to provide evidence that typical everyday movements show a clear impact on heart rate regulation. 40 healthy participants performed two everyday movements: (1) calmly kneeling down ("tie one's shoes") and standing up again and (2) raising the arms to the horizontal ("expressive yawning"). Both movements elicited reproducible pattern in the sequence of heart periods. Local minima and local maxima appeared in the transient period of approx. 30s. The regulatory response for ergometer cycling, which was used as control, did not show a pattern formation. Calmly performed everyday movements are able to elicit rich cardiac regulatory responses including specific patterns in heart rate. These newly described patterns have multiple implications for clinical and rehabilitative medicine, basic research, digital health data processing, and public health. If carried out regularly these regulatory responses may help to mitigate the burden of physical inactivity and enrich cardiovascular regulation.

Chronic Metabolic Syndrome develops a frailty of cardiac rhythm similar to aging in rats

Heart rhythm decreases and alterations depend on aging and correlate with lifestyle and metabolic alterations like obesity, dyslipidemia, and chronic inflammation; these alterations may also produce ventricular hypertrophy and atrial fibrillation, increasing lethal arrhythmias. The high sucrose diet in young adult Wistar rats produces metabolic syndrome from the eighth week that continues twenty-six weeks later. In this work, we analyzed the changes presented by the heart during six months of metabolic syndrome. After this period, the rats were anesthetized, and the electrocardiogram was recorded. We observed that metabolic syndrome produced bradycardia and arrhythmias. The electrocardiogram showed an 18 % decrease in the heart rate in rats with metabolic syndrome and a decreased ability to regulate heart rate variability using the p-p interval Poincare graph. The electrical activity recorded in the sinus node showed alteration in the morphology and propagation of the action potential, therefore, a dysfunction in the pacemaker and supraventricular arrhythmias. This data correlated with the increase in the collagen and lipid area in the pacemaker that produced unexcitable segments, which induced lethal arrhythmias by alterations in electrical activity and premature aging and frailty, like those described in humans. We proposed that the changes in electrical and morphological alterations in the sinus node that are associated with metabolic syndrome are the cause of cardiovascular frailty and premature aging of the heart.

Differences in heart rate responses to upright posture are associated with variations in the high-frequency power of heart rate variability.

High resting heart rate is a cardiovascular risk factor, but limited data exist on the underlying hemodynamics and reproducibility of supine-to-upright increase in heart rate. We recorded noninvasive hemodynamics in 574 volunteers [age, 44.9 yr; body mass index (BMI), 26.4 kg/m2; 49% male] during passive head-up tilt (HUT) using whole body impedance cardiography and radial artery tonometry. Heart rate regulation was evaluated using heart rate variability (HRV) analyses. Comparisons were made between quartiles of supine-to-upright heart rate changes, in which heart rate at rest ranged 62.6-64.8 beats/min (P = 0.285). The average upright increases in heart rate in the quartiles 1-4 were 4.7, 9.9, 13.5, and 21.0 beats/min, respectively (P < 0.0001). No differences were observed in the low-frequency power of HRV, whether in the supine or upright position, or in the high-frequency power of HRV in the supine position. Upright high-frequency power of HRV was highest in quartile 1 with lowest upright heart rate and lowest in quartile 4 with highest upright heart rate. Mean systolic blood pressure before and during HUT (126 vs. 108 mmHg) and the increase in systemic vascular resistance during HUT (650 vs. 173 dyn·s/cm5/m2) were highest in quartile 1 and lowest in quartile 4. The increases in heart rate during HUT on three separate occasions several weeks apart were highly reproducible (r = 0.682) among 215 participants. To conclude, supine-to-upright increase in heart rate is a reproducible phenotype with underlying differences in the modulation of cardiac parasympathetic tone and systemic vascular resistance. As heart rate at rest influences prognosis, future research should elucidate the prognostic significance of these phenotypic differences.NEW & NOTEWORTHY Subjects with similar supine heart rates are characterized by variable increases in heart rate during upright posture. Individual heart rate increases in response to upright posture are highly reproducible as hemodynamic phenotypes and present underlying differences in the modulation of cardiac parasympathetic tone and systemic vascular resistance. These results indicate that resting heart rate obtained in the supine position alone is not an optimal means of classifying people into groups with differences in cardiovascular function.

