Decreased Heart Rate Variability Research Articles

Possibilities of detecting and correcting decreased heart rate variability in patients with coronary artery disease in combination with depressive disorders in a cardiology department

Aim . To identify the presence and the correction method of decreased heart rate variability (HRV) in patients with chronic coronary artery disease (CAD) and comorbid depressive disorders (DD). Materials and methods . 79 patients with CAD (with class II–III angina pectoris and myocardial infarction that occurred more than 6 months ago) were divided into two groups. The first group included 50 CAD patients with depression, and the second – 29 CAD patients without depression. 17 patients received agomelatine (1st subgroup), 12 patients received fluvoxamine and fluoxetine (2nd subgroup), and 21 patients refused to take antidepressants (3rd subgroup). Initially and after 6 months, the HRV parameters were evaluated using the SCHILLER MT-200 Holter-ECG apparatus (Switzerland). Results . A significant decrease in HRV was revealed in the patients with depression compared to the patients without it: SDNN (96 [83; 117] ms vs. 110 [98; 127] ms; p = 0.02), SDANN (80.5 [67; 94] ms vs. 91 [79; 102] ms; p = 0.03), SDNNindex (46.5 [38; 56] ms vs. 55 [48; 66] ms; p = 0.006), rMSSD (29 [23; 38] ms vs. 33 [29; 45] ms; p = 0.04), pNN50% (3.9 [2.4; 5,7] vs. 5.7 [2.9; 12.6]; p = 0.03). Initially, the 1st, 2nd, and 3rd subgroups did not differ in all HRV parameters. Against the background of antidepressant therapy, there were significant differences between the 2nd and 3rd subgroups in SDNN (110 [96; 140] ms vs. 85.5 [75; 103] ms; p = 0.008), SDANN (93.7 ± 22.9 ms vs. 72.7 ± 21.4 ms; p = 0.02), SDNNindex (55.8 ± 16.4 ms vs. 42.4 ± 10.8 ms; p = 0.01) and pNN50% (7.8 ± 6.7 vs. 3.6 ± 1.8; p = 0.02), as well as between the 1st and 3rd subgroups (SDANN (93.6 ± 28.5 ms vs. 72.7 ± 21.4 ms; p = 0.03), rMSSD (36.5 [28.5; 51] ms vs. 26.5 [25; 32] ms; p = 0.02)). Conclusion . In patients with CAD with comorbid DD, significant impairment of heart rhythm regulation occurs due to a pronounced decrease in HRV, which can seriously affect the course and prognosis of CAD. Prescribing modern antidepressants can be used as a method of correcting autonomic dysfunction in patients with CAD with comorbid depression.

The Association Between Heart Rate Variability and Quality of Life in Patients with Functional Somatic Syndrome and Healthy Controls.

Functional somatic syndrome (FSS) includes a spectrum of somatic symptoms with insufficient medical explanation. Its underlying pathophysiology is considered to include dysfunctional stress-responsive systems or autonomic dysfunction. Among the autonomic dysfunction readouts, decreased heart rate variability (HRV) has been shown to be characteristic in patients with FSSs. However, its association with quality of life (QOL) has not been clearly examined. We examined the association between short-term resting HRV and QOL in patients with FSS (n = 47) and healthy controls (n = 28). The time domain parameters of HRV were mean heart rate per minute (HR), coefficient of variation of R-R intervals (CvRR) and root mean square of successive differences (RMSSD). The frequency domain parameters of HRV were low-frequency (LF) power and high-frequency (HF) power by power spectrum analysis. The Japanese version of the WHO's QOL scale (WHOQOL-BREF) (WHO/QOL26) was used for the QOL assessment. There was a significant positive association between the RMSSD and HF power of HRV and all the QOL domains in patients with FSSs who had lower QOL scores on average than controls, while there was no association between HRV and any of the QOL domains in the control group. HF power was more dominantly associated with QOL than the other variables in patients with FSS based on the analysis with a multiple linear regression model. The present study elucidated that the HF power of HRV was dominantly associated with QOL in patients with FSSs who had lower QOL than controls. Vagal index of HRV could be a valuable indicator of the pathological condition and a significant predictor of health-related QOL in patients with FSSs.

