SDNN Values Research Articles

HEART RATE VARIABILITY IN FOOTBALL PLAYERS AND TRACK AND FIELD ATHLETES

Objective of the study: To investigate the state of the autonomic nervous system in athletes based on heart rate variability indicators. Materials and methods: The study was conducted on 142 male athletes (67 football players and 75 track and field athletes) aged 17-20 years, with an average age of 18.5±1.5 years. Depending on the type of higher nervous activity, athletes were divided into 4 groups: sanguine (41.55%), choleric (28.87%), phlegmatic (19.01%), and melancholic (10.56%). Heart rate variability (HRV) was studied using the "BioMouse" system. A t-test for independent samples (Welch's t-test) was used to analyze the significance of differences between the groups. Results of the study: It was found that the highest adaptive capabilities were observed in phlegmatic athletes, who demonstrated high SDNN and HF values, as well as a low tension index (IN). Their calm temperament allows for better adaptation to physical exertion and maintaining a balance between sympathetic and parasympathetic activity. The lowest adaptive capabilities were observed in melancholics, who showed high IN and LF values, as well as low SDNN and HF, indicating an imbalance in the autonomic nervous system and lower resilience to physical stress. Overall, beginner athletes tended to have slightly higher heart rates and lower HRV indicators (SDNN), LF, and HF compared to more experienced athletes of the 2nd-3rd ranks. This is due to the fact that first-year athletes have not yet fully adapted to physical loads, leading to more pronounced dominance of the sympathetic nervous system and less parasympathetic activity. KEYWORDS: variability, heart rate, athletes, football players, track and field athletes, autonomic nervous system, physical exertion

Проблеми відновлення функціональних резервів кваліфікованих спортсменів різних вікових груп у ММА після змагальної діяльності

Topicality. Taking into account the complexity of competitive activities in MMA, the question of determining clear time limits necessary for the complete recovery of the body of individuals of different age groups, using modern methods of assessing the adaptation reserves of the body, cause conflicting views among researchers regarding the effective mechanisms of their implementation. The Purpose of the Research. To determine the effectiveness of recovery of functional reserves of qualified athletes of different age groups in MMA after competitive activity. Methods. 40 qualified MMA athletes (young men) of different age groups (14–16 and 17–18 years) participated in the research. The research was conducted after the performance of the examined athletes at two high-level tournaments, which were held with an interval of 2 days. 4 groups were formed. Representatives of the first (14–16 years old) and third groups (17–18 years old) took part in only one tournament. Athletes of the second (14–16 years old) and fourth (17–18 years old) took part in matches in both competitions. Using indicators of heart rate variability and biochemical analysis of cortisol concentration in the blood, the nature of adaptive changes of the participants' bodies to a given physical stimulus was determined. 2 tests were used: execution by athletes of a series of lateral kicks on the makiwara for 15 and 40 s with maximum force. The Results. It was established that at the beginning of the study, the athletes of groups 2 and 4, who were trained in duels only during one competition, had a less strained regulation of the heart rhythm (LF/HF<1,15) compared to representatives of the other two groups. In athletes of groups 1 and 3, in response to exercise, we observed a decrease in SDNN values by an average of 26,2 % and LF by 24,3 % against the background of an increase in HF parameters by 2,8 %. Representatives of the other two groups, on the contrary, showed an increase in SDNN (+25,9 % and +34,8 %) and LF value by an average of 26,9 % against a background of a decrease in HF parameters by 22,0 % in response to exercise during 40 p. It was found that in athletes of groups 1 and 3, the concentration of cortisol in blood serum is 40,3 % higher than the parameters fixed in representatives of groups 2 and 4, but do not go beyond the physiological norm. Among the subjects of group 1, the level of the studied hormone in response to special loads for 40 seconds shows a significant decrease by 40,5 %, and among the participants of group 3 by 50,1 % compared to the state of rest. Among other participants, we observe an adequate reaction to a stressful stimulus, which is manifested in the growth of this steroid hormone in blood serum (+32,5 % in athletes of the 2nd group; +11,8 % in the 4th group). Conclusions. The results revealed in the research show that qualified MMA athletes of adolescent and youth age, after participating for a short period of time simultaneously in two international tournaments, during the recovery period need to reduce loads to 40–45 % of 1 PM and use only aerobic mode of energy supply. It was established that during the recovery period, the use of specialized for this type of sport load leads to the manifestation of compensatory mechanisms associated with the activation of gluconeogenesis processes and the strengthening of the vagal influence on the sinus node of the heart of athletes.

