Altered Heart Rate Variability Research Articles

Depression Associated with Reduced Heart Rate Variability Predicts Outcome in Adult Congenital Heart Disease.

In adult congenital heart disease (ACHD), major depressive disorder (MDD) represents a frequent comorbidity. In non-CHD, adverse outcome is predicted by MDD and heart rate variability (HRV), whereas in ACHD their prognostic relevance is unknown. We prospectively evaluated 171 patients (age 35.6 ± 11.4 years; male 42.7%, mean observation time 54.7 ± 14.9 months). Binary regression analysis calculated the association between MDD and HRV. Cox proportional survival analysis estimated their impact on decompensated heart failure and all-cause mortality (HF/death), supraventricular and ventricular tachycardia (SVT/VT), and hospitalization due to unexpected cardiac causes. Exclusively MDD with moderate/severe symptoms showed significantly lower HRV as derived from frequency-domain analysis (Symindex) (p = 0.013). In multivariate Cox regression analysis, patients stratified according to the lower quartile of the Symindex comorbid with MDD (n = 16) exhibited poorer prognosis regarding HF/death (Hazard Ratio (HR): 7.04 (95%CI:(1.87–26.5)), SVT/VT (HR: 4.90 (95%CI:1.74–9.25)) and hospitalization (HR: 3.80 (95%CI:1.36–10.6)). An additional independent predictor was N-terminal pro-B-type natriuretic peptide elevation (p < 0.001), indicating advanced HF and heart disease complexity (p < 0.001). Autonomic nervous system dysfunction measured by altered HRV is considered to be one of the pathways linking MDD and adverse outcomes in cardiac diseases. Our results exceed the existing literature by demonstrating that MDD with decreased HRV is associated with poorer prognosis in ACHD.

Association between postsurgical pain and heart rate variability: protocol for a scoping review

IntroductionSurgical interventions can elicit neuroendocrine responses and sympathovagal imbalance, ultimately affecting cardiac autonomic function. Cardiac complications account for 30% of postoperative complications and are the leading cause of morbidity and...

Psychotropic treatment in patients with arrhythmia: About a case

IntroductionIt is knowed the relationship between psychological problems and cardiovascular disease. Pychological alterations can cause cardiovascular diseases, and a cardiovascular event can trigger psychological alterations.ObjectivesThe aim was to present a clinical case about a young man with cardiovascular alterations and depressive symptoms and to analyze the role played by cardiovascular drugs, psychoactive drugs, and their interactions.MethodsWe present the clinical case and search the relation between cardiovascular disease and depressive symptoms and treatment at scientific literature of last five years.ResultsA 38-year-old man comes to the emergency room with symptoms of palpitations, fatigue and shortness of breath for 2 weeks. An electrocardiogram is performed showing premature ventricular beats. The patient reports that he is sadder recently due to the loss of work, for which he is prescribed sertraline 50 mg daily and is referred to cardiology. No medical history or consumption of alcohol, tobacco or other toxins. The cardiologist requests ergometry, echocardiography, and Holter monitoring, resulting in all normal tests, with no evidence of ischemia. Bisoprolol 2.5 mg daily is prescribed and sertraline 50 mg daily is maintained. After two months, the patient reports feeling better in spirit. The control electrocardiogram is normal and the patient reports disappearance of palpitations. You are referred to your family doctor.ConclusionsElevation of cortisol, platelet hyperactivity, and alteration in heart rate variability were found in depressives. The SSRIs would be the ones of choice. Dual serotonin and noraderaline reuptake inhibitors should be avoided. Other atypical drugs such as bupropion or trazodone should be considered.DisclosureNo significant relationships.

Altered Heart Rate Variability in Patients With Schizophrenia During an Autonomic Nervous Test.

