Low-frequency Heart Rate Variability Research Articles

Changes in interoceptive accuracy related to emotional interference in somatic symptom disorder

ObjectiveThe somatic symptom disorder (SSD) is characterized by one or more distressing or disabling somatic symptoms accompanied by an excessive amount of time, energy and emotion related to the symptoms. These manifestations of SSD have been linked to alterations in perception and appraisal of bodily signals. We hypothesized that SSD patients would exhibit changes in interoceptive accuracy (IA), particularly when emotional processing is involved.MethodsTwenty-three patients with SSD and 20 healthy controls were recruited. IA was assessed using the heartbeat perception task. The task was performed in the absence of stimuli as well as in the presence of emotional interference, i.e., photographs of faces with an emotional expression. IA were examined for correlation with measures related to their somatic symptoms, including resting-state heart rate variability (HRV).ResultsThere was no significant difference in the absolute values of IA between patients with SSD and healthy controls, regardless of the condition. However, the degree of difference in IA without emotional interference and with neutral facial interference was greater in patients with SSD than in healthy controls (p = 0.039). The IA of patients with SSD also showed a significant correlation with low-frequency HRV (p = 0.004) and high-frequency HRV (p = 0.007).ConclusionSSD patients showed more significant changes in IA when neutral facial interference was given. These results suggest that bodily awareness is more affected by emotionally ambiguous stimuli in SSD patients than in healthy controls.

Do Decision-Making Styles Predict Vagal Control? The Role of Resting Heart Rate Variability.

Decision-making styles are a habit-based propensity that drive behavior and affect daily life. Rational and intuitive decision-making styles have been associated with good mental health. However, the underlying mechanisms are not clear. In the last decade, high basal levels of heart rate variability (HRV) have been proposed as an index of health and emotional control, and this could be one of the variables involved in the effects of decision making on health. Therefore, the aim of this study is to analyze the capability of decision-making styles to predict resting HRV. A cross-sectional study was conducted in a sample of 199 (119 women) young university students, and a resting ECG was recorded to extract frequency domain HRV variables. Subsequently, participants completed sociodemographic data and the General Decision-Making Style questionnaire (GDMS). Results showed that the intuitive style predicted high-frequency HRV, while the avoidant style predicted less low-frequency HRV. This study presents new data on the relationship between decision-making style and HRV, suggesting that the intuitive style has a cardioprotective effect, while the avoidant style is related to lower HRV, which has been associated with health vulnerability. In conclusion, this study contributes to the understanding of HRV and its potential as a biomarker for cognitive styles that may improve health.

Analysis of Heart Rate Variability in Individuals Affected by Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) produces alterations in the autonomic nervous system (ANS), which explains the cardiac manifestations observed in patients. The assessment of heart rate variability (HRV) is what best reflects the activity of the ANS on heart rate. The Polar H7 Bluetooth® device proves to be a non-invasive and much faster technology than existing alternatives for this purpose. The goal of this study is to determine HRV using Polar H7 Bluetooth technology in ALS patients, comparing the obtained measurements with values from healthy individuals. The sample consisted of 124 participants: 68 diagnosed with ALS and 56 healthy individuals. Using Polar H7 Bluetooth technology and the ELITE HRV application, various HRV measurements were determined for all participants, specifically the HRV index, RMSSD, RMSSD LN, SDNN index, PNN50, LF, HF, LF/HF ratio, HR average, and HF peak frequency. Statistically significant differences were observed between ALS patients and healthy individuals in the HRV index, RMSSD, RMSSD LN, SDNN index, PNN50, HF, and LF, where healthy individuals exhibited higher scores. For the HR average, the ALS group showed a higher value. Values were similar when comparing men and women with ALS, with only a higher HF peak frequency observed in women. The Polar H7 Bluetooth® device is effective in determining heart rate variability alterations in ALS, being a promising prognostic tool for the disease.

Heart Rate Variability, Deceleration Capacity of Heart Rate, and Death: A Veteran Twins Study.

