Sympathetic activation and parasympathetic withdrawal are commonly observed during acute exacerbations of chronic obstructive pulmonary disease (COPD). We have demonstrated previously that noninvasive positive-pressure ventilation (NPPV) improves parasympathetic neural control of heart rate in patients with obstructive sleep apnea. We hypothesized that NPPV may exert such beneficial effects in COPD as well. Therefore, we assessed the acute effects of NPPV on systemic blood pressure and indexes of heart rate variability (HRV) in 23 patients with acute exacerbations of COPD. The measurements of HRV in the frequency domain were computed by an autoregressive spectral technique. The use of NPPV resulted in significant increases of oxygen saturation (from 89.2±1.0 to 92.4±0.9 %, p<0.001) in association with reductions in systolic and diastolic blood pressures and heart rate (from 147±3 to 138±3 mm Hg, from 86±2 to 81±2 mm Hg, from 85±3 to 75±2 bpm, p<0.001 for all variables), and increases in ln-transformed high frequency band of HRV (from 6.4±0.5 to 7.4±0.6 ms2/Hz, p<0.01). Reductions in heart rate and increases in ln-transformed HF band persisted after NP PV withdrawal. In conclusion, these findings suggest that NPPV may cause improvements in the neural control of heart rate in patients with acute exacerbations of COPD., P. Skyba, P. Joppa, M. Orolín, R. Tkáčová., and Obsahuje bibliografii a bibliografické odkazy
Systolic blood pressure (SBP) changes control the cardiac interbeat intervals (IBI) duration via baroreflex. Conversely, SBP is influenced by IBI via non- baroreflex mechanisms. Both causal pathways (feedback - baroreflex and feedforward - non- baroreflex) form a closed loop of the SBP- IBI interaction. The aim of this study was to assess the age -related changes in the IBI - SBP interaction. We have non -invasively recorded resting beat -to- beat SBP and IBI in 335 healthy subjects of different age, ranging from 11 to 23 years. Using a linear autoregressive bivariate model we obtained gain (Gain SBP,IBI, used traditionally as baroreflex sensitivity) and coherence (CohSBP,IBI) of the SBP-IBI interaction and causal gain and coherence in baroreflex (Gain SBP → IBI , Coh SBP → IBI ) and coherence in non- baroreflex (CohIBI→SBP) directions separately. A non -linear approach was used for causal coupling indices evaluation (C SBP → IBI , C IBI → SBP ) quantifying the amount of information transferred between signals. We performed a correlation to age analysis of a ll measures. CohIBI→SBP and CIBI→SBP were higher than CohSBP→IBI and CSBP→IBI, respectively. Gain SBP,IBI increased and Coh SBP → IBI decreased with age. The coupling indices did not correlate with age. We conclude that the feedforward influence dominated at rest. The increase of Gain SBP,IBI with age was not found in the closed loop model. A decrease of Coh SBP → IBI could be related to a change in the cardiovascular control system complexity during maturation., J. Svačinová, M. Javorka, Z. Nováková, E. Závodná, B. Czippelová, N. Honzíková., and Obsahuje bibliografii
Previous studies have demonstrated that central injection of L-carnosine (β-alynyl-L-histidine), dipeptide synthesized in mammalian muscles, affects renal sympathetic nerve activity (RSNA) and blood pressure (BP) in anesthetized rats. In the present study, using urethane-anesthetized rats, we examined the dose-dependent effects of intravenous (IV) injection of various doses of anserine, dipeptide of similar structure to L-carnosine, on RSNA, BP and heart rate (HR). We found that injection of a low dose of anserine (1 μg) significantly suppressed RSNA, BP and HR. Conversely, a high dose (1000 μg) of anserine significantly elevated RSNA, BP and HR. Pretreatment with lateral cerebral ventricular (LCV) injection of thioperamide, a histaminergic H3-receptor antagonist, eliminated the effects of a low dose of anserine on RSNA, BP and HR. LCV injection of diphenhydramine, a histaminergic H1-receptor antagonist, abolished the effects of a high dose of anserine on RSNA, BP and HR. These findings suggest that anserine affects RSNA, BP and HR in a dose-dependent manner, and that the histaminergic nerve may be involved in the dose-different effects of anserine in rats., M. Tanida ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The aim of this study was to assess carotid baroreflex responses during graded lower body negative pressure (LBNP). In 12 healthy subjects (age 29±4 years) we applied sinusoidal neck suction (0 to -30 mmHg) at 0.1 Hz to examine the sympathetic modulation of the heart and blood vessels and at 0.2 Hz to assess the effect of parasympathetic stimulation on the heart. Responses to neck suction were determined as the change in spectral power of RR-interval and blood pressure from baseline values. Measurements were carried out during progressive applications (0 to -50 mmHg) of LBNP. Responses to 0.1 and 0.2 Hz carotid baroreceptor stimulations during low levels of LBNP (-10 mmHg) were not significantly different from those measured during baseline. At higher levels of LBNP, blood pressure responses to 0.1 Hz neck suction were significantly enhanced, but with no significant change in the RR-interval response. LBNP at all levels had no effect on the RR-interval response to 0.2 Hz neck suction. The unchanged responses of RR-interval and blood pressure to neck suction during low level LBNP at -10 mmHg suggest no effect of cardiopulmonary receptor unloading on the carotid arterial baroreflex, since this LBNP level is considered to stimulate cardiopulmonary but not arterial baroreflexes. Enhanced blood pressure responses to neck suction during higher levels of LBNP are not necessarily the result of a reflex interaction but may serve to protect the circulation from fluctuations in blood pressure while standing., C. M. Brown, M. J. Hecht, B. Neundörfer, M. J. Hilz., and Obsahuje bibliografii
