High-frequency Ratio Of Heart Rate Variability Research Articles

The impact of outdoor soundscapes at nursing homes on physiological indicators in older adults

This research explores the impact of outdoor soundscapes at nursing homes on the physiological health of older adults. Using virtual reality, the study recreated the outdoor environments at nursing homes for 57 seniors in a lab setting, continuously monitoring physiological indicators such as skin conductance level, heart rate, low to high-frequency heart rate variability ratio, respiratory frequency, blink frequency, and pupil diameter. The comparison of these indicators with corresponding soundscapes revealed the diverse effects of different nursing home outdoor scenarios on the physiological health of older adults. Furthermore, analysis of the temporal marginal effects of these indicators highlighted the significant influence of time on the physiological responses of seniors in various soundscapes, showing fluctuations in each indicator at different times. Finally, to understand the channels of impact, the study examined how acoustic features at nursing homes affect seniors' physiological indicators. The findings suggest that increased loudness and roughness in soundscapes elevate seniors' heart rates and cardiovascular risks, while a moderate increase in LAeq and fluctuation strength in dynamic scenarios might have positive stimulative effects on the physiological functions of the older adults.

Left ventricular mechanical, cardiac autonomic and metabolic responses to a single session of high intensity interval training.

High-intensity interval training (HIIT) produces significant health benefits. However, the acute physiological responses to HIIT are poorly understood. Therefore, we aimed to measure the acute cardiac autonomic, haemodynamic, metabolic and left ventricular mechanical responses to a single HIIT session. Fifty young, healthy participants completed a single HIIT session, comprising of three 30-s maximal exercise intervals on a cycle ergometer, interspersed with 2-min active recovery. Cardiac autonomics, haemodynamics and metabolic variables were measured pre-, during and post-HIIT. Conventional and speckle tracking echocardiography was used to record standard and tissue Doppler measures of left ventricular (LV) structure, function and mechanics pre- and post-HIIT. Following a single HIIT session, there was significant post-exercise systolic hypotension (126 ± 13 to 111 ± 10mmHg, p < 0.05), parallel to a significant reduction in total peripheral resistance (1640 ± 365 to 639 ± 177dyne⋅s⋅cm5, p < 0.001) and significant increases in baroreceptor reflex sensitivity and baroreceptor effectiveness index (9.2 ± 11 to 24.8 ± 16.7ms⋅mmHg-1 and 41.8 ± 28 to 68.8 ± 16.2, respectively) during recovery compared to baseline. There was also a significant increase in the low- to high-frequency heart rate variability ratio in recovery (0.7 ± 0.48 to 1.7 ± 1, p < 0.001) and significant improvements in left ventricular global longitudinal strain (- 18.3 ± 1.2% to - 29.2 ± 2.3%, p < 0.001), and myocardial twist mechanics (1.27 ± 0.72 to 1.98 ± 0.72°·cm-1, p = 0.028) post-HIIT compared to baseline. A single HIIT session is associated with acute improvements in autonomic modulation, haemodynamic cardiovascular control and left ventricular function, structure and mechanics. The acute responses to HIIT provide crucial mechanistic information, which may have significant acute and chronic clinical implications.

Development and Clinical Application of a Novel Autonomic Transient Response-Based Screening System for Major Depressive Disorder Using a Fingertip Photoplethysmographic Sensor.

Over 350 million people across the world suffer from major depressive disorder (MDD). More than 10% of MDD patients have suicide intent, while it has been reported that more than 40% patients did not consult their doctors for MDD. In order to increase consultation rate of potential MDD patients, we developed a novel MDD screening system which can be used at home without help of health-care professionals. Using a fingertip photoplethysmograph (PPG) sensor as a substitute of electrocardiograph (ECG), the system discriminates MDD patients from healthy subjects using autonomic nerve transient responses induced by a mental task (random number generation) via logistic regression analysis. The nine logistic regression variables are averages of heart rate (HR), high frequency (HF) component of heart rate variability (HRV), and the low frequency (LF)/HF ratio of HRV before, during, and after the mental task. We conducted a clinical test of the proposed system. Participants were 6 MDD patients (4 females and 2 males, aged 23–60 years) from Shizuoka Saiseikai General Hospital psychiatry outpatient unit and 14 healthy volunteers from University of Electro-Communications (6 females and 8 males, aged 21–63 years). The average PPG- and ECG (as a reference)-derived HR, HF and LF/HF were significantly correlated with each other (HR; r = 1.00, p < 0.0001, HF; r = 0.98, p < 0.0001, LF/HF; r = 0.98, p < 0.0001). Leave-one-out cross validation (LOOCV) revealed 83% sensitivity and 93% specificity. The proposed system appears promising for future MDD self-screening at home and are expected to encourage psychiatric visits for potential MDD patients.

