Significant Increase In Heart Rate Research Articles

Influence of tobacco smoking on the functional state of the male cardiovascular system

The paper presents the data on functional state of the male cardiovascular system, depending on the period of tobacco smoking. The analysis of the research results shows that tobacco smoking leads to a significant increase in heart rate, blood pressure, pulsatility, average dynamic arterial pressure, minute blood volume, and circulatory efficiency ratio. Gradually increasing, the heart rate reached a maximum value of 86.6 (P <0.001) beats per minute in the group with over 20 years of smoking, while in the control group it was 73.2.The highest level of systolic and diastolic blood pressure was 138.7 (P<0.001) and 88.8 (P<0.001) mm Hg. in the group of smokers with the smoking experience of more than 20 years, while in non-smokers the indicators were 114.1 and 73.9, respectively. The maximum level of pulsatility was 49.9 (P<0.001) and that of average dynamic arterial pressure — 109.8 (P<0.001) mm Hg., identified in the group of smokers with over 20 years of smoking, while the initial levels were 40.2 and 90.8, respectively. The range of systolic blood volume between the groups was 4.3 ml. Minute blood volume in groups of men under 20 years and over increased to 4.11 (P <0.01) and 4.06 (P <0.02) l/min, while in the group of non-smokers it accounted for 3.69. The increase in the duration of tobacco smoking led to a slight increase in peripheral resistance. As the smoking period lengthens, the circulatory efficiency value undergoes a gradual increase, reaching a maximum value of 4,323 (P <0.001) in the group with over 20 years of smoking, while in the control group it was 1,898. The difference between the maximum and minimum circulatory efficiency values between the experimental male groups was 1.3.

Safety of Electrotherapy Treatment in Patients with Knee Osteoarthritis and Cardiac Diseases.

To assess the safety of electrotherapy applied in the knee area in patients with known atrial arrhythmias or ischemic heart disease, as it is not known whether this treatment induces or aggravates arrhythmias during or immediately after therapy. The analytical and transversal study involved 46 patients with degenerative knee osteoarthritis (OA), with or without cardiac diseases, from the Clinical Rehabilitation Hospital inpatient center, Cluj-Napoca, Romania. All patients underwent a 10-day physical therapy program for knee OA (electrotherapy, massage and kinesiotherapy). Heart rate and the total number of ventricular and supraventricular extrasystoles were evaluated before and after treatment, by 24 h Holter ECG monitoring. There was no significant increase in heart rate or in the number of ventricular or supraventricular extrasystoles before or after electrotherapy treatment, regardless of the positive or negative history of arrhythmia or ischemic heart disease (all p > 0.05). Mean values during day 1 were: 35.15 (95% CI [9.60-60.75]) for ventricular ones extrasystoles and 91.7 (95% CI [51.69-131.7]) for supraventricular ones, which during day 2 were 38.09 (95% CI [3.68-72.50]), 110.48 (95% CI [48.59-172.36]), respectively. One of the most important things to consider when dealing with an OA patient is that they are most likely older than 65 years, which increases the chance of having a cardiac disease. This raises the need for viable interventions regarding the management of this disease in patients that probably have multiple comorbidities, and where pharmacological and surgical management are not possible, limited or have multiple side effects. Electrotherapy used for treating knee OA did not cause a significant increase in heart rate or number of ventricular and supraventricular extrasystoles in this category of patients.

Syncope recurrence and long-term heart rate variability after cardioneuroablation for vasovagal syncope: a systematic review and meta-analysis