Intake of Dark and Milk Chocolate Differently Affects Autonomic Nervous Control of the Heart During Rest and Mental Stress

Objective Chocolate is a popular food that may affect the activity of the autonomic nervous system (ANS). The aim of this study was to determine the effect of a single dose of dark or milk chocolate on ANS cardiac control during rest and mental stress induced by the Stroop test (ST). Methods Healthy participants, divided into DARK or MILK chocolate groups, ingested corresponding type of chocolate (1 g/kg body weight). They underwent measurement of ANS during relaxation and ST before and 2 h after chocolate consumption. ANS control was assessed by determination of heart rate (HR) and heart rate variability using parameters related to complex autonomic modulation (TP, SDNN) or primary vagal modulation (HFnu, RMSSD). Results HR was always increased during ST in both groups. Relaxation HR values after chocolate ingestion were higher only in the DARK chocolate group. During ST, values of TP, SDNN and HFnu decreased before and after chocolate ingestion in the DARK group, but only before chocolate ingestion in the MILK group. RMSSD values decreased during ST before and after chocolate ingestion in both groups. Relaxation TP, RMSSD and HFnu values after chocolate ingestion were lower in the DARK but not in the MILK group. Conclusion The results suggest that even a single dose of milk chocolate attenuates changes in ANS cardiac control induced by mental stress, whereas a single dose of dark chocolate has an activating effect on the heart via modification of ANS cardiac control at rest. Different levels of sugars and cocoa biologically active compounds in the two types of chocolate could explain the observed effects.

Heart rate variability: Obtaining the stress score from SDNN values

BACKGROUND: Heart Rate Variability (HRV) is a non-invasive method of assessing the autonomic nervous system response during exercise and fatigue. OBJECTIVE: The aim of the study was to analyze the validity and feasibility of the stress score index (SS) calculated from SDNN values during exercise. METHODS: 18 Men performed 2 running tests: 1) incremental exercise test; 2) 10-minute constant load test. Subjects underwent HRV analysis during the constant load test, before both tests, and afterward in a seated position at 3 intervals (0’–5’, 5’–10’, 10’–15’). The relationship between SDNN and SD2 was analyzed before, during, and after the test. SS was calculated as 1/SD2*1000. The Bland-Altman test analyzed the reliability of ESS. The bias, limits of agreement (LoA), standard deviation of difference, intraclass correlation (ICC), and person coefficient were calculated. RESULTS: The bias was 0.15 ± 2.54 (UperLOA: 2.54; LowerLOA: -2.23). In all conditions, SD2 and SDNN showed a positive linear relationship (r2 = 0.986); SS and ESS were correlated; and SS and ESS described a positive linear relationship (r2 = 0.993). CONCLUSIONS: The SS index calculation from SDNN is a reliable alternative during exercise.

Which indices of heart rate variability are the best predictors of mortality after acute myocardial infarction? Meta-analysis of observational studies

BackgroundCardiovascular disease is the first cause of death globally with myocardial infarction as the main event. Heart rate variability (HRV) has been associated with an increased risk of mortality post-myocardial infarction. However, which indices of heart rate variability are the best predictors for total and cardiac mortality post-myocardial infarction remains unclear. We performed a systematic review to evaluate this association. Methods and resultsPubMed, Google Scholar, Embase and Cochrane databases were searched for studies with HRV as a predictive mortality marker. Two authors independently selected papers and extracted data and disagreements were solved with a third author. HRV indices included were SDNN, SDANN, HRV index, Total power, RMSSD, LF, HF, ULF, VLF, and LF/HF. For these clinical and statistical heterogeneity was assessed, forest and funnel plot graphs were made and sensitivity analysis, cumulative and regression meta-analysis were performed. Stata 16 was used for statistical analysis.Out of 19.960 articles found, 332 were initially selected for abstract screening and 27 finally fulfilled the criteria and allowed the extraction of data. After a sensitivity analysis, low values of SDNN, HRV index, ULF, VLF, Total Power, LF, LF/HF ratio and HF showed a statistically significant association with cardiac mortality, but SDNN index had the highest association (RR 4.19, CI95% 3.36–5.22, I2 39.7%). For total mortality, HRV index, VLF, ULF, LF, Total power, SDNNN, LF/HF ratio, HF were significantly associated, but HRV index was the index with highest association, (RR 3.60, CI95% 2.30–5.64, I2 27.5%). ConclusionsBased on a sensitivity analysis, the best index associated with cardiac mortality post-myocardial infarction is low values of SDNN and for total mortality is low values of HRV index.

