Increase In HR Research Articles

Chemogenetic stimulation of phrenic motor output and diaphragm activity.

Impaired respiratory motor output contributes to morbidity and mortality in many neurodegenerative diseases and neurologic injuries. We investigated if expressing designer receptors exclusively activated by designer drugs (DREADDs) in the mid-cervical spinal cord could effectively stimulate phrenic motor output to increase diaphragm activation. Two primary questions were addressed: 1) does effective DREADD-mediated diaphragm activation require focal expression in phrenic motoneurons (vs. non-specific mid-cervical expression), and 2) can this method produce a sustained increase in inspiratory tidal volume? Wild type (C57/bl6) and ChAT-Cre mice received bilateral intraspinal (C4) injections of an adeno-associated virus (AAV) encoding the hM3D(Gq) excitatory DREADD. In wild-type mice, this produced non-specific DREADD expression throughout the mid-cervical ventral horn. In ChAT-Cre mice, a Cre-dependent viral construct was used to drive neuronal DREADD expression in the C4 ventral horn, targeting phrenic motoneurons. Diaphragm EMG was recorded in isoflurane-anesthetized spontaneously breathing mice at 4-9 weeks post-AAV delivery. The DREADD ligand JHU37160 (J60) caused a bilateral, sustained (>1 hour) increase in inspiratory EMG bursting in both groups; the relative increase was greater in ChAT-Cre mice. Additional experiments in ChAT-Cre rats were conducted to determine if spinal DREADD activation could increase inspiratory tidal volume (VT) during spontaneous breathing, assessed using whole-body plethysmography without anesthesia. Three-to-four months after intraspinal (C4) injection of AAV driving Cre-dependent hM3D(Gq) expression, intravenous J60 resulted in a sustained (>30 min) increase in VT. Subsequently, phrenic nerve recordings performed under urethane anesthesia confirmed that J60 evoked a > 200% increase in inspiratory output. We conclude that targeting mid-cervical spinal DREADD expression to the phrenic motoneuron pool enables ligand-induced, sustained increases in phrenic motor output and VT. Further development of this technology may enable application to clinical conditions associated with impaired diaphragm activation and hypoventilation.

Abstract 4145890: P-Wave Parameters on 12-Lead Electrocardiogram after Catheter Ablation: A Comparison between Pulsed Field Ablation and Cryoablation

Background: Catheter ablation (CA) is a well-established treatment for atrial fibrillation (AF). The most popular current methods of CA include radiofrequency ablation (RFA) and cryoablation (CRYO) which are thermal methods of ablation known to affect the autonomic nervous system through ablation of cardiac ganglionated plexi (GP). Pulsed[SC1] -field ablation (PFA) is a newer method of CA with demonstrated efficacy that preferentially affects cardiac cells and spares surrounding structures such as GP through irreversible electroporation which does not lead to chronic fibrosis like RFA or CRYO. Elevations in the marker the marker P terminal force (PTF) have been associated with AF/stroke and have been known to correlate with atrial fibrosis, and higher PTF after cryoablation for patients with paroxysmal AF has been associated with an increased risk of recurrence. The differences in P-wave parameters pre and post PFA have not been studied. Objective: To investigate the differences in P-wave parameters after PFA and compare them to CRYO. Methods: We identified 40 patients who underwent PFA (20 patients) or CRYO (20 patients) for paroxysmal AF and compared P-wave parameters including duration and amplitude in leads aVF, V1 and the PTF calculated as the duration x amplitude of the terminal negative component of the P-wave in V1. Data were obtained from 12-lead electrocardiograms obtained pre and post ablation. Results: The mean age of patients in our study was 61 with 75% male and 33% on antiarrythmics. We noticed a significant reduction in PTF for patients who underwent CRYO (54 mVmS at baseline compared to 36.8 mVmS after CRYO, p = 0.04) and no significant reduction in PTF for patients who underwent PFA (46 mVmS at baseline compared to 38 mVmS after PFA, p = 0.27). There was also a significant increase in HR after CRYO (65 bpm at baseline compared to 78 bpm after CRYO, p=0.01) and no significant change in HR after PFA (61 bpm at baseline compared with 60 bpm after PFA, p=0.8). There was no statistical difference in both groups looking at aVF or total V1 duration or amplitude pre and post ablation. Conclusions: CRYO leads to a significant change in PTF after ablation while PFA does not, consistent with the notion that PFA does not lead to fibrosis and PTF is not a useful marker for measuring risk of recurrence of AF post PFA.