Heart Rate Variability and the Efficacy of Biofeedback in Heroin Users with Depressive Symptoms.

ObjectiveLow heart rate variability (HRV) has been confirmed in heroin users, but the effects of heart-rate-variability–biofeedback in heroin users remain unknown. This study examined (1) correlations between depression and HRV indices; (2) group differences in HRV indices among a heroin-user group, a group with major depressive disorder but no heroin use, and healthy controls; and (3) the effects of heart-rate-variability–biofeedback on depressive symptoms, HRV indices, and respiratory rates within the heroin group.MethodsAll participants completed a depression questionnaire and underwent electrocardiogram measurements, and group differences in baseline HRV indices were examined. The heroin group underwent electrocardiogram and respiration rate measurements at baseline, during a depressive condition, and during a happiness condition, before and after which they took part in the heart-rate-variability–biofeedback program. The effects of heart-rate-variability–biofeedback on depressive symptoms, HRV indices, and respiration rates were examined.ResultsThere was a negative correlation between depression and high frequency of HRV, and a positive correlation between depression and low frequency to high frequency ratio of HRV. The heroin group had a lower overall and high frequency of HRV, and a higher low frequency/high frequency ratio than healthy controls. The heart-rate-variability–biofeedback intervention increased HRV indices and decreased respiratory rates from pre-intervention to post-intervention.ConclusionReduced parasympathetic and increased sympathetic activations were found in heroin users. Heart-rate-variability–biofeedback was an effective non-pharmacological intervention to restore autonomic balance.

Cerebrovascular and Autonomic Responses to Thai Traditional Massage in Patients with Ischemic Stroke

Thai traditional massage therapy has shown potential in improving vascular and autonomic functions but the potential benefits of massage for patients with ischemic stroke are yet to be explored. PURPOSE: To determine acute effects of Thai traditional massage on cerebral blood flow velocity and heart rate variability in patients with ischemic stroke. METHODS: Thirteen patients (55±3 years) with a single episode of ischemic stroke due to thrombosis of cerebral arteries (onset ≤2 years) were randomly assigned into either Thai traditional massage (TTM; n=6) or sham control (CON; n=7) group. TTM consisted of petrissage, friction, and passive stretching on the whole body for 60 minutes. Cerebral blood flow velocity (CBFV) in the middle cerebral artery using the transcranial Doppler ultrasound and heart rate variability (HRV) using the frequency domain analysis were measured before and 0, 60, 120 min, and 24 hr after TTM or sham. RESULTS: CBFV increased (p<0.05) 60 min after TTM. This measure returned to baseline values within 120 min. High frequency (HF) component of HRV increased 0, 60, and 120 min after TTM (all p<0.05). There were no significant changes in total power (TP) and low frequency (LF) components as well as the LF:HF ratio of HRV. CBFV was positively associated with TP (r=0.74) and LF (r=0.63) components of HRV (all p<0.05) at 60 min post-TTM. No significant changes in these variables were observed during the sham control condition. CONCLUSIONS: Our study demonstrated that one session of Thai traditional massage acutely improves cerebral blood flow in patients with ischemic stroke possibly through increases in parasympathetic nervous activity. Acknowledgments: This study was supported by Government Research Budget Chulalongkorn University 2015 and The 90th Anniversary Research Fund, Chulalongkorn University, Thailand.

Heart Rate Variability during Inpatient Psychosomatic Treatment - A Naturalistic Observational Study.

We tested the hypothesis that inpatient psychosomatic treatment would improve both psychological distress and autonomic dysfunction, indexed as heart rate variability (HRV). 135 patients (mean age 47.2 years, 68.1% women) were enrolled. The most frequent diagnoses were somatoform disorders, adjustment disorders, major depression, eating disorders, and anxiety disorders.Mean duration of treatment was 21.8 ± 7.3 days. Complete HRV data were available on 105 patients. At the beginning of the treatment, psychological distress correlated with the low frequency/ high frequency ratio of HRV, indicating a shift of autonomic balance towards sympathetic predominance. Following treatment, psychological distress had improved, but parasympathetic activity was even lower. Tricyclic antidepressant use was associated with an increase in heart rate. No other associations between antidepressant use and autonomic function were observed. Reductions of psychological distress may not be reflected by improved autonomic function. Studies on interventions that may improve both psychological distress and autonomic dysfunction are desirable.