Autonomic function can be measured noninvasively using heart rate variability (HRV), which indexes overall sympathovagal balance. Deceleration capacity (DC) of heart rate is a more specific metric of vagal modulation. Higher values of these measures have been associated with reduced mortality risk primarily in patients with cardiovascular disease, but their significance in community samples is less clear. This prospective twin study followed 501 members from the VET (Vietnam Era Twin) registry. At baseline, frequency domain HRV and DC were measured from 24-hour Holter ECGs. During an average 12-year follow-up, all-cause death was assessed via the National Death Index. Multivariable Cox frailty models with random effect for twin pair were used to examine the hazard ratios of death per 1-SD increase in log-transformed autonomic metrics. Both in the overall sample and comparing twins within pairs, higher values of low-frequency HRV and DC were significantly associated with lower hazards of all-cause death. In within-pair analysis, after adjusting for baseline factors, there was a 22% and 27% lower hazard of death per 1-SD increment in low-frequency HRV and DC, respectively. Higher low-frequency HRV and DC, measured during both daytime and nighttime, were associated with decreased hazard of death, but daytime measures showed numerically stronger associations. Results did not substantially vary by zygosity. Autonomic inflexibility, and especially vagal withdrawal, are important mechanistic pathways of general mortality risk, independent of familial and genetic factors.

Abstract P241: Stress-Induced Autonomic Dysfunction is Associated With Mental Stress-Induced Myocardial Ischemia in Patients With Coronary Artery Disease

Background: Mental stress-induced myocardial ischemia (MSIMI) is associated with adverse cardiovascular outcomes in individuals with coronary artery disease (CAD), but the mechanisms underlying this phenomenon are unknown. We examined the relationship between stress-induced autonomic dysfunction, measured by lower heart rate variability (HRV) in response to stress, and MSIMI in patients with stable CAD. We hypothesized that stress-induced autonomic dysfunction is associated with higher odds of MSIMI. Methods: In 735 participants with stable CAD, we measured high frequency (HF) and low frequency (LF) HRV in 5-minute intervals before and during a standardized laboratory-based speech stressor using Holter monitoring. MSIMI was evaluated with single-photon emission computed tomography myocardial perfusion imaging. HRV at rest and stress were categorized into low (lowest quartile) versus high (upper three quartiles) categories; low category was used as an indicator of autonomic dysfunction. Multivariable logistic regression models were used to examine the association of autonomic dysfunction with MSIMI. Results: The mean age was 58 (SD ±10) years, 35% were women, 44% were Black participants, and 16% developed MSIMI. Compared with high stress HRV, low stress HRV (both HF and LF) was associated with higher odds of MSIMI after adjusting for demographic and clinical factors. LF HRV at rest was also significantly associated with MSIMI with slightly reduced effect estimates. Conclusions: In individuals with CAD, mental stress-induced autonomic dysfunction may be an independent mechanism in the pathogenesis of MSIMI.

Exposure to prenatal stressors and infant autonomic nervous system regulation of stress.

The purpose of this study was to determine the relationship between fetal exposure to maternal prenatal stressors and infant parasympathetic (PNS) and sympathetic (SNS) nervous function at 3 timepoints across the first year of life. Autonomic nervous system impairments may mediate associations between gestational exposure to stressors and later infant health problems. Heart rate variability (HRV) provides a sensitive index of PNS and SNS function. However, no studies have assessed longitudinal associations between prenatal stressors and infant HRV measures of both PNS and SNS over the first year of life. During the third trimester of pregnancy, 233 women completed measures of life stressors and depression. At 1, 6 and 12 months of age, a stressor protocol was administered while infant electrocardiographic (ECG) data were collected from a baseline through a post-stressor period. HRV measures of PNS and SNS activity (HF, LF, LF/HF ratio) were generated from ECG data. We used multilevel regression to examine the aims, adjusting for maternal depression and neonatal morbidity. There were no associations between prenatal stressors and any baseline or reactivity HRV metric over the infant's first year of life. However, exposure to more stressors was associated with lower post-stressor LF HRV at both 6 (β = -.44, p = .001) and 12 (β = -.37, p = .005) months of age. Findings suggest potential alterations in development of the vagally mediated baroreflex function as a result of exposure to prenatal stressors, with implications for the infants' ability to generate a resilient recovery in response to stressors.

