Changes In Heart Rate Variability Parameters Research Articles

Effect of Piracetam and Iron Treatment on Heart Rate Variability in Patients With Breath-Holding Spell

BackgroundBreath-holding spells are a benign condition primarily seen in 3% to 5% of healthy children aged between six months and five years. Although no specific treatment is recommended due to its benign nature, iron and piracetam are used in severe or recurrent cases. We planned to compare the heart rate variability (HRV) before and after treatment with 24-hour Holter monitoring in patients receiving iron and piracetam treatment and investigate the treatment's effectiveness. MethodsTwenty-five patients who applied to the outpatient clinic between 2013 and 2015 due to breath-holding spells were included in the study. The patients who received piracetam and iron therapy and underwent 24-hour rhythm Holter monitoring were evaluated retrospectively. ResultsFourteen (56%) of these patients were evaluated as having cyanotic-type and 11 (44%) patients were assessed as having pale-type breath-holding spells. A significant difference was found only between hourly peak heart rate and total power in the group receiving iron treatment. Significant differences were also found among the minimum heart rate, mean heart rate, the standard deviation of RR intervals, the mean square root of the sum of the squares of their difference between adjacent RR intervals, spectpow, and low frequency before and after the treatment in the patients who started piracetam treatment (P < 0.05). ConclusionsOur study is critical as it is the first to investigate the effects of treatment options on various HRV in patients with breath-holding spells. There were statistically significant changes in HRV parameters in patients receiving piracetam, and the number of attacks decreased significantly. Piracetam treatment contributes positively to the breath-holding spell with regard to efficacy and HRV, therefore it can be used to treat breath-holding spells.

Clinical, polysomnographic, and heart rate variability in highland obstructive sleep apnea patients responding to one-night nocturnal oxygen supplementation: A post-hoc analysis from a randomized, crossover trial

Objective/Background: This study aimed to explore the clinical, polysomnographic, and heart rate variability (HRV) characteristics of highland obstructive sleep apnea (OSA) patients receiving one-night nocturnal oxygen supplementation (NOS) and to identify factors predicting response. Patients/methodsThirty-four highland OSA patients living in Shangri-La were randomly assigned to receive NOS and sham oxygen in a randomized, placebo-controlled, crossover trial. Clinical assessments, polysomnography, and HRV were measured. A responder was defined as a ≥50% reduction in apnea-hypopnea index (AHI) with NOS compared with sham oxygen. ResultsEighteen participants responded and 16 did not respond, with a median (interquartile range [IQR]) age of 46.5 (36.5-53.0) and 48.0 (44.3-53.3) years, respectively. The median treatment effect (95% CI) on total AHI was -23.2/h (-30.0 to -17.5) and -12.0/h (-16.6 to -7.6) in responders and non-responders (p = 0.004), with similar effects on oxygen desaturation index. The mean OAH duration was prolonged by 7 s in responders together with improved sleep quality and daytime blood pressure. The mean OAH duration at baseline predicted responses to NOS with a sensitivity and specificity of 88.9% and 68.7% (AUC 0.809) at a cut-off point of 24.9 s. Changes in HRV parameters were negatively correlated with changes in mean oxygen saturation and daytime systolic blood pressure only in responders. ConclusionsNOS significantly improved OSA severity and clinical outcomes in responders, which was related to improvements in parasympathetic activity. Highlanders with shorter mean OAH may be suitable candidates for NOS. These findings provide new information about tailored treatment strategies for highland OSA patients.

Heart Rate Variability in Normotensive and Hypertensive Adults After a Year of Receiving Oxford/AstraZeneca COVID-19 Vaccine: A Cross-Sectional Observational Study.