563 Effect of PHOX2B Genotype and Age on Heart Rate Variability in Pediatric Patients with Congenital Central Hypoventilation Syndrome

Abstract Introduction Congenital Central Hypoventilation Syndrome (CCHS) is a rare neurocristopathy causing a wide array of cardiac autonomic nervous system (ANS) abnormalities (abnormal heart rate (HR) regulation, decreased HR variability (HRV), prolonged sinus pauses). CCHS is caused by mutations throughout the PHOX2B gene. Different types and locations of PHOX2B mutations have been associated with different levels of CCHS cardiac phenotype severity. We hypothesized that HRV in CCHS will be influenced by age and PHOX2B genotype. Methods PHOX2B mutation-confirmed CCHS patients in our cohort followed longitudinally with serial Holter monitoring were included. HRV measures were extracted from Holter monitoring reports and analyzed using linear mixed-effect models. Additional analyses explored which variables predicted sinus pauses and cardiac pacemaker implantation using linear and logistic regression. Only data preceding implantation of a cardiac pacemaker were included in analysis. Results 97 patients (0–18 years old) were enrolled in the study: 21 with the 20/25 genotype, 21 with the 20/26 genotype, 26 with the 20/27 genotype, 7 with genotypes ranging from 20/28-20/33, and 22 with non-polyalanine repeat expansion mutations (NPARMs). There were 965 total observations (Holters). The following HRV metrics were analyzed: min- and max-HR, longest-RR, SDNN, ASDNN5, SDANN5, and RMSDD. Statistically significant differences were observed between PHOX2B genotypes for min-HR and longest-RR (ps<0.05). Age by genotype interactions emerged such that certain metrics in HRV had different developmental trajectories by genotype (ps<0.05). Min-HR and longest-RR predicted eventual cardiac pacemaker implantation (AUCs>0.78). As for predictors of sinus pauses, different HRV metrics emerged as predictors across PHOX2B genotypes suggesting their utility in predicting cardiac pacemaker implantation dependent on genotype. Conclusion HRV in patients with CCHS is dependent on age and PHOX2B genotype, with significant differences in HRV metrics between patients with PHOX2B genotypes 20/25, 20/26, and 20/27 and the patients with 20/28-20/33 genotypes as well as those with NPARMs. Consistent with treatment guidelines, min-HR and longest-RR were predictive of eventual cardiac pacemaker implantation. Differences in the HRV metrics which predict sinus pauses as well as the overall group differences observed and trajectory-based differences may improve anticipatory management by earlier risk identification for prolonged sinus pauses in CCHS. Support (if any) None

Influence of a 100-mile ultramarathon on heart rate and heart rate variability

AimsThis study aimed to investigate the impact of an ultramarathon (UM) with a distance of 100 miles on heart rate (HR) and heart rate variability (HRV).Methods28 runners (25 men and...

Environmentally relevant secondhand smoke and time‐dependent changes in cardiovascular regulation in mice

BACKGROUND Secondhand smoke (SHS), a significant source of indoor air pollution, is a significant risk factor for cardiovascular morbidity and mortality. SHS-induced autonomic dysfunction, evidenced as increased sympathetic nerve activity and decreased heart rate variability (HRV), has been implicated as an important underlying mechanism for cardiovascular consequences. Previously, we have demonstrated that acute exposure (3 d) to 30 mg/m3 of SHS was sufficient to reduce HRV in mice. Here, we sought to characterize the time course of SHS-induced changes to cardiovascular regulation resulting from chronic exposure to environmentally relevant SHS (3 mg/m3). METHODS Male C57BL/6J mice (11 wk) implanted with BP/ECG telemetry devices were exposed to either filtered air (FA, n=18) or SHS (3 mg/m3, 6 hr/d, 5 d/wk, n=17) for 12 weeks, followed by 4 weeks of FA (representing a SHS “recovery” window). Monthly, 36 hours of continuous BP and ECG recordings were obtained during non-exposure days. Data were divided into three 12-hour periods: The dark cycle (dark 1) immediately after the 5th day of exposure, and the following light and dark (dark 2) cycles. Spontaneous baroreflex sensitivity (BRS) was determined with the sequence method. Standard time domain HRV parameters were obtained during periods of low activity. RESULTS SHS decreased overall HRV (SDNN) during the dark 1 cycle (-15%, -7%, and -28% for 4, 8, and 12 wk, respectively, p < 0.05). Similarly, SHS significantly reduced short-term HRV (rMSSD) during the dark 1 cycle (-16%, -12%, and -20% for 4, 8, and 12 wk, respectively, p < 0.05). SHS exposure did not affect HRV beyond the initial 12 hours after exposure ended (light and dark 2 cycles). These data suggest that SHS attenuates cardiac vagal regulation. SHS also reduced pulse pressure (~2 mmHg, p < 0.05) for the entire 36-hr recording window after 4, 8, and 12 wks of exposure, an effect that persisted even after 4 wks of recovery. There was a trend for lower BRS after 12 wks of SHS exposure during the dark 1 cycle. Intriguingly, initial exposure to SHS significantly elevated diastolic BP (~3 mmHg) during the dark 1 cycle at 4 wks; this effect was not observed with longer exposure to SHS (8 or 12 wks). Taken together, these data suggest that SHS exposure poses a greater risk to cardiac function than vascular function, and that vasculature regulation may be more protected from SHS-induced autonomic effects. CONCLUSIONS Chronic SHS reduces autonomic regulation of the cardiovascular function, particularly the regulation of the heart. Except for reduced pulse pressure, these autonomic effects were transient, and reversed themselves in the absence of SHS exposure, underscoring the importance and efficacy of public smoking bans.