Embodimetrics: A Principal Component Analysis Study of the Combined Assessment of Cardiac, Cognitive and Mobility Parameters.

There is a growing body of literature investigating the relationship between the frequency domain analysis of heart rate variability (HRV) and cognitive Stroop task performance. We proposed a combined assessment integrating trunk mobility in 72 healthy women to investigate the relationship between cognitive, cardiac, and motor variables using principal component analysis (PCA). Additionally, we assessed changes in the relationships among these variables after a two-month intervention aimed at improving the perception-action link. At baseline, PCA correctly identified three components: one related to cardiac variables, one to trunk motion, and one to Stroop task performance. After the intervention, only two components were found, with trunk symmetry and range of motion, accuracy, time to complete the Stroop task, and low-frequency heart rate variability aggregated into a single component using PCA. Artificial neural network analysis confirmed the effects of both HRV and motor behavior on cognitive Stroop task performance. This analysis suggested that this protocol was effective in investigating embodied cognition, and we defined this approach as "embodimetrics".

A framework for the interpretation of heart rate variability applied to transcutaneous auricular vagus nerve stimulation and osteopathic manipulation.

Reports on autonomic responses to transcutaneous auricular vagus nerve stimulation (taVNS) and osteopathic manipulative techniques have been equivocal, partly due to inconsistent interpretation of heart rate variability (HRV). We developed a mechanistic framework for the interpretation of HRV based on a model of sinus node automaticity that considers autonomic effects on Phase 3 repolarization and Phase 4 depolarization of the sinoatrial action potential. The model was applied to HRV parameters calculated from ECG recordings (healthy adult humans, both genders) before (30 min), during (15 min), and after (30 min) a time control intervention (rest, n = 23), taVNS (10 Hz, 300 μs, 1-2 mA, cymba concha, left ear, n = 12), or occipitoatlantal decompression (OA-D, n = 14). The experimental protocol was repeated on 3 consecutive days. The model simulation revealed that low frequency (LF) HRV best predicts sympathetic tone when calculated from heart rate time series, while high frequency (HF) HRV best predicts parasympathetic tone when calculated from heart period time series. Applying our model to the HRV responses to taVNS and OA-D, revealed that taVNS increases cardiac parasympathetic tone, while OA-D elicits a mild decrease in cardiac sympathetic tone.

The effects of anesthetic drug choice on heart rate variability and echocardiography parameters in cats

Heart rate variability (HRV) is one of the assessments of cardiovascular risk during general anesthesia. This study aimed to assess the effects of an anesthetic drug on HRV in cats and to provide information for clinical applications. Twenty-four healthy client-owned cats of various breeds, 12 females and 12 males scheduled for elective surgery, were enrolled in this study. The cats were premedicated and induced with 4 protocols: protocol 1, diazepam (0.3 mg/kg) and propofol (2–4 mg/kg) IV; protocol 2, diazepam (0.3 mg/kg) and alfaxalone (1–3 mg/kg) IV; protocol 3, diazepam (0.3 mg/kg) and ketamine (3–5 mg/kg) IV; and protocol 4, xylazine (1 mg/kg) and tiletamine/zolazepam (Zoletil) (5 mg/kg) IM. The heart rate and HRV of the 24 cats were collected before and at least 1 h after administering the anesthetic drugs. Echocardiography was performed to evaluate heart function. Oscillometric blood pressure monitoring was used to obtain the mean blood pressure. After anesthetic drug administration, higher heart rates were found in cats premedicated and induced with alfaxalone (p = 0.045) than in the other protocols. The lowest heart rate (HR) values were found in cats in protocol 4 using xylazine and Zoletil. The HRV low frequency (LF) and high frequency (HF) power ratios increased in all protocols except for cats premedicated and intubated with propofol. The standard deviation of the regular sinus beats (SDNN) was higher in cats premedicated and induced with ketamine than in other anesthetic protocols (p = 0.015). An increase in sympathetic activity and reduced HRV is associated with high blood pressure and left atrial dimension. The percentage of fractional shortening (FS) decreased in cats premedicated with ketamine. The results showed that the anesthesia method using diazepam and propofol caused the least disturbance of HRV compared with other anesthesia methods that were used in this study.