Background and aim Heart rate variability (HRV) helps in assessing the autonomic nervous system's function, which has been implicated in cardiovascular disease risk. HRV has been found to be deranged in hypertension. In addition, studies have shown that COVID-19 infection and vaccination can affect HRV. However, the long-term effect of HRV on hypertension has not been explored after COVID-19 vaccination. The objective of this study was to observe the HRV in hypertensive adults after one year of receiving the Oxford/AstraZeneca COVID-19 vaccine and to compare it with normotensive adults. Methods The study included 105 normotensives (blood pressure below 120/80 mmHg) and 75 hypertensive participants who had received the Oxford/AstraZeneca COVID-19 vaccine one year prior. HRV was measured using the PowerLab system (ADInstruments) with the participants in a sitting posture. The HRV parameters assessed included the time domain, frequency domain, and nonlinear measures. Data were presented in descriptive and inferential statistical terms, and the parameters of two groups of individuals were compared by either an unpaired t-test or the Mann-Whitney U test. Results A total of 105 normotensive participants with a mean age of 42.51 ± 9.28 years and 75 hypertensive participants with a mean age of 44.24 ± 10.19 years comprised the sample (p=0.24). Normotensive individuals had a higher standard deviation of RR intervals, a higher coefficient of variation of RR intervals, a higher standard deviation of heart rate, and a higher percentage of successive differences in RR intervals in the time domain. They also had higher values of very low-frequency power, low-frequency (LF) power, and high-frequency (HF) power in the frequency domain. The LF/HF ratio was not significantly different between the two groups. In nonlinear analysis, SD2, a measure of long-term heart rate variability, was higher in normotensive individuals. Conclusion The Oxford/AstraZeneca COVID-19 vaccine did not have a significant effect on HRV parameters in normotensive and hypertensive adults one year after vaccination. However, changes in HRV parameters were observed between supine and standing positions, suggesting the importance of postural changes in HRV assessment.

Heart rate variability modification as a predictive factor of sudden unexpected death in epilepsy: How far are we? A systematic review and meta-analysis.

Sudden unexpected death in epilepsy (SUDEP) is a sudden, unexpected death in people with epilepsy, with or without evidence of an epileptic seizure. The pathophysiological mechanism underlying SUDEP appears to be partly associated with an autonomic nervous system (ANS) dysfunction. Heart rate variability (HRV) analysis is a reliable, non-invasive method for detecting fluctuations in the ANS. In this systematic review we analyzed the data available in the literature on changes in HRV parameters in patients with SUDEP. We carried out a systematic search of the literature to identify the quantitative variations of HRV in epileptic patients with SUDEP. The following databases were used: Pubmed, Google Scholar, EMBASE, and CrossRef. A pooled analysis was carried out, and the results obtained were compared using mean difference (MD). The review was registered on the PROSPERO platform (CRD42021291586). Seven articles were included, with a total of 72 SUDEP cases associated with altered HRV parameters. Generally, a reduction of SDNN (standard deviation of the RR intervals) and RMSSD (root mean square differences of successive RR intervals) was reported in most SUDEP patients. According to MD, the SUDEP patients showed no differences in time and frequency domain parameters compared to controls. However, a trend toward increased low frequency and high frequency ratio (LF/HF) was observed in the SUDEP patients. HRV analysis is a valuable method for assessing cardiovascular risk and cardioautonomic impairment. Although a possible association between HRV variation and SUDEP has been reported, further studies are needed to assess the potential role of HRV modifications as a SUDEP biomarker.

Pediatric sleep apnea: Characterization of apneic events and sleep stages using heart rate variability

Heart rate variability (HRV) is modulated by sleep stages and apneic events. Previous studies in children compared classical HRV parameters during sleep stages between obstructive sleep apnea (OSA) and controls. However, HRV-based characterization incorporating both sleep stages and apneic events has not been conducted. Furthermore, recently proposed novel HRV OSA-specific parameters have not been evaluated. Therefore, the aim of this study was to characterize and compare classic and pediatric OSA-specific HRV parameters while including both sleep stages and apneic events. A total of 1610 electrocardiograms from the Childhood Adenotonsillectomy Trial (CHAT) database were split into 10-min segments to extract HRV parameters. Segments were characterized and grouped by sleep stage (wake, W; non-rapid eye movement, NREMS; and REMS) and presence of apneic events (under 1 apneic event per segment, e/s; 1–5 e/s; 5–10 e/s; and over 10 e/s). NREMS showed significant changes in HRV parameters as apneic event frequency increased, which were less marked in REMS. In both NREMS and REMS, power in BW2, a pediatric OSA-specific frequency domain, allowed for the optimal differentiation among segments. Moreover, in the absence of apneic events, another defined band, BWRes, resulted in best differentiation between sleep stages. The clinical usefulness of segment-based HRV characterization was then confirmed by two ensemble-learning models aimed at estimating apnea-hypopnea index and classifying sleep stages, respectively. We surmise that basal sympathetic activity during REMS may mask apneic events-induced sympathetic excitation, thus highlighting the importance of incorporating sleep stages as well as apneic events when evaluating HRV in pediatric OSA.

