Background Many cardiocirculatory mechanisms are involved in the adaptation to orthostatic stress. While these mechanisms may be impaired in Fontan patients. However, it is yet unclear how Fontan patients, who exhibit a critical fluid balance, respond to orthostatic stress. Angiotensin converting enzyme inhibitors are often prescribed to Fontan patients, but they may negatively influence orthostatic tolerance. Therefore, we evaluated the response to orthostatic stress in pediatric Fontan patients before and after treatment with enalapril. Methods Thirty-five Fontan patients (aged 14 years) with moderate-good systolic ventricular function without pre-existent enalapril treatment were included. Before and after a three-month enalapril treatment period, the hemodynamic response to head-up tilt test was evaluated by various parameters including cardiac index, blood pressure, cerebral blood flow, aortic stiffness and cardiac autonomous nervous activity. Thirty-four healthy subjects (aged 13 years) served as controls. Results Fontan patients had a decreased cerebral blood flow and increased aortic stiffness in the supine position compared to controls, while all other factors did not differ. Patients and controls showed a comparable response to head-up tilt test for most parameters. Twenty-seven patients completed the enalapril study with a mean dosage of 0.3±0.1mg/kg/day. Most parameters were unaffected by enalapril, only the percent decrease in cardiac index to tilt was higher after treatment, but the cardiac index during tilt was not lower (3.0L/min/m2 pre-enalapril versus 2.8L/min/m2 after treatment; P = 0.15). Conclusion Pediatric Fontan patients adequately respond to orthostasis with maintenance of blood pressure and cerebral blood flow and sufficient autonomic response. Enalapril treatment did not alter the response. Clinical trial information Scientific title: ACE inhibition in Fontan patients: its effect on body fluid regulation (sAFE-study). The Netherlands National Trial Register: Trail NL6415. Registered 2017-07-20. Trial information: https://www.trialregister.nl/trial/6415

Objective
Dysregulated children experience significant impairment in regulating their affect, behavior, and cognitions and are at risk for numerous adverse sequelae. The unclear phenomenology of their symptoms presents a barrier to evidence-based diagnosis and treatment.
Method
The cognitive, behavioral, and psychophysiological mechanisms of dysregulation were examined in a mixed clinical and community sample of 294 children ages 7-17 using the Research Domain Criteria constructs of cognitive control and frustrative nonreward.
Results
Results showed that caregivers of dysregulated children viewed them as having many more problems with everyday executive function than children with moderate or low levels of psychiatric symptoms; however, during standardized assessments of more complex cognitive control tasks, performance of dysregulated children differed only from children with low symptoms on tests of cognitive flexibility. In addition, when frustrated, dysregulated children performed more poorly on the Go/No-Go Task and demonstrated less autonomic flexibility as indexed by low respiratory sinus arrhythmia and pre-ejection period scores.
Conclusion
The findings of this study suggest that autonomic inflexibility and impaired cognitive function in the context of frustration may be mechanisms underlying childhood dysregulation.

The present study describes a device (AMD43) for ambulatory measurement of respiration rate and respiratory sinus arrhythmia from the combined electrocardiogram (ECG) and thoracic impedance signals. Respiratory time intervals derived from this ambulatory device closely corresponded to those derived from simultaneous recordings with a ‘classical’ laboratory set-up. Good cross-instrument comparison was also found for respiratory sinus arrhythmia parameters derived with both the peak-to-trough and spectral analyses methods. It is discussed how simultaneous measurement of respiration rate, respiratory sinus arrhythmia may be used to asses cardiac vagal tone in real-life situations.

This paper describes the Ambulatory Monitoring System (AMS) for measuring and scoring heart rate, heart rate variability, and the amount of body movement during normal daily activities. After a technical description of the system, results from a validation study are presented in which heart rate and heart rate variability measured with the AMS showed predictable variation with time of day, posture, physical activity and the type of activity that the subjects were engaged in. It is con-cluded that the Ambulatory Monitoring System is a valid system for non-invasive real-life monitoring of heart rate and heart rate variability.