Long term intraocular pressure fluctuation and epiretinal membrane in patients with glaucoma or glaucoma suspect

Aims/Purpose: The associations between ERM and glaucoma were suggested in several studies. In an animal model undergoing intermittent IOP elevations, a reactive gliosis, a phenotype of ERM, was found in the optic nerve head. We investigated the association between intraocular pressure (IOP) fluctuation and idiopathic ERM in patients with glaucoma or glaucoma suspect.Methods: In this retrospective study, a total of 84 patients with glaucoma or glaucoma suspect were included. Among them, forty one patients had no ERM and forty three patients had ERM. Long‐term fluctuation of IOP was defined as the standard deviation (SD) of IOP at all visits. Patients were divided into two groups according to the median value of SD of IOP: the low IOP fluctuation group and high IOP fluctuation group. Among patients with available heart rate variability (HRV) data, the relationship between the HRV parameter and IOP fluctuation was analysed.Results: Patients with ERM was older and had higher IOP fluctuation and higher proportion of having history of cataract surgery and greater macular thickness (p = 0.018, 0.049, 0.013, < 0.001). The high IOP fluctuation group showed higher proportion of patients with ERM (62.5%) than the low IOP fluctuation group (36.4%, p = 0.028). In the multiple logistic analysis, higher IOP fluctuation group were associated with the presence of ERM (p = 0.047). Among patients with ERM, eyes with stage 3 or 4 ERM had worse visual field defects based on mean deviation than those with stage 1 or 2 ERM (p = 0.025). The high IOP fluctuation group showed higher level of low frequency HRV, an index of sympathetic cardiac control than the low IOP fluctuation group (p = 0.027). Intereye comparison in eyes with ERM and the fellow eyes without ERM, eyes with ERM (2.2 ± 0.9 mmHg) had higher fluctuation of IOP than those without ERM (2.0 ± 0.8 mmHg, p = 0.029).Conclusions: In conclusion, long‐term IOP fluctuation had the relevance to idiopathic ERM in patients with glaucoma or glaucoma suspect. In glaucoma patients with ERM, more advanced stage ERMs were associated with worse visual field damage. Further studies are needed to determine if long‐term IOP fluctuation affects the progression of glaucoma and ERM.

Asymptomatic Autonomic Dysregulation after Recovery from Mild COVID-19 Infection Revealed by Analysis of Heart Rate Variability Responses to Task Load.

(1) Background: The coronavirus disease 2019 (COVID-19) infection is often followed by various complications, which can cause disturbances in daily life after recovery from the infectious state, although etiological mechanisms are not fully elucidated. Previous studies have indicated that autonomic dysregulation is an underlying factor, and it is of interest to clarify whether autonomic dysregulation is also present in the asymptomatic subjects after COVID-19 infection (post-COVID-19) for early detection of post-COVID-19 complications. (2) Methods: In the present study, autonomic activity was assessed using heart rate variability (HRV) analysis in the workers who recovered from mild COVID-19 infection (n = 39). They took a leave of absence for an average of 11.9 days and returned to the original work without complications. HRV was measured after an average of 9.3 days from return. High-frequency (HF) and low-frequency (LF) HRV parameters and heart rate (HR) were recorded during a three-behavioral-state paradigm of approximately 5 min length composed of initial rest, task load, and post-task rest periods and were compared with the data of the workers without the history of COVID-19 infection (normal, n = 38). (3) Results: The HRV and HR scores at the initial rest in the post-COVID-19 subjects showed no difference from those in the control. It is found that the post-COVID-19 subjects exhibited an attenuation of LF/HF increment during the task load and an excessive increase of HF together with a decrease of LF, LF/HF and HR during the post-task rest period in comparison with the initial rest scores. (4) Conclusions: These abnormalities are evaluated as asymptomatic autonomic dysregulation in response to task load, are frequently present after COVID-19 infection, and could be related to the generation of complications.