The Heart's Function as a Pump Assessed via Impedance Cardiography and the Autonomic System Balance in Patients with Early-Stage Acromegaly.

Acromegaly is a rare, chronic disease that involves structural and functional abnormalities of the cardiovascular system. Acromegaly likely affects interactions between the cardiovascular system and the autonomic nervous system (ANS). Therefore, assessing the relationship between sympathetic-parasympathetic balance by analyzing heart rate variability (HRV) and the hemodynamic profile via impedance cardiography (ICG) may be useful in learning the exact nature of interactions between the ANS and the cardiovascular system. The purpose of this study was to assess a possible association between HRV and ICG-based parameters of cardiac function in patients newly diagnosed with acromegaly. This observational cohort study was conducted on 33 patients (18 men, mean age of 47 years) newly diagnosed with acromegaly and no significant comorbidities. A correlation analysis (Spearman's rank coefficient R) of the parameters assessed via ICG and the HRV assessed via 24 h ambulatory electrocardiography was performed. ICG assessments included the following parameters: stroke volume index (SI), cardiac index (CI), acceleration index (ACI), velocity index (VI), and Heather index (HI). The analysis of HRV included both time-domain parameters (pNN50, SDNN, SDSD, rMSSD) and frequency-domain parameters (total power (TP) and its individual frequency bands: low-frequency (LF day/night), high-frequency (HF day/night), and the LF/HF ratio (day/night)). Frequency-domain HRV analysis showed the following correlations: (1) lower nighttime LF values with higher ACI (R = -0.38; p = 0.027) and HI (R = -0.46; p = 0.007) values; (2) higher nighttime HF values with higher ACI (R = 0.39; p = 0.027) and HI (R = 0.43; p = 0.014) values; (3) lower nighttime LF/HF values with higher ACI (R = -0.36; p = 0.037) and HI (R = -0.42; p = 0.014) values; (4) higher nighttime TP values with higher SI values (R = 0.35; p = 0.049). Time-domain parameters of HRV showed a significant correlation only between the nighttime values of SDSD and SI (R = 0.35; p = 0.049) and between the daytime and nighttime values of SDNN and HR (R = -0.50; p = 0.003 and R = -0.35; p = 0.046). In multivariate regression, only ACI was revealed to be independently related to HRV. In patients newly diagnosed with acromegaly, the relationship between the sympathetic-parasympathetic balance assessed via HRV and the hemodynamic profile assessed via ICG was revealed. Better function of the left ventricle was associated with a parasympathetic shift in the autonomic balance.

Yoga and Naturopathy intervention on psychological comorbidities and autonomic function for irritable bowel syndrome patient: A case study

Irritable bowel syndrome (IBS) is a common functional disorder of the gut-brain axis, characterized by abdominal pain and altered bowel habits. A 38-year-old male patient with a sedentary lifestyle, diagnosed with IBS based on Rome IV criteria, was underwent Yoga and Naturopathy interventions for one month in our outpatient department. The result showed a reduced Irritable Bowel Syndrome Severity Score (IBS-SSS) (315 to 109) and perceived stress (PSS) score (29 to 12) level. Heart rate variability (HRV) analysis showed increased SDNN (35.4 to 48.3 ms) and RMSSD (41.3 to 58.3 ms) values, indicative of improved HRV. Notably, parasympathetic dominance was observed, evidenced by increased pNN50% (14.56 to 18.41) and H.F (41.92 to 59.63 n.u) values, while the LF/HF ratio (1.381 to 0.675) decreased. This case report suggests that lifestyle change through Yoga and Naturopathic intervention is useful in the management of IBS with psychological co-morbidities .

