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Academic literature on the topic 'Sympathetic heart tonus'
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Journal articles on the topic "Sympathetic heart tonus"
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Feghiu, Iuliana, Sergiu Cobilețchi, Galina Frunza, Sergiu Șandru, and Anatol Scripnic. "Changes of autonomic tonus of the heart during induction of general anesthesia with two intravenous anaesthetics." Moldovan Medical Journal 62(4) (November 28, 2019): 3–8. https://doi.org/10.5281/zenodo.3556445.
Full textAbstract:
<strong>Background:</strong> Induction of general anesthesia with midazolam or thiopental is often associated with cardiovascular changes. <strong>Material and methods:</strong> The study group involved 94 patients. The analysis of heart rate variability and the changes in cardiac vegetative tonus was performed after premedication with fentanyl solution and after induction of general anesthesia with midazolam combined with fentanyl (midazolam group) or thiopental combined with fentanyl (thiopental group). <strong>Results:</strong> After administration of fentanyl in doses of 1.0 mkg/kg for premedication there were no significant changes of heart rate variability and vegetative heart tonus in both groups. Administration of midazolam 0.2-0.3 mg/kg combined with fentanyl 1.0 mkg/kg for induction of general anesthesia leads to a significant reduction of heart rate variability. The LFun (marker of sympathetic heart tonus) reduced by 24.2% (69.1 (95%CI 65.9-72.3) vs 52.4 (95%CI 42.9-70.0) (p=0,02), meantime the HFun (marker of parasympathetic cardiac tonus) enhanced by 34,9% (30,9 (95%CI 27.6-34.1) vs 47.5(95% CI 30.4-57.4) (p=0.01). Administration of thiopental 6.0-7.0 mg/kg combined with fentanyl 1.0 mkg/kg for induction of general anesthesia leads to a significant reduction of heart rate variability. <strong>Conclusions:</strong> Administration of fentanyl solution in doses 1.0 mkg/kg for premedication is not associated with significant changes of vegetative tonus of the heart. Administration of midazolam in combination with fentanyl for induction of general anesthesia leads to significant decrease of heart rate variability and enhanced parasympathetic cardiac tonus. Induction of general anesthesia with thiopental and fentanyl leads to enhanced sympathetic tonus of the heart and reduced parasympathetic tonus of the heart.
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Feghiu, Iuliana, Sergiu Cobiletchi, and Sergiu Sandru. "Sympathetic-parasympathetic cardiac autonomic tonus during induction of anesthesia with propofol and fentanyl." Moldovan Medical Journal 62 (2) (June 15, 2019): 20–25. https://doi.org/10.5281/zenodo.3233910.
Full textAbstract:
<strong>Background: </strong>Administration of propofol and fentanyl for induction of general anesthesia is often associated with cardiovascular instability. This effect can be caused by changes in the cardiac autonomic tonus induced by the drugs. In the literature there is no consensus regarding the effect of propofol and fentanyl on sympathetic or parasympathetic balance of the heart. <strong>Material and methods:</strong> There was performed a randomized prospective study which was approved by the Ethic Committee. Written informed consent was signed by all patients. The study group involved 47 patients scheduled for surgical intervention, anesthetic risk ASA I-II. The analysis of heart rate variability and the changes in cardiac autonomic tonus was performed with Holter ECG at rest, after premedication with fentanyl solution and after induction of general anesthesia with propofol and fentanyl. <strong>Results:</strong> After administration of fentanyl in doses of 1.0 mkg/kg for premedication there were not significant changes of heart rate variability and autonomic heart tonus. Administration of propofol 2.5 mg/kg combined with fentanyl 1.0 mkg/kg for induction of general anesthesia leads to significant changes in heart rate variability. There was a considerable reduction of heart rate variability. The LFun (marker of sympathetic heart tonus) has enhanced by 6.8% compared with previous stage (67.1 (95% CI 63.1-71.1) vs 72.0 (95% CI 67.9-76.1) (p=0.004). The HFun (marker of parasympathetic cardiac tonus) has reduced by 19.8% (32.9 (95% CI 28.9-36.8) vs 26.4 (95% CI 20.4-34.3) (p=0.007). After administration of propofol and fentanyl for induction of general anesthesia the LFun/HFun ratio has enhanced by 30.8% (2.7 (95%CI 2.1-3.4) vs 3.9 (95%CI9 2.9-4.8) (p=0.003), signaling an enhanced sympathetic heart tonus. <strong>Conclusions:</strong> Administration of fentanyl solution in doses 1.0 mkg/kg for premedication is not associated with significant changes of autonomic tonus of the heart. Administration of propofol 2.5 mg/kg in combination with fentanyl 1.0 mkg/kg for induction of general anesthesia leads to significant enhanced sympathetic cardiac tonus.