The aim of the study was to evaluate short-term heart rate variability (HRV) as an index of cardiac autonomic control in rats with lipopolysaccharide (LPS)-induced endotoxemia. Animals were injected intraperitoneally with LPS (100 μg/kg b.w.) and control group with an equivalent volume of saline. ECG recordings were done before (base) and 60, 120, 180, 240 and 300 min after LPS or saline administration. HRV magnitude was quantified by time and frequency-domain analysis (mean RR interval, SDRR, RMSSD, spectral powers in low (LF) and high frequency (HF) bands. Heart tissue homogenates and plasma were analyzed to determine interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α) and oxidative stress level (TBARS). Administration of lipopolysaccharide was followed by continuous rise in colonic body temperature compared to saline-treated controls. Endotoxemia in rats was accompanied by significant decrease in HRV spectral activity in high-frequency range at maximal body temperature (logHFpower: 1.2±0.5 vs. 1.9± 0.6 ms2, P<0.01). Increased IL-6 was found in heart tissue homogenates of LPS rats (8.0±0.6 vs. 26.4±4.8 pg/ml, (P<0.05). In conclusions, reduced HRV in HF band may indicate a decreased parasympathetic activity in LPS-induced endotoxemia as basic characteristics of altered cardiac control during response to endotoxemia., I. Zila, D. Mokra, J. Kopincova, M. Kolomaznik, M. Javorka, A. Calkovska., and Obsahuje bibliografii
Heart rate (HR) and heart rate variability (HRV) in newborns is influenced by genetic determinants, gestational and postnatal age, and other variables. Premature infants have a reduced HRV. In neonatal HRV evaluated by spectral analysis, a dominant activity can be found in low frequency (LF) band (combined parasympathetic and sympathetic component). During the first postnatal days the activity in the high frequency (HF) band (parasympat hetic component) rises, together with an increase in LF band and total HRV. Hypotrophy in newborn can cause less mature autonomic cardiac control with a higher contribution of sympathetic activity to HRV as demonstrated by sequence plot analysis. During quiet sleep (QS) in newborns HF oscillations increase - a phenomenon less expressed or missing in premature infants. In active sleep (AS), HRV is enhanced in contrast to reduced activity in HF band due to the rise of spectral activity in LF band. Comparison of the HR and HRV in newborns born by physiological vaginal delivery, without (VD) and with epidural anesthesia (EDA) and via sectio cesarea (SC) showed no significant differences in HR and in HRV time domain parameters. Analysis in the frequency domain re vealed, that the lowest sympathetic activity in chronotropic cardiac chronotropic regulation is in the VD group. Different neonatal pathological states can be associated with a reduction of HRV and an improvement in the health conditions is followed by ch anges in HRV what can be use as a possible prognostic marker. Examination of heart rate variability in neonatology can provide information on the maturity of the cardiac chronotropic regulation in early postnatal life, on postnatal adaptation and in pathological conditions about the potential dysregulation of cardiac function in newborns, especially in preterm infants., K. Javorka, Z. Lehotska, M. Kozar, Z. Uhrikova, B. Kolarovszki, M. Javorka, M. Zibolen., and Obsahuje bibliografii
Major depressive disorder is associated with abnormal autonomic regulation which could be noninvasively studied using pupillometry. However, the studies in adolescent patients are rare. Therefore, we aimed to study the pupillary light reflex (PLR), which could provide novel important information about dynamic balance between sympathetic and parasympathetic nervous system in adolescent patients suffering from major depression. We have examined 25 depressive adolescent girls (age 15.2±0.3 y ear) prior to pharmacotherapy and 25 age/gender-matched healthy subjects. PLR parameters were measured separately for both eyes after 5 min of rest using Pupillometer PLR-2000 (NeurOptics, USA). The constriction percentual change for the left eye was significantly lower in depressive group compared to control group (-24.12±0.87 % vs. - 28.04±0.96%, p˂0.01). Furthermore, average constriction velocity and maximum constriction velocity for the left eye were significantly lower in depressive group compared to control group (p˂0.05, p˂0.01, respectively). In contrast, no significant between-groups differences were found for the right eye. Concluding, this study revealed altered PLR for left eye indicating a deficient parasympathetic activity already in adolescent major depression. Additionally, the differences between left and right eye could be related to functional lateralization of autonomic control in the central nervous system., A. Mestanikova, I. Ondrejka, M. Mestanik, D. Cesnekova, Z. Visnovcova, I. Bujnakova, M. Oppa, A. Calkovska, I. Tonhajzerova., and Obsahuje bibliografii