Resposta aguda do sistema nervoso autônomo a diferentes estímulos auditivos musicais em mulheres

Objective. To compare the acute response of the autonomic nervous system (ANS) before exposure to auditory stimuli of different musi­cal styles in women. Method. Cross-sectional study with 27 women aged between 18 and 30 years old, apparently healthy. Volunteers remained at rest for 10 minutes and were exposed to classical music (64-84 dB) and heavy metal (75-84 dB) for 10 minutes, via headset, and their heart rate variability (HRV) was recorded during the entire period. Statistical indices were analyzed in the time domain and in­dexes in the frequency domain: low frequency component (LF), high frequency (HF) and LF / HF ratio of HRV. Results. There was an increase in the LF index (p=0.04) and decrease in HF index (p=0.02) in comparing stimuli of heavy metal and classical music. There was also a difference in LF/HF ratio (p=0.007) when comparing classical and heavy metal music. Conclusion. The acute response to exposure of the SNA musical auditory stimuli through headphones attended incremental component of the sympathetic, parasympathetic with­drawal and increased sympathetic-vagal balance component in heavy metal style compared to classical music.

Adolescent chronic fatigue syndrome; a follow-up study displays concurrent improvement of circulatory abnormalities and clinical symptoms

BackgroundThe pathophysiology of chronic fatigue syndrome (CFS) in adolescents is unknown, and the clinical course and prognosis is still questioned. Recent research indicates that abnormalities of autonomic cardiovascular control may play an important role. The aim of this research project was to perform a follow-up study of adolescents with chronic fatigue syndrome, focusing on clinical symptoms and autonomic cardiovascular control.Methods47 adolescents (12-18 years old) with CFS were recruited from the outpatient clinic at the Department of Pediatrics, Oslo University Hospital. In a primary visit and a follow-up visit (3-17 months later), we evaluated: a) a wide range of complaints and symptoms and b) cardiovascular variables at baseline and during a 20° head-up tilt-test (HUT).ResultsAt the second visit, patients reported significant improvement regarding functional impairments, fatigue severity, muscular pain, concentration problems, post-exertional malaise and the problem of non-relieving rest. Also, at the second visit, baseline heart rate (HR), blood pressure, total peripheral resistance index (TPRI) and LF/HF (low-frequency:high-frequency heart rate variability ratio, an index of sinus node sympathovagal balance derived from spectral analyses of heart rate) were significant lower, and the increases in HR, mean blood pressure (MBP), diastolic blood pressure (DBP) and TPRI during tilt were significantly less pronounced as compared to the first visit. There was a significant correlation between changes in autonomic symptom score, fatigue severity score and functional impairment score from the first to the second visit.ConclusionsThe majority of adolescents with CFS experienced an improvement over time in functional impairment, self-reported fatigue and additional symptoms, and a concurrent improvement of autonomic cardiovascular control. A possible connection between clinical symptoms and abnormal autonomic control in CFS might represent a focus for further research.

Polymorphisms of adrenergic cardiovascular control genes are associated with adolescent chronic fatigue syndrome

To explore the frequency of polymorphisms in adrenergic cardiovascular control genes in adolescent with chronic fatigue syndrome (CFS) and the relation of such polymorphisms to cardiovascular variables. DNA from 53 patients with CFS, 12-18 years old, was analysed for five single nucleotide polymorphisms (SNPs) in the genes catechol-O-methyltransferase (COMT), the β₂ -adrenergic receptor (two SNPs), the β₁ -adrenergic receptor and the α₂(a) -adrenergic receptor. Frequencies were compared to a reference population constructed from the National Center for Biotechnology Information (NCBI) database, and associations between frequencies and autonomic cardiovascular responses during a 20° head-up tilt-test were explored. For the COMT SNP Rs4680, patients with CFS had a higher frequency of the AA genotype and a lower frequency of the G containing genotypes (AG and GG), when compared to the reference sample (p = 0.046). Also, the AA genotype was associated with a smaller increase in LF/HF ratio (low-frequency:high-frequency heart rate variability ratio, an index of cardiac sympathovagal balance) during head-up tilt when compared to the AG/GG genotypes. For the β₂ -adrenergic receptor SNP Rs1042714, patients with CFS had a lower frequency of the GG genotype and a higher frequency of the genotypes containing C (CG and CC) (p = 0.044). CFS might be related to polymorphisms of COMT and the β₂ -adrenergic receptor. More details of the molecular mechanisms remain to be investigated.