Cardioneuroablation for the treatment of carotid sinus syndrome

Abstract Introduction Carotid sinus syndrome (CSS), characterized by exaggerated vagal responses leading to asystolic pauses with carotid sinus massage (CSM), often necessitates pacemaker implantation. This study investigates cardioneuroablation (CNA) as an alternative management strategy for CSS. Methods Prospective study of consecutive patients referred for CNA. All patients underwent CSM, atropine test, 24-hour Holter monitoring and SF-36 quality of life questionary before the procedure and at 6 months. The objective of the study was to assess syncope free survival, grade of cardioinhibition with CSM and heart rate variation (HRV) and quality of life after the procedure. Results A total of 13 patients (84.6% male, mean age 63.8 ± 12.3 years) were included. After a median follow-up of 11.2 (10.6-16.3) months, none of the patients experienced syncope (0%) and none of the patients required pacemaker implantation. After the procedure all the patients had a negative CSM and only one patient (7.7%) had a positive CSM at 6 months (Figure 1). There was an improvement in the energy and health change items in the SF-36 quality of life questionary (Figure 2). There was a reduction in HR increase in the atropine test at 6 months (pre-CNA: 66% (52-84) vs. post-CNA 27.4% (21.9-90.9); p=0.027) and in most of the 24-hour Holter monitoring HRV parameters. Conclusions Cardioneuroablation emerges as a promising and effective alternative to pacemaker implantation in managing cardioinhibitory CSS. Further research is warranted to solidify these findings and explore the long-term effects of CNA in this scenario.Figure 1Figure 2

Endocardial ablation of ganglionated plexus for the treatment of carotid sinus syndrome.

Carotid sinus syndrome (CSS), characterized by exaggerated vagal responses leading to asystolic pauses with carotid sinus massage (CSM), often necessitates pacemaker implantation. This study investigates cardioneuroablation (CNA) as an alternative strategy for CSS. Prospective study of consecutive patients referred for CNA due to CSS. All patients underwent CSM, atropine test and 24-h Holter monitoring before the procedure and at 6 months. The primary objective was the absence of any cardioinhibitory response to CSM following CNA. Secondary objectives included the combined endpoint of syncope and presyncope-free survival, pacemaker-free survival, differences in heart rate variation (HRV), as well as differences in the pre- and postprocedure atropine tests and in the SF-36 quality-of-life questionnaire. A total of 13 consecutive patients (84.6% male, mean age 63.8 ± 12.3 years) were included. CSM revealed a symptomatic asystolic pause in all patients before CNA (7.3 [5.6-10.5] s). After the procedure, all the patients had a negative CSM, and only one patient (7.7%) had a positive CSM at 6 months. After a median follow-up of 11.2 (10.6-16.3) months, syncope or presyncope-free survival was 84.6%, and none required pacemaker implantation. There was an improvement in the energy and health change items in the SF-36 questionnaire. There was a reduction in HR increase in the atropine test at 6 months (pre-CNA: 66% [52-84] vs. post-CNA 26.0% (19.8-29.3]; p = .008) and in HRV parameters. In this proof-of-efficacy study, performed in patients affected by asystolic CSS, CNA was effective in reducing the rate of cardioinhibitory responses, suggesting a potential efficacy in also reducing syncopal recurrences. Controlled trials are warranted to corroborate clinical findings.

Effect of Lead, Cadmium, and Their Combination on the Heart Rate Regulation in Nonlinear Rats.