Myocardial strain parameters and autonomic balance in various variants of the postinfarction course in patients receiving high-dose atorvastatin therapy

Aim. To study parameters of left ventricular (LV) strain and heart rate variability (HRV) in patients with ST-segment elevation myocardial infarction (STEMI) in various variants of postinfarction receiving high-dose atorvastatin therapy.Material and methods. The study included 96 patients with STEMI. All patients underwent two-dimensional speckle tracking echocardiography and 24-hour electrocardiographic monitoring with HRV analysis. The included individuals were divided into groups without pathological LV remodeling (R (-), n=57) and with pathological post-infarction LV remodeling (R (+), n=39), the criterion for which was an increase in end-diastolic and/or end-systolic volume &gt;20% and &gt;15%, respectively. Further, depending on the achievement of target low-density lipoprotein cholesterol (LDL-C) (1,5 mmol/l and/or a decrease of more than 50%), the following subgroups were identified: 17 (43,6%) people, who reached target LDL-C levels (group 1), 22 (56,4%) patients, who did not reach target LDL-C levels (group 2). Similar subgroups were identified in the R (-) group as follows: 28 (49,1%) people, who reached target LDL-C levels (group 3) and 29 (50,9%) people, who did not reach target LDL-C levels (group 4).Results. Starting from the 12th week of follow-up, worsening of global longitudinal (GLS), circumferential (GCS), and radial (GRS) strain (p&lt;0,01) was registered in group 2. In group 1, worsening of these parameters was registered only by the 48th week (p&lt;0,01). In group 3, an increase in GLS was revealed by the 48th week (p=0,001), GCS and GRS — by the 12th week (p&lt;0,05). In group 4, favorable changes were observed only in GLS and GCS by the 48th week (p&lt;0,01). A significant change in HRV parameters was observed in group 3. By the 48th week, there was an increase in temporal indicators (SDNN, SDNNi, SDANN, RMSSD, pNN50) (p&lt;0,0001) and total spectrum power (p=0,0001) due to an increase in all frequency indicators (p&lt;0,001), while the index of autonomic balance L/H decreased by 33% (p=0,002). In group 4, only SDNN, SDANN and pNN50 (p&lt;0,05), as well as the total spectrum power (p=0,001) increased, but no change in frequencies. According to intergroup analysis in the acute period of STEMI, group 4 patients had higher HRV than in group 3 (p&lt;0,05).Conclusion. High-dose atorvastatin therapy improves LV strain characteristics and autonomic balance during the rehabilitation period after STEMI.

Особенности желудочковой экстрасистолии на фоне коморбидной патологии у юных спортсменов

Aim: to assess the role of autonomic disorders and undifferentiated connective tissue dysplasia (UCTD) of the heart in children with ventricular extrasystoles (VE) engaged in sports. Patients and Methods: the study included 52 athlete boys with newly diagnosed cardiac arrhythmia in the form of ventricular extrasystoles. The study group (n=34) consisted of children with moderate VE severity co-existing with asympaticotonic type of autonomic dysfunction syndrome (ADS) amid undifferentiated connective tissue dysplasia mostly affecting the heart (UCTDH). The study group was split into two subgroups: subgroup 1 (n=11) – children with monotopic VE persisting at load and subgroup 2 (n=23) – children with occasionally appearing VE which reduced in the vertical position and/or at load. The control group (n=18) consisted of children with moderate VE amid UCTDH without ADS manifestations. A comprehensive clinical and laboratory assessment was performed in all patients. Results: on Holter monitoring (HM), in patients of the study group, subgroup 1, a sinus rhythm was recorded with the presence of 9,000- 15,000 VE per day (single or paired). The power spectral analysis of heart rate variability (HRV) in the subgroup 1 children demonstrated that in most cases (10 (90.9%)) there were low levels of the total power (TP) (р&lt;0.05) and high values of the high-frequency component (HF) (p&lt;0.05) as compared to those in the control group children. Also, a significant decrease in creatine phosphokinase-MB activity in the blood serum was found in children of the study group, subgroup 1, as compared to the reference values (р&lt;0.05). The VE development in the study group, subgroup1, children was caused by the combined exposure to sport loads and the autonomic control of cardiovascular function amid UCTDH. In the study group, subgroup 2, children the laboratory testing did not demonstrate any statistically significant changes in creatine phosphokinase-MB activity in the blood serum as compared to the reference values (р&gt;0.05). On HM, in most of the subgroup 2 children, a sinus rhythm was recorded with the presence of 6,000-9,000 VE per day. The changes in HRV parameters and their spectrogram in 19 (82.6%) cases were common for asympaticotonic type. As compared to the values in the control group children, TP was slightly lower (р&gt;0.05) along with a high HF level (р&gt;0.05). A half of the control group children had a moderate increase in creatine phosphokinase-MB activity in the blood serum (р&lt;0.05), while in other cases its values did not differ considerably from the normal range. On HM, in most cases a normal sinus rhythm with usually single EV, 300-5,000 per day, was recorded. The main measurements of the power spectral analysis of HRV and spectrogram indicators suggested that children of this group had sufficient body energy supply. The presence of VE in the control group children was associated with the impact of sport loads on the heart with dysplasia. Conclusion: the authors have distinguished the clinical variants of heart rhythm disorders in young athletes with different levels of body energy supply, VE patterns, etc. In young athletes, ventricular extrasystoles are characterized by a persisting occurrence in cases with asympaticotonic type of autonomic disorders amid UCTDH. They are associated with a decrease in energy supply of the body, in particular, the myocardial muscle. Occasionally occurring VE were recorded in athletes without significant disturbances in energy supply. KEYWORDS: ventricular extrasystoles, autonomic dysfunction syndrome, undifferentiated connective tissue dysplasia of the heart, energy supply, athletes. FOR CITATION: Cherkasov N.S., Doronina T.N., Prakhov A.V., Semenova I.A. Characteristics of ventricular extrasystoles co-occurring with comorbidities in young athletes. Russian Journal of Woman and Child Health. 2023;6(1):45–49 (in Russ.). DOI: 10.32364/2618-8430-2023-6-1-45-49.