Abstract Background Cardioneuroablation (CNA) has emerged as a promising therapy in patients with refractory vasovagal syncope (VVS). Well-designed randomized clinical trials (RCT) are lacking. Purpose To provide an estimate of the procedural success rate of CNA, including subgroup analysis by method and target of ablation, as well as serial measurements of autonomic tone after CNA with heart rate variability (HRV). Methods A systematic search of studies was performed in MEDLINE and EMBASE according to the PRISMA guidelines, from inception to 14 February 2022. Observational studies and clinical trials reporting success rates were included. Quality assessment was performed using the CONSORT and STROBE recommendations. The primary outcome was freedom from syncope after CNA. Meta-analysis was performed with a random-effects model. The secondary outcome was serial HRV analysis (heart rate, SDNN, rMSSD and LF/HF ratio) analysed with one-way ANOVA with Bonferroni's correction for multiple testing. Results A total of 465 patients were included across 14 studies (mean age 40±4 years; 54% females). All included studies were of intermediate quality (median 17, IQR 16–18). Procedural approach to CNA was variable: 50 patients (10.8%) by mapping of fractionated electrograms, 73 patients (15.7%) with the spectral method, 210 (45.2%) with high frequency stimulation, 73 (15.7%) with a purely anatomically guided method, and 59 patients (12.6%) with a combination. The target was bi-atrial in 168 patients (36.1%), left atrium only in 259 patients (55.7%), and right atrium only in 38 patients (8.2%). The freedom from syncope was 91.9% (95% CI 88.1–94.6%; I2=6.9%, p=0.376; Figure 1). CNA limited to right atrial ablation was associated with a significantly lower success rate (p<0.0001; 81.5%, 95% CI 51.9–94.7%) versus left atrial ablation only (94.0%, 95% CI 88.6–96.9%) and bi-atrial ablation (92.7%, 95% CI 86.8–96.1%). Subgroup analysis according to the technique used to identify GPs did not show any significant difference in success rate (p=0.206). Ten studies (n=317, 68.2%) reported at least one HRV parameter. Results are presented in Figure 2 with the mean and standard deviations. There were significant increases in heart rate, and significant decrease in SDNN, rMSSD and LF/HF ratios for each follow-up timepoint available (p<0.0001 for all analyses). Recovery of these parameters was observed in 2 studies, but these were not associated with an increased risk in syncope recurrence. Conclusion This meta-analysis suggests a high procedural success rate of CNA in VVS of 92%. CNA induces long-term changes in HRV, however some studies reported recovery of these parameters without an association with syncope recurrence. Therefore, HRV changes may not be an appropriate surrogate endpoint for clinical response. Well-designed double-blind, multi-center sham controlled RCTs are needed to provide evidence for future treatment guidelines. Funding Acknowledgement Type of funding sources: Foundation.

Cortisol response under low intensity exercise during cognitive-behavioral therapy is associated with therapeutic outcome in panic disorder-an exploratory study.

Patients with Panic Disorder (PD) show an abnormal stress-induced functioning of the Hypothalamic-Pituitary-adrenal (HPA)-axis. Different protocols for stress induction are of rather low relevance for the psychotherapeutic treatment. In practice, interoceptive exposure is often realized as Low Intensity Exercise (LIE), as compared to an incremental cycle exercise test to exhaustion. Currently, it is not known, whether LIE displays an effective interoceptive stressor 1.) leading to a significant anxiety induction; 2.) a comparable HPA- and Sympathetic-Adreno-Medullar (SAM)-axis response in both patients and healthy controls; 3.) stress responses under LIE are associated with treatment outcomes. N = 20 patients with PD and n = 20 healthy controls were exposed to ten minutes of LIE on an exercise bike. LIE was applied as part of the interoceptive exposure, during an intensive Cognitive-Behavioral Therapy (CBT) in a day clinic. Heart rate was monitored and salivary cortisol samples collected. Before and after the LIE, state anxiety/ arousal were assessed. In order to evaluate psychopathology, the Panic and Agoraphobia Scale, Mobility Inventory, Agoraphobic Cognitions Questionnaire and Body Sensations Questionnaire were applied, before (T1) and after five weeks (T2) of an intensive CBT. LIE led to a significant and similar heart rate increase in both groups. Cortisol decreased over time in both groups, especially in male patients. A higher psychopathology before, and after CBT, was associated with a significantly lower cortisol response under LIE. In the present study, LIE led to a divergent stress response: while there was a significant heart rate increase, cortisol decreased over time, particularly in male patients. A lower reactivity of the HPA-axis seems to be associated with a lower treatment outcome, which may affect extinction based learning. The findings suggest, that interoceptive stimuli should be designed carefully in order to be potent stressors.

Six HIT Sessions Improve Cardiorespiratory Fitness and Metabolic Flexibility in Insulin Resistant and Insulin Sensitive Adolescents with Obesity.