Dose-dependent increases in heart rate variability and arterial compliance in overweight and obese adults with DHA-rich fish oil supplementation

Heart rate (HR) variability and large arterial compliance can be improved using fish oils. DHA, a component of fish oil, has cardiovascular health benefits, but its effect on HR variability (HRV) and arterial compliance is yet to be quantified. Sixty-seven overweight or obese adults (thirty-six males and thirty-one females; 53 (sem 2) year; BMI 31.7 (sem 1.1) kg/m(2)) were randomly allocated to consume either 6 g/d sunola oil (control; n 17), fish oil (260 mg DHA+60 mg EPA per g) at doses of 2 g/d (n 16), 4 g/d (n 17) or 6 g/d (n 17). Blood pressure, HR and compliance of large and small arteries were measured while supine at baseline and after 12 weeks in all participants, and HRV was assessed in a subgroup of forty-six participants. There was no effect of fish oil on blood pressure, small artery compliance or HR. However, the low frequency:high frequency ratio of HRV decreased with increasing doses of fish oil (r - 0.34, P = 0.02), while large artery compliance increased (r 0.34, P = 0.006). Moreover, the changes in these biomarkers were significantly correlated (r - 0.31, P = 0.04) and may reflect fish oil-induced improvements in arterial function and cardiac autonomic regulation.

Study of Autonomic Nervous Activity of Night Shift Workers Treated with Laser Acupuncture

The aim of this study was to evaluate the impact of laser acupuncture on the autonomic nervous system (ANS) of the night shift worker. Many articles have demonstrated that levels of affective disorders and stress are high in night shift workers. We applied laser energy to the Neiguan point (PC6) to examine the impact of laser acupuncture on the ANS of 45 healthy young males who were night shift workers and evaluated their heart-rate variability (HRV). The laser group (n = 15) received laser acupuncture (9.7 J/cm(2), 830 nm) for 10 min, and the placebo group (n = 15) received sham laser treatment. The effects before and after this intervention on the HRV of the subjects were assessed, along with those seen after 30 min of lying down. After treatment and after the 30-min rest period, the independent-sample t-test showed that both groups exhibited statistically significant differences in high-frequency (HF) HRV, low-frequency (LF) HRV, and the LF:HF ratio of HRV (p < 0.05). Compared with the placebo group, the paired-samples t-test showed that after laser treatment the treatment group had a statistically significant improvement in HF HRV (p = 0.001), LF HRV (p = 0.001), and the LF:HF HRV ratio (p = 0.02). Laser acupuncture stimulation applied to the Neiguan point increased vagal activity and suppression of cardiac sympathetic nerves. This effect was positive and could be used to help patients who have circadian rhythm disorders.

Effects of deep and superficial experimentally induced acute pain on muscle sympathetic nerve activity in human subjects.

Human studies conducted more than half a century ago have suggested that superficial pain induces excitatory effects on the sympathetic nervous system, resulting in increases in blood pressure (BP) and heart rate (HR), whereas deep pain is believed to cause vasodepression. To date, no studies have addressed whether deep or superficial pain produces such differential effects on muscle sympathetic nerve activity (MSNA). Using microneurography we recorded spontaneous MSNA from the common peroneal nerve in 13 awake subjects. Continuous blood pressure was recorded by radial arterial tonometry. Deep pain was induced by intramuscular injection of 0.5 ml hypertonic saline (5%) into the tibialis anterior muscle, superficial pain by subcutaneous injection of 0.2 ml hypertonic saline into the overlying skin. Muscle pain, with a mean rating of 4.9 +/- 0.8 (S.E.M.) on a 0-10 visual analog scale (VAS) and lasting on average 358 +/- 32 s, caused significant increases in MSNA (43.9 +/- 10.0%), BP (5.4 +/- 1.1%) and HR (7.0 +/- 2.0%) - not the expected decreases. Skin pain, rated at 4.9 +/- 0.6 and lasting 464 +/- 54 s, also caused significant increases in MSNA (38.2 +/- 12.8%), BP (5.1 +/- 2.1%) and HR (5.6 +/- 2.0%). The high-frequency (HF) to low-frequency (LF) ratio of heart rate variability (HRV) increased from 1.54 +/- 0.25 to 2.90 +/- 0.45 for muscle pain and 2.80 +/- 0.52 for skin pain. Despite the different qualities of deep (dull and diffuse) and superficial (burning and well-localized) pain, we conclude that pain originating in muscle and skin does not exert a differential effect on muscle sympathetic nerve activity, both causing an increase in MSNA and an increase in the LF:HF ratio of HRV. Whether this holds true for longer lasting experimental pain remains to be seen.