Experimental evaluation of ECG signal denoising methods based on HRV indices and their application in indoor thermal comfort study under different temperatures

The heart rate variability (HRV) features extracted from an electrocardiogram (ECG) signal have been widely used to help improve the performance of thermal comfort models, with the ECG signal denoising method being very important. In this study, 20 volunteers were recruited for experiments in a well-controlled chamber. Their ECG signals (a total of 6,000,000 sets of data) were collected under stable and variable temperature environments. With the use of the setup database, four denoising methods were compared: the fast Fourier transform (FFT), wavelet transform, Chebyshev filter, and Butterworth filter. When the performance of these methods was evaluated from ECG images, the Butterworth filter exhibited a more comprehensive and smoother representation of the original signal. Judging from denoising indices, the Butterworth filter exhibited the best performance, with its denoising indices surpassing those of fast Fourier transform and wavelet transform by differences ranging from 26% to 122%. Judging from HRV index and R-peak positioning, the data processed by Butterworth exhibited the highest reliability (93.5%), outperforming FFT (30.0%), the wavelet filter (72.5%), and the Chebyshev filter (78.5%). Furthermore, the 5th-order Butterworth filter exhibited the largest signal-to-noise ratio (SNR) with 1.1–34.4% larger and the smallest percent root-mean-square difference (PRD) with 15.2–66.1% smaller compared to other orders. Next, the characteristics of denoised HRV features under different temperatures were studied. During a temperature rise stage, the fitting R2 values of rMSSD, SDNN, and HR with temperature were 0.85, 0.64, and 0.78, respectively; meanwhile, during the subsequent temperature drop stage, the fitting R2 values were 0.78, 0.84, and 0.78, respectively. This suggests that changes in temperature can be effectively reflected by HRV indices. When gender was taken into consideration, the HR of females showed a 55.8% higher fitting level compared to males.

The physiological measurement and evaluation of empathy of video content

The COVID-19 pandemic has led to a surge in video content consumption, but measuring viewers' empathy towards the content has been limited to subjective evaluations or attached physiological apparatus. In this study, we introduced a novel non-contact physiological method for measuring empathy towards video content by assessing the synchronization of facial micromovements between the subject and object (i.e., person) within the media. We recorded facial micromovements and heart rate variability (HRV) remotely using a camera while 62 subjects watched one video each, designed and validated to elicit one of four two-dimensional emotions: pleasant-aroused, pleasant-relaxed, unpleasant-aroused, and unpleasant-relaxed. We also collected the subjects' self-assessed emotions and empathy using a questionnaire. The results confirmed that the stimuli effectively induced the intended arousal in the subjects, as evidenced by both self-reported emotions and HRV responses that suggested higher arousal was associated with stronger activity in the sympathetic nervous system. A closer examination of HRV indicators, such as SDNN and Total Power values, showed an amplification during the unpleasant state. We interpret this as the body's dynamic response to stressors, underlining the autonomic nervous system's proactive role in responding to such stimuli. In a broader context, our results emphasized that while subjects showcased augmented empathy during aroused conditions, the introduction of stressors, represented by unpleasant content, led to a dampening of this empathetic response. This findings demonstrate the potential of non-contact physiological methods for measuring empathy toward video content.

Inflammation and autonomic balance in cirrhosis: Association between sympathetic nervous system and osteopontin, interleukin‐22, interleukin‐6 and interleukin‐1Ra concentrations according to portal hypertension and disease severity

AbstractBackgroundThe autonomic nervous system is linked to hyperdynamic circulation in cirrhosis and several studies have highlighted the crucial role that systemic inflammation elicits in altering sympathovagal equilibrium with the consequent reduction in heart rate variability (HRV).To investigate the correlation between time‐domain HRV parameters, serum cytokines concentrations and portal hypertension, we studied a cohort of patients with cirrhosis, accounting for etiology and treatments.MethodsIn this cross‐sectional, observational cohort study, 107 outpatients with non‐alcoholic cirrhosis were assessed consecutively by abdominal ultrasound and by upper gastrointestinal endoscopy to search for esophagogastric varices. 24‐h electrocardiogram Holter monitoring with time‐domain HRV measurement (square root of the mean of successive differences of Normal‐to‐Normal [NN] [RMSSD], standard deviation or the square root of variance [SDNN] and standard deviation of the means of the NN intervals calculated over a 5‐min period [SDANN]) was performed and serum concentrations of osteopontin (OPN), interleukin (IL)‐22, IL‐6, IL‐1Ra and IL‐17 were obtained in all patients.ResultsIL‐6, OPN, IL‐22 and IL‐1Ra concentrations in cirrhotic patients were associated with disease severity expressed by Child‐Pugh and MELD score, to some portal hypertension's indirect signs and some of its complications. A significant increase in systemic concentrations of OPN in patients with hepatocellular carcinoma was encountered. SDANN and SDNN values were indirectly related to serum levels of IL‐6, OPN, IL‐1Ra and IL‐22.ConclusionsThis study underlines the interaction between the alteration of the ANS and the activation of inflammatory pathways that characterize cirrhosis taking into account clinical characteristics and treatments.