Reduced heart rate variability (HRV) and dysfunction of the autonomic nervous system (ANS) have been observed in schizophrenia patients. HRV parameters of schizophrenia patients in the resting state have been well-documented; however, these parameters of schizophrenia patients who experience continuous psychophysiological stress remain unclear. The objective of this study was to systematically explore the linear and nonlinear HRV parameters between schizophrenia patients and normal controls and to detect the adaptive capabilities of HRV of schizophrenia patients during the stimulation tests of autonomic nervous system. Forty-five schizophrenia patients and forty-five normal controls, matched for age, sex and body mass index, completed a 14 min ANS test. Thirteen linear and nonlinear HRV parameters of all subjects under the ANS test were computed and statistically analyzed between groups and between sessions. The STROBE checklist was adhered to in this study. All time-domain HRV features in the ANS test were significantly different between schizophrenia patients and normal controls (p < 0.01). The schizophrenia patients showed significantly low values in the Poincaré indices, which revealed significantly decreased heart rate fluctuation complexity compared with that of normal controls (p < 0.001). In addition, the normal controls, not schizophrenia patients, showed significant differences between the recovery and stress states in the parameters of low frequency, high frequency, and nonlinear dynamics. Schizophrenia patients showed autonomic dysfunction of the heart in a series of stimulation tests of the autonomic nervous system and could not regain normal physiological functions after stress cessation. Our findings revealed that the dynamic parameters of HRV in psychophysiological stress are sensitive and practical for a diagnosis of schizophrenia.

Paclitaxel mitigates structural alterations and cardiac conduction system defects in a mouse model of Hutchinson-Gilford progeria syndrome.

AimsHutchinson–Gilford progeria syndrome (HGPS) is an ultrarare laminopathy caused by expression of progerin, a lamin A variant, also present at low levels in non-HGPS individuals. HGPS patients age and die prematurely, predominantly from cardiovascular complications. Progerin-induced cardiac repolarization defects have been described previously, although the underlying mechanisms are unknown.Methods and resultsWe conducted studies in heart tissue from progerin-expressing LmnaG609G/G609G (G609G) mice, including microscopy, intracellular calcium dynamics, patch-clamping, in vivo magnetic resonance imaging, and electrocardiography. G609G mouse cardiomyocytes showed tubulin-cytoskeleton disorganization, t-tubular system disruption, sarcomere shortening, altered excitation–contraction coupling, and reductions in ventricular thickening and cardiac index. G609G mice exhibited severe bradycardia, and significant alterations of atrio-ventricular conduction and repolarization. Most importantly, 50% of G609G mice had altered heart rate variability, and sinoatrial block, both significant signs of premature cardiac aging. G609G cardiomyocytes had electrophysiological alterations, which resulted in an elevated action potential plateau and early afterdepolarization bursting, reflecting slower sodium current inactivation and long Ca+2 transient duration, which may also help explain the mild QT prolongation in some HGPS patients. Chronic treatment with low-dose paclitaxel ameliorated structural and functional alterations in G609G hearts.ConclusionsOur results demonstrate that tubulin-cytoskeleton disorganization in progerin-expressing cardiomyocytes causes structural, cardiac conduction, and excitation–contraction coupling defects, all of which can be partially corrected by chronic treatment with low dose paclitaxel.

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.

Interictal autonomic dysfunction.

Epilepsy is associated with autonomic dysfunction. Here, we provide an up-to-date review on measures of interictal autonomic function, focusing on heart rate variability (HRV), baroreflex sensitivity (BRS) and electrodermal activity (EDA). Resting HRV, BRS and EDA are altered in patients with epilepsy compared with healthy controls. A larger body of work is available for HRV compared with BRS and EDA, and points to interictal HRV derangements across a wide range of epilepsies, including focal, generalized, and combined generalized and focal epilepsies. HRV alterations are most pronounced in temporal lobe epilepsy, Dravet syndrome and drug-resistant and chronic epilepsies. There are conflicting data on the effect of antiseizure medications on measures of interictal autonomic function. However, carbamazepine has been associated with decreased HRV. Epilepsy surgery and vagus nerve stimulation do not appear to have substantial impact on measures of interictal autonomic function but well designed studies are lacking. Patients with epilepsy, particularly those with longstanding uncontrolled seizures, have measurable alterations of resting autonomic function. These alterations may be relevant to the increased risk of premature mortality in epilepsy, including sudden unexpected death in epilepsy, which warrants investigation in future research.

Long-Term Influence of Concussion on Cardio-Autonomic Function in Adolescent Hockey Players.

