scholarly journals Sympathovagal Imbalance in Prehypertensive Offspring of Two Parents versus One Parent Hypertensive

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
G. K. Pal ◽  
Pravati Pal ◽  
Nivedita Nanda ◽  
V. Lalitha ◽  
T. K. Dutta ◽  
...  

Objective. Though prehypertension has strong familial predisposition, difference in pathophysiological mechanisms in its genesis in offspring of both parents and single parent hypertensive have not been elucidated.Methods. Body mass index (BMI), waist-hip ratio (WHR), basal heart rate (BHR), blood pressure (BP), HR and BP response to standing, deep breathing difference, BP response to handgrip and spectral indices of heart rate variability (HRV) were analyzed in normotensive offspring of two parents hypertensive (Group I), normotensive offspring of one parent hypertensive (Group II), prehypertensive offspring of two parents hypertensive (Group III) and prehypertensive offspring of one parent hypertensive (Group IV).Results. Sympathovagal imbalance (SVI) in prehypertensive offspring was observed due to increased sympathetic and decreased vagal activity. In group III, SVI was more prominent with greater contribution by vagal withdrawal. LF-HF ratio, the marker of SVI was correlated more with diastolic pressure, 30 : 15 ratio and E : I ratio in prehypertensives and the degree of correlation was more in group III prehypertensives.Conclusion. Vagal withdrawal plays a critical role in development of SVI in prehypertensive offspring of hypertensive parents. The intensity of SVI was more in offspring of two parents hypertensive compared to single parent hypertensive.

2019 ◽  
Vol 126 (1) ◽  
pp. 124-131 ◽  
Author(s):  
Christoph Siebenmann ◽  
Camilla K. Ryrsø ◽  
Laura Oberholzer ◽  
James P. Fisher ◽  
Linda M. Hilsted ◽  
...  

Hypoxia increases heart rate (HR) in humans by sympathetic activation and vagal withdrawal. However, in anaesthetized dogs hypoxia increases vagal activity and reduces HR if pulmonary ventilation does not increase and we evaluated whether that observation applies to awake humans. Ten healthy males were exposed to 15 min of normoxia and hypoxia (10.5% O2), while respiratory rate and tidal volume were volitionally controlled at values identified during spontaneous breathing in hypoxia. End-tidal CO2 tension was clamped at 40 mmHg by CO2 supplementation. β-Adrenergic blockade by intravenous propranolol isolated vagal regulation of HR. During spontaneous breathing, hypoxia increased ventilation by 3.2 ± 2.1 l/min ( P = 0.0033) and HR by 8.9 ± 5.5 beats/min ( P < 0.001). During controlled breathing, respiratory rate (16.3 ± 3.2 vs. 16.4 ± 3.3 breaths/min) and tidal volume (1.05 ± 0.27 vs. 1.06 ± 0.24 l) were similar for normoxia and hypoxia, whereas the HR increase in hypoxia persisted without (8.6 ± 10.2 beats/min) and with (6.6 ± 5.6 beats/min) propranolol. Neither controlled breathing ( P = 0.80), propranolol ( P = 0.64), nor their combination ( P = 0.89) affected the HR increase in hypoxia. Arterial pressure was unaffected ( P = 0.48) by hypoxia across conditions. The hypoxia-induced increase in HR during controlled breathing and β-adrenergic blockade indicates that hypoxia reduces vagal activity in humans even when ventilation does not increase. Vagal withdrawal in hypoxia seems to be governed by the arterial chemoreflex rather than a pulmonary inflation reflex in humans. NEW & NOTEWORTHY Hypoxia accelerates the heart rate of humans by increasing sympathetic activity and reducing vagal activity. Animal studies have indicated that hypoxia-induced vagal withdrawal is governed by a pulmonary inflation reflex that is activated by the increased pulmonary ventilation in hypoxia. The present findings, however, indicate that humans experience vagal withdrawal in hypoxia even if ventilation does not increase, indicating that vagal withdrawal is governed by the arterial chemoreflex rather than a pulmonary inflation reflex.