Abstract 13303: Influence of ARNI on Cardiac Autonomic Nervous System

Background Mortality in heart failure with reduced ejection fraction (HFrEF) is associated with imbalance of cardiac autonomic nervous system (CANS). Sacubitril/ Valsartan (ARNI) reduces risk of death and HFrEF hospitalization. Whether ARNI exerts effects on CANS has not been studied. Accordingly, we prospectively compared heart rate variability (HRV) as a noninvasive measure of CANS before and after initiation of ARNI therapy. Methods: The study was as a single-arm prospective interventional study. Patients with HFrEF underwent echocardiography and standardized 30-minute 12-lead Holter ECG recording before and 3 months after initiation of ARNI therapy. Study endpoints were changes in HRV parameters (standard deviation of normal-to-normal intervals (SDNN), mean square of differences between consecutive R-R intervals (RMSSD), periodic repolarization dynamics (PRD) and deceleration capacity (DC) as well as left ventricular ejection fraction (LVEF) and heart rate (HR). Results: Between June 2021 and March 2022 we recruited 63 consecutive patients. At follow-up 48 (76.2%) patients were still on ARNI and therefore analyzed. Mean age was 65±13 years, 88% were male. All patients received identical beta-blockers dosage at baseline and follow-up. Heart rate was reduced by ~12% (P=0.005). SDNN increased by ~42% (P&lt;0.001), RMSSD by ~55% (P&lt;0.001) and ~DC by 370% (P&lt;0.001). No change in PRD was observed (P=0.13). These results were accompanied by increased LVEF (28±6% vs. 38±10%, P&lt;0.001) and reduced plasma nt-proBNP levels (5083±790 pg/ml vs. 1838±621 pg/ml, P=0.002). NYHA class improved from III to II. Conclusion Significant increase of parasympathetic CANS tone was observed after initiation of ARNI therapy as evidenced by decreased HR, increased DC, SDNN and RMSSD. Part of the beneficial effects of ARNI might be related to the accentuation of parasympathetic CANS modulating mortality risk and risk for HFrEF hospitalizations.

Abstract 13649: Differential Effect of Variable Autonomic Modulation Stimulation Parameters on Autonomic Function

Introduction: Reduced heart rate variability (HRV) is associated with increased risk of cardiovascular morbidity and mortality. Previous studies have shown that transcutaneous vagus nerve stimulation (tVNS) increases HRV and improves autonomic function, but the effect of variable stimulation parameters on autonomic function remains unclear. Hypothesis: We examined the effect of variable stimulation parameters of tVNS on autonomic function. Methods: Healthy volunteers were recruited for this study. Each participant underwent autonomic function testing consisting of HRV during deep breathing and mental arithmetic stress test (MAST), with and without tVNS. Participants were randomized to 4 groups of different stimulation parameters in a 2x2 fashion (frequency 5Hz and 20Hz; amplitude 1mA below discomfort threshold or 50% below discomfort threshold). tVNS was applied for 5 minutes for each session. HRV was analyzed in a blinded fashion using Kubios software. Results were compared with 2-way ANOVA, adjusted for multiple comparisons. Results: Thirty participants were included (mean age 39±14 years, 70% female). Stimulation amplitude was 26±13 mA and 14±7 mA in the 1mA below and 50% below discomfort threshold groups (p=0.001). There was a greater change in HRV parameters with 20Hz vs. 5Hz stimulation versus baseline during MAST (low frequency: -8.1±2.8%, vs. 1.4±1.8%, p=0.01; high frequency 8.2±3.7% vs. -1.3±1.8%, p=0.03; SD2 of Poincare plot -7.9±2.9 ms vs. 4.2±3.1 ms, p=0.005, respectively; Figure). No differences were observed between the 2 different amplitude groups. Conclusions: Stimulation frequency may influence the acute effect of autonomic modulation on autonomic function parameters. These findings have implications for autonomic modulation study design. Further studies in disease states are warranted.