The Functional States of the Participants of a Marine Arctic Expedition with Different Levels of Vitamin D in Blood.

(1) Background: The vitamin D level in blood is one of the markers of the functional reserves of the human body and can contribute to more successful adaptation in the Arctic. (2) Methods: The study involved 38 participants in the project "Arctic Floating University-2021". The determination of vitamin D content was carried out at the beginning of the expedition. A dynamic study was carried out for 20 days in the morning and in the evening. The functional state parameters of the participants were assessed using psychophysiological and questionnaire methods. Statistical methods: Mann-Whitney U-test and correlation analysis. (3) Results: It was found that at the beginning of the expedition, the functional state of participants with more severe vitamin D deficiency is characterized by a shorter average duration of RR intervals (p = 0.050) and reduced SDNN values (p = 0.015). The higher the content of vitamin D, the greater increase in speed (r = 0.510), the higher the increase in projective performance (r = 0.485), and the smaller the increase in projective stress (r = -0.334). Significant relationships between the subjective characteristics of functional states and the vitamin D of participants have not been established. (4) Conclusion: With an increase in the severity of vitamin D deficiency in the blood, the adaptive capabilities of participants decrease during an expedition to the Arctic.

Heart Rate Variability Impairment Is Associated with Right Ventricular Overload and Early Mortality Risk in Patients with Acute Pulmonary Embolism.

The association between heart rate variability (HRV) and mortality risk of acute pulmonary embolism (APE), as well as its association with right ventricular (RV) overload is not well established. We performed an observational study on consecutive patients with confirmed APE. In the first 48 h after admission, 24 h Holter monitoring with assessment of time-domain HRV, echocardiography and NT-proBNP (N-terminal pro-B-type natriuretic peptide) measurement were performed in all participants. We pre-examined 166 patients: 32 (20%) with low risk of early mortality, 65 (40%) with intermediate-low, 65 (40%) with intermediate-high, and 4 (0.02%) in the high risk category. The last group was excluded from further analysis due to sample size, and finally, 162 patients aged 56.3 ± 18.5 years were examined. We observed significant correlations between HRV parameters and echocardiographic signs of RV overload. SDNN (standard deviation of intervals of all normal beats) correlated with echocardiography-derived RVSP (right ventricular systolic pressure; r = -0.31, p = 0.001), TAPSE (tricuspid annulus plane systolic excursion; r = 0.21, p = 0.033), IVC (inferior vena cava diameter; r = -0.27, p = 0.002) and also with NT-proBNP concentration (r = -0.30, p = 0.004). HRV indices were also associated with APE risk stratification, especially in the low-risk category (r = 0.30, p = 0.004 for SDNN). Univariate and multivariate analyses confirmed that SDNN values were associated with signs of RV overload. In conclusion, we observed a significant association between time-domain HRV parameters and echocardiographic and biochemical signs of RV overload. Impaired HRV parameters were also associated with worse a clinical risk status of APE.

Evaluation of cardiovascular autonomic dysfunction in symptomatic post COVID-19 patients