We studied heart rate variability (HRV) and the concentrations of heavy metals in the heart tissue after 14-fold peroral administration of heavy metal salts: lead acetate (50 mg/kg), cadmium chloride (5 mg/kg), and their combination. After administration of lead, its concentration in the myocardium exceeded the control values by 1.2 times or did not change in case of combination with cadmium; after administration of cadmium, its concentration in the myocardium exceeded the control value by 6.1 times or by 2 times after combined administration. After lead administration, a moderate increase in HR, low values of stress and centralization indices, and an increase in the power in all ranges of the HRV spectrum were recorded. After cadmium intoxication, a tendency to a decrease in heart rhythm variability, a moderate increase in HR, stress and centralization indices, and an increase in the contribution of VLF waves in the HRV spectrum were observed. After combined administration, a pronounced increase in HR and stress index and a moderate increase in the centralization of heart rhythm control were recorded, which was similar to changes in HRV observed after administration of cadmium alone. In the experiment, the concentration of cadmium in the myocardium increased to a much greater extent than the concentration of lead. After lead administration, the autonomous type of regulation persisted and parasympathetic influences increased. Cadmium apparently acts as a stress factor and increases the role of sympathoadrenal influences and central ergotropic structures in the heart rhythm regulation.

SP5.11 - The Impact of Total Pelvic Exenteration on Surgeon Fatigue: Is it time we monitor our surgeons?

Abstract Aims Total pelvic exenteration surgery (TPE) is a radical procedure requiring significant surgeon mental and physical stamina. Literature surrounding surgeon fatigue remains minimal. This study investigated impact of performing high complexity TPE on surgeon fatigue. Methods Two surgeons ([#1]/[#2]) delivering high complexity TPEs between 1st November 2022 – 1st September 2023 in a tertiary centre (110/annum) were assessed using a predefined protocol. Surgeon heart rate, concentration performance (d2 Brickencamp test) and Surgery Task Load Index (SURG-TLX) were measured across intraoperative stages (mobilisation, dissection, reconstruction). Surgeons underwent baseline cardiopulmonary exercise testing. Results All-cause mortality rate was 0% at median follow up of 3 (1-11) months. Baseline VO2 max and anaerobic thresholds: #1 = 37.6 mL/kg/min, 50% and #2 = 54.3 mL/kg/min, 70%. Mean error rate (ER): d2 test 1 and 2: #1 = 3.58% [0.91%–8.60%] [SD = 3.16, 95% CI = 0.27 to 6.91], #2 = 4.46% [1.37%–7.23%] [SD = 2.55, 95% CI = 1.79 to 7.14]. Greater HR deviation correlated with higher test 2 ER for both subjects (p>0.05). During dissection, mean HR increased from baseline: mean of 70% [#1] and 51.9% [#2]; max HR 106.7% [#1] and 111.5% [#2]. Subjects demonstrated smaller mean HR increase from baseline during dissection operating together versus with junior trainees (#1 = 46.7% [p< 0.001] and #2 = 48.1% [p>0.05]). SURG-TLX situational stress domain was most impacted. Conclusions Surgeon HR fluctuations corresponded with significant intraoperative events. Assistant dependent HR fluctuation and increased average d2 ER was demonstrated by greater HR deviations during dissection. Further investigation optimising strategies minimising surgeon fatigue is required.

Pausing propofol during neurosurgery to record intraoperative electrocorticography is feasible;10 years of clinical experience

ObjectiveIntraoperative electrocorticography (ioECoG) during neurosurgery is influenced by anesthetics. In our center we stop the propofol to enable interpretation of ioECoG. We reported our clinical experience and evaluated awareness and hemodynamic changes during the propofol-free periods (PFP). MethodsWe retrospectively included surgeries with paused propofol administration to record ioECoG (period: 2008–2019). Clinical reports were screened for symptoms of awareness. We compared mean arterial blood pressure (MAP; mmHg) and heart rate (HR;bpm) during PFP to baseline (ten minutes preceding PFP). An increase > 15% was defined as clinically relevant. The association between hemodynamic changes and clinical characteristics was analyzed using logistic regression models. ResultsPropofol administration was paused 742 times in 352 surgeries (mean PFP duration 9 ± 5 min). No signs of awareness were reported. MAP and HR increased > 15% in 54 and six PFPs. Five PFPs showed both MAP and HR increases. Prolonged PFP was associated with having MAP and HR increase during surgery (OR=1.18, 95%CI [1.12–1.26]). ConclusionsSigns of inadequate sedation depth were rare. MAP and HR increases were related to the length of PFP. SignificanceWe summarize 10 years of clinical experience with pausing propofol administration during epilepsy surgery to record ioECoG without evidence of awareness.