Predicting Post-Traumatic Stress Disorder Treatment Response Using Heart Rate Variability to Virtual Reality Environment and Modified Stroop Task: An Exploratory Study.

Predicting treatment response can inform treatment decisions, expectations, and optimize use of mental health treatment resources. This study examined heart rate (HR), heart rate variability (HRV), and a modified Stroop task (mStroop) to predict post-traumatic stress disorder (PTSD) treatment response. We report on an observational, longitudinal study with 45 U.S. veterans in outpatient PTSD care, who had deployed to Iraq or Afghanistan. HR and HRV were collected before, during, and after virtual reality (VR) combat and civilian scenes. HRV recovery was defined as HRV after a 3-minute VR simulation minus HRV during a VR scene. mStroop threat variables included index scores for combat and general threat. Self-report data were collected at baseline and 6 months later. The outcome variable was the 17-item Clinician Administered PTSD Scale (CAPS). Controlling for baseline CAPS and number of combat experiences, the following baseline HRV recovery variables were significant predictors of 6-month CAPS: standard deviation of normal beat to beat interval (SDNN) after combat scene minus SDNN during combat scene and low-frequency (LF HRV) after civilian scene minus LF during civilian scene. HRV at rest, HR reactivity, HR recovery, and mStroop scores did not predict treatment response. In conclusion, HRV recovery variables in the context of a standardized VR stressor were significant predictors of PTSD treatment response after controlling for baseline CAPS and number of combat experiences. The direction of this relationship indicates that greater baseline HRV recovery predicts lower 6-month PTSD symptom severity. This was an exploratory study in need of replication.

Analysis of the correlation between heart rate variability and palpitation symptoms in female patients with long COVID.

To analyze the correlation between heart rate variability (HRV) and palpitation symptoms in female patients with long COVID. A total of 272 female healthcare workers who were infected with SARS-CoV-2 for the first time in December 2022 at Fuzhou First Hospital affiliated with Fujian Medical University, were selected as study subjects. These subjects were divided into three groups based on their symptoms: a group with palpitations (70 cases), a group without palpitations but with other symptoms (124 cases), and a group consisting of asymptomatic cases (78 cases). The study compared the general information, COMPASS-31 scores, quality of life scores, and HRV parameters among the three groups. Furthermore, it analyzed the factors influencing palpitation symptoms in female patients with long COVID. Compared to the other two groups, the HRV parameters SDNN, HRVIndex, LF, and TP were significantly reduced in the group with palpitations (p < 0.05). Multivariate analysis revealed that HRVIndex (p = 0.016; OR: 0.966, 95% CI: 0.940∼0.994) had a significant impact on palpitation symptoms in female patients with long COVID. The symptoms of palpitations in female patients with long COVID were found to be related to HRV parameters. Autonomic dysfunction may be connected to the occurrence of palpitation symptoms in long COVID.