1991 ◽  
Vol 81 (2) ◽  
pp. 241-248 ◽  
Author(s):  
W. Wieling ◽  
A. D. J. ten Harkel ◽  
J. J. van Lieshout

1. In 31 consecutively referred patients (20 females, 11 males) with overt or suspected orthostatic disorders, the changes in blood pressure and heart rate that occur in the first 2 min of standing were analysed. 2. Blood pressure was measured continuously by Finapres. The blood pressure and heart rate responses after 1–2 min of standing (early steady-state response) were used to classify the patients as follows: group I (n = 17, age 42 ± 17 years), normal early steady-state blood pressure and heart rate responses; group II (n = 5, age 40 ± 14 years), combination of normal early steady-state blood pressure and postural tachycardia; group III (n = 9, age 51 ± 14 years), hypotensive orthostatic response with (4/9) or without (5/9) postural tachycardia. We examined whether additional information could be obtained by beat-to-beat analysis of the initial circulatory response (first 30 s). It was quantified by identifying the blood pressure trough and overshoot and the maximum heart rate and relative bradycardia. 3. The initial drop in systolic and diastolic blood pressures did not differ between the three groups. A recovery of blood pressure with a systolic and/or diastolic blood pressure overshoot was present in all group I and II patients, but was absent in all except two patients in group III. The initial maximum heart rate increase did not differ between the three groups. The relative bradycardia was less in groups II and III than in group I. 4. We conclude that analysis of the beat-to-beat blood pressure changes in the first 30 s after the onset of standing provides almost all the information that is necessary to determine abnormalities in orthostatic circulatory control.


2020 ◽  
Author(s):  
Yan Xu ◽  
Suyun Qian ◽  
Kaihu Yao ◽  
Fang Dong ◽  
Wenqi Song ◽  
...  

Abstract Background Staphylococcus aureus (S. aureus) accessory gene regulator (agr) system plays a critical role in staphylococcal pathogenesis. Our study aimed to investigate the relationship between agr group, the genetic background, virulence genes and disease types distribution of S. aureus isolated from different clinical sources among Chinese children.Methods S. aureus strains were isolated from Beijing Children’s hospital from October 2017 to October 2019. Isolates were typed by multilocus sequence typing (MLST), staphylococcal protein A (spa), agr, and staphylococcal cassette chromosome mec (SCCmec) typing (for methicillin-resistant S. aureus [MRSA] isolates). Furthermore, all isolates were tested for the presence of 19 selected virulence genes.Results A total of 191 non-repetitive S. aureus clinical isolates were collected and the agr type I was the most prevalent (84.8%). S. aureus isolates were divided into 33 sequence types (STs), 20 clonal complexes (CCs) and 59 spa types, ST59 (39.8%) and t437 (37.7%) were the predominant types. CC59, CC25, CC22, CC951, CC8, and CC398 isolates possessed agr group I; CC15 isolates harbored agr group II; CC30 strains were characterized as agr group III, and CC121 harbored agr group IV. Of the 19 virulence genes, the tst gene was more prevalent among agr group III compared to other groups (p = 0.006); eta and etb genes were more prevalent among agr group IV than other groups (p = 0.003 and 0.001, respectively); nearly all strains that harbored the lukS/F-PV gene (98.3%) belonged to agr group I (p = 0.004); the frequencies of bbp and ebpS genes belonged to agr group I were statistically lower than that of other groups (p < 0.001). Among 161 diagnoses, the frequency of strains from cellulitis patient harbored agr group III was higher than that of other groups (p = 0.046), and one strain isolated from staphylococcal scalded skin syndrome (SSSS) patient, which was identified as agr type IV (p = 0.021).Conclusions The results indicated that the S. aureus agr type was linked to the genetic background. Besides, a possible relationship between the agr group, several virulence determinants, and specific disease types was observed.


2013 ◽  
Vol 58 (No. 2) ◽  
pp. 87-95 ◽  
Author(s):  
Amarpal ◽  
RA Ahmad ◽  
P. Kinjavdekar ◽  
HP Aithal ◽  
AM Pawde ◽  
...  