Longitudinal changes in HRV across pregnancy and postpartum: Effect of negative partner relationship qualities

During pregnancy, there are significant physiological changes to support a healthy fetus. Parasympathetic activity normatively decreases across pregnancy, and psychological stress can promote even further decreased heart rate variability (HRV). This study evaluated (1) changes in vagally-mediated HRV from pregnancy to postpartum, (2) changes in vagally-mediated HRV from pregnancy to postpartum based on negative partner relationship qualities, and (3) changes in depressive symptoms from pregnancy to postpartum based on negative partner relationship qualities. 78 participants in their 3rd trimester self-reported their relationship quality with their partner at the first visit. Depressive symptoms and vagally-mediated HRV were evaluated at rest at five time points from 3rd trimester to 12 months postpartum. On average, the only significant increase in vagally-mediated HRV occurred between the 3rd trimester and 4–6 weeks postpartum. However, those who reported more negative partner relationship qualities during their 3rd trimester of pregnancy maintained lower vagally-mediated HRV levels across all of the first year postpartum and significantly lower vagally-mediated HRV at both 4 and 8 months postpartum as compared to people who reported fewer negative partner relationship qualities. Across the first year postpartum, people reporting more negative partner relationship qualities experienced more severe depressive symptoms than their counterparts with fewer negative partner relationship qualities; however, there was no difference in the rate of change of depressive symptoms across the first year postpartum based on negative partner relationship qualities. Because lower vagally-mediated HRV is associated with depressive symptoms, future work should explore the temporal relationship between vagally-mediated HRV and depressive symptoms in the postpartum period.

Relationship between spectral indicators of heart rate variability and fasting glucose level in healthy persons and elderly patients with discirculatory atherosclerotic encephalopathy

Objective — to establish the peculiarities and relationship of spectral indicators of heart rate variability (HRV), fasting glucose level and lipid profile indicators in practically healthy persons and in elderly patients with dyscirculatory atherosclerotic encephalopathy (DEP). Materials and methods. The study involved 77 subjects of various age, who were divided into two groups: group 1 consisted of apparently healthy persons (19 subjects of middle age and 27 elderly subjects) and group 2 that included patients with DAP manifestations (15 subjects of middle age and 16 elderly persons). In the groups of elderly persons, the subgroups were extracted based on the fasting glucose levels: lower than 6.1 mmol/l and 6.1 mmol/l. The measurements of systolic and diastolic blood pressure were performed in a sitting position after at least 10 min of rest. Plasma glucose levels were determined by a standard glucoseoxidase method, lipid profile was determined by using the automatic analyzer. To assess the risk of cardiovascular disease development, calculations were performed for the indices of the cardiovascular risk: Castelli index and Boizel index. All patients with DEP manifestations underwent 24‑hour Holter ECG monitoring, and healthy people underwent 5 min ECG. Results. The incidence of fasting hyperglycemia in patients with 1 — 2 stage DEP manifestations was in 3.4 times higher (p &lt; 0.05) vs healthy subjects of the same age. The significant correlation has been reveled between age and HDL‑C (r = 0.47, р &lt; 0.05), atherogenic index (r = –0.40, р &lt; 0.05), heart rate (r = –0.45, р &lt; 0.05), Castelli index (r = –0.40, р &lt; 0.05), Boizel index (r = –0.31, р &lt; 0.05), heart rate (r = –0.45, р &lt; 0.05). Moreover, correlation has been established between Boizel index and heart rate (r = +0.44, р &lt; 0.05), heart rate and LF/HF (r = +0.57, р &lt; 0.05), between TG and heart rate (r = +0.43, р &lt; 0.05), LF/HF (r = +0.53, р &lt; 0.05) and between levels of very low density lipoprotein cholesterol and heart rate (r = +0.44 р &lt; 0.05), LF/HF (r = +0.53, р &lt; 0. 05). It has been established that hyperglycemia and dyslipidemia significantly affected spectral heart rate variability indices in patients with encephalopathy manifestations. Conclusions. With ageing, the frequency of fasting hyperglycemia in patients with 1 — 2 stage DEP manifestations was significantly higher in 3.4 times in comparison with practically healthy individuals of the same age. In the group of practically healthy persons over 60 years old, the tendency has been revealed towards a decrease in the spectral parameters of HRV LF and HF, which indicates HRV decrease. With the development of 1 — 2 stages DEP, even in the middle age, a significant decrease in the value of HF (parasympathetic influence) and a significant increase in the value of LF (sympathetic activity) were revealed. In elderly people with signs of 1 — 2 stage DEP with normoglycemia and fasting hyperglycemia against the background of dyslipidemia, the sympathetic link of the autonomic nervous system is activated, accompanied by an increase in the index of vascular complications. In patients with 1 — 2 stages DEP and fasting hyperglycemia, this tendency was even more pronounced. This fact can serve as confirmation that in the development of pre‑diabetic disorders (fasting hyperglycemia) one of the pathogenic mechanisms is the violation of the central regulatory mechanisms, which in turn leads to the violation of the autonomic balance with the prevalence of sympathicotonia, and a decrease in the parasympathetic effect on the heart, which leads to development of autonomous cardiac neuropathy.