Modulation of the autonomic nervous system by one session of spinal low-level laser therapy in patients with chronic colonic motility dysfunction.

Patients with a defecation disorder may not evoke a normal defecation reflex, or the reflex may be excessive, as a dysfunction of the spinal autonomic nervous system. Treatment with various forms of lumbar and sacral neuromodulation have shown symptom improvement, but potential changes in autonomic functioning are rarely studied. Here we evaluate the effects on autonomic function of a single session of low-level laser therapy (LLLT) on the lumbar and sacral spine in 41 patients with chronic gastrointestinal motor dysfunction. The LLLT protocol used red LED light at a wavelength of 660 nm for 10 min and infrared LED light at a wavelength of 840 nm for 10 min, followed by infrared laser light at a wavelength of 825 nm for 10 min. Effects on the autonomic nervous system were assessed by measuring heart rate variability (HRV) changes. Respiratory Sinus Arrhythmia (RSA) and Root Mean Square of Successive Differences (RMSSD) were used to quantify parasympathetic reactivity; the Baevsky’s Stress Index (SI) reflected sympathetic activity while the ratios SI/RSA and SI/RMSSD were used to show shifts in autonomic dominance. The results indicate that lumbar and sacral neuromodulation using light arrays reduced, whereas stimulation by the laser probes significantly increased parasympathetic activity. The light arrays increased whereas the laser probes significantly decreased sympathetic activity (SI). The entire protocol shifted the autonomic balance toward parasympathetic activity. The comparison of actual vs. sham neuromodulation proved that the change in HRV parameters was due to actual light stimulation and not due to the arrays and probe touching the skin. In conclusion, a single session of LLLT markedly affects autonomic nervous system activity reflected in changes in HRV which is only possible by generating activity in the spinal autonomic nerves. These results warrant a study into the effects of LLLT on restoring autonomic dysfunction in chronic refractory colonic motility disorders.

Dynamics of Cardiac Autonomic Responses During Hemodialysis Measured by Heart Rate Variability and Skin Sympathetic Nerve Activity: The Impact of Interdialytic Weight Gain.

Background: Autonomic nervous regulation plays a critical role in end-stage kidney disease (ESKD) patients with cardiovascular complications. However, studies on autonomic regulation in ESKD patients are limited to heart rate variability (HRV) analysis. Skin sympathetic nerve activity (SKNA), which noninvasively reflects the sympathetic nerve activity, has not been used in ESKD patients. Methods: Seventy-six patients on maintenance hemodialysis (MHD) treatment (a 4-h HD session, three times a week) were enrolled. Utilizing a noninvasive, single-lead, high-frequency recording system, we analyzed the dynamic change in HRV parameters and SKNA during HD. The different characteristics between the subgroups divided based on interdialytic weight gain (IDWG, <3 kg or ≥3 kg) were also demonstrated. Results: After the HD, values for heart rate (75.1 ± 11.3 to 80.3 ± 12.3 bpm, p < 0.001) and LF/HF (1.92 ± 1.67 to 2.18 ± 2.17, p = 0.013) were significantly higher than baseline. In subgroup analysis, average voltage of skin sympathetic nerve activity (aSKNA) in IDWG ≥3 kg group was lower than the IDWG <3 kg group at the end of MHD (1.06 ± 0.30 vs 1.32 ± 0.61 μV, p = 0.046). Moreover, there was a linear correlation between mean heart rate (HR) and aSKNA in low IDWG patients (p < 0.001), which was not found in high IDWG patients. At the 1-year follow-up, high IDWG patients had a higher incidence of cardiovascular hospitalization (p = 0.046). Conclusions: In MHD patients, a gradual activation of sympathetic nerve activity could be measured by HRV and aSKNA. A lower aSKNA at the end of HD and a loss of HR-aSKNA correlation in overhydrated patients were observed. Extensive volume control is promising to improve the autonomic nervous function and clinical outcomes in this population.