A combination of drugs may be preferred over the use of a single agent to induce deep sedation. A synergistic interaction between the drugs reduces the dose requirements of the drugs thereby minimising the unwanted side effects associated with each drug and improving recovery. The present study was undertaken to evaluate the suitability of dexmedetomidine and dexmedetomidine in combination with midazolam-fentanyl or midazolam-fentanyl-ketamine for different levels of sedation, analgesia and anaesthesia in dogs. In a prospective, blinded, randomised clinical trial, 12 mixed breed dogs were divided into three groups. Animals of Group I were injected with dexmedetomidine 20 &mu;g/kg. Animals of Group II received 20 &mu;g/kg dexmedetomidine + 0.2 mg/kg midazolam + 4 &mu;g/kg fentanyl and animals of Group III were administered with 20 &mu;g/kg dexmedetomidine + 0.2 mg/kg midazolam + 4 &mu;g/kg fentanyl + 10 mg/kgketamine. All the drugs were given simultaneously via the intramuscular route. Jaw relaxation, palpebral reflex, pedal reflex and response to intubation were recorded and graded on a numerical scale. Values of heart rate, respiratory rate, rectal temperature and mean arterial pressure were recorded at baseline and then at predetermined intervals up to 120 min. Onset of sedation time, onset of recumbency time, time to return of righting reflex, standing recovery time and complete recovery time were recorded. Maximal muscle relaxation, sedation and analgesia were observed in animals of Group III, which was followed in decreasing order by Groups II and I. Heart rate decreased significantly (P &lt; 0.05) after administration of drugs in Groups I and II but a significant (P &lt; 0.05) increase was recorded in Group III. Respiratory rate decreased significantly (P &lt; 0.05) in all the groups. Rectal temperature decreased non-significantly in all the groups. Mean arterial pressure initially increased significantly (P &lt; 0.01) in Groups I and III followed by a decrease in Group I, but in Group III it remained above the base line. In Group II, MAP decreased throughout the study period. Onset of sedation time and onset of recumbency time were significantly (P &lt; 0.05) shorter in Group III as compared to Group I. Time to return of righting reflex, standing recovery time and complete recovery time did not differ significantly between the groups. It is concluded that dexmedetomidine provides a reliable moderate sedation and analgesia. Addition of midazolam and fentanyl enhances sedation, analgesia and muscle relaxation induced by dexmedetomidine. Addition of ketamine produced deep sedation and complete anaesthesia with lesser cardiopulmonary depression. Thus, dexmedetomidine can be used safely in combination with midazolam, fentanyl and ketamine for different levels of sedation, analgesia and anaesthesia in dogs. &nbsp;


2021 ◽  
pp. 49-52
Author(s):  
Aleksey Vlasov

In the presented work, we have assessed the features of peripheral oxygenation in children with congenital malformations of the surgical profile under various types of combined anesthesia. The aim of the study. To assess the state of peripheral oxygenation in newborns and infants with congenital malformations with various types of anesthetic support. Materials and research methods. A retrospective study included 150 newborns and infants with congenital malformations of the surgical profile, depending on the anesthesia (inhalation + regional anesthesia; inhalation + intravenous anesthesia and total intravenous). The parameters of pulse oximetry were analyzed: peripheral oxygenation, heart rate. Additionally, the concentration of oxygen in the respiratory mixture of children was taken into account. Research results. Peripheral saturation did not critically decrease at all stages of observation, with the exception of a decrease in the indicator in children of group I compared with group III at the stage of induction into anesthesia (97.79±2.45 versus 98.79±1.63, at p˂0.05, respectively) and at the most painful moment of the operation (96.29±3.47 versus 98.10±2.47, with p˂0.05). At the painful moment of the operation, it was in children of group I that a drop in heart rate was noted compared to group III (127.98±13.77 and 136.10±15.37, respectively, with p˂0.05) and group II (134.02±18.43, at p>0.05) against the background of a decrease in SpO2. Newborns and group I infants required higher oxygen concentrations in the breathing mixture. A significant difference in the indicator is noted between groups I and III at the traumatic stage – 0.47±0.29 and 0.33±0.2, with p˂0.05, respectively, and immediately after the operation – 0.34±0,19 and 0.26±0.13, with p˂0.05, respectively. Conclusions. The expediency and effectiveness of pulse oximetry for children with congenital malformations at all stages of anesthetic support during surgical treatment was confirmed. The risk group for the formation of oxygen deficiency in organs and tissues, the occurrence of pain during the operation were newborns and infants, for whom combined anesthesia was chosen in the form of an inhalation method and regional anesthesia. In the case of the appointment of this type of anesthetic support, it is necessary to more closely monitor the indicators and promptly correct the deterioration of the child's condition