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Lujan, Heidi L., Gurunanthan Palani, Ying Chen, Jean D. Peduzzi, and Stephen E. DiCarlo. "Targeted ablation of cardiac sympathetic neurons reduces resting, reflex and exercise-induced sympathetic activation in conscious rats." American Journal of Physiology-Heart and Circulatory Physiology 296, no. 5 (2009): H1305—H1311. http://dx.doi.org/10.1152/ajpheart.00095.2009.
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Cholera toxin B subunit conjugated to saporin (SAP, a ribosomal inactivating protein that binds to and inactivates ribosomes) was injected in both stellate ganglia to evaluate the physiological response to targeted ablation of cardiac sympathetic neurons. Resting cardiac sympathetic activity (cardiac sympathetic tonus), exercise-induced sympathetic activity (heart rate responses to graded exercise), and reflex sympathetic activity (heart rate responses to graded doses of sodium nitroprusside, SNP) were determined in 18 adult conscious Sprague-Dawley male rats. Rats were randomly divided into the following three groups ( n = 6/group): 1) control (no injection), 2) bilateral stellate ganglia injection of unconjugated cholera toxin B (CTB), and 3) bilateral stellate ganglia injection of cholera toxin B conjugated to SAP (CTB-SAP). CTB-SAP rats, compared with control and CTB rats, had reduced cardiac sympathetic tonus and reduced heart rate responses to graded exercise and graded doses of SNP. Furthermore, the number of stained neurons in the stellate ganglia and spinal cord (segments T1–T4) was reduced in CTB-SAP rats. Thus CTB-SAP retrogradely transported from the stellate ganglia is effective at ablating cardiac sympathetic neurons and reducing resting, exercise, and reflex sympathetic activity. Additional studies are required to further characterize the physiological responses to this procedure as well as determine if this new approach is safe and efficacious for the treatment of conditions associated with excess sympathetic activity (e.g., autonomic dysreflexia, hypertension, heart failure, and ventricular arrhythmias).
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Khasanova, D. R., V. N. Medvedev, N. L. Nikulin, and E. A. Vergasov. "Vegetative disorders in children with congenital heart diseases of pale type." Kazan medical journal 79, no. 1 (1998): 32–37. http://dx.doi.org/10.17816/kazmj63449.
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The tendency to increase the sympathetic tonus in rest in all age groups especially in 4 children under school age and girls in pubertal period is revealed during the investigation of vegetative egulation by the mathematical analysis of the heart rhythm variability in children with congenital heart diseases of pale type.
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Lujan, Heidi L., Anne Tonson, Robert W. Wiseman, and Stephen E. DiCarlo. "Chronic, complete cervical6–7 cord transection: distinct autonomic and cardiac deficits." Journal of Applied Physiology 124, no. 6 (2018): 1471–82. http://dx.doi.org/10.1152/japplphysiol.01104.2017.
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Spinal cord injury (SCI) resulting in tetraplegia is a devastating, life-changing insult causing paralysis and sensory impairment as well as distinct autonomic dysfunction that triggers compromised cardiovascular, bowel, bladder, and sexual activity. Life becomes a battle for independence as even routine bodily functions and the smallest activity of daily living become major challenges. Accordingly, there is a critical need for a chronic preclinical model of tetraplegia. This report addresses this critical need by comparing, for the first time, resting-, reflex-, and stress-induced cardiovascular, autonomic, and hormonal responses each week for 4 wk in 12 sham-operated intact rats and 12 rats with chronic, complete C6–7 spinal cord transection. Loss of supraspinal control to all sympathetic preganglionic neurons projecting to the heart and vasculature resulted in a profound bradycardia and hypotension, reduced cardiac sympathetic and parasympathetic tonus, reduced reflex- and stress-induced sympathetic responses, and reduced sympathetic support of blood pressure as well as enhanced reliance on angiotensin to maintain arterial blood pressure. Histological examination of the nucleus ambiguus and stellate ganglia supports the profound and distinct autonomic and cardiac deficits and reliance on angiotensin to maintain cardiovascular stability following chronic, complete cervical6–7 cord transection. NEW & NOTEWORTHY For the first time, resting-, reflex-, and stress-induced cardiovascular, autonomic, and hormonal responses were studied in rats with chronic, complete C6–7 cord transection. Loss of supraspinal control of all sympathetic preganglionic neurons reduced cardiac sympathetic and parasympathetic tonus, reflex and stress-induced sympathetic responses, and sympathetic support of blood pressure as well as enhanced reliance on angiotensin to maintain arterial blood pressure. Histological examination supports the distinct deficits associated with cervical cord injury.