Metabolic Heat Production Modulates the Cardiovascular Drift-V̇O2max Relationship Independent of Aerobic Fitness in Women.

The purpose of this study was to test the hypothesis that cardiovascular (CV) drift and associated decrements in maximal oxygen uptake (V̇O2max) are greater in high-fit compared to low-fit women during exercise at the same %V̇O2max, but comparable at the same rate of metabolic heat production. Six high-fit (HI) and 6 low-fit (LO) women cycled in 35 °C for 15 min or 45 min at the same relative intensity (60% V̇O2max; 15REL and 45REL) or fixed rate of heat production (500 W; 15FX and 45FX), immediately followed by a GXT to measure V̇O2max. The separate 15- and 45-min trials permitted measurements of V̇O2max over the same time interval as CV drift. During 45REL, higher heat production in HI (496 ± 51 W vs. 364 ± 44 W in LO) resulted in greater end-exercise core temperature (38.7 ± 0.4 °C vs. 38.2 ± 0.1 °C, P = 0.03); greater increases in HR [15 beats·min-1 (10%) vs. 10 beats·min-1 (6%), P = 0.03] and decreases in SV [11 mL·beat-1 (16%) vs. 5 mL·beat-1 (8%), P = 0.001]; and larger reductions in V̇O2max (16% vs. 5%, P = 0.04) compared to LO. During 45FX, temperature responses, CV drift and decreased V̇O2max were not different between groups (all P > 0.05), despite differences in %V̇O2max (60% vs. 75% for HI and LO, respectively). We conclude metabolic heat production modulates the CV drift-V̇O2max relationship, independent of fitness level. These results support previous findings showing the magnitude of CV drift is proportional to reductions in V̇O2max.

Microplastic-induced hepatic adverse effects evaluated in advanced quadruple cell human primary models following three weeks of repeated exposure

Nano and microplastics are defined as particles smaller than 100 nm and 5 mm respectively. The widespread production and use of plastics in everyday life has resulted in significant accumulation of plastic debris in the environment. Over the last two decades there are increased concerns regarding the potential entry and accumulation of plastics in the human body with ingestion being one of the most important routes of exposure. However, the magnitude and nature of potential toxic effects of plastic exposure to human health is not yet fully understood. The liver is the body's principal detoxification organ and critically to this study recognized as the main accumulation site for particulates. In this study as the first of its kind the health impacts of long term low repeated polystyrene microplastics (1 and 5 μm) exposure was investigated in a functionally active 3D liver microtissue model, composed of primary human hepatocytes, Kupffer cells, sinusoidal endothelial cells and hepatic stellate cells. The highlight from the data includes microplastic-induced dose (3.125–25 μg/ml) and time dependent (up to 504 h) increase in cell death and inflammation manifested by enhanced release of IL6, IL8 and TNF-α. The exposure to repeated dosing of the plastics also resulted in notable pathology manifested as aberrant tissue architecture, such as dilated bile canaliculi and large lipid droplets inside the hepatic cells. This toxicity matched extremely well to the accumulation of the materials with the cells of microtissue predominately in the organ macrophages. This study highlights the real issue and danger of microplastic exposure with potential for long-term accumulation and adverse effects of non-biodegradable plastics within the liver.

Analysis of heart rate variability during emergency flight simulator missions in fighter pilots

IntroductionManaging emergency situations in different simulated flight segments can entail a workload that could affect the performance of military pilots. The aim was to analyse the modifications in neurovegetative balance...