2011 ◽  
Vol 89 (7) ◽  
pp. 521-526 ◽  
Author(s):  
Therese Ruane-O’Hora ◽  
W.J. Hall ◽  
F. Markos

In the literature there appears to be variability in reported levels of certain hormones during haemorrhage, specifically adrenocorticotrophic hormone (ACTH) and β-endorphin. It is possible that this variability may be due to the choice of anaesthetic. Therefore, the effect of 3 common research-only anaesthetic agents (alphaxalone–alphadolone, propofol, and pentobarbitone) on ACTH and β-endorphin levels during haemorrhage was assessed in pigs. Animals were divided into 3 groups: group I received alphaxalone–alphadolone (n = 5), group II received propofol (n = 6), and group III received pentobarbitone (n = 6). Pigs were subjected to a continuous fixed-volume haemorrhage under one of the above anaesthetics while being mechanically ventilated. ACTH and β-endorphin levels increased significantly during haemorrhage under propofol and pentobarbitone anaesthesia but not with alphaxalone–alphadolone. For ACTH there was no significant difference between the groups, whereas for β-endorphin there was a significant difference between the propofol- and pentobarbitone-anaesthetized pigs. The increase in heart rate during haemorrhage was significantly different between the alphaxalone–alphadolone and propofol as well as between the propofol and pentobarbitone groups. The drop in blood pressure was only significantly different between the alphaxalone–alphadolone- and propofol-anaesthetized pigs. These results indicate that the choice of anaesthetic agent can affect the hormone response to haemorrhage and may account for the variable hormone levels reported in the published literature to date.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
G. K. Pal ◽  
P. Shyma ◽  
S. Habeebullah ◽  
Pravati Pal ◽  
Nivedita Nanda ◽  
...  

Objective. In this study, we have assessed sympathovagal imbalance (SVI) by spectral analysis of heart rate variability (HRV) that contributes to the genesis of early-onset PIH.Methods. Body mass index (BMI), basal heart rate (BHR), blood pressure (BP) and HRV indices such as LFnu, HFnu, LF-HF ratio, mean RR, SDNN and RMSSD were assessed in normal pregnant women (Control group) and pregnant women having risk factors for PIH (Study group) at all the trimesters pregnancy. Retrospectively, those who did not develop PIH (Study group I) were separated from those who developed PIH (Study group II). Study group II was subdivided into early-onset and late-onset PIH. Sympathovagal balance (LF-HF ratio) was correlated with BMI, BHR and BP.Results. LF-HF ratio was significantly high in study group II compared to study group I and control group, and in early-onset PIH group compared to the late-onset category at all the trimesters of pregnancy, which was significantly correlated with BHR and BP. Alteration in HFnu in early-onset category was more prominent than the alteration in LFnu.Conclusion. Though the SVI in PIH is contributed by both sympathetic overactivity and vagal withdrawal, especially in early-onset type, SVI is mainly due to vagal inhibition.


2001 ◽  
Vol 13 (1) ◽  
pp. 47-59
Author(s):  
Hélène Perrault ◽  
Maria Tzovanis ◽  
Dominique Johnson ◽  
André Davignon ◽  
Claude Chartrand ◽  
...  

This study compares the autonomic responses of 9 adolescents (mean ± SEM: 17±1 years) successfully operated for tetralogy of Fallot (TOF) in early childhood and 8 age-matched healthy controls (CTRL) using R-R and blood pressure variability. Continuous ECG and BP recordings were obtained during spontaneous and controlled respiration (CR) at 0.20 Hz as well as after an 85° head-up tilt (HUT) and during steady-state cycling at heart rates of 100 and 120 bpm, selected to reflect partial and complete cardiac vagal withdrawal. TOF exhibited total R-R variance and HF power (ms2) lower than CTRL under both spontaneous (938 ± 322 vs. 1,714 ± 296) and CR (1,541 ± 527 vs. 4,725 ± 1,207; p < .05), which may be indicative of a lower cardiac vagal activity. HUT decreased the R-R HF component, which remained lower in TOF than CTRL and increased the diastolic BP LF component in TOF but not in CTRL. Exercise decreased the R-R HF power more in TOF than CTRL. The exaggerated diastolic BP and limited heart rate responses to tilting and the more marked vagal withdrawal at Ex120 in TOF may be suggestive of a disturbance in the cardiac sympathetic response. Further studies are needed to confirm these observations on larger groups of young adults successfully operated for TOF.