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Grebenyuk, O. V., N. G. Katayeva, N. S. Novikova, and M. V. Svetlic. "Heart rate variability with orhtoclinostatic load in patients with neuroreflex syncopal states." Bulletin of Siberian Medicine 9, no. 4 (2010): 44–48. http://dx.doi.org/10.20538/1682-0363-2010-4-44-48.
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The initial vegetative tonus and vegetative reactivity were studied in patients with neuroreflectory syncopal states (NSS) during passive orthostatic testing in the orthostatic and clinical phases. The variability of the heart rhythm was estimated on the Neiron-spektr device. During the orthostatic testing, the insufficient activity of the sympathetic part of the nervous system in NSS patients was observed compared to the control group. During the clinostatic testing, the indices of NSS patients approached the normal values.
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STORY, GINA M., STEPHEN E. DICARLO, DAVID W. RODENBAUGH, et al. "Inactivation of one copy of the mouse neurotrophin-3 gene induces cardiac sympathetic deficits." Physiological Genomics 2, no. 3 (2000): 129–36. http://dx.doi.org/10.1152/physiolgenomics.2000.2.3.129.
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Story, Gina M., Stephen E. DiCarlo, David W. Rodenbaugh, Dean E. Dluzen, Jan Kucera, Michael B. Maron, and Jon M. Walro. Inactivation of one copy of the mouse neurotrophin-3 gene induces cardiac sympathetic deficits. Physiol Genomics 2: 129–136, 2000.—Whether two copies of the neurotrophin-3 (NT3) gene are necessary for proper development of cardiac sympathetic innervation was investigated in mice carrying a targeted inactivation of the NT3 gene. Heterozygous (+/−) and null (−/−) mutant mice had fewer stellate ganglion neurons than did wild-type (+/+) mice at postnatal day 0 ( P0 or birth), and this deficit was maintained between adult ( P60) +/− and +/+ mice. The sympathetic innervation of the heart matured postnatally in +/+ and +/− mice. Tyrosine hydroxylase (TH)-positive axons were restricted largely to the epicardium at P0, were concentrated around large blood vessels in the myocardium at P21, and were present among cardiac myocytes at P60. Cardiac norepinephrine (NE) concentrations paralleled the growth of the sympathetic axons into the heart. NE concentrations were equivalent among +/+, +/−, and −/− mice at birth, but differences between +/− and +/+ mice increased with age. Adult +/− mice also exhibited lower resting heart rates and sympathetic tonus than +/+ mice. Thus deletion of one copy of the NT3 gene translates into anatomical, biochemical, and functional deficits in cardiac sympathetic innervation of postnatal mice, thereby indicating a gene-dosage effect for the NT3 gene.
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Apor, Péter, Máté Petrekanich, and Júlianna Számadó. "Heart rate variability analysis in sports." Orvosi Hetilap 150, no. 18 (2009): 847–53. http://dx.doi.org/10.1556/oh.2009.28605.
Full textAbstract:
Differences in the duration of the cycles reflects the balance of the sympathetic and parasympathetic influence on the heart. Variancy in the heart rate correlates to the breathing cycle, to baroreflex sensitivity, to day and night alternations and to changes in the vegetative tone evoked by physical exercises. Analysis of the time and/or frequency power domain of the heart rate variancy is expected to have diagnostic value in physiological and pathological situations as adaptation to training, overtraining, heart disease etc. Both time- and frequency domains reflect the same physiological phenomenon but from different point of view. Vagus tonus is reflected in the high frequency part of the range of variancy, while an increased sympathetic tone enriches the low frequency part of the variations of the duration of the consecutive heart cycles. This technically simple and relatively inexpensive method has inspired a couple of clinical and sports medical studies. Certain tendencies seem to be clear, but for individual diagnosis or for prognosis the data must be treated very carefully.