Heart rate variability in patients with acute ST-segment elevation myocardial infarction after COVID-19

Aim. To compare heart rate variability parameters in patients after a coronavirus disease 2019 (COVID-19) with acute ST elevation myocardial infarction (STEMI) during the inhospital and post-hospital periods.Material and methods. A total of 140 patients with STEMI were divided into 2 groups: I — patients with STEMI who had COVID-19 (n=52) in the period of 1,5-6 months before acute coronary syndrome, II — comparison group (n=88), which included patients with STEMI without prior COVID-19. All patients underwent infarct-related artery stenting within the first 24 hours from the onset. Heart rate variability (HRV) parameters were determined for all patients on days 2-3 and days 9-11 and 6 months after the hospitalization for STEMI.Results. Patients in group I showed more pronounced changes in HRV indicators on days 2-3 of STEMI: RMSSD (root square of successive RR intervals) by 21% (p=0,026), variations (Var) (the difference between the minimum and maximum RR intervals) by 33% (p=0,013), VLF (total very low-frequency HRV) by 7% (p=0,009) were higher, and HF (highfrequency HRV) by 40% (p=0,003), pNN50% (ratio of the number of consecutive RR interval pairs differing by &gt;50 ms to the total number of RR intervals) by 66% (p=0,038) were lower than in the control group, respectively. On days 9-11 of the disease in patients with a history of STEMI and COVID-19, in contrast to the control group, there was a more pronounced increase in the SDNN (standard deviation of RR intervals) by 46% (p=0,005), VLF by 42% (p=0,031), whereas in the control group there were an increase of only 22% (p=0,004) and 11% (p=0,022), respectively. The HF value in the main group increased by 25% (p=0,007), while in the control group it decreased by 19% (p=0,030). Six months after STEMI in the main group, the RMSSD decreased by 19% (p=0,009), Var by 16% (p=0,041), VLF by 30% (p=0,025), LF (low-frequency component HRV) by 11% (p=0,005), while the control group these parameters decreased by 20% (p=0,006), 21% (p=0,001), 9% (p=0,011), and 7% (p=0,016), respectively.Conclusion. In patients with STEMI and prior COVID-19, the initial HRV values differ from similar HRV parameters in patients with STEMI without prior COVID-19. In the hospital and post-hospital periods, the changes of HRV in patients with and without COVID-19 are multidirectional as follows: pronounced sympathetic hyperactivity predominates, and slower recovery of HRV in patients after COVID-19 predominates.

A Diet Pattern Characterized by Sugar-Sweetened Beverages Is Associated with Lower Decision-Making Performance in the Iowa Gambling Task, Elevated Stress Exposure, and Altered Autonomic Nervous System Reactivity in Men and Women.

The executive brain mediates and facilitates a set of cognitive functions, such as decision making, planning, self-regulation, emotional regulation, and attention. Executive dysfunction and related diseases are a rising public health concern. Evidence supports a link between nutritional factors and executive function (EF), but relatively little information exists about the relationship between diet patterns and this higher order cognitive ability. We and others have reported on the relationships between body weight regulation and affective decision making, as measured by performance in the Iowa Gambling Task (IGT). However, little is known about the relationships between performance in this decision-making task and whole diet patterns. In this study, we tested whether data-derived diet patterns based on energy-adjusted food intake data from the Block Food Frequency Questionnaire were associated with decision-making performance in the IGT. Secondarily, we examined the influence of these diet patterns on self-reported chronic stress exposure and heart rate variability, which is a marker of autonomic nervous system (ANS) activity. In prior studies, stress and ANS activity were shown to influence decision-making performance in the IGT. In this study, five distinct diet patterns were identified by cluster and factor analyses. A diet pattern best characterized by elevated sugar-sweetened beverage and added sugar consumption was associated with the lowest decision-making performance (p = 0.0049) and higher stress exposure (p = 0.0097). This same diet pattern was associated (p = 0.0374) with an IGT-affiliated decline in high-frequency HRV and an increase in low-frequency HRV, suggesting diet-induced ANS regulatory shifts in response to performing the EF task. Compared to the sugar-sweetened beverage diet pattern, diet patterns defined by more fruits/vegetables and low red meat (p = 0.0048) or higher omega-3 fatty acids and seafood (p = 0.0029) consumption were associated with lower chronic stress exposure. All outcomes were statistically adjusted for differences in BMI, age, sex, education level, and sensorimotor ability. Our findings provide new information that further supports the potential importance of whole diet patterns on cognitive disease prevention.