Central stress pathways in the development of cardiovascular disease.

Mental stress is of essential consideration when assessing cardiovascular pathophysiology in all patient populations. Substantial evidence indicates associations among stress, cardiovascular disease and aberrant brain-body communication. However, our understanding of the flow of stress information in humans, is limited, despite the crucial insights this area may offer into future therapeutic targets for clinical intervention. Key terms including mental stress, cardiovascular disease and central control, were searched in PubMed, ScienceDirect and Scopus databases. Articles indicative of heart rate and blood pressure regulation, or central control of cardiovascular disease through direct neural innervation of the cardiac, splanchnic and vascular regions were included. Focus on human neuroimaging research and the flow of stress information is described, before brain-body connectivity, via pre-motor brainstem intermediates is discussed. Lastly, we review current understandings of pathophysiological stress and cardiovascular disease aetiology. Structural and functional changes to corticolimbic circuitry encode stress information, integrated by the hypothalamus and amygdala. Pre-autonomic brain-body relays to brainstem and spinal cord nuclei establish dysautonomia and lead to alterations in baroreflex functioning, firing of the sympathetic fibres, cellular reuptake of norepinephrine and withdrawal of the parasympathetic reflex. The combined result is profoundly adrenergic and increases the likelihood of cardiac myopathy, arrhythmogenesis, coronary ischaemia, hypertension and the overall risk of future sudden stress-induced heart failure. There is undeniable support that mental stress contributes to the development of cardiovascular disease. The emerging accumulation of large-scale multimodal neuroimaging data analytics to assess this relationship promises exciting novel therapeutic targets for future cardiovascular disease detection and prevention.

Cardiorhythm in postural changes depending on the autonomic centers reactivity

Postural changes are accompanied by the formation of an adaptive response of the cardiovascular system. This is manifested by a change in heart rate variability. The features of the reaction largely depend on the excitability (reactivity) of the vegetative centers. The aim of the study was to identify individual features of heart rate regulation in postural changes depending on the reactivity of sympathetic and parasympathetic autonomic centers in students. Material and Methods. In 50 men, temporal, frequency, geometric and calculated indicators of heart rate variability were determined in a horizontal position, with active orthostasis, passive orthostasis and passive antiorthostasis. The reactivity of the sympathetic system was assessed by the change of heart rate in active orthostasis. The reactivity of the parasympathetic system was determined by K30:15. Results and Discussion. With normal and high sympathetic reactivity, active orthostasis causes an increase in the low-frequency power of the spectrum, stress index, heart rate, a decrease in the high-frequency component and the duration of cardiac intervals. The changes are more pronounced with high sympathetic reactivity. In passive orthostasis, high sympathetic reactivity is manifested by a large increase in heart rate, shortening of cardiac intervals and a decrease in the proportion of the spectrogram high-frequency component. Passive antiorthostasis with normal sympathetic reactivity causes a decrease in the adequacy of the regulation processes and an expansion of the scatterogram. In subjects with high parasympathetic reactivity with active orthostasis, the increase in the stress index is less than with normal and low reactivity. With low parasympathetic reactivity, the indicator of the adequacy of the regulation processes is greater than with normal and high reactivity, and the increase in heart rate and shortening of the minimum cardiac interval is greater than with normal. In passive orthostasis, the proportion of the high-frequency component decreases, the proportion of the ultra-low-frequency component increases, the modal cardiointerval shortens, which is more pronounced with low parasympathetic reactivity than with normal. In passive antiorthostasis, the ultra-low frequency component decreases in individuals with normal reactivity. With high reactivity, the maximum value of the high-frequency component increases and the adequacy of the regulation processes decreases. Conclusion. Active and passive orthostasis is accompanied by activation of sympathetic centers. It is more pronounced with high reactivity of the sympathetic department and low reactivity of the parasympathetic. Passive antiorthostasis stimulates the activity of parasympathetic cardiac centers in subjects with normal, high parasympathetic reactivity and normal sympathetic reactivity.