Abstract Background The COVID-19 disease is known for its severe respiratory complications, however it was found to have some cardiovascular complication in post COVID-19 patients. The heart rate variability (HRV) is a non invasive, objective and reliable method for assessment of autonomic dysfunction in those recovered patients. Purpose We aimed to evaluate the cardiac autonomic function by using valid HRV indices in subjects who recovered from mild to moderate acute COVID-19 but still symptomatic. Methods The study Group composed of 50 subjects with confirmed history of mild to moderate post COVID 19. All subjects underwent routine 2D echocardiography assessment in addition to 2D speckle tracking and 24 hours Holter monitoring for HRV analysis. Results The mean age of the study population was 42±18 years, symptoms were reported as follows 27 (54%) had Dyspnea, 17 (34%) had palpitations, 7 (14%) had dizziness. Time domain parameters SDNN, SDANN and rMSSD were diminished with mean SDNN value being markedly impaired in 12 (24%) patient, while frequency domain parameters as assessed by LF/HF ratio with mean of 1.837 with 8% of patients being impaired. SDNN was significantly reduced in elderly patients (p=0.001), smokers (p=0.019) and hypertensive (p=0.016) and those complaining mainly of palpitation (p=0.006). SDNN was significantly reduced in patient with impaired LV diastolic function (p=0.009), in patients with reduced MAPSE (p=0.047), reduced TAPSE (p=0.00) and impaired Global longitudinal strain (0.000). Conclusion Patients with post COVID-19 syndrome have abnormalities in the HRV which indicates some degree of dysfunction in the autonomic nervous system and consequently impaired parasympathetic function in this population, however this have been also correlating with subtle impairment of the left ventricular systolic function. We believe that this preliminary research can serve a starting point for future research in this direction. Funding Acknowledgement Type of funding sources: None.

Impaired heart rate variability one and six months post acute COVID-19

Abstract Background Long COVID-19 syndrome is an increasingly recognized problem. Post-infectious cardiac autonomic dysfunction is commonly reported. This study aims to evaluate autonomic dysfunction by means of Heart rate variability (HRV) on post-COVID-19 patients. Methods Hospitalized patients for COVID-19 (either at the medical ward or Intensive Care Unit (ICU)) were followed up at 1 and 6 months after hospital discharge. Medical history and clinical information were collected. HRV was assessed by 24-hour ambulatory electrocardiography Holter, with the measure of the standard deviation of normal RR intervals in 24 h, ms (SDNN). The comparison was conducted with age and sex-matched non-COVID-19 controls. Results Thirty-four patients hospitalized with COVID-19 (20.6% admitted in ICU) were examined 1-month and 6-months post-hospital discharge. SDNN was significantly (p<0.001) reduced in the COVID-19 group (111±23 ms) compared to the control subjects (152±24 ms) 1-month after discharge. Subgroup analysis between COVID-19 group revealed that ICU subjects presented significantly (p<0.001) reduced SDNN compared to the medical ward, respectively (83±20 ms vs. 118±17 ms). At 6-months, an improvement was noted at SDNN 24h (6-month: 133±24 vs. control: 151±24 ms, p=0.004; 1-month: 111±23 ms vs. 6-month: 133±24 ms, p<0.001). Also at 6-months, ICU subjects noted significantly (p=0.003) reduced SDNN 24h compared to medical ward subjects (107±17 ms vs. 140±20 ms). On the 6-months follow-up, 32% of the subjects had “long-COVID-19” symptoms. Subjects with long COVID-19 symptoms had low SDNN values (“long-COVID-19”: 112±17 ms vs. non-“long-COVID-19”: 142±20 ms, p=0.001) Conclusion Patients hospitalized for COVID-19 have reduced SDNN, at one month post-hospital discharge which is improved at the six months follow-up. These findings emphasize the increased sympathetic drive activity in the post-acute COVID-19 phase and imply a link between autonomic dysfunction and long COVID-19. Funding Acknowledgement Type of funding sources: None.

Short-Term HRV Detection and Human Fatigue State Analysis Based on Optical Fiber Sensing Technology.

Mental fatigue is a key cause of chronic diseases and traffic accidents, which is difficult to be quantitatively evaluated. In order to non-intrusively detect fatigue state, an optical fiber sensing system is proposed, which is non-invasive and does not require direct contact with skin. The fiber sensor was fabricated through phase mask exposure method and packaged by sensitivity-enhanced structure, which can suppress transverse force and increase signal amplitude by 5%. A fatigue-inducing experiment was carried out, and the heartbeat signals of 20 subjects under different fatigue states were collected by the proposed sensing system. A series of heart rate variability indicators were calculated from the sensing signals, and their statistical significance for fatigue was analyzed. The experiment results showed that the values of SDNN and LF/HF increased significantly with subjects’ fatigue level. This study shows that the proposed fiber optic sensing system has practical value in fatigue state monitoring.

Autonomic and cardiorespiratory responses to the active tilt test in individuals with Parkinson disease: cross-sectional study.