This study examined the acute immunological effects of two laboratory stressors, expected to evoke distinct patterns of cardiac autonomic activity; namely an “active coping” time-paced memory test, and a “passive coping” stressful video showing surgical operations. We measured salivary S-IgA, IgA-subclasses (IgA1, IgA2), and secretory component (SC). SC is responsible for the transport of S-IgA across the epithelium, and thus a rate-determining step in S-IgA secretion. Thirty-two male undergraduates were subjected to both stressors and a control video (a didactic television program). The memory test induced a typical “fight-flight” response, characterized by increases in heart rate and blood pressure in association with a decrease in cardiac preejection period (PEP) and vagal tone. The surgical video produced a “conservation-withdrawal”-like response, characterized by an enhanced vagal tone, a decrease in heart rate, and a moderate sympathetic coactivation (as indicated by a shortened PEP and an increased systolic pressure). The memory test induced an increase in the concentration and, to a lesser extent, in the output of S-IgA, IgA], and SC. The output of IgA2 was not significantly affected. For the surgical video, a different pattern emerged: During stressor exposure S-IgA remained unaffected, against the background of a small increase in SC output. However, 10 min after the surgical video S-IgA levels had decreased. This decrease in S-IgA was paralleled by a decrease in IgA1, but not IgA2. We conclude that acute stress can have both enhancing and suppressive effects on secretory immunity, the IgA1 subclass in particular. The mechanisms that underlie these divergent responses may include stressor-specific patterns of autonomic activation.

Explored the effect of repeating a laboratory stressor and a real-life stress exposure on the correlation of the reactivity to both types of stressors. 49 male university students’ HRs were monitored during exposure to the same stressful lab task 3 times, with 1-wk intervals. Ss’ HRs were also monitored during 2 examinations. Despite the repeated exposures, the relationship between the average response to the repeated lab task and to the exams remained small and insignificant. The moderate association between reactivity to lab tasks and to real-life stress is not primarily a problem of reliability, but rather of the difference in the nature of the 2 stress situations. The difference in time scale may frustrate a real-life to lab comparison, and different physiological mechanisms may be operating during short and prolonged exposure to stress. (PsycINFO Database Record (c) 2016 APA, all rights reserved)

Objective 
To test the validity of ambulatory heart rate (HR) assessment with a cuff ambulatory blood pressure (ABP) monitor.
Design 
Cross-instrument comparison of HR measured intermittently by a cuff ABP monitor (SpaceLabs, Redmond, Washington, USA), with HR derived from continuous electrocardiogram (ECG) recordings (1) in a controlled laboratory experiment and (2) during long-term recording in a true naturalistic setting.
Participants 
Six normotensive subjects participated in the laboratory study. A total of 109 male white-collar workers underwent ambulatory monitoring, of which 30 were mildly hypertensive.
Methods 
Four different laboratory conditions (postures: lying, sitting, standing, walking), repeated twice, were used to assess the short-term effects of cuff inflation on the HR. To test the actual ambulatory validity, participants simultaneously wore a continuous HR recorder and the ABP monitor from early morning to late evening on 2 workdays and one non-workday. Diary and vertical accelerometery information was used to obtain periods of fixed posture and (physical) activity across which HR from both devices was compared.
Results. 
Laboratory results showed that the ABP device reliably detected HR during blood pressure measurement, but that this HR was systematically lower than the HR directly before and after the blood pressure measurement. The ambulatory study confirmed this systematic underestimation of the ongoing HR, but additionally showed that its amount increased when subjects went from sitting to standing to light physical activity (2.9; 4.3 and 9.1 bpm (beats/min), respectively). In spite of this activity-dependent underestimation of HR, the correlation of continuous ECG and intermittent ABP-derived HR was high (median r = 0.81). Also, underestimation was not different for normotensives and mild hypertensives.
Conclusions 
A direct effect of cuff inflation leads to the underestimation of ongoing HR during cuff-based ABP measurement. Additional underestimation of HR occurs during periods with physical activity, probably due to behavioural freezing during blood pressure measurements. HR underestimation was not affected by hypertensive state. When its limitations are taken into account, ABP-derived ambulatory HR can be considered a reliable and valid measure.