Concussion may negatively influence cardiovascular function and the autonomic nervous system, defined by alteration in heart rate variability (HRV). Differences in HRV most commonly emerge during a physical challenge, such as the final steps of the return-to-sport progression. To assess the effect of concussion history on aspects of cardio-autonomic function during recovery from a bout of submaximal exercise in adolescent male hockey athletes. Case-control study. Research laboratory. Thirty-three male athletes participating in Midget-AAA hockey were divided into those with (n = 15; age = 16 ± 1 years, height = 1.78 ± 0.06 m, mass = 73.9 ± 7.4 kg, 10.5 ± 1.6 years of sport experience, 25.2 ± 18.3 months since last injury) or without (n = 18; age = 16 ± 1 years, height = 1.78 ± 0.05 m, mass = 74.8 ± 7.6 kg, 10.6 ± 1.9 years of sport experience) a concussion history. Those with a concussion history were binned on total count: 1 concussion or 2 or more concussions. All athletes underwent 5 minutes of resting HRV assessment, followed by 20 minutes of aerobic exercise at 60% to 70% of their maximal target heart rate and a 9-minute, postexercise HRV assessment. Heart rate variability measures of mean NN interval, root mean square of successive differences, and standard deviation of NN interval (SDNN). Group demographic characteristics were not different. When the control and concussed groups were compared, group and time main effects for heart rate recovery, root mean square of successive differences, and SDNN (P values < .01), and an interaction effect for SDNN (P < .05) were demonstrated. Recovery trends for each group indicated that a history of 2 or more concussions may negatively affect cardio-autonomic recovery postexercise. Our findings suggest that those with more than 1 previous concussion may be associated with a greater risk for long-term dysautonomia. Future use of HRV may provide clinicians with objective guidelines for concussion-management and safe return-to-participation protocols.

Four weeks of trauma-informed yoga intervention and autonomic tone in female veteran and non-veteran college students

Introduction: Female college students (veteran and non-veteran) are exposed to cumulative stressors and trauma that may lead to an imbalanced autonomic nervous system. Yoga has emerged as an efficacious intervention for psychological and physical trauma; however, the therapeutic dose of intervening yoga is unknown. Additionally, the frequency, duration, and type of yoga needed to achieve a therapeutic dose appear to be population specific when applied to trauma victims. The purpose of the study was to examine whether a short-term trauma-informed yoga intervention altered metrics of autonomic tone as assessed by heart rate variability (HRV) in female veteran and non-veteran college students. Methods: Nine female college students (age: 33 years ± 11, veteran, n = 4, non-veteran, n = 5) engaged in trauma-informed yoga once per week for one-hour over a four-week intervention. Repeated measures ANOVA were performed on the HRV variables lnRMSSD, lnHF, lnLF, and LF:HF. Results: Findings indicated no effect of the intervention on HRV as measured by lnRMSSD (p = .116), lnHF (p = .073), lnLF (p = .316), and LF:HF (p = .131). Further, no acute alterations in HRV were observed following a single session of trauma-informed yoga (p > .05). Conclusion: The findings of the study revealed no significant effect of trauma-informed yoga on HRV following a single session or after a four-week yoga intervention.

Study of cyclical alteration in heart rate variability among young eumenorrheic women

Study of cyclical alteration in heart rate variability among young eumenorrheic women

Parasympathetic Nervous Activity Associated with Discoordination Between Physical Acceleration and Heart Rate Variability in Patients with Sleep Apnea.

Sleep apnea syndrome (SAS) often accompanies alterations in heart rate variability (HRV). The severity of SAS is sometimes evaluated using the oxygen desaturation index (ODI). We hypothesized that effects of the autonomic nervous system could be involved in the coordination between HRV and physical acceleration during free movement in patients with SAS. Among 33 women aged 60years or older, 19 had a high ODI (>5). Their HRV and physical acceleration were simultaneously obtained every minute for 24hours. The low frequency/high frequency (LF/HF) ratio and the high frequency in normalized units (HFnu) were used as HRV indices. Low levels of %Lag0, defined as the percentage of the lag=0 min in 1h, indicated coordination between physical acceleration and HRV. Nineteenparticipants were divided into group A (high %Lag0 before sleep [n=9]) or group B (low %Lag0 [n=10]). In group B participants with a high ODI and low %Lag0 in the hour after waking, HFnu was significantly increased compared to that in group A participants with high ODI and high %Lag0 in the hour after waking (p<0.05). These results suggest that close associations between high ODI and discoordination between HRV and physical acceleration may be due to higher parasympathetic nervous system activity after waking.

Rapid Screening of Physiological Changes Associated With COVID-19 Using Soft-Wearables and Structured Activities: A Pilot Study.