The Parkinson disease (PD) is frequently associated with autonomic dysfunctions. However, data regarding the influence of PD on the autonomic responses to postural changes is limited. To analyze and compare the autonomic responses, evaluated through linear and non-linear methods of heart rate variability, and cardiorespiratory parameters in two groups: Parkinson disease (PDG) and control (CG), at rest and during the active tilt test. A total of 48 participants were analyzed (PDG: n = 25;73.40 ± 7.01 years / CG: n = 23;70.17 ± 8.20 years). The autonomic modulation and cardiorespiratory parameters were evaluated at rest and during the active tilt test. To assess the autonomic modulation the linear indices, at the time (rMSSD, SDNN) and frequency (LF, HF, LF/HF) domains, and the non-linear indices, obtained through the Poincaré plot (SD1, SD2, SD1/SD2), were calculated. The cardiorespiratory parameters evaluated were heart rate (HR), systolic (SBP), and diastolic blood pressure (DBP), peripheral oxygen saturation (SpO2), and respiratory rate. At rest, the PDG presented significantly lower values of rMSSD, SDNN, LF, HF, SD1, SD2, and DBP, and higher values of SpO2. During test, in the PD group, modifications were observed in HR, and SBP, besides a reduced parasympathetic response, and an increased global modulation. The qualitative analysis of the Poincaré plot showed that the PDG has a lower dispersion of the RR intervals during rest and the active tilt test. Individuals with PD present reduced global variability and parasympathetic modulation at rest, and reduced parasympathetic response and damage in HR regulation when performing the active tilt test, compared with controls.

Ocular and Hemodynamic Factors Contributing to the Central Visual Function in Glaucoma Patients With Myopia.

PurposeThe purpose of this study was to investigate the ocular and hemodynamic factors contributing to the central visual function in glaucoma patients with myopia.MethodsThis study was a prospective observational study, which included 236 eyes of 140 patients with normal-tension glaucoma (NTG), which includes 114 eyes with mild myopia (axial length ≥24 and <26 mm) and 122 eyes with moderate-to-severe myopia (axial length ≥26 mm). Ocular characteristics were axial length and posterior pole profiles, including peripapillary atrophy (PPA) to disc area ratio, disc tilt ratio, disc torsion, and disc-foveal angle. Hemodynamic factors included standard deviation of the mean of qualified normal-to-normal intervals (SDNN) of a heart rate variability (HRV) test and vessel density (VD) parameters from optical coherence tomography angiography (OCTA). The root mean square error was estimated as a measure of the VD fluctuation. Association between ocular characteristics and VD parameters of the OCTA with the central sensitivity of the 10-degree visual field or the presence of central scotoma were analyzed.ResultsDeep layer VD of the peripapillary and macular areas showed significant differences between mild and moderate-to-severe myopia (P = 0.034 and P = 0.045, respectively). Structural parameters, especially PPA to disc area ratio, had significant correlation with peripapillary VD parameters in myopic eyes. Lower SDNN value (ß = 0.924, P = 0.011), lower deep VD of the macular area (ß = 0.845, P = 0.001), and greater fluctuation of deep VD in the peripapillary area (ß = 1.517, P = 0.005) were associated with the presence of central scotoma in patients with glaucoma with myopia in multivariate logistic regression analysis.ConclusionsThe structural changes by myopia, especially in the peripapillary region, affected VD parameters in myopic eyes. Lower deep VD and greater VD fluctuation in the peripapillary region showed association with central scotoma in patients with glaucoma with myopia, suggesting both structural and vascular changes by myopia may be related to central visual function in glaucoma patients with myopia.

Omega-3 fatty acids in bipolar patients with a low omega-3 index and reduced heart rate variability: the \u201cBIPO-3\u201d trial