Different exercise training modalities similarly improve heart rate variability in sedentary middle-aged adults: the FIT-AGEING randomized controlled trial

PurposeThis study aimed to investigate the influence of different exercise training modalities on heart rate variability (HRV) in sedentary middle-aged adults; and to study whether changes in health-related outcomes (i.e., body composition and cardiometabolic risk) are associated with those hypothetical HRV changes in sedentary middle-aged adults.MethodsA total of 66 middle-aged adults (53.6 ± 4.4 years old; 50% women) were enrolled in the FIT-AGEING study. We conducted a 12-week randomized controlled trial. The participants were randomly assigned to 4 groups: (a) a control group (no exercise); (b) a physical activity recommendation from the World Health Organization group (PAR); (c) a high-intensity interval training group (HIIT); and (d) a high-intensity interval training group adding whole-body electromyostimulation (HIIT + EMS).ResultsAll exercise training modalities induced changes in HRV parameters (all P ≤ 0.001) without statistical differences between them (all P > 0.05). We found associations between changes in body composition and cardiometabolic risk and exercise-related changes in HRV.ConclusionOur results suggest that different exercise interventions (i.e., PAR, HIIT and HIIT + EMS) induced an enhancement of HRV in sedentary middle-aged adults. Our findings support the notion that exercise-related changes in HRV are associated with changes in body composition and cardiometabolic risk after the intervention programClinical trial registryNCT03334357 (ClinicalTrials.gov). November 7, 2017 retrospectively registered.

Аssessment of vegetative regulation of the heart rate in patients with pulmonary TB

SummaryAim. To evaluate features of vegetative regulation of the heart rate in patients with pulmonary TB. Methods. The authors analyzed examination results of 109 patients with different forms of pulmonary TB (the main group). The comparison group consisted of 63 individuals with-out TB or heart disease. To identify features of vegetative regulation of the heart rate, all patients underwent 3-lead 24-hour ECG monitoring and assessment of heart rate variability (HRV) indices using spectral and time-domain analyses. The results were processed using MS Excel 2016 for Windows and Statistica 10 software programmes; nonparametric methods were used. Results. According to our research data, pulmonary TB patients had signifi-cantly lower values of the time-domain analysis of HRV: SDNN in 28% of cases (р&lt;0.05); RMSSD in 22% of cases (р&lt;0.05). The spectral analysis data showed HF in 91% of cases (р&lt;0.05), LF in 61% of cases (р&lt;0.05), a rigid circa-dian rhythm of the heart rate in 55% of cases (p&lt;0.05), and the increased index of vagosympathetic balance in 93% of cases (р&lt;0.05). The sympathicotonic type of vegetative regulation was detected in 93% of cases, the balanced initial vegetative type of HRV — in 5% of cases, and the parasympathicotonic type — in 2% of cases. The authors established a direct strong correlation between indices of RMSSD and HF, r=0.81 (p&lt;0.05). The changes in HRV parameters were not linked with clinical forms of TB (р&gt;0.05). Conclusion. Initial sympathicotonia prevails in patients with pulmonary TB, which indicates intensive work of the cardiovascular system, which in its turn leads to the increased risk of adverse cardiac events. Patients with pulmonary TB should undergo dynamic 24-hour Holter monitoring for timely correction of vegetative re-gulation of the heart rate.

Use of the Polar V800 and Actiheart 5 heart rate monitors for the assessment of heart rate variability (HRV) in horses

Heart rate variability (HRV) is a commonly used metric in animal science to quantify an aspect of the physiological response to stressors. HRV analysis relies upon accurate detection of the electrical activity of the heart to define inter-beat interval (IBI). In horses, this can be problematic due to specific features of the equine ECG waveform and a high incidence of 2nd-degree atrioventricular (AV) block in clinically normal horses at rest.The current study validates the collection and interpretation of IBI data from two heart rate monitors (HRMs) principally designed for human personal monitoring (Polar V800 and Actiheart 5). 30 min of synchronous IBI data was collected using the two HRMs and a 4-lead telemetric ECG that is widely used in equine veterinary clinical practice (Televet 100). The study was conducted using a mixed sample (n = 17) of general riding horses, with (n = 4) and without (n = 13) cardiac dysrhythmias. HRV data was derived from each IBI data set and compared following application of a series of correction factors.There was a very strong inter-class correlation of HRV parameters from both the Actiheart 5 and Polar V800 with the Televet 100 data. Both HRMs providing an acceptable level of agreement with both time and frequency domain HRV parameters. The data from the Actiheart 5 were found to be interchangeable with the Televet 100 in respect of beat detection whereas the Polar V800 data required a 0.4 s artefact correction to give best agreement. Both HRMs have utility in equine research for demonstrating the direction and magnitude of change in HRV parameters, although users must apply appropriate artefact correction to maximise data validity.