Effects of agomelatine on heart rate variability in patients with coronary artery disease and depression

Aim. To determine heart rate variability (HRV) in depressed patients with chronic coronary artery disease (CAD) and to assess the effects of agomelatine on HRV.Methods. 74 patients with CAD (class 3-4 angina pectoris) were recruited in a study. Patients (n = 45) with CAD and depression were assigned to Group 1, whereas CAD patients (n = 29) without any signs of depression were assigned to Group 2. 17 patients received agomelatine (Subgroup 1) and 28 patients did not take any antidepressants (Subgroup 2). HRV was measured using SCHILLER MT-200 Holter-ECG apparatus at baseline and after 6 months.Results. Patients with depression demonstrated a significant decrease in HRV compared to non-depressed patients (pNN50% (3.9 [2.2; 5.4] vs 5.7 [2.9; 12.6], p = 0.03), SDANN (81 [63; 97] ms vs 91 [79; 102] ms, p = 0.06), SDNNindx (46 [36; 56] ms vs 55 [48; 66] ms, p = 0.002), rMSSD (28 [21; 36] ms vs 33 [ 29; 45] ms, p = 0.02), SDNN (97 [75; 121] ms vs 110 [98; 127] ms, p = 0.02). Subgroups 1 and 2 did not differ in HRV (p&gt;0.05). After 6 months, significant differences in the following parameters were found in those patients who received agomelatine therapy and those who did not: rMSSD (36.5 [28.5; 51] ms vs 26.5 [25; 32] ms, p = 0.02), SDANN (88 [72,5; 114,5] ms vs 67,5 [58; 83] ms, p = 0.03), SDNN strives to a significant difference - 100 [87; 133.5] ms vs 85.5 [75; 103] ms, p = 0.07.Conclusion. HRV significantly decreased in depressed patients with CAD suggesting autonomic dysfunction and worsening their prognosis. Agomelatine therapy in patients with CAD is effective in treating heart rate variability and reducing the risk of developing life-threatening arrhythmias.Key

In Touch with the Heartbeat: Newborns' Cardiac Sensitivity to Affective and Non-Affective Touch.

The sense of touch is the first manner of contact with the external world, providing a foundation for the development of sensorimotor skills and socio-affective behaviors. In particular, affective touch is at the core of early interpersonal interactions and the developing bodily self, promoting the balance between internal physiological state and responsiveness to external environment. The aim of the present study is to investigate whether newborns are able to discriminate between affective touch and non-affective somatosensory stimulations and whether affective touch promotes a positive physiological state. We recorded full-term newborns’ (N = 30) heart rate variability (HRV)—which reflects oscillations of heart rate associated with autonomic cardio-respiratory regulation—while newborns were presented with two minutes of affective (stroking) and non-affective (tapping) touch alternated with two minutes of resting in a within-subject design. The results revealed that non-affective touch elicits a decrease in HRV, whereas affective touch does not result in a change of HRV possibly indicating maintenance of calm physiological state. Thus, newborns showed cardiac sensitivity to different types of touch, suggesting that early somatosensory stimulation represents scaffolding for development of autonomic self-regulation with important implications on infant’s ability to adaptively respond to the surrounding social and physical environment.