Objective: Controlling the spread of the COVID-19 pandemic largely depends on scaling up the testing infrastructure for identifying infected individuals. Consumer-grade wearables may present a solution to detect the presence of infections in the population, but the current paradigm requires collecting physiological data continuously and for long periods of time on each individual, which poses limitations in the context of rapid screening. Technology: Here, we propose a novel paradigm based on recording the physiological responses elicited by a short (~2 minutes) sequence of activities (i.e. “snapshot”), to detect symptoms associated with COVID-19. We employed a novel body-conforming soft wearable sensor placed on the suprasternal notch to capture data on physical activity, cardio-respiratory function, and cough sounds. Results: We performed a pilot study in a cohort of individuals (n=14) who tested positive for COVID-19 and detected altered heart rate, respiration rate and heart rate variability, relative to a group of healthy individuals (n=14) with no known exposure. Logistic regression classifiers were trained on individual and combined sets of physiological features (heartbeat and respiration dynamics, walking cadence, and cough frequency spectrum) at discriminating COVID-positive participants from the healthy group. Combining features yielded an AUC of 0.94 (95% CI=[0.92, 0.96]) using a leave-one-subject-out cross validation scheme. Conclusions and Clinical Impact: These results, although preliminary, suggest that a sensor-based snapshot paradigm may be a promising approach for non-invasive and repeatable testing to alert individuals that need further screening.

Vibration Perception Threshold and Heart Rate Variability as methods to assess chemotherapy-induced neuropathy in women with breast cancer – a pilot study

PurposeChemotherapy-induced peripheral neuropathy (CIPN) is a recognized adverse effect of standard (neo)adjuvant chemotherapy in breast cancer (BC) treatment. However, there is no consensus on a validated method for assessing CIPN. Heart rate variability (HRV) and vibration perception threshold (VPT) could be used as objective measures to describe CIPN. The aim of this pilot study was to investigate whether subjectively reported CIPN was associated with altered HRV and VPT in BC patients. MethodsWe performed a cross-sectional pilot study evaluating 30 BCE patients previously treated with chemotherapy, 26 BCE patients who did not receive chemotherapy, and 22 controls without breast cancer. Self-reported CIPN was registered for the BC patients. All participants were subjected to multi-frequency vibration analyses to determine VPT along with short ECG measurements to determine HRV measures. ResultsSelf-reported CIPN was registered in 14 (46.6%) BC patients treated with chemotherapy. The VPT at 64 Hz (P = 0.022) and mean HR (P = 0.022) were significantly higher and the HRV measures SDNN (P = 0.023), RMSSD (P = 0.007), LF (P = 0.050) and HF (P = 0.045) were significantly lower in BC patients reporting CIPN compared to controls when adjusted for age. VPT at 64 Hz and 125 Hz were significantly higher in BC patients not reporting CIPN compared to controls when adjusted for age. ConclusionWe found elevated VPT and mean HR along with decreased HRV parameters in 14 BCE patients reporting CIPN. These findings support the need for further investigation into whether HRV and vibration analysis could contribute to an objective assessment of CIPN.

Cyclical alteration in heart rate variability among young eumenorrheic women

Introduction: The female sex hormones are known to have a cardioprotective role in premenopausal women compared to postmenopausal women.1,2,5 The key hormone estrogen and progesterone shows a cyclical variation along the different phases of menstrual cycle. Parasympathetic activity via vagus is known to improve the cardiac function compared to sympathetic activity.3 Heart rate variability (HRV) is one of the sensitive and non-invasive method to record the cardiac autonomic activity.4 Thus we chose this study to assess how the female sex hormones affect autonomic activity on the heart during the phases of menstrual cycle. Aim: To assess the effect of cyclical alteration in female sex hormones on cardiac autonomic activity by HRV. Materials and Methods: After getting institutional ethics committee clearance, short term HRV (5 minutes) was recorded in fifty young female volunteers aged between 20-30 years within normal range of BMI and regular menstrual cycle in supine posture after 10 minutes rest using PHYSIO PAC PP4 Medicaid system Chandigarh in the autonomic function lab, Department of Physiology, Sri Venkateshwaraa Medical College Hospital and Research Center, Ariyur, Pondicherry. Statistical analysis was done using SPSS 17 version. Results: The sympathetic parameters like (low frequency domain) LF nu, LF/HF ratio was significantly increased in the premenstrual phase. The parasympathetic parameters like (high frequency domain) HF nu, TP (total power) were significantly increased in the proliferative phase of the menstrual cycle. Conclusion: Thus the cardioprotective role of female sex hormones in premenopausal women was more pronounced in the proliferative phase of menstrual cycle. Keywords: Heart rate variability, Cardioprotective, Premenstrual phase, Proliferative phase.