Heart Rate Variability in Postoperative Patients with Nonfunctioning Pituitary Adenoma.

BackgroundDecreased heart rate variability (HRV) has been reported to be associated with cardiac autonomic dysfunction. Hypopituitarism in nonfunctioning pituitary adenoma (NFPA) is often linked to increased cardiovascular mortality. We therefore hypothesized that postoperative NFPA patients with hormone deficiency have an elevated risk of HRV alterations indicating cardiac autonomic dysfunction.MethodsA total of 22 patients with NFPA were enrolled in the study. Between 3 and 6 months after surgery, a combined pituitary function test (CPFT) was performed, and HRV was measured. The period of sleep before the CPFT was deemed the most stable period, and the hypoglycemic period that occurred during the CPFT was defined as the most unstable period. Changes in HRV parameters in stable and unstable periods were observed and compared depending on the status of hormone deficiencies.ResultsIn patients with adrenocorticotropic hormone (ACTH) deficiency with other pituitary hormone deficiencies, the low frequency to high frequency ratio, which represents overall autonomic function and is increased in the disease state, was higher (P=0.005). Additionally, the standard deviation of the normal-to-normal interval, which decreases in the autonomic dysfunction state, was lower (P=0.030) during the hypoglycemic period. In panhypopituitarism, the low frequency to high frequency ratio during the hypoglycemic period was increased (P=0.007).ConclusionHRV analysis during CPFT enables estimation of cardiac autonomic dysfunction in patients with NFPA who develop ACTH deficiency with other pituitary hormone deficiencies or panhypopituitarism after surgery. These patients may require a preemptive assessment of cardiovascular risk.

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.

Z-score neurofeedback, heart rate variability biofeedback, and brain coaching for older adults with memory concerns.

Background:The three-month, multi-domain Memory Boot Camp program incorporates z-score neurofeedback (NFB), heart rate variability (HRV) biofeedback, and one-on-one coaching to teach memory skills and encourage behavior change in diet, sleep, physical fitness, and stress reduction.Objective:This prospective trial evaluates the Memory Boot Camp program for adults ages 55 to 85 with symptoms of Mild Cognitive Impairment (MCI) and subjective memory complaints.Methods:Participants were evaluated via the Montreal Cognitive Assessment (MoCA), NeuroTrax Global Cognitive Score, measures of anxiety, depression, sleep, quality of life, quantitative electroencephalography (QEEG), and HRV parameters at four timepoints: baseline, pre-program, post-program, and follow-up. The trial included a three-month waiting period between baseline and pre-program, such that each participant acted as their own control, and follow-up took place six months after completion of the program.Results:Participants’ MoCA scores and self-reported measures of anxiety, depression, sleep quality, and quality of life improved after treatment, and these changes were maintained at follow-up. Physiological changes in HRV parameters after treatment were not significant, however, breathing rate and QEEG parameters were improved at post-program and maintained at follow-up. Finally, participants’ improvement in MoCA score over the treatment period was correlated with their improvement in two brain oscillation parameters targeted by the z-score NFB protocol: relative power of delta and relative power of theta.Conclusions:Trial results suggest that the Memory Boot Camp program is a promising treatment strategy for older adults with symptoms of MCI and subjective memory complaints.

Particulate matter air pollution and reduced heart rate variability: How the associations vary by particle size in Shanghai, China

BackgroundIt remains unclear which size of particles has the strongest effects on heart rate variability (HRV). ObjectiveTo explore the association between HRV parameters and daily variations of size-fractionated particle number concentrations (PNCs). MethodsWe conducted a longitudinal repeated-measure study among 78 participants with a 24-h continuous ambulatory Holter electrocardiographic recorder in Shanghai, China, from January 2015 to June 2019. Linear mixed-effects models were employed to evaluate the changes of HRV parameters associated with PNCs of 7 size ranges from 0.01 to 10 μm after controlling for environmental and individual confounders. ResultsOn the concurrent day, decreased HRV parameters were associated with increased PNCs of 0.01–0.3 μm, and smaller particles showed greater effects. For an interquartile range increase in ultrafine particles (UFP, those < 0.1 μm, 2453 particles/cm3), the declines in very-low-frequency power, low-frequency power, high-frequency power, standard deviation of normal R-R intervals, root mean square of the successive differences between R-R intervals and percentage of adjacent normal R-R intervals with a difference ≥ 50 ms were 5.06% [95% confidence interval (CI): 2.09%, 7.94%], 7.65% (95%CI: 2.73%, 12.32%), 9.49% (95%CI: 4.64%, 14.09%), 5.10% (95%CI: 2.21%, 7.91%), 8.09% (95%CI: 4.39%, 11.65%) and 24.98% (95%CI: 14.70%, 34.02%), respectively. These results were robust to the adjustment of criteria air pollutants, temperature at different lags, and the status of heart medication. ConclusionsParticles less than 0.3 μm (especially UFP) may dominate the acute effects of particulate air pollution on cardiac autonomic dysfunction.