To evaluate the effect of high-intensity interval training (HIT) on the cardiorespiratory performance and substrate oxidation pattern in insulin-resistant and insulin-sensitive obese adolescents. Methods: We recruited 25 obese adolescents in three schools, and trained them in six HIT sessions, comprising of six series at 100% and recovery at 50% peak velocity (Vpeak). For the evaluation, the participants were divided into two groups: insulin-resistant (IR, n = 12; HOMA index ≥3.16) and insulin-sensitive (IS, n = 13). All participants underwent cardiopulmonary and indirect calorimetry testing. We compared the effects of HIT before and after the intervention among the two groups. The data were analyzed using Student’s t and Mann–Whitney (intergroup comparisons) and Student’s t and Wilcoxon (pre- and post-training comparisons) tests; and Cohen’s d (influence of HIT). Results: There was a significant post-training increase in Vpeak, oxygen consumption (VO2), velocity (V), and heart rate (HR) at the exertion intensity at the first ventilatory anaerobic threshold (VAT1) in both groups (p < 0.05; d < 0.02). The exercise promoted changes in substrate oxidation rates of the groups, with an increase in carbohydrate oxidation (CHOox) for both IR (p = 0.064) and IS (p = 0.034). Conclusion: Six HIT sessions improved cardiorespiratory performance in both groups and increased CHOox in insulin-sensitive obese adolescents, suggesting its utility for increasing physical fitness and controlling glycemia in these population groups.

Stair walking effects on feelings of energy and fatigue: Is 4-min enough for benefits?

Even low intensity exercise bouts of at least 15 min can improve feelings of energy (FOE) and reduce systolic blood pressure. However, little is known about the psychological outcomes of briefer exercise bouts, particularly for modes of exercise that are more intense than level walking, and readily available to many working adults. This study assessed the effects of a 4-min bout of stair walking on FOE and feelings of fatigue (FOF). Thirty-six young adult participants were randomized to either stair walking or seated control groups. All participants walked on level-ground from a laboratory to a nearby stairwell (~90 s) and were seated for 4 min before beginning their experimental condition. Stair-walking participants walked up and down one flight of 16 stairs at their own pace for 4 min, while control participants remained seated during that time. Participants walked back to the laboratory for post-condition assessments. Measures of blood pressure, heart rate, rated perceived exertion (RPE), and the intensity of feelings of mental energy, mental fatigue, physical energy, and physical fatigue were assessed pre-and post-condition. Separate one-way ANOVAs were conducted on change scores for all variables. The stair climbing group experienced significant increases in heart rate [F(1,34) = 13.167, p < 0.001] and RPE [F(1,34) = 93.844, p < 0.001] that were not observed in the seated control group. Four minutes of self-paced stair climbing resulted in small changes and non-significant differences within and between groups in blood pressure as well as FOE and FOF. Although a 4-min self-paced exercise bout can convey short-term physiological health benefits, a 4-min bout of self-paced indoor stair walking in a stairwell was insufficient to lower blood pressure or change subjective FOE and fatigue in a sample that exhibited better than typical FOE and FOF at the pre-test.

6-NitroDopamine is an endogenous modulator of rat heart chronotropism

6-Nitrodopamine (6-ND) is released by rat vas deferens and exerts a potent contractile response that is antagonized by tricyclic antidepressants and α1-, β1- and β1/β2-adrenoceptor antagonists. The release of 6-ND, noradrenaline, adrenaline and dopamine from rat isolated right atria was assessed by tandem mass spectrometry. The effects of the catecholamines were evaluated in both rat isolated right atria and in anaesthetized rats. 6-ND was the major catecholamine released from the isolated atria and the release was significantly reduced in nitric oxide synthase inhibitor L-NAME pre-treated atria or in atria obtained from L-NAME chronically treated animals, but unaffected by tetrodotoxin. 6-ND (1 pM) significantly increased the atrial frequency, being 100 times more potent than noradrenaline and adrenaline. Selective β1-blockers reduced the atrial frequency only at concentrations that prevented the increases in atrial frequency induced by 6-ND 1pM. Conversely, β1-blockade did not affect dopamine (10 nM), noradrenaline (100 pM) or adrenaline (100 pM) effect. The reductions in atrial frequency induced by the β1-adrenoceptor antagonists were absent in L-NAME pre-treated atria and in atria obtained from chronic L-NAME-treated animals. Tetrodotoxin did not prevent the reduction in atrial frequency induced by L-NAME or by β1-blockers treated preparations. In anaesthetized rats, at 1 pmol/kg, only 6-ND caused a significant increase in heart rate. Inhibition of 6-ND synthesis by chronic L-NAME treatment reduced both atrial frequency and heart rate. The results indicate that 6-ND is a major modulator of rat heart chronotropism and the reduction in heart rate caused by β1-blockers are due to selective blockade of 6-ND receptor.