Comparative effectiveness of 10-week equipment-based pilates and diaphragmatic breathing exercise on heart rate variability and pulmonary function in young adult healthy women with normal BMI – a quasi-experimental study

BackgroundThe positive effects of Pilates and slow-controlled breathing exercises on health are examined in different studies. The purpose of the study was to investigate the effects of 10-week equipment-based Pilates, slow-controlled breathing exercises, and a combination of both on heart rate variability (HRV), pulmonary function, and body composition (BC) in young adult healthy women with normal BMI.MethodsForty female participants were assigned to either equipment-based Pilates group (PG), slow-controlled breathing exercise group (BG), equipment-based Pilates + breathing exercise group (PBG), and control groups (CG). Equipment-based Pilates exercise consists of training for two days a week and 50 min per day, and breathing exercises were done twice a week for 15 min a day for 8 weeks. In addition, PBG performed a 15-minute breathing exercise after each Pilates session. Pilates sessions were created with Reformer, Cadillac, Ladder Barrel, Chair Barrel, and Spine Corrector. On the other hand, breathing exercises were based on a controlled 5 s inhale and 5 s exhale cycles.ResultsBefore and after the implementation, pulmonary function, HRV, and BC parameters were measured. The body weight and BMI improved in PG and PBG, and the percent body fat decreased only in PBG (p < 0.05). Both PG and PBG noted significant changes in HRV indices SDSD, SDNN, TP, HF, and LF. However, the RMSSD was recorded higher in only PBG. Similar changes were found in pulmonary parameters. The FVC, FEV1, VC, IC, TV, MVV, and VE im-proved in PBG. PG showed increases in VC and TV. The only changes found in BG were PEF and ERV.ConclusionsThe finding highlights the ample effect of combined breathing and Pilates exercise on HRV, pulmonary function and body composition which has important implications for health promotion.

Association between depressive symptoms and heart rate variability in older patients admitted for rehabilitation: a cross-sectional study

Heart rate variability (HRV) is associated with depressive symptoms, but this relationship in older inpatients undergoing rehabilitation remains unclear. This study investigated the relationship between HRV and depressive symptoms in older inpatients undergoing rehabilitation. Fifty patients aged ≥65 years were assessed for depressive symptoms using the Geriatric Depression Scale. HRV was assessed by frequency analysis. The relationship between depressive symptoms and HRV indices, age, sex, Short Physical Performance Battery (SPPB) score, Mini-Mental State Examination score was examined using simple linear regression. Next, the predictors from the simple linear regression analysis significant at the 0.15 level were inputted in a multiple regression model. Multiple regression analysis revealed that very low frequency HRV [β = −2.13, 95% confidence interval (CI) −3.15 to −1.11, P &lt; 0.05] and SPPB score (β = −0.30, 95% CI −0.52 to −0.08, P &lt; 0.05) were negatively associated with depressive symptoms: the lower the HRV and the more severe the mobility impairment, the higher the severity of the depressive symptoms. Very low frequency (VLF) HRV and physical performance, as measured by the SPPB score, were associated with depressive symptoms in older patients undergoing rehabilitation. VLF HRV may serve as a useful biomarker for detecting depressive symptoms in this population.

Stress reappraisal improves the autonomic nervous system response of test anxious individuals: Evidence from heart rate variability