Differential hemodynamic adaptations to tilt test in patients with idiopathic atrial fibrillation

AbstractThe hemodynamic response during the transition from the supine to standing position in idiopathic atrial fibrillation (AF) patients is not completely understood. This study aimed to analyze the hemodynamic changes that occur during the head‐up tilt test in idiopathic AF patients. We investigated the hemodynamic changes during the head‐up tilt test with impedance cardiography in 40 AF patients (12 with AF rhythm‐AFr and 28 with sinus rhythm‐AFsr) and 38 non‐AF controls. Patients with AFr had attenuated SVI decrease after standing when compared to AFsr and non‐AF [ΔSVI in mL/m2: −1.3 (−3.4 to 1.7) vs. −6.4 (−17.3 to −0.1) vs. −11.8 (−18.7 to −8.0), respectively; p < 0.001]. PVRI decreased in AFr but increased in AFsr and non‐AF [ΔPVRI in dyne.seg.m2/cm5: −477 (−1148 to 82.5) vs. 131 (−525 to 887) vs. 357 (−29 to 681), respectively; p < 0.01]. Similarly, compared with non‐AF patients, AFr patients also had a greater HR and greater CI increase after standing. The haemodynamic response to orthostatic challenge suggests differential adaptations between patients with AF rhythm and those reverted to sinus rhythm or healthy controls. Characterizing the hemodynamic phenotype may be relevant for the individualized treatment of AF patients.

Endocardial ablation of ganglionated plexus for the treatment of carotid sinus syndrome

Abstract Introduction Carotid sinus syndrome (CSS), characterized by exaggerated vagal responses leading to asystolic pauses with carotid sinus massage (CSM), often necessitates pacemaker implantation. This study investigates cardioneuroablation (CNA) as an alternative management strategy for CSS. Methods Prospective study of consecutive patients referred for CNA. All patients underwent CSM, atropine test, 24-hour Holter monitoring and SF-36 quality of life questionary before the procedure and at 6 months. The objective of the study was to assess syncope free survival, grade of cardioinhibition with CSM and heart rate variation (HRV) and quality of life after the procedure. Results A total of 13 patients (84.6% male, mean age 63.8 ± 12.3 years) were included. After a median follow-up of 9.2 (8.6-14.3) months, none of the patients experienced syncope (0%) and none of the patients required pacemaker implantation. After the procedure all the patients had a negative CSM and only one patient (7.7%) had a positive CSM at 6 months (Figure 1). There was an improvement in the energy and health change items in the SF-36 quality of life questionary. There was a reduction in HR increase in the atropine test at 6 months (pre-CNA: 66% (52-84) vs. post-CNA 27.4% (21.9-90.9); p=0.027) and in most of the 24-hour Holter monitoring HRV parameters (Figure 2). Conclusions Cardioneuroablation emerges as a promising and effective alternative to pacemaker implantation in managing cardioinhibitory CSS. Further research is warranted to solidify these findings and explore the long-term effects of CNA in this scenario.Maximum RR interval with CSMHeart rate increase in the atropine tes

Esophageal pressure monitoring and its clinical significance in severe blast lung injury.