Effects of a 3-Month Physical Training on Cortisol and Testosterone Responses in Women After Bariatric Surgery

Although it is well established that physical activity (PA) may partially correct the metabolic and hormonal alterations observed in patients with obesity, knowledge of its impact after bariatric surgery (BS) remains poor. The purpose of this study was to assess the repercussions of physical training on cortisol and testosterone responses in post-BS women. According to a randomized clinical trial, a PA group (11 women) started a 3-month physical training 6weeks after BS, whereas no specific activity was proposed to a control group (9 women). Submaximal exercise (i.e., 30min at 60% VO2peak) was performed by all subjects just before and after the 3-month period. Blood samples were taken at rest, after 10, 20, and 30min of exercise and 10min of passive recovery for cortisol and testosterone analyses. Blood glucose, blood lactate, and heart rate were assessed at the same time. Before the program, a significant increase in cortisol, blood lactate, and heart rate was observed in all subjects during the submaximal exercise vs. rest, with no change in blood glucose and testosterone. After vs. before the 3-month period, no modification in any parameter was noted at rest in either group. However, during exercise, lack of cortisol increase and lower heart rate were found in the PA group only, with disappearance of the increase in blood lactate in both groups. Our results show some beneficial effects of physical training on hormonal and physical parameters. Further studies are needed to determine the biological and clinical significance of these adaptations induced by physical training in women after BS.

Comparision of intravenous magnesium sulphate and lignocaine in attenuation of pressor response to laryngoscopy and endotracheal intubation

Endotracheal intubation and laryngoscopy are noxious stimuli and provoke cardiovascular and autonomic responses because of sympathoadrenal stimulation. Attenuation of significant increases in heart rate and blood pressure decreases the risk of complications.Various pharmacological and non-pharmacological methods have been tried to attenuate hemodynamic response to laryngoscopy and endotracheal intubation. None of the approaches have proved to be ideal.In view of it present study was undertaken to evaluate and compare effects of intravenous magnesium sulphate 30mg/kg and lignocaine 2mg/kg in attenuation of pressor response to laryngoscopy and endotracheal intubation.Prospective randomized controlled study was conducted in which 60 American society of Anesthesiologist 1 patients, aged 18-60yrs, undergoing elective surgery under general anesthesia were selected. Patients were randomized into 2 groups: Group 1 with thirty patients who received MgSO4 30mg/kg and Group 2 with thirty patients who received lignocaine 2 mg/kg intravenous bolus. Anesthesia was induced using premedication glycopyrolate, midazolam, ondansetron injection Fentanyl was administered as analgesic agent. Study drug Injection mgso4 was administered 90sec before induction with injection propofol as induction agent followed by injection succinylscoline to facilitate intubation. Laryngoscopy and intubation response in both groups were studied by recording Heart Rate (HR), blood pressure (BP), at baseline,after administering drug, at laryngoscopy, after intubation, 1min,3min,5minsafter intubation.Study revealed that Group 1 patients had significant decreasing trend in HR and MAP recorded till 5mins after intubation. Mgso4 has vasodilator properties and significantly suppresses release of catecholamines and hence can attenuate stress response to laryngoscopy and endotracheal intubation better than lignocaine.

КОНТРОЛЬ ЧАСТОТЫ СЕРДЕЧНЫХ СОКРАЩЕНИЙ У ПРЫГУНОВ ЧЕРЕЗ НАРТЫ

The article presents a study on the control and dynamics of heart rate in athletes involved in sled jumping. The relevance of the study lies in the fact that athletes of various levels were controlled. Many researchers study the physiological processes of athletes in various sports, but the reaction of an athlete’s body to jumping over sleds still remains unexplored. The purpose of the study: control and dynamics of heart rate in athletes of different qualifications. Materials and methods. The study was carried out using a Polar FT80 heart rate monitor. The study involved athletes of various skill levels from dischargers to the master of sports of the Russian Federation. Results. Indicators of the dynamics of heart rate of athletes of different skill levels have significant differences and features. The average heart rate in athletes of the masters of sports of the Russian Federation and candidates for the master of sports increased sharply until the fortieth jump over the sled, then stabilized. A significant increase in heart rate from the moment the jumps began and at the end of the first 20 sledges was observed in athletes under the numbers of the dischargers. Conclusion. The indicators of heart rate in the process of performing sled jumps in athletes of different sports qualifications were revealed. The heart rate range is determined in the value of 170-190 beats / min, at which it is possible to overcome the largest number of sleds.