Monitorization of Autonomic Stress Response of Nurse Students in Hospital Clinical Simulation.

The aims of this study were to analyze the autonomic stress response of nurse degree students during a hospital clinical simulation and to analyze differences in the autonomic stress response of nurse degree students during a hospital clinical simulation depending on their psychological profile. We analyzed in 45 nurse students their psychological profile (purpose in life, coping flexibility, perceived stress, Framingham Type A Behavior, and personality) and the autonomic modulation by the heart rate variability in a hospital clinical simulation. Students presented decreased heart rate variability and different autonomic stress responses depending on the different psychological parameters evaluated. We concluded that a hospital clinical simulation produced a large sympathetic modulation of nurse students that was maintained during the entire clinical simulation. The autonomic response was modulated by the psychological profile of students, showing higher purpose in life, perceived stress, and neuroticism, presenting higher parasympathetic modulation.

Pre-ictal heart rate variability alterations in focal onset seizures and response to vagus nerve stimulation

PurposeVagus nerve stimulation (VNS) is an effective and well-known treatment for drug resistant epilepsy (DRE) patients since 1997, yet prediction of treatment response before implantation is subject of ongoing research. Neuroimaging and neurophysiological studies investigating the vagal afferent network in resting state documented that differences in between epilepsy patients were related to treatment response. This study investigated whether an event-related parameter, pre-ictal heart rate variability (HRV) is associated with response to VNS therapy. MethodsDRE patients underwent video-electroencephalography (EEG) recording before VNS implantation. HRV parameters (time, non-linear and frequency domain) were assessed for every seizure during two 10 min timeframes: baseline (60 min before seizure onset) and pre-ictal (10 min before seizure onset). Pre-ictal HRV parameter alterations were correlated with VNS response after one year of VNS therapy and seizure characteristics (temporal/extratemporal, left/right or bilateral). Results104 seizures from 22 patients were evaluated. Eleven patients were VNS responders with a seizure frequency reduction of ≥ 50 % after one year of VNS. In VNS responders no changes in HRV parameters were found while in VNS non-responders the time domain and non-linear HRV variables decreased significantly (p = 0.024, p = 0.005, p = 0.005) during the pre-ictal time frame. 10/11 VNS non-responders had a seizure lateralization to the left compared to 4/11 VNS responders. ConclusionVNS non-responders were characterized by a significant decrease of pre-ictal HRV (time domain/non-linear variables) suggesting a sudden autonomic imbalance probably due to an impaired central autonomic function that makes it at the same time unlikely to respond to VNS.

Heart Rate Variability as a Possible Predictive Marker for Acute Inflammatory Response in COVID-19 Patients.

ABSTRACTIntroductionIncreases in C-reactive protein (CRP) are used to track the inflammatory process of COVID-19 and are associated with disease state progression. Decreases in heart rate variability (HRV) correlate with worsening of disease states. This observational study tracks changes in HRV relative to changes in CRP in COVID-19 patients.Materials and MethodsIn accordance with an Institutional Review Board-approved study, 17 patients were followed using the wearable, noninvasive Tiger Tech Warfighter Monitor (WFM) that records HRV from a single limb electrocardiogram. Intermittent, daily short-segment data sets of 5 to 7 minutes over a minimum of 7 days were analyzed. Changes in HRV were compared to changes in CRP.ResultsDecreases in HRV of greater than 40% preceded a 50% increase in CRP during the ensuing 72 hours in 10 of the 12 patients who experienced a dramatic rise in CRP. The effectiveness of HRV as a leading indicator of a rise in CRP was evaluated; the sensitivity, specificity, positive predictive value, and negative predictive value for 40% decreases in HRV preceding 50% increases in CRP were 83.3%, 75%, 90.9%, and 60%, respectively.ConclusionSubstantial decreases in HRV preceded elevations in CRP in the ensuing 72 hours with a 90.9% positive predictive value. Early detection of increasing inflammation may prove vital in mitigating the deleterious effects of an abnormal inflammatory response, particularly in COVID-19 patients. This capability could have a major impact in triage and care of moderate to severe COVID-19 patients in major medical centers as well as field hospitals. This study demonstrates the potential value of short-segment, intermittent HRV analysis in COVID-19 patients.