227: Altered Heart Rate Variability Predicts Mortality Early Among Critically Ill COVID-19 Patients

INTRODUCTION: The novel coronavirus (SARS-CoV-2) has led to a large cascade of transmissions resulting in high numbers of individuals hospitalized for the coronavirus disease 2019 (COVID-19), an impact still being accounted across the globe In this study, we seek to evaluate whether novel heart rate variability (HRV) measures can predict mortality within 24 hours of admission to the ICU among critically ill COVID-19 patients METHODS: All medical, surgical, neurocritical, transplant, and cardiac ICU admissions with COVID-19 between March 1 through April 31st, 2020 within Emory Healthcare system were screened Patients were selected to be included in the analysis if they were in the ICU for greater than 24 hours, had at least one positive qRT-PCR test for SARS-CoV-2 earlier in their hospitalization EKG (250 Hz) was then analyzed for each patient over a 300 second (s) observational window, that was shifted by 30s in each iteration for the first 24 hrs after admission MATLAB® was used to analyze the continuous EKG and extract relevant HRV features We use the Kruskal-Wallis and Steel-Dwass tests (P < 0 05) for statistical analysis and interpretations of HRV multiple measures RESULTS: A total of 312 COVID-19 patients were identified in a clinical chart review for SARS-CoV-2 by use of quantitative RT-PCR (qRT-PCR), of which 85 patients were admitted to the ICU and had sufficient data quality The median HRV aggregates, including AC, DC, LFHF, VLF, SD1, SD2, SD1SD2, RMSSD, and pNN50 were all statistically significant (FDR p<0 01) between survivors and nonsurvivors pNN50 and VLF displayed characteristics of muted temporal variability over the course of the first 24 hrs within nonsurvivors CONCLUSIONS: Heart rate variability is broadly implicated across patients positive for SARS-CoV-2, and admitted to the ICU for critical illness, between survivors and non-survivors HRV measures across all domains, including time-frequency and nonlinear features, demonstrate statistical significance in predicting outcomes Temporal trajectories of these markers further suggest significant decoupling between the cohorts as the disease progresses, with salient decoupling noticeable as early as 12 hrs into the ICU stay

Autonomic nervous system activity and the risk of nosocomial infection in critically ill patients with brain injury

PurposeNosocomial infection contributes to adverse outcome after brain injury. This study investigates whether autonomic nervous system activity is associated with a decreased host immune response in patients following stroke or traumatic brain injury (TBI).MethodsA prospective study was performed in adult patients with TBI or stroke who were admitted to the Intensive Care Unit of our tertiary university hospital between 2013 and 2016. Heart rate variability (HRV) was recorded daily and assessed for autonomic nervous system activity. Outcomes were nosocomial infections and immunosuppression, which was assessed ex vivo using whole blood stimulations with plasma of patients with infections, matched non-infected patients and healthy controls.ResultsOut of 64 brain injured patients, 23 (36%) developed an infection during their hospital stay. The ability of brain injured patients to generate a host response to the bacterial endotoxin lipopolysaccharides (LPS) was diminished compared to healthy controls (p < 0.001). Patients who developed an infection yielded significantly lower TNF-α values (86 vs 192 pg/mL, p = 0.030) and a trend towards higher IL-10 values (122 vs 84 pg/mL, p = 0.071) following ex vivo whole blood stimulations when compared to patients not developing an infection. This decreased host immune response was associated with altered admission HRV values. Brain injured patients who developed an infection showed increased normalized high-frequency power compared to patients not developing an infection (0.54 vs 0.36, p = 0.033), whereas normalized low-frequency power was lower in infected patients (0.46 vs 0.64, p = 0.033).ConclusionBrain injured patients developing a nosocomial infection show parasympathetic predominance in the acute phase following brain injury, reflected by alterations in HRV, which parallels a decreased ability to generate an immune response to stimulation with LPS.

Altered heart rate variability during sleep in mild cognitive impairment.