Blood oxygen level with long-term use of N95 face mask in dental practice during the coronavirus pandemic “Covid-19”

Wearing a mask for a long time, particularly N95, is sometimes uncomfortable, annoying, and confining, making catching breath difficult and reducing the oxygen level in the blood. The study aimed to investigate the change in blood oxygen level when wearing an N95 mask for three hours among dental practitioners in dental clinics and the impact of low O2 levels on the general status of students while working in a stressful environment. Material and methods . The sample included 82 adult healthy senior dental students attending the student oral surgery clinical sessions. All Participants had their oxygen saturation Spo 2 measured using a portable pulse oximeter before, 1hour, 2hours, and 3 hours after wearing the mask, and were allowed to describe their feeling of discomfort throughout the study. Systolic and diastolic blood pressure (SBP and DBP), and heart rate (HR) were also measured before and 3 hours after wearing the mask. Results . 84.15% (n= 69) of the participants reported some discomfort affecting their general status and clinical performance. There was a statistically significant increase in mean heart rate after three hours ( P -value = 0.001) while there was no statistically significant change in mean systolic/diastolic blood pressure after three hours ( P -value = 0.630) and ( P -value=0.407) respectively. On the other hand, the mean Oxygen saturation after three hours showed a statistically significantly lower value compared with baseline measurement. Conclusion . This study revealed a decrease in the oxygen saturation (SpO2) and a slight increase in pulse rate compared to baseline values in all students three hours after wearing an N95 face mask. In addition, the N95 mask induced discomfort in breathing, a decrease in physical performance, and increased fatigue not related to prolonged standing and stress.

Blood oxygen level with long-term use of N95 face mask in dental practice during the coronavirus pandemic “Covid-19”

Wearing a mask for a long time, particularly N95, is sometimes uncomfortable, annoying, and confining, making catching breath difficult and reducing the oxygen level in the blood. The study aimed to investigate the change in blood oxygen level when wearing an N95 mask for three hours among dental practitioners in dental clinics and the impact of low O2 levels on the general status of students while working in a stressful environment. Material and methods . The sample included 82 adult healthy senior dental students attending the student oral surgery clinical sessions. All Participants had their oxygen saturation Spo 2 measured using a portable pulse oximeter before, 1hour, 2hours, and 3 hours after wearing the mask, and were allowed to describe their feeling of discomfort throughout the study. Systolic and diastolic blood pressure (SBP and DBP), and heart rate (HR) were also measured before and 3 hours after wearing the mask. Results . 84.15% (n= 69) of the participants reported some discomfort affecting their general status and clinical performance. There was a statistically significant increase in mean heart rate after three hours ( P -value = 0.001) while there was no statistically significant change in mean systolic/diastolic blood pressure after three hours ( P -value = 0.630) and ( P -value=0.407) respectively. On the other hand, the mean Oxygen saturation after three hours showed a statistically significantly lower value compared with baseline measurement. Conclusion . This study revealed a decrease in the oxygen saturation (SpO2) and a slight increase in pulse rate compared to baseline values in all students three hours after wearing an N95 face mask. In addition, the N95 mask induced discomfort in breathing, a decrease in physical performance, and increased fatigue not related to prolonged standing and stress.

Short and long-term outcomes of children with autoimmune congenital heart block treated with a combined maternal-neonatal therapy. A comparison study.

The short and long-term outcomes of children with anti-Ro/La-related congenital heart block treated with a combined maternal-neonatal therapy protocol were compared with those of controls treated with other therapies. Sixteen mothers were treated during pregnancy with a therapy consisting of daily oral fluorinated steroids, weekly plasma exchange and fortnightly intravenous immunoglobulins and their neonates with intravenous immunoglobulins (study group); 19 mothers were treated with fluorinated steroids alone or associated to intravenous immunoglobulins or plasma exchange (control group). The combined-therapy children showed a significantly lower progression rate from 2nd to 3rd degree block at birth, a significant increase in heart rate at birth and a significantly lower number of pacemaker implants during post-natal follow-up with respect to those treated with the other therapies. The combined therapy produced better short and long term outcomes with respect to the other therapies studied.

Extracardiac Vagal Stimulation-Assisted Cardioneuroablation: Dynamically Evaluating the Impact of Sequential Ganglionated Plexus Ablation on Vagal Control of SAN and AVN in Patients with Sinoatrial Node Dysfunction.