Autonomic Nervous System Activity during Refractory Rise in Intracranial Pressure.

Refractory intracranial hypertension (RIH) is a dramatic increase in intracranial pressure (ICP) that cannot be controlled by treatment. Recent reports suggest that the autonomic nervous system (ANS) activity may be altered during changes in ICP. Our study aimed to assess ANS activity during RIH and the causal relationship between rising in ICP and autonomic activity. We reviewed retrospectively 24 multicenter (Cambridge, Tromso, Berlin) patients in whom RIH developed as a pre-terminal event after acute brain injury (ABI). They were monitored with ICP, arterial blood pressure (ABP), and electrocardiography (ECG) using ICM+ software. Parameters reflecting autonomic activity were computed in time and frequency domain through the measurement of heart rate variability (HRV) and baroreflex sensitivity (BRS). Our results demonstrated that a rise in ICP was associated to a significant rise in HRV and BRS with a higher significance level in the high-frequency HRV (p < 0.001). This increase was followed by a significant decrease in HRV and BRS above the upper-breakpoint of ICP where ICP pulse-amplitude starts to decrease whereas the mean ICP continues to rise. Temporality measured with a Granger test suggests a causal relationship from ICP to ANS. The above results suggest that a rise in ICP interacts with ANS activity, mainly interfacing with the parasympathetic-system. The ANS seems to react to the rise in ICP with a response possibly focused on maintaining the cerebrovascular homeostasis. This happens until the critical threshold of ICP is reached above which the ANS variables collapse, probably because of low perfusion of the brain and the central autonomic network.

Sulprostone-Induced Gastric Dysrhythmia in the Ferret: Conventional and Advanced Analytical Approaches.

Nausea and emesis resulting from disease or drug treatment may be associated with disrupted gastric myoelectric activity (GMA). Conventional analytical techniques can determine the relative degrees of brady-, normo-, and tachygastric power, but lose information relative to the basic slow wave shape. The aim of the present study was to investigate the application of advanced analytical techniques in the analysis of disrupted GMA recorded after administration of sulprostone, a prostaglandin E3/1 agonist, in ferrets. Ferrets were implanted with radiotelemetry devices to record GMA, blood pressure, heart rate (HR) and core body temperature 1 week before the administration of sulprostone (30 μg/kg) or vehicle (saline, 0.5 mL/kg). GMA was initially analyzed using fast Fourier transformations (FFTs) and a conventional power partitioning. Detrended fluctuation analysis (DFA) was also applied to the GMA recordings to reveal information relative to the fluctuation of signals around local trends. Sample entropy (SampEn) analysis was used for examining the regularity of signals. Conventional signal processing techniques revealed that sulprostone increased the dominant frequency (DF) of slow waves, with an increase in the percentage power of the tachygastric range and a decrease in the percentage power of the normogastric range. DFA revealed that sulprostone decreased the fluctuation function, indicative of a loss of the variability of GMA fluctuations around local trends. Sulprostone increased SampEn values, indicating a loss of regularity in the GMA data. Behaviorally, sulprostone induced emesis and caused defecation. It also increased blood pressure and elevated HR, with an associated decrease in HR variability (HRV). Further analysis of HRV revealed a decrease in both low-frequency (LF) and high-frequency (HF) components, with an overall increase in the LF/HF ratio. Sulprostone did not affect core body temperature. In conclusion, DFA and SampEn permit a detailed analysis of GMA, which is necessary to understand the action of sulprostone to modulate gastric function. The action to decrease HRV and increase the LF/HF ratio may be consistent with a shift toward sympathetic nervous system dominance, commonly seen during nausea.