BackgroundResearch suggests that a low omega-3 index may contribute to the low heart rate variability and the increased risk of cardiovascular morbidity and mortality in bipolar disorders. However, so far, no intervention trial with EPA and DHA has been conducted in bipolar patients attempting to increase their heart rate variability.Methods119 patients with bipolar disorder according to DSM-IV were screened, with 55 euthymic bipolar patients—owing to inclusion criteria (e.g. low omega-3 index (< 6%), SDNN < 60 ms.)—being enrolled in a randomized, double-blind, 12-week parallel study design with omega-3 fatty acids (4 capsules of 530 mg EPA, 150 mg DHA) or corn oil as a placebo, in addition to usual treatment. Heart rate variability as well as the omega-3 index were measured at baseline and at the endpoint of the study.ResultsA total of 42 patients (omega-3: n = 23, corn oil: n = 19) successfully completed the study after 12 weeks. There was a significant increase in the omega-3 index (value at endpoint minus value at baseline) in the omega-3 group compared to the corn oil group (p < 0.0001). However, there was no significant difference in the change of the SDNN (value at endpoint minus value at baseline) between the treatment groups (p = 0.22). In addition, no correlation between changes in SDNN and change in the omega-3 index could be detected in the omega-3 group (correlation coefficient = 0.02, p = 0.94) or the corn oil group (correlation coefficient = − 0.11, p = 0.91). Similarly, no significant differences between corn oil and omega-3 group regarding the change of LF (p = 0.19), HF (p = 0.34) and LF/HF ratio (p = 0.84) could be demonstrated.ConclusionsIn our randomized, controlled intervention trial in euthymic bipolar patients with a low omega-3 index and reduced heart rate variability no significant effect of omega-3 fatty acids on SDNN or frequency-domain measures HF, LF and LF/HF ratio could be detected. Possible reasons include, among others, the effect of psychotropic medication present in our trial and/or the genetics of bipolar disorder itself. Further research is needed to test these hypotheses.Trial registration ClinicalTrials.gov, NCT00891826. Registered 01 May 2009–Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT00891826

How do different types of physical activity affect echocardiography findings and heart rate variability in children?

This study aims to investigate how different types of regular physical activity affect cardiac functions in school children. This is a cross-sectional review of 15 children who are not engaged with any regular physical activity (controls) and 60 athletes who swim (n=15), play basketball (n=15), play volleyball (n=15), and play tennis (n=15) regularly. The children who are not engaged with any sports, the children who swim, and the children who play basketball, volleyball and tennis are statistically similar with respect to age, sex, height, weight and body mass index (p&gt;0.05 for all). When compared to the controls and other athletes, the swimmer children have significantly higher left ventricle diastolic mass, higher left ventricle posterior wall systolic thickness, lower mitral A wave, higher mitral annular plane systolic excursion and higher mitral E/A ratio (p=0.006, p=0.035, p=0.030, p=0.025 and p=0.043 respectively). The swimmer children have significantly lower interventricular septum E and A waves and significantly longer left ventricle IVRT than the controls and other athletes (p=0.001, p=0.040 and p=0.004 respectively). When compared with the controls and other athletes, the swimmer children have significantly lower p-wave dispersion and QT dispersion values (p=0.038 and p=0.035 respectively). The swimmer children have significantly higher total power and SDNN values than the controls and other athletes (p=0.046 and p=0.026 respectively). Swimming might contribute to the growth of cardiac muscles and help to improve the cardiac conduction system and enhance parasympathetic innervation of the heart in children.

Utonomic and hemodynamic effects of pre-anesthetic use of clonidine in healthy dogs

The aim of this study was to evaluate the effects of pre-anesthetic use of clonidine on time-domain heart rate variability (HRV) and arterial blood pressure in healthy anesthetized dogs. Six healthy adult mixed-breed dogs were administered a clonidine (clonidine group, CLG) and 30 days later, a placebo (control group, CG) preanesthetic protocol, in addition to propofol, isoflurane, and an bolus of tramadol and the continuous infusion thereafter. The total time mean values of HRV meanNN, SDNN, SDANN, SDNNI, and rMSSD were higher in the CL group, as observed in some HRV variables on tramadol bolus time (T4), tramadol continuous infusion (T8), and tracheal extubation time (T10). No significant differences in arterial blood pressure were observed, however, two dogs had a second-degree atrioventricular block (Mobitz II) at the tramadol bolus time (T4). These results led us to conclude that the clonidine anesthetic protocol resulted in sympathetic outflow block and an increase in parasympathetic tone, without significant effects on blood pressure. Notably, cardiac electrical disturbance in two dogs in the CL group. Although the pre-anesthetic use of clonidine in dogs with fear-based behavioral problems should be considered, its association with tramadol should be avoided or carried out with caution owing to the existing cardiovascular risk.