Cardioneuroablation (CNA) is proposed as a promising therapy for patients with sinoatrial node dysfunction (SND) that is mediated by excessive vagal tone. However, a series of urgent questions about CNA remain unanswered. From December 2020 to March 2022, six patients with symptomatic SND who underwent CNA were summarized in this report. Sequential CNA targeting Ao-SVC GP, PMLGP, RAGP, and LSGP was performed in patients, guided by fractionated intracardiac electrograms and dynamically evaluated by extracardiac vagal stimulation (ECVS). The results showed that Ao-SVC GP ablation led to a significant increase in heart rate (HR) and the elimination of sinus arrest evoked by ECVS, while the vagal responses of atrial ventricular block were eliminated by the ablation of PMLGP and LSGP. Post-procedure HR increased up to 64–86% of the maximum HR of an atropine test at baseline. The median HR from Holter monitoring increased from 52.8 ± 2.1 bpm at baseline to 73.0 ± 10.4 bpm after the procedure (p = 0.012) and to 71.3 ± 10.1 bpm at the six-month follow-up (p = 0.011). Bradycardia-related symptoms disappeared in all patients at the six-month follow-up. This case series reveals the feasibility of using the ECVS-assisted sequential CNA technique and indicates the critical role of ECVS in dynamically evaluating the impact of sequential CNA on the vagal control of SAN and AVN.

ELEVATED RESTING HEART RATE AS INDEPENDENT IN-HOSPITAL PROGNOSTIC MARKER IN COVID-19

Objective: SARS-CoV-2 infection could be complicated by serious autonomic imbalance caused directly by the virus or through secondary release of inflammatory cytokines. Some studies suggested that elevated resting heart rate (HR) and resting tachycardia, being markers of an increased adrenergic cardiac drive, are associated with poor prognosis in COVID-19 syndrome. Design and method: We performed a retrospective analysis in an inpatient cohort of 389 subjects diagnosed with SARS-CoV-2 infection to investigate the prognostic relevance of HR in predicting the maximum care intensity needed during hospitalization according to the following four severity outcome classes: I) no need for oxygen support/need for low flow oxygen therapy; II) need for high flow oxygen therapy/continuous positive airway pressure; III) transfer to the Intensive Care Unit; IV) death. HR assessments were recorded on admission and during the first 3 and 7 days of hospitalization. Results: For each class increase in maximum care intensity we observed a corresponding significant increase in HR, considering both data collected on admission (average HR value: 90.1 ± 17 beats/minute, p-value trend = 0.0397), and during the first 3 days (p-value trend &lt; 0.0006) or 7 days (p-value trend &lt; 0.0001) of hospitalization. The significant trend was maintained after adjustment for age, sex, comorbidities and fever and in the subpopulation of patients (n = 118) not receiving drugs potentially active on HR both before and during hospitalization. Kaplan-Meier curves for survival based on HR displayed a significant decreased survival in patients with higher HR. Conclusions: The assessment of HR during hospitalization provides information on the clinical outcome of patients affected by SARS-CoV-2 infection independently of other confounders. HR as an in-hospital prognostic marker can be obtained both through a first assessment at the admission or mean values over the course of hospitalization with an increase of its accuracy by a 7-days longitudinal evaluation. Further studies might elucidate the association between SARS-CoV-2 infection with multiple autonomic abnormalities.

Effects of Low-Load Blood Flow Restriction Training on Hemodynamic Responses and Vascular Function in Older Adults: A Meta-Analysis.

Background: The combination of low-load (LL) training with blood flow restriction (BFR) has recently been shown to trigger a series of hemodynamic responses and promote vascular function in various populations. To date, however, evidence is sparse as to how this training regimen influences hemodynamic response and vascular function in older adults. Objective: To systematically evaluate the effects of LL-BFR training on hemodynamic response and vascular function in older adults. Methods: A PRISMA-compliant systematic review and meta-analysis were conducted. The systematic literature research was performed in the following electronic databases from their inception to 30 February 2022: PubMed, Web of Science, Scopus, EBSCO host, the Cochrane Library and CNKI. Subsequently, a meta-analysis with inverse variance weighting was conducted. Results: A total of 1437 articles were screened, and 12 randomized controlled trials with a total 378 subjects were included in the meta-analysis. The meta-analysis results showed that LL-BFR training caused a significant acute increase in heart rate (WMD: 4.02, 95% CI: 0.93, 7.10, p < 0.05), systolic blood pressure (WMD: 5.05, 95% CI: 0.63, 9.48, p < 0.05) and diastolic blood pressure (WMD: 4.87, 95% CI: 1.37, 8.37, p < 0.01). The acute hemodynamic response induced by LL-BFR training is similar to that elicited by high-load (HL) training. Training volume, cuff pressure and width were identified as significant moderators in our subgroup and meta-regression analyses. After 30 min of training, resting systolic blood pressure significantly decreased (WMD: −6.595, 95% CI: −8.88, −3.31, p < 0.01) in the LL-BFR training group, but resting hemodynamic indexes exhibited no significant differences compared with common LL and HL training; long-term LL-BFR training resulted in significant improvements in flow-mediated vasodilation (FMD) (WMD: 1.30, 95% CI: 0.50, 2.10, p < 0.01), cardio ankle vascular index (CAVI) (WMD: 0.55, 95% CI: 0.11, 0.99, p < 0.05) and ankle brachial index (ABI) (WMD: 0.03, 95% CI: 0.00, 0.06, p < 0.05) in older adults. Conclusion: This systematic review and meta-analysis reveals that LL-BFR training will cause an acute hemodynamic response in older adults, which can return to normal levels 30 min after training, and systolic blood pressure significantly decreased. Furthermore, the beneficial effect of LL-BFR training on vascular function is to improve FMD, CAVI and ABI of older adults. However, due to the influence of the quality of the included studies and the sample size, more high-quality studies are needed to confirm such issues as BFR pressure and training risk.