Acute Electrocardiographic Changes during Smoking and Tobacco Chewing

Background: Smoking increases the risk of coronary artery disease. Very few studies have evaluated the temporal relationship of electrocardiographic changes with smoking. We sought to study and compare the electrocardiogram (ECG) changes during smoking and tobacco chewing in current smokers and tobacco chewers presenting with atypical chest pain with either negative or mild positive exercise ECG test (treadmill test [TMT]). Materials and Methods: We screened male smokers and tobacco chewers with atypical chest pain with TMT. A total of 60 patients, 30 in each group in whom TMT was either negative or mildly positive, underwent a 24-h Holter monitoring. We asked patients to note down their time of smoking and tobacco chewing along with the timing of symptoms if any. Results: All patients were male with an average age of 45 years in smokers and 42 years in the tobacco chewer group. The mean number of cigarettes consumed was 6 ± 2.8 and tobacco chewed was 5 ± 4.7 g/day. Heart rate (HR) in smokers increased from 82.5 ± 14.56/min 10 min before smoking to 90.63 ± 15.34/min, during smoking with peak HR achieved at the time of smoking (P &lt; 0.0001). HR in the tobacco chewers peaked at 10 min after chewing from 80.62 ± 13.52/min 10 min before to 87.89 ± 13.86/min 10 min after chewing (P &lt; 0.0001). Smoking was associated with a significant increase in supraventricular ectopics (VEs) from 3.98/h before smoking to 7.43/h during and 6.92/h after smoking (P &lt; 0.0001). Two patients in the smoker subgroup had spontaneous smokeless tobacco -T changes lasting for 10–25 min. Smoking was associated with a significant decrease in HR variability (HRV) index than the controls (P = 0.023). Tobacco chewing was not associated with any significant changes in the HRV parameter. Conclusions: Smoking and tobacco chewing both significantly increase the HR acutely. Smoking leads to an increase in both supraventricular and VEs. We observed reduced HRV in patients who smoked cigarettes.

Emergency Medicine Residents Experience Acute Stress While Working in the Emergency Department.

IntroductionAcute stress may impair cognitive performance and multitasking, both vital in the practice of emergency medicine (EM). Previous research has demonstrated that board-certified emergency physicians experience physiologic stress while working clinically. We sought to determine whether EM residents have a similar stress response, and hypothesized that residents experience acute stress while working clinically.MethodsWe performed a prospective observational study of physiologic stress including heart rate (HR), heart rate variability (HRV), and subjective stress in EM residents during clinical shifts in the emergency department. HR and HRV were measured via 3-lead Holter monitors and compared to baseline data obtained during weekly educational didactics. Subjective stress was assessed before and after clinical shifts via a Likert-scale questionnaire and written comments.ResultsWe enrolled 21 residents and acquired data from 40 shifts. Residents experienced an increase in mean HR of eight beats per minute (P < 0.001) and decrease in HRV of 53.9 milliseconds (P = 0.005) while working clinically. Subjective stress increased during clinical work (P <0.001). HRV was negatively correlated with subjective stress, but this did not reach statistical significance (P = 0.09).ConclusionEM residents experience acute subjective and physiologic stress while working clinically. HR, HRV, and self-reported stress are feasible indicators to assess the acute stress response during residency training. These findings should be studied in a larger, more diverse cohort of residents and efforts made to identify characteristics that contribute to acute stress and to elicit targeted educational interventions to mitigate the acute stress response.

Elevated circulating growth differentiation factor 15 is related to decreased heart rate variability in chronic kidney disease patients

Background Growth differentiation factor 15(GDF15) is a distant member of the superfamily of the transforming growth factor beta (TGF-β). It has been established that increased GDF15 levels are associated with an increased risk of cardiovascular disease. However, the detail effect of GDF15 on cardiovascular system in patients with chronic kidney disease (CKD) needs detail analysis. Methods Patients with CKD who did not need dialysis were enrolled in the study. Blood pressure (BP), endothelial function, pulse wave velocity (PWV) and heart rate variability (HRV) were taken in all subjects. Plasma GDF15 concentration was measured by an enzyme-linked immunosorbent assay. Results Among the 355 participants, the mean age was 57.4 (±14.2) years old and the mean estimated glomerular filtration rate (eGFR) was 50.1 (±33.2) mL/min/1.73m2. The average plasma GDF15 level was 1394.7 (±610.1) pg/mL. Higher GDF15 concentrations were significantly associated with decreased eGFR and increased urine protein-to-creatinine ratio (uPCR). In multivariable models, after adjusting for potential confounders, plasma GDF15 has negative concerning with HRV parameters including the standard deviation of the normal-to-normal (NN) interval (SDNN), the square root of the mean of the sum of the squares of differences between adjacent NN intervals (RMSSD) and Triangular Index. Conclusion We observed there was a link between increased plasma of GDF15 and decreased HRV. The mechanisms and prediction of GDF15 in the cardiovascular disease with CKD needs further discussion and study.

Disorganized attachment in adolescence: Emotional and physiological dysregulation during the Friends and Family Interview and a conflict interaction.