In this study, we tested the hypothesis that experimental stress induces a specific change of left-right electrodermal activity (EDA) coupling pattern, as indexed by pointwise transinformation (PTI). Further, we hypothesized that this change is associated with scores on psychometric measures of the chronic stress-related psychopathology. Ninety-nine university students underwent bilateral measurement of EDA during rest and stress-inducing Stroop test and completed a battery of self-report measures of chronic stress-related psychopathology. A significant decrease in the mean PTI value was the prevalent response to the stress conditions. No association between chronic stress and PTI was found. Raw scores of psychometric measures of stress-related psychopathology had no effect on either the resting levels of PTI or the amount of stress-induced PTI change. In summary, acute stress alters the level of coupling pattern of cortico-autonomic influences on the left and right sympathetic pathways to the palmar sweat glands. Different results obtained using the PTI, EDA laterality coefficient, and skin conductance level also show that the PTI algorithm represents a ne w analytical approach to EDA asymmetry description., M. Světlák ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The relationship between baroreflex sensitivity expressed in ms/mm Hg (BRS) or in Hz/mm Hg (BRSf) in hypertensives with stroke in comparison with a group of stroke-free patients was evaluated. Twenty-six patients (aged 66±10 years, 11 females/ 15 males) with a history of the first ever ischemic stroke (6 months and more after stroke onset), which was neuroradiologically confirmed, were studied. These were compared to 30 hypertensive patients without history of any cardiovascular event, being of similar age and sex. BRS and BRSf were determined by the sequence and spectral methods (fiveminute non-invasive beat-to-beat recording of blood pressure and inter-beat interval, controlled breathing at a frequency of 0.1 Hz). A significant negative correlation between spontaneous BRS and blood pressure (BP) represented by the grade of hypertension was present (r = -0.52, p<0.001). Differences between hypertensives with and without stroke were detected in BRS obtained by the spectral method (BRS spect p=0.0237, BRSf spect p=0.0285) or BRS obtained by sequence method (BRS seq p=0.0532, BRSf seq p=0.0273). The greatest decline in BRS values was in hypertensive stroke patients with metabolic syndrome, who had BRS values below 3 ms/mm Hg. We found out that BRS and BRSf were more impaired in stroke patients with essential hypertension even 6 months and more after stroke onset than in stroke-free hypertensive patients. This finding was independent of age-dependent decrease of BRS. Examination of baroreflex sensitivity as a marker of autonomic dysfunction along with global cardiovascular risk stratification of individuals seems to be a method for identifying patients at high residual cardiovascular risk., D. Čelovská ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Inflammation and other immune responses are involved in the variety of diseases and disorders. The acute response to endotoxemia includes activation of innate immune mechanisms as well as changes in autonomic nervous activity. The autonomic nervous system and the inflammatory response are intimately linked and sympathetic and vagal nerves are thought to have anti-inflammation functions. The basic functional circuit between vagus nerve a nd inflammatory response was identified and the neuroimmunomodulation loop was called cholinergic anti-inflammatory pathway. Unique function of vagus nerve in the anti-inflammatory reflex arc was found in many experimental and pre-clinical studies. They br ought evidence on the cholinergic signaling interacting with systemic and local inflammation, particularly suppressing immune cells function. Pharmacological/electrical modulation of vagal activity suppressed TNF-α and other proinflammatory cytokines prod uction and had beneficial therapeutic effects. Many questions related to mapping, linking and targeting of vagal-immune interactions have been elucidated and brought understanding of its basic physiology and provided the initial support for development of Tracey's inflammatory reflex. This review summarizes and critically assesses the current knowledge defining cholinergic anti-inflammatory pathway with main focus on studies employing an experimental approach and emphasizes the potential of modulation of va gally-mediated anti-inflammatory pathway in the treatment strategies., I. Zila, D. Mokra, J. Kopincova, M. Kolomaznik, M. Javorka, A. Calkovska., and Obsahuje bibliografii