Cardiovascular autonomic dysfunction, as measured by short-term diurnal heart rate variability (HRV), has been reported in older adults with mild cognitive impairment (MCI). However, it is unclear whether this impairment also exists during sleep in this group. We, therefore, compared overnight HRV during sleep in older adults with MCI and those with subjective cognitive impairment (SCI). Older adults (n = 210) underwent overnight polysomnography. Eligible participants were characterized as multi-domain MCI or SCI. The multi-domain MCI group was comprised of amnestic and non-amnestic subtypes. Power spectral analysis of HRV was conducted on the overnight electrocardiogram during non-rapid eye movement (NREM), rapid eye movement (REM), N1, N2, N3 sleep stages, and wake periods. High-frequency HRV (HF-HRV) was employed as the primary measure to estimate parasympathetic function. The MCI group showed reduced HF-HRV during NREM sleep (p = 0.018), but not during wake or REM sleep (p > 0.05) compared to the SCI group. Participants with aMCI compared to SCI had the most pronounced reduction in HF-HRV across all NREM sleep stages-N1, N2, and N3, but not during wake or REM sleep. The naMCI sub-group did not show any significant differences in HF-HRV during any sleep stage compared to SCI. Our study showed that amnestic MCI participants had greater reductions in HF-HRV during NREM sleep, relative to those with SCI, suggesting potential vulnerability to sleep-related parasympathetic dysfunction. HF-HRV, especially during NREM sleep, may be an early biomarker for dementia detection.

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.

Exaggerated potassium current reduction by oxytocin in visceral sensory neurons following chronic intermittent hypoxia

Oxytocin (OT) from the hypothalamus is increased in several cardiorespiratory nuclei and systemically in response to a variety of stimuli and stressors, including hypoxia. Within the nucleus tractus solitarii (nTS), the first integration site for cardiorespiratory reflexes, OT enhances synaptic transmission, action potential (AP) discharge, and cardiac baroreflex gain. The hypoxic stressor obstructive sleep apnea, and its CIH animal model, elevates blood pressure and alters heart rate variability. The nTS receives sensory input from baroafferent neurons that originate in the nodose ganglia. Nodose neurons express the OT receptor (OTR) whose activation elevates intracellular calcium. However, the influence of OT on other ion channels, especially potassium channels important for neuronal activity during CIH, is less known. This study sought to determine the mechanism (s) by which OT modulates sensory afferent-nTS mediated reflexes normally and after CIH. Nodose ganglia neurons from male Sprague-Dawley rats were examined after 10d CIH (6% O2 every 3min) or their normoxic (21% O2) control. OTR mRNA and protein were identified in Norm and CIH ganglia and was similar between groups. To examine OTR function, APs and potassium currents (IK) were recorded in dissociated neurons. Compared to Norm, after CIH OT depolarized neurons and reduced current-induced AP discharge. After CIH OT also produced a greater reduction in IK that where tetraethylammonium-sensitive. These data demonstrate after CIH OT alters ionic currents in nodose ganglia cells to likely influence cardiorespiratory reflexes and overall function.

Immediate Effects of Yoga Based Relaxation Technique Yoga Nidra on Heart Rate Variability in Young and Healthy Volunteers

Introduction: Cardiovascular autonomic functions are affected by the negative influences of stress which bring about alterations in heart rate variability (HRV). Yoga based relaxation techniques like Yoga Nidra have been found to relieve stress as shown by improved HRV. This study was conducted to assess the immediate effects of a yoga based guided relaxation technique, Yoga Nidra on HRV parameters in young and healthy volunteers.&#x0D; Methods: This was an interventional study conducted in the Department of Clinical Physiology, Institute of Medicine, Maharajgunj. Fifty two male medical students were divided into supine rest group (n=26) and Yoga Nidra group (n=26). HRV indices were recorded before and after supine rest and Yoga Nidra. Intra-group and inter-group comparisons of the HRV parameters were done before and after the interventions.&#x0D; Results: In comparison to the supine rest, Yoga Nidra produced significant increase in values of HF (1460.72 Vs 3272.99; p=0.03) and HFnu (50.32 Vs 62.68; p=0.004); and significant reduction in the values of LFnu (49.68 Vs 37.32; p=0.004) and LF:HF ratio (0.99 Vs 0.59; p=0.004), which suggested that the parasympathetic modulating response of Yoga Nidra was better than that of supine rest.&#x0D; Conclusion: Yoga Nidra, a yoga based relaxation technique brings better relaxation response than supine rest as indicated by the significantly improved HRV indices.