Prodromal Physiologic Changes During Copper Sulfate‐Induced Nausea and Vomiting: Potential Use of Intestinal EMG Recordings as a Marker for Nausea

Although emetic responses are present during many disease states, there is no consensus regarding the physiologic changes that signal the onset of nausea. In this study, 10 adult felines (6 males and 4 females) were instrumented to chronically record, during the awake state, the electrocardiogram, diaphragm and abdominal muscle electromyographic (EMG) activity, and EMG activity from the stomach and duodenum before and after the gavage or intragastric infusion of saline or copper sulfate (CuSO4, doses ranging from 83 to 322 mg). Intragastric CuSO4 is a prototypical emetic stimulus that triggers emesis primarily by activating a gastrointestinal vagus nerve‐to‐brain pathway. CuSO4 infusion elicited a significant increase in heart rate, decrease in respiratory rate, and a disruption in gastric (baseline~6 CPM, cycles‐per‐minute) and intestinal (baseline~20 CPM) EMG activity several minutes prior to vomiting (see Fig. 1). The change in EMG activity was most consistent in the intestine. Administration of saline did not induce these physiologic changes. Increasing the dose of CuSO4 did not alter the physiologic changes induced by the treatment. In some animals, a second bout of vomiting occurred following the first episode, when prodromal changes of the intestinal EMG were less pronounced. It is postulated that the intestinal EMG activity was related to a retrograde movement of chyme from the intestine to the stomach. These findings suggest that monitoring of intestinal EMG activity may be the best indicator of the onset of nausea following treatments and in disease conditions associated with emesis.

The Effect of Meditation on Heart Rate Variability

Heart rate variability (HRV) has been utilized in both medicine and sports sciences as an important marker for managing stress, indicating diseased states, and monitoring training/recovery. HRV reflects the autonomic balance of the sympathetic (SNS) and parasympathetic (PNS) nervous systems. High PNS activity is correlated to high HRV. The frequency and time domains of an ECG may be analyzed to determine the influence of PNS activity. HRV has been shown to be influenced by exercise training; however, meditation and guiding breathing techniques may also influence HRV.PURPOSETo evaluate the effect of a short, guided meditation session on the measures of heart rate variability of inexperienced meditators.METHODS39 participants (18‐21 years) volunteered and gave informed consent. During the experimental session, a Polar H10 heart rate monitor was fitted around the subject to record a 15‐minute ECG. The breathing protocol consisted of sitting in a comfortable position and continuous 5‐minute stages of spontaneous breathing (SP1), controlled breathing (CB), and returning to spontaneous breathing (SP2). During CB, a 6 breath/min guided protocol was followed using a commercially available App. A one‐way ANOVA with repeated measures was conducted for each variable using SPSS, p &gt; 0.05.RESULTSCB produced a significant increase in heart rate from 70.6+11.9 bpm to 72.9+10.4 bpm (p&lt;0.005) during CB, and then decreased to 71.7+10.3 bpm (p&lt;0.05). Measures of the frequency domain included high frequency (HF) and low frequency (LF) power. HF significantly decreased from 49.2+21.1 nu during SP1, to 16.6+9.9 nu (p&lt;0.005), and returned to 34.6+18.3 nu (p&lt;0.005). For LF, SP1 was 50.9+21.0 nu, significancy increased to 83.4+9.9 nu (p&lt;0.005), and returned to 65.4+18.3 nu (p&lt;0.005). The measures of the time domain included rMSSD and SDNN. rMSSD at SP1 was 60.9+33.8, significantly increased to 74.2+36.6 (p&lt;0.005), and returned to 56.0+33.1 (p&lt;0.005). The SP1 for SDNN was 62.7+31.4, significantly increased to 110.4+39.6 (p&lt;0.005), and returned to 66.1+29.7 (p&lt;0.005). CONCLUSION: The direction and magnitude of change in frequency domain (HR, HF and LF) may initially suggest a dampening of the PNS. However, CB has been shown to initiate SNS activity which is represented in the frequency measures. In short‐term HRV measures, rMSSD and SDNN are the more appropriate measures to consider for the PNS activity. Thus, the results of this study indicate that a short session of CB may stimulate a PNS response.