2018 ◽  
Vol 125 (6) ◽  
pp. 1804-1811 ◽  
Author(s):  
Timothée Fontolliet ◽  
Vincent Pichot ◽  
Aurélien Bringard ◽  
Nazzareno Fagoni ◽  
Alessandra Adami ◽  
...  

We performed the first analysis of heart rate variability (HRV) at rest and during exercise under full autonomic blockade on the same subjects, to test the conjecture that vagal tone withdrawal occurs at exercise onset. We hypothesized that between rest and exercise there would be 1) no differences in total power (PTOT) under parasympathetic blockade, 2) a PTOT fall under β1-sympathetic blockade, and 3) no differences in PTOT under blockade of both autonomic nervous system branches. Seven men [24 (3) yr, mean (SD)] performed 5-min cycling (80 W) supine, preceded by 5-min rest during control and with administration of atropine, metoprolol, and atropine + metoprolol (double blockade). Heart rate and arterial blood pressure were continuously recorded. HRV and blood pressure variability were determined by power spectral analysis, and baroreflex sensitivity was determined by the sequence method. At rest, PTOT and the powers of low- and high-frequency components of HRV (LF and HF, respectively) were dramatically decreased with atropine and double blockade compared with control and metoprolol, with no effects on LF-to-HF ratio and on the normalized LF (LFnu) and HF (HFnu). During exercise, patterns were the same as at rest. Comparing exercise with rest, PTOT varied as hypothesized. For systolic and diastolic blood pressure, resting PTOT was the same in all conditions. During exercise, in all conditions, PTOT was lower than in control. Baroreflex sensitivity decreased under atropine and double blockade at rest and under control and metoprolol during exercise. The results support the hypothesis that vagal suppression determined disappearance of HRV during exercise. NEW & NOTEWORTHY This study provides the first demonstration, by systematic analysis of heart rate variability at rest and during exercise under full autonomic blockade on the same subjects, that suppression of vagal activity is responsible for the disappearance of spontaneous heart rate variability during exercise. This finding supports previous hypotheses on the role of vagal withdrawal in the control of the rapid cardiovascular response at exercise onset.


2013 ◽  
Vol 68 (7) ◽  
pp. 20-23
Author(s):  
L. V. Poskotinova ◽  
D. B. Demin ◽  
E. V. Krivonogova ◽  
M. N. Dieva ◽  
N. M. Khasanova

Objective. The aim was to determine the nature of cardiovascular reactions during a single session of heart rate variability (HRV) biofeedback in order to increase vagal effects on heart rhythm in patients with different initial levels of blood pressure (BP). Participants and methods. 33 people with normal blood pressure (group I), 20 people with uncorrected arterial hypertension (AH) grade 1-2 (group II) and 22 people with AH grade 1-2 taking antihypertensive drugs (group III) were observed. The parameters of heart rate variability (HRV), BP and pulse oximetry in the initial stage, during a single HRV biofeedback session and after this session in order to increase the total power of the HRV spectrum (each stage was 5 min). Results. In patients of group II low success of HRV biofeedback session, a high sympathetic reactivity and reduced oxygen blood saturation were determined. A reactivity of vagal mechanism is more pronounced in persons of group III than in those of group II. It is reflected in a significant increase in their total power of the HRV spectrum compared to the initial values and in uptrend saturation levels during the biofeedback session. Conclusions. The ability to HRV biofeedback in order to increase the total power of the HRV spectrum for standard short recording (5 min) can be seen as a test to determine the safety reserves of vagal autonomic cardiovascular regulation in persons with increased blood pressure. 


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