BackgroundStress belief plays an important role in stress response. This study investigated whether individuals with high test anxiety/low test anxiety (HTA/LTA) held different stress belief, and tested the effect of stress reappraisal on reducing test anxiety related autonomic nervous system (ANS) response. Methods51 HTA students and 49 LTA students were recruited using the Test Anxiety Scale (TAS). They completed a 10-min intelligence test (including preparation, test, and recovery phases), then were randomly assigned to reappraisal group and control group to complete the test again. Heart rate variability (HRV) was recorded throughout the protocol. Beliefs about Stress Scale was obtained before and after the experiment. Stress belief were manipulated using a 2-min film clip that orienting participant to the enhancing nature of stress. Emotional changes were assessed. ResultsHTA individuals held more negative stress beliefs and showed greater emotional arousal during the test than the LTA individuals. Their negative stress belief was associated with higher TAS score and worse HRV response. (2) When facing an exam, LTA individuals exhibited increased low-frequency HRV and stable high-frequency HRV, while HTA individuals showed stable low-frequency HRV and decreased high-frequency HRV. (3) HTA individuals who underwent reappraisal showed a reduction in test anxiety and in low-frequency/high-frequency HRV ratio. ConclusionsThe ANS activity of HTA individuals is imbalanced in the test situations. Stress belief is a meaningful variable in anxiety related ANS activity. Stress reappraisal can effectively reduce test anxiety and improve the balance of ANS activity of HTA individuals.

FABP3, FABP4, and heart rate variability among patients with chronic schizophrenia.

The prevalence of cardiovascular disease (CVD) and CVD-related deaths in patients with schizophrenia is high. An elevated risk of CVD has been associated with low heart rate variability (HRV). There is increasing evidence that fatty acid-binding protein (FABP)3 and FABP4 play roles in the development and progression of CVD. This study aimed to explore the association of circulating FABP3/FABP4 levels with HRV in patients with chronic schizophrenia. We included 265 consecutive patients with chronic schizophrenia who attended a disease management program. We used an enzyme-linked immunosorbent assay for the measurement of plasma concentrations of FABP3 and FABP4. Standard HRV was recorded at baseline following a standard protocol. Mean high- and low-frequency (HF/LF) HRV values were analyzed by tertile of FABP3 and FABP4 using one-way analysis of variance, and linear regression analysis was performed to assess trends. A positive association between FABP3 and creatinine was found in multiple regression analysis. In addition, negative associations between levels of hematocrit, hemoglobin, HF HRV, and estimated glomerular filtration rate (eGFR) with FABP3 were also found. Moreover, positive associations between FABP4 with body mass index, diabetes mellitus, hypertension, systolic blood pressure, low-density lipoprotein-cholesterol, triglycerides, creatinine, and FABP3 were found. Furthermore, negative associations between levels of high-density lipoprotein-cholesterol, eGFR, and HF HRV with FABP4 were found. We also found a significant inverse association between FABP3 and HF HRV (p for trend = 0.008), and significant inverse associations between FABP4 with HF and LF HRV (p for trend = 0.007 and 0.017, respectively). Together, this suggests that elevated levels of FABP3 and FABP4 may be linked to health problems related to CVD in patients with chronic schizophrenia.

Effects of sleep fragmentation and partial sleep restriction on heart rate variability during night

We developed a cross-over study design with two interventions in randomized order to compare the effects of sleep fragmentation and partial sleep restriction on cardiac autonomic tone. Twenty male subjects (40.6 ± 7.5 years old) underwent overnight polysomnography during 2 weeks, each week containing one undisturbed baseline night, one intervention night (either sleep restriction with 5 h of sleep or sleep fragmentation with awakening every hour) and two undisturbed recovery nights. Parameters of heart rate variability (HRV) were used to assess cardiac autonomic modulation during the nights. Sleep restriction showed significant higher heart rate (p = 0.018) and lower HRV-pNN50 (p = 0.012) during sleep stage N1 and lower HRV-SDNN (p = 0.009) during wakefulness compared to the respective baseline. For HR and SDNN there were recovery effects. There was no significant difference comparing fragmentation night and its baseline. Comparing both intervention nights, sleep restriction had lower HRV high frequency (HF) components in stage N1 (p = 0.018) and stage N2 (p = 0.012), lower HRV low frequency (LF) (p = 0.007) regarding the entire night and lower SDNN (p = 0.033) during WASO during sleep. Sleep restriction increases sympathetic tone and decreases vagal tone during night causing increased autonomic stress, while fragmented sleep does not affect cardiac autonomic parameters in our sample.