The current study examined the effects of attachment on autonomy, relatedness, and emotion regulation during an attachment interview (Friends and Family Interview; FFI) and a Parent×Child Conflict interaction (Family Interaction Task; FIT) in 49 adolescents (11 to 17 years old). Disorganized adolescents displayed behaviors promoting autonomy and relatedness less frequently and at a lower extent than organized ones in the FIT with mothers but not with fathers. Disorganized adolescents also showed a steeper decrease in heart rate variability (HRV) than organized ones, during both the FFI and the FITs. Moreover, disorganized adolescents responded with a more marked increase in skin conductance level to the FIT with mothers than organized individuals. Dismissing adolescents showed behaviors promoting autonomy and relatedness less frequently and to a lesser extent than secure ones, while displaying more often behaviors undermining autonomy and relatedness in the FITs. Dismissing adolescents also showed a more pronounced decrease in HRV during the FFI than secure and preoccupied individuals; no differences were found between these groups in HRV during the FITs. The results suggest that disorganized adolescents had more difficulties in regulating their emotions during both the FFI and the FITs, whereas dismissing individuals seemed effectively challenged only during the interview.

Heart rate variability and inflammatory bowel disease in humans

The autonomic nervous system (ANS) maintains homeostasis in the gastrointestinal tract, including immunity, inflammation and motility, through the brain-gut axis. To date, the associations between ANS function and inflammatory bowel disease (IBD) have been controversial and inconclusive in human studies. PubMed, Cochrane Library, and Embase were searched through February 2020 for articles reporting these association between heart rate variability (HRV), an indirect measure of ANS activity, and IBD. The standardized mean differences and 95% confidence intervals (CIs) were calculated. Ten eligible studies involving 273 ulcerative colitis patients, 167 Crohn's disease patients and 208 healthy controls were included. The values of the total power (SMD = −0.83, 95% CI = −1.44, −0.21), high frequency (SMD = −0.79, 95% CI = −1.20, −0.38), RR interval (SMD = −0.66, 95% CI = −1.04, −0.27), standard deviation of the RR intervals (SMD = −1.00, 95% CI = −1.73, −0.27), percentage of RR intervals with a greater than 50-millisecond variation (SMD = −0.82, 95% CI = −1.33, −0.30) and the square root of the mean squared differences in successive RR intervals (SMD = −0.71, 95% CI = −1.15, −0.26) of the IBD patients were lower than those of the healthy controls, and moderate to large effect sizes were observed in all HRV indices, except for low frequency (SMD = −0.41, 95% CI = 0.95, 0.13). IBD was strongly associated with an overall decrease in HRV, indicating substantially decreased ANS activity. Furthermore, the parasympathetic nerve displayed a stronger inverse association with ANS activity than the sympathetic nerve, indicating ANS dysfunction in patients with IBD.

Heart Rate Variability in Children With Autism Spectrum Disorder and Associations With Medication and Symptom Severity.

Decreased heart rate variability (HRV) is considered a common marker of autonomic dysfunction that contributes to poor health outcomes. While some studies have suggested that children with autism spectrum disorder (ASD) show reduced HRV, research is yet to consider whether this may be associated with medication use and symptom severity. This study examined the relationship between resting state HRV, medication use and symptom severity in children diagnosed with ASD. Children with ASD (N = 86), aged between 3 and 12 years (M = 8.09), were compared to 44 neurotypical children of similar age (M = 7.15). Laboratory assessment of HRV involved 5 min of non-invasive baseline electrocardiogram assessments while participants viewed an age-appropriate non-verbal animated video. Time-domain and frequency-domain HRV measures were analyzed. ASD symptom severity was assessed using the Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) and Social Responsiveness Scale (SRS-2). Results indicated that children with ASD exhibited reduced resting HRV relative to neurotypical children. Subsequent analyses within the ASD group suggested that this group difference was greater in children who were taking psychotropic medication (N = 36). Our data also provides tentative evidence of a relationship between HRV and social impairment symptoms in children with ASD, with more severe repetitive behaviors (as measured by the ADOS-2) associated with decreased resting HRV. Overall, these findings suggest that HRV may be atypical in children with ASD and suggest the importance of exploring HRV as a risk factor for cardiovascular health in this group. LAY SUMMARY: Cardiac activity, such as heart rate variability (HRV), can provide insight into the autonomic nervous system. This study reports on the association between resting-state HRV and autonomic nervous system activity in young children with autism spectrum disorder (ASD) compared to neurotypical children. These results may help us understand what underlies autonomic nervous system dysfunction and the potential pathophysiological mechanisms leading to increased cardiovascular risk in ASD.