Role of central irisin in the cardiorespiratory and metabolic control of adult rats

Irisin has been identified as an important exercise‐induced myokine that acts in different physiological systems; however, little is known about the participation of irisin in cardiorespiratory and basal metabolic control. Therefore, the present study evaluated the effect of intracerebroventricular (icv) injection of vehicle or irisin (IR, 0.425 µg/µL) in the fourth ventricle (4V) of adult male rats on the cardiorespiratory and metabolic control during wakefulness and sleep under room air, hypercapnia (7% CO2) and hypoxia (10% O2). Our data show a tendency of reduction in basal ventilation of IR group during wakefulness (VEH: 1056.2 ± 61.8 vs IR: 816.9 ± 30.5 mL.Kg‐1.min‐1), due to a reduction in respiratory frequency (VEH: 105.1 ± 5.3 vs IR: 85.9 ± 5.1 breaths.min‐1) and a consequent decrease in arterial partial pressure of O2 (VEH: 95.1 ± 2.4 vs IR: 88.7 ± 3.1 mmHg). No difference was observed in metabolic rate; however, central IR promoted a reduction in the air convection requirement (VEH: 57.2 ± 4.7 vs IR: 39.6 ± 3.7). Regarding the cardiovascular parameters, central injection of IR caused a significant increase in heart rate during hypoxia exposure (VEH: 342.5 ± 38.0 vs IR: 406.2 ± 16.8 beats.min‐1) without changing arterial pressure. These effects were only observed in awake conditions, with no changes evidenced during sleep. No difference in cardiorespiratory and metabolic parameter were observed under CO2 exposure after central IR injection. Therefore, our preliminary results suggest that IR caused a hypoventilation under room air conditions, possibly due to a lower ventilation, increased heart rate under hypoxic conditions, suggesting that this myokine also acts in the central nervous system to modulate breathing and cardiovascular parameters.

ВЛИЯНИЕ ЛИПОПОЛИСАХАРИДА БАКТЕРИАЛЬНОГО ПРОИСХОЖДЕНИЯ НА ФУНКЦИОНАЛЬНУЮ АКТИВНОСТЬ СЕРДЦА В УСЛОВИЯХ IN VIVO

Lipopolysaccharide of bacterial origin (LPS) belongs to the group of PAMPs (pathogen-associated molecular patterns). LPS is a component of the outer membrane of gram-negative bacteria. As a pro-inflammatory factor, LPS binds to “toll-like receptors 4” (TLR4) and thus activates the production of cytokines. Cytokines are known to provoke the development of arrhythmia, disrupt the processes of electromechanical coupling and lead to the damage of myocardium during myocarditis. We have investigated the effects of the intraperitoneal administration of LPS (10µg/100g of body mass) on the electrocardiographic parameters of frogs’ heart, such as the heart rate (HR), the velocity of impulse transmission through the atrioventricular node to the ventricle (PR), amplitude (QRS), and the duration of the ventricular complex (QT). LPS induced a significant increase of heart rate and shortening of the duration of the ventricular complex, as compared with the control group. In addition, we have investigated the contraction amplitude (mechanical systole) of the isolated frog heart in the ex vivo conditions, where LPS was found to cause a negative inotropic effect. Based on these results, it can be assumed that the overactivation of the immune system as mimicked by the administration of LPS in vivo is responsible for the cross-talk between the altered heart functional activity (increase of pacemaker rhythm, decrease of the amplitude of contractions) and a rapid formation of the ventricular complex. These effects might be responsible for the decrease in cardiac output and chronic heart failure characteristic for myocarditis.