Evolution of Heart Rate Variability and Heart Rate Turbulence in Patients with Depressive Illness Treated with Selective Serotonin Reuptake Inhibitors.

Background and objectives: Major depressive disorder (MDD) and cardiovascular diseases (CVDs) represent serious and prevalent medical conditions. Autonomic nervous system (ANS) dysfunctions, expressed by parameters of heart rate variability (HRV) and heart rate turbulence (HRT), have been repeatedly associated with depression. The aim of our study was to identify potential HRV and HRT alterations in patients with MDD, before and after selective serotonin reuptake inhibitor (SSRI) therapy, and to observe any correlations between these parameters and the severity of depressive symptoms. Another aim was to evidence if there was a normalization or improvement of HRV and HRT parameters that paralleled the reduction of the intensity of depressive symptoms. Materials and Methods: We studied heart rate variability (HRV) and heart rate turbulence (HRT) in a sample of 78 patients, aged under 51 years, who were referred to our outpatient clinic between June 2017 and December 2019, for complaints in the context of a new onset major depressive disorder (MDD), before and after therapy with SSRIs. Results: By using 24 h Holter ECG monitoring, we evidenced alterations of HRV and HRT parameters, significantly correlated with the severity of depressive symptoms (p < 0.001), as assessed by the Montgomery–Åsberg Depression Rating Scale (MADRS). Our results indicated that these parameters improved following one and six months of SSRI therapy, when a partial or total remission of depressive symptoms was achieved (p < 0.001). Changes in HRV parameters were correlated with the reduction of the severity of depression. Conclusions: In our study group, we highlighted, through 24 h ECG Holter monitoring, frequent and clear HRV and HRT abnormalities that were statistically correlated with the severity of depressive symptoms. Furthermore, we were able to document a progressive improvement of these parameters, which corresponded with the improvement of depressive symptoms under SSRI therapy, when compared to the values measured before the commencement of antidepressant pharmacotherapy.

A Pilot Study of the Reliability and Agreement of Heart Rate, Respiratory Rate and Short-Term Heart Rate Variability in Elite Modern Pentathlon Athletes.

Research on reliability of heart rate variability (HRV) parameters in athletes has received increasing attention. The aims of this study were to examine the inter-day reliability of short-term (5 min) and ultra-short-term (1 min) heart rate (HR), respiratory rate (RespRate) and HRV parameters, agreement between short-term and ultra-short-term parameters, and association between differences in HR, RespRate and HRV parameters in elite modern pentathletes. Electrocardiographic recordings were performed in stable measurement conditions with a week interval between tests. Relative reliability was evaluated by intra-class correlation coefficients, absolute reliability was evaluated by within-subject coefficient of variation, and agreement was evaluated using Bland–Altman (BA) plot with limits of agreement and defined a priori maximum acceptable difference. Short-term HR, RespRate, log transformed (ln) root mean square of successive normal-to-normal interval differences (lnRMSSD), ln high frequency (lnHF) and SD2/SD1 HRV indices and ultra-short-term HR, RespRate and lnRMSSD presented acceptable, satisfactory inter-day reliability. Although there were no significant differences between short-term and ultra-short-term HR, RespRate and lnRMSSD, no parameter showed acceptable differences with BA plots. Differences in time-domain and non-linear HRV parameters were more correlated with differences in HR than with differences in RespRate. Inverse results were observed for frequency-domain parameters. Short-term HR, RespRate, lnRMSSD, lnHF, and SD2/SD1 and ultra-short-term HR, RespRate and lnRMSSD could be used as reliable parameters in endurance athletes. However, practitioners should interpret changes in HRV parameters with regard to concomitant differences in HR and RespRate and caution should be taken before considering 5 min and 1 min parameters as interchangeable.