9
Lujan, Heidi L., and Stephen E. DiCarlo. "Direct comparison of cervical and high thoracic spinal cord injury reveals distinct autonomic and cardiovascular consequences." Journal of Applied Physiology 128, no. 3 (2020): 554–64. http://dx.doi.org/10.1152/japplphysiol.00721.2019.
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A wide range of spinal cord levels (cervical 8–thoracic 6) project to the stellate ganglia (which provides >90% of sympathetic supply to the heart), with a peak at the thoracic 2 (T2) level. We hypothesize that despite the proximity of the lesions, high thoracic spinal cord injuries (i.e., T2–3 SCI) do not closely mimic the hemodynamic responses recorded with cervical SCI (i.e., C6–7 SCI). To test this hypothesis, rats were instrumented with an intra-arterial telemetry device (Data Sciences International PA-C40) for recording arterial pressure, heart rate, and locomotor activity as well as a catheter within the intraperitoneal space. After recovery, rats were subjected to complete C6–7 spinal cord transection ( n = 8), sham transection ( n = 4), or T2–3 spinal cord transection ( n = 7). After the spinal cord transection or sham transection, arterial pressure, heart rate, and activity counts were recorded in conscious animals, in a thermoneutral environment, for 20 s every minute, 24 h/day for 12 consecutive weeks. After 12 wk, chronic reflex- and stress-induced cardiovascular and hormonal responses were compared in all groups. C6–7 rats had hypotension, bradycardia, and reduced physical activity. In contrast, T2–3 rats were tachycardic. C6–7 rats compared with T2–3 and spinal intact rats also had reduced cardiac sympathetic tonus, reduced reflex- and stress induced cardiovascular responses, and reduced sympathetic support of blood pressure as well as enhanced reliance on angiotensin to maintain arterial blood pressure. Thus injuries above and below the peak level (T2) of spinal cord projections to the stellate ganglia have remarkably different outcomes. NEW & NOTEWORTHY Twelve consecutive weeks of resting hemodynamic data as well as chronic reflex- and stress-induced cardiovascular, autonomic, and hormonal responses were compared in spinal intact and C6–7 and T2–3 spinal cord-transected rats. C6–7 rats compared with T2–3 and spinal intact rats had reduced cardiac sympathetic tonus, reduced reflex- and stress-induced cardiovascular responses, and reduced sympathetic support of blood pressure as well as enhanced reliance on angiotensin to maintain arterial blood pressure. Thus injuries above and below the peak level (T2) of spinal cord projections to the stellate ganglia have remarkably different outcomes.
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Sforza, Roche, and Pichot. "Determinants of Nocturnal Cardiovascular Variability and Heart Rate Arousal Response in Restless Legs Syndrome (RLS)/Periodic Limb Movements (PLMS)." Journal of Clinical Medicine 8, no. 10 (2019): 1619. http://dx.doi.org/10.3390/jcm8101619.
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Recent studies have suggested that restless legs syndrome is associated with an increased prevalence of cardiovascular diseases mediated by sympathetic activation occurring during periodic limb movements. The aim of this study was to establish which factors affect the degree of sympathetic activation during the basal condition and during periodic limb movements that may contribute to increased vascular risk. Fifty untreated restless legs syndrome patients aged 62.6 ± 11.1 y, free of cardiovascular diseases, were examined. Heart rate variability was calculated during wakefulness and all sleep stages, during periods with and without periodic limb movements. Heart rate changes before and after periodic limb movement onset were analyzed to assess the arousal response to periodic limb movements. Both analyses took into account the effects of age, gender, periodic limb movement duration, periodic limb movement index, periodic limb movement interval and periodicity, and magnitude of muscular activity (electromyogram power). Compared to periods without periodic limb movements, a significant increase in sympathetic activity occurred in periods with periodic limb movements, independent of age, sex and periodic limb movement characteristics. Data obtained from the cardiac arousal response to periodic limb movements showed that electromyogram power is the factor affecting sympathetic tonus. These results suggest that other factors, such as electromyogram power and individual susceptibility, should be considered in the assessment of the vascular risk related to restless legs syndrome.