The incidence of blast lung injury (BLI) has been escalating annually due to military conflicts and industrial accidents. Currently, research into these injuries predominantly uses animal models. Despite the availability of various models, there remains a scarcity of studies focused on monitoring respiratory mechanics post-BLI. Consequently, our objective was to develop a model for monitoring esophageal pressure (Pes) following BLI using a biological shock tube (BST), aimed at providing immediate and precise monitoring of respiratory mechanics parameters post-injury. Six pigs were subjected to BLI using a BST, during which Pes was monitored. We assessed vital signs; conducted blood gas analysis, hemodynamics evaluations, and lung ultrasound; and measured respiratory mechanics before and after the inflicted injury. Furthermore, the gross anatomy of the lungs 3h post-injury was examined, and hematoxylin and eosin staining was conducted on the injured lung tissues for further analysis. The pressure in the experimental section of the BST reached 402.52 ± 17.95KPa, with a peak pressure duration of 53.22 ± 1.69ms. All six pigs exhibited an anatomical lung injury score ≥3, and pathology revealed classic signs of severe BLI. Post-injury vital signs showed an increase in HR and SI, along with a decrease in MAP (p < 0.05). Blood gas analyses indicated elevated levels of Lac, CO2-GAP, A-aDO2, HB, and HCT and reduced levels of DO2, OI, SaO2, and OER (p < 0.05). Hemodynamics and lung ultrasonography findings showed increased ELWI, PVPI, SVRI, and lung ultrasonography scores and decreased CI, SVI, GEDI, and ITBI (p < 0.05). Analysis of respiratory mechanics revealed increased Ppeak, Pplat, Driving P, MAP, PEF, Ri, lung elastance, MP, Ptp, Ppeak - Pplat, and ΔPes, while Cdyn, Cstat, and time constant were reduced (p < 0.05). We have successfully developed a novel respiratory mechanics monitoring model for severe BLI. This model is reliable, repeatable, stable, effective, and user-friendly. Pes monitoring offers a non-invasive and straightforward alternative to blood gas analysis, facilitating early clinical decision-making. Our animal study lays the groundwork for the early diagnosis and management of severe BLI in clinical settings.

DEVELOPMENT TRENDS IN HUMAN RESOURCE MANAGEMENT OF AGRICULTURAL ENTERPRISES IN THE CONTEXT OF DIGITALISATION

The subject of the study is the development of personnel management of agricultural enterprises in the context of digitalisation. Methodology. The study uses general scientific methods, in particular, theoretical generalisation, methods of analysis and synthesis, statistical analysis, as well as graphical methods to visualise the results of the study. The aim is to study the main trends in the development of personnel management of agricultural enterprises in the context of digitalisation. Results. The main trends in the digitalisation of HR management in agricultural enterprises indicate the widespread use of modern digital technologies to optimise and improve the efficiency of HR management in agriculture. One of the key trends is the use of digital tools in recruitment and selection, including websites and online platforms for job search, social media for attracting candidates, automated candidate management systems and analytical tools for assessing candidates. Digitalisation allows agricultural enterprises to respond more efficiently and quickly to staffing needs, attract and retain talented employees, and increase the overall productivity and competitiveness of the industry. Such technological changes are becoming a key element of agricultural business development in the current environment and play a significant role in ensuring its success and sustainability in the future. The main trends in the digitalisation of HR management in agricultural enterprises include several key aspects aimed at using modern digital technologies to optimise HR management and increase efficiency. First, digital tools such as online platforms, websites and social media are used in recruitment and selection to attract and select candidates for vacant positions. The second trend is the automation of administrative HR processes. Digital systems can automate time tracking, payroll, leave calculation and other aspects of HR management, freeing up managers' time for more strategic tasks. The third trend is the development of online learning and electronic platforms for staff development. The use of digital tools for training and development of employees allows them to improve their skills and adapt them to changes in the industry. The fourth trend is the use of analytics to make management decisions. HR data analysis allows managers to obtain objective information about the productivity and needs of their staff, which helps them make informed management decisions. In addition, the development of flexible working arrangements and remote work is another important trend. Digital technologies provide the ability to work from anywhere, which helps to attract and retain talent regardless of where they live.

Electrocardiographic and Autonomic Nervous System Changes after Changes in the Posture of Children and Adolescents with Duchenne Muscular Dystrophy.

Duchenne Muscular Dystrophy (DMD) is a rare inherited neuromuscular disease. At first, cardiac involvement may be asymptomatic. Therefore, assessing patients using non-invasive methods can help detect any changes. Analyze the electrocardiogram (ECG) test and heart rate variability (HRV) of the DMD group and compare the information with that of the age-matched control group. A prospective study with 27 male patients with DMD (11.9 years old), who underwent clinical evaluation, ECG, echocardiogram, and Holter monitoring. ECG (200% increase) was assessed by two independent observers. HRