Reliability of wavelet analysis of heart rate variability during rest and exercise

The reliability of wavelet analysis (DWT), of heart rate variability during rest and exercise was examined for this study. All twenty-three participants visited the lab on two separate occasions no less than four weeks apart. All twenty-three participants were subjected to the spontaneous breathing (SB1), and HG60 exercise condition. Of those twenty-three participants, nine performed the HG20 exercise condition as well. It was found that during the SB1 condition, the R-R intervals were fairly reliable between days. However, the reliability of all the HRV parameters (SDNN, spectral components and wavelet components) were quite poor. Interestingly, however, during HG20, the reliability of the HRV parameters was much more promising. The ability of DWT to detect changes in sympathovagal balance with incremental handgrip exercise was seen, despite a very low number of participants

Design, Evaluation, and Application of Heart Rate Variability Analysis Software (HRVAS)

The analysis of heart rate variability (HRV) has become an increasingly popular and important tool for studying many disease pathologies in the past twenty years. HRV analyses are methods used to non-invasively quantify variability within heart rate. Purposes of this study were to design, evaluate, and apply an easy to use and open-source HRV analysis software package (HRVAS). HRVAS implements four major categories of HRV techniques: statistical and time-domain analysis, frequency-domain analysis, nonlinear analysis, and time-frequency analysis. Software evaluations were accomplished by performing HRV analysis on simulated and public congestive heart failure (CHF) data. Application of HRVAS included studying the effects of hyperaldosteronism on HRV in rats. Simulation and CHF results demonstrated that HRVAS was a dependable HRV analysis tool. Results from the rat hyperaldosteronism model showed that 5 of 26 HRV measures were statistically significant (p\u3c0.05). HRVAS provides a useful tool for HRV analysis to researchers

Acupuncture and sports medicine : effects and application perspectives

Vor dem Hintergrund der gestiegenen medizinischen und sozioökonomischen Relevanz von Akupunktur und Laserakupunktur werden im Rahmen der vorliegenden Arbeit Anwendungsfelder und Forschungsperspektiven in der präventiven und rehabilitativen Sportmedizin skizziert. Hierzu zählen insbesondere die Therapie von Sportverletzungen und Sportschäden, die Steigerung der körperlichen Leistungsfähigkeit, die Unterstützung und Förderung der Regeneration sowie die Vorbeugung von belastungsinduziertem Asthma. Aufbauend auf den aktuellen Forschungsstand werden eigene Originalarbeiten vorgestellt, die sich mit der Evaluation spezifischer Effekte der Akupunktur und Laserakupunktur befassen.Against the background of the increasing medical and socioeconomic importance of acupuncture and laser acupuncture, the present work aims at outlining scientific and practical applications in fields related to preventive and rehabilitative sports medicine. These include, in particular, the treatment of acute and chronic sports injuries, the enhancement of physical performance, the promotion of recovery, as well as the prevention of exercise-induced asthma. Based on current research, the author presents his original investigations dealing with specific effects of acupuncture and laser acupuncture

J Occup Environ Med

Objectives:Laser Doppler blood flow measurements have been used for diagnosis or detection of peripheral vascular dysfunction. This study used a rat tail model of vibration-induced vascular injury to determine how laser Doppler measurements were affected by acute and repeated exposures to vibration, and to identify changes in the Doppler signal that were associated with the exposure.Methods:Blood flow was measured immediately after a single exposure to vibration, or before vibration exposure on days 1, 5, 10, 15, and 20 of a 20 days exposure.Results:After a single exposure to vibration, average tail blood flow was reduced. With 20 days of exposure, there was a reduction in the amplitude of the arterial pulse on days 10 to 20 in vibrated rats and days 15 to 20 in control rats.Conclusions:More detailed statistical analyses of laser Doppler data may be needed to identify early changes in peripheral circulation after exposure to vibration.CC999999/Intramural CDC HHS/United States2019-05-23T00:00:00Z30507789PMC6531854636

Dynamics of cardiac autonomic regulation during isometric sustained weight test in hypertensive patients

Background: The Sustained Weight Test (SWT) is an isometric exercise test that has great practical value for carrying out massive studies on hypertension, however, is insufficient knowledge of the dynamics of cardiac autonomic regulation during this test. The aim of this study was to determine variations in the dynamics of cardiac autonomic regulation and in hemodynamic response during SWT in hypertensive subjects. Methods: A quasi-experimental study was conducted on 15 hypertensive patients of both sexes, paired with 30 normotensive individuals, measuring arterial blood pressure, entropy sample and the Heart Rate Variability (HRV) in time-frequency with the Continuous Wavelet Transform Morlet-type (CWT  morlet) through the electrocardiographic signal of the polygraph AD Instruments in the functional states of Rest and SWT. Results: A significant increase in heart rate and blood pressure was found, as well as a decrease in sample entropy in the functional states of normotensive and hypertensive patients. In hypertensive patients, an early response pattern increased with multiple fluctuations during SWT in the time-frequency analysis of HRV with the CWT morlet. Conclusions: SWT produces an increase in blood pressure, which is more frequent and evident in hypertensive subjects. Cardiac autonomic regulation during SWT increases the sympathetic and decreases the parasympathetic components, manifesting itself in hypertensive patients with a pattern of imbalance in the regulation of both sympathetic and parasympathetic response

Somatosensory stimulation modulates heart rate variability changes induced by isometric handgrip exercise

Functional imaging reveals overlapping forebrain and basal ganglia regions associated with heart rate (HR) and heart rate variability (HRV) regulation. Somatosensory stimulation (STIM) and isometric handgrip (HG) were used to test the hypotheses that a) STIM would modulate HG-induced changes to HR and HRV, and b) HG+STIM would produce different cortical activation relative to HG alone (n=12). During STIM, high-frequency (HF)-HRV increased (p\u3c0.05), whereas HR did not change. During HG, HF-HRV decreased (p\u3c0.01) while HR increased (p\u3c0.001). HG+STIM reversed the HG-induced change in HF-HRV (p\u3c0.01). However, the HR response to HG remained unaffected. HG increased insular activation, while ventral medial prefrontal cortex (vMPFC) activity decreased. HG+STIM produced similar vMPFC deactivation. However, insular activation was no longer evident. These data indicate that somatosensory inputs through STIM can modulate HG-induced changes to HF-HRV. Different insular activations during HG versus HG+STIM suggest afferent signals to the insula may inhibit descending motor signals affecting HF-HRV

Oleuropein effects on rat and human microcirculation

The aim of the present study was to investigate oleuropein effects on microvascular responses. First, we investigated the in vivo effects of oleuropein on rat pial microcirculation submitted to hypoperfusion-reperfusion injury. Therefore, we studied acute microvascular responses such as arteriolar vasodilation, permeability increase, leukocyte adhesion and capillary perfusion, by fluorescence microscopy. The working hypothesis was that this polyphenol may induce nitric oxide (NO) release from endothelial cells and consequently protect cerebral blood flow distribution and cerebral tissue. Rat cerebral cortical eNOS protein levels were evaluated as well as the impact of oxidative stress induced by hypopefusion and reperfusion on brain tissue, utilizing DCFH-DA. The second part of the study was aimed to evaluate oleuropein effects on skin microvascular blood flow oscillations of hyperlipidemic obese patients, by laser Doppler flowmetry (LDF). Therefore, hyperlipidemic obese females were administered with a hypocaloric and hypolipidic diet plus oleuropein for three months. These data were compared with the response of hyperlipidemic obese patients administered with hypocaloric and hypolipidic diet. Under baseline conditions and at the end of the study, nutritional status and lipid profile were evaluated as well as skin blood flow oscillations and reactive hyperemia by LDF. The results of the experimental study in rats indicate that oleuropein significantly improved in vivo microvascular responses after hypoperfusion-reperfusion injury. In particular, 20 mg/Kg b.w. of oleuropein induced a dilation by 28 ±2% of baseline (p < 0.01 vs. hypoperfused group) in order 3 arterioles and significantly reduced microvascular leakage (NGL: 0.13 ± 0.03; p < 0.01 vs. hypoperfused group) as well as leukocyte adhesion on venular walls (2.0 ± 0.5/100 µm v.l./30 sec; p < 0.01 vs. hypoperfused group), at the end of reperfusion. Moreover, this polyphenol was able to preserve capillary perfusion at the end of reperfusion (-26.0±4.5% of baseline; p<0.01 vs. hypoperfused group). These responses were associated to the increased eNOS expression in cortex and in striatum of treated animals. Oleuropein was also able to reduce neuronal damage and ROS production at the end of reperfusion, compared with hypoperfused animals. On the other hand, the results of the clinical study revealed that three months of hypocaloric and hypolipidic diet associated to oleuropein significantly improved nutritional status and lipid profile of hyperlipidemic obese patients. Total and LDL cholesterol, indeed, decreased by 15.0±1.2 and 16.5±1.3%, respectively, in patients treated with diet (OD group), and by 21.3±1.5 and 21.2±1.4%, respectively, in subjects treated with diet plus oleuropein (OL group). Moreover, laser Doppler measurements showed an increase in skin perfusion, compared to baseline conditions and control group (+25.6±1.4% of baseline), while the spectral analysis of skin blood flow oscillations revealed an increase in the NO-dependent and myogenic-related frequency components. Furthermore, PORH response improved in oleuropein-treated group, compared to controls. In conclusion, oleuropein appeared able to protect rat pial microcirculation from hypoperfusion-reperfusion injury increasing nitric oxide release from endothelial cells, reducing oxidative stress and, consequently, preserving pial blood flow distribution. Interestingly, this polyphenol showed beneficial effects also in humans; three months of hypocaloric and hypolipidic diet plus oleuropein increased smooth muscle cell functions and microvascular responses in hyperlipidemic obese patients, improving tissue perfusion