Objective 
Vasomotor symptoms (VMS) are prevalent symptoms that can have a negative impact on quality of life. VMS have also been linked to cardiovascular disease risk, yet the mechanisms underlying these associations have not been elucidated. Some initial works link VMS to adverse adipokine profiles or cytokines produced by adipose tissue. However, results are not entirely consistent and are based entirely on self-report VMS, which is influenced by a range of memory and reporting biases. The aim of this work was to test whether physiologically assessed VMS are associated with lower adiponectin, the most abundant adipokine in the body, controlling for confounding factors. We also consider whether adiponectin explains previously documented relationships between VMS and carotid atherosclerosis.
Methods 
A total of 300 peri- and postmenopausal nonsmoking women aged 40 to 60 years enrolled in the MsHeart study comprised the analytic sample. Women were free of hormone therapy or other medications impacting VMS, insulin-dependent diabetes, and cardiovascular disease. Participants underwent ambulatory physiologic VMS monitoring, physical measures, a carotid ultrasound, and fasting phlebotomy.
Results 
More frequent physiologically assessed VMS were associated with lower adiponectin (B [SE] = −0.081 [0.028], P = 0.004; or 0.081 lower μg/mL in adiponectin for each additional VMS over 24 hours), controlling for age, race/ethnicity, education, insulin resistance, and waist circumference. Associations were not explained by endogenous estradiol. Adiponectin did not explain associations between VMS and carotid atherosclerosis.
Conclusions 
Physiologic VMS were associated with lower adiponectin after considering potential confounders. The role of adipokines in VMS and in links between VMS and health warrants further attention.

STUDY OBJECTIVES: Recent work indicates that cardiac sympathetic activity is not influenced by the circadian system and instead decreases after sleep onset. However, little is known about the pattern of change in cardiac sympathetic activity during NREM/REM sleep cycles and whether this is associated with alterations in slow-wave activity (SWA). To address these questions, we examined SWA, cardiac sympathetic activity, heart rate and rectal and foot temperatures during the first three NREM/REM sleep cycles and during transitions between NREM and REM sleep.
DESIGN: Subjects were required to maintain a constant sleep-wake cycle for at least a week and have at least one adaptation night, before their night of recording.
SETTING: Individual temperature controlled bedrooms.
PARTICIPANTS: 10 young healthy males and females.
INTERVENTIONS: NA.
MEASUREMENTS AND RESULTS: All variables showed the greatest change in the first NREM cycle. Specifically, SWA, sympathetic activity, heart rate and foot temperature increased while rectal temperature decreased. After the initial increase, cardiac sympathetic activity decreased across the sleep phase, in association with a decrease in heart rate. Cardiac sympathetic activity did not significantly alter across NREM-REM cycles.
CONCLUSIONS: The results suggest that increases in heart rate and cardiac sympathetic activity early in the sleep period are, in part, a compensatory reaction to the concomitant thermoregulatory changes observed. These results also indicate that the effect of time asleep on cardiac sympathetic activity may be greater than the influence of sleep cycles. These results are discussed with reference to the recuperative value of naps.

Autonomous sensory meridian response (ASMR) is a warm tingling sensation which is often accompanied by feelings of calmness and relaxation. The present study examined the effects of an ASMR video on mood, attention, heart rate (HR), electrodermal activity (EDA), electroencephalography (EEG) and the interaction with personality factors in 38 young adults (33 females and 5 males). Based on the ASMR-checklist responses of having tingles during watching the ASMR video 15 participants out of 38 were classified as ASMR-experiencers. Mood, attention and personality characteristics were measured by the Profile of Mood States, the Flanker task and HEXACO. EEG, HR and EDA were recorded during the ASMR and control videos. Depressive feelings decreased after watching the ASMR video in individuals experiencing tingles relative to those not experiencing tingles. Furthermore, in all participants, irrespective of experiencing tingles, a decrease of HR during watching the ASMR video was found. In ASMR-experiencers scoring low on Conscientiousness EDA tended to increase and HR tended-relatively to the group not experiencing tingles—to decrease during watching the ASMR video. EEG recordings indicated that watching the ASMR video was associated with decreased alpha power in ASMR-sensitive participants and decreased theta as well as increased beta power in the whole group of participants. The observed ASMR-induced decrease of alpha and theta power and increase of beta power and (only in low conscientious participants) EDA may reflect that, apart from relaxation, ASMR is related to arousal and focused attention.