Can peripheral psychophysiological markers predict response to exposure-based cognitive behavioral therapy in youth with severely impairing irritability? A study protocol

BackgroundIrritability, an increased proneness to anger, is a primary reason youth present for psychiatric care. While initial evidence supports the efficacy of exposure-based cognitive behavioral therapy (CBT) for youth with clinically impairing irritability, treatment mechanisms remain unclear. Here, we propose to measure peripheral psychophysiological indicators of arousal—heart rate (HR)/electrodermal activity (EDA)—and regulation—heart rate variability (HRV)—during exposures to anger-inducing stimuli as potential predictors of treatment efficacy. The objective of this study is to evaluate whether in-situ biosensing data provides peripheral physiological indicators of in-session response to exposures.MethodsBlood volume pulse (BVP; from which HR and HRV canl be derived) and EDA will be collected ambulatorily using the Empatica EmbracePlus from 40 youth (all genders; ages 8-17) undergoing six in-person exposure treatment sessions, as part of a multiple-baseline trial of exposure-based CBT for clinically impairing irritability. Clinical ratings of irritability will be conducted at baseline, weekly throughout treatment, and at 3-month and 6-month follow-ups via the Clinical Global Impressions Scale (CGI) and the Affective Reactivity Index (ARI; clinician-, parent-, and child-report). Multilevel modeling will be used to assess within- and between-person changes in physiological arousal and regulation throughout exposure-based CBT and to determine whether individual differences are predictive of treatment response.DiscussionThis study protocol leverages a wearable biosensor (Empatica) to continuously record HR/HRV (derived from BVP) and EDA during in-person exposure sessions for youth with clinically impairing irritability. Here, the goal is to identify changes in physiological arousal (EDA, HR) and regulation (HRV) over the course of treatment in tandem with changes in clinical symptoms.Trial registrationThe participants in this study come from an overarching clinical trial (trial registration numbers: NCT02531893 first registered on 8/25/2015; last updated on 8/25/2023). The research project and all related materials were submitted and approved by the appropriate Institutional Review Board of the National Institute of Mental Health (NIMH).

Electric Burn Injury and Cardiac Autonomic Function

Electrical injuries are a common form of mechanical trauma that can cause significant damage to the skin and underlying tissues, as well as potentially affect other systems of the body, including the cardiovascular system. Electric burn injury can affect cardiac autonomic function, potentially leading to arrhythmias and heart failure. The autonomic nervous system plays a critical role in regulating cardiac function, acting as the primary regulator of heart rate and contractility. The balance between the two systems, sympathetic and parasympathetic, is essential for optimal cardiovascular function and can be assessed through measures of cardiac autonomic function. The most commonly utilized method is using the electrocardiogram (ECG) in combination with the impedance cardiogram (ICG). The pre-ejection period (PEP) can be extracted from ECG during the left ventricular ejection as a measure of cardiac sympathetic control, and the respiratory sinus arrhythmia can be extracted from ECG during respiration as a measure of cardiac parasympathetic control. This literature review explores the current understanding of how electric burn injury affects cardiac autonomic function and its potential influence on cardiac function. It also emphasize the need of further research to understand the precise mechanisms involved in the effects of electric burn injury on cardiac autonomic function and to develop effective treatment strategies to prevent adverse cardiovascular outcomes.

The Effect of Exercise on Cold-Induced Neurovegetative Dysautonomia Blindness

The autonomic nervous system (ANS) is responsible for regulating heart rate and blood pressure and maintaining homeostasis during physiological stresses. Nervous dysautonomias are often observed in patients presenting cardiovascular symptoms. Despite that, other important but less known conditions can be encountered. We report the case of a 19-year-old young man who presented for blindness occurring in the cold and improving with exercise. Investigations revealed neurovegetative dysautonomia with significant vagal hyperactivity associated with central B-sympathetic hyperactivity. Our patient received treatment based on hygienic and dietary measures with a combination of an anti-hypotensive drug such as Etilefrine. 2 months later, a re-evaluation showed a clear improvement, confirmed during the control neurovegetative exploration but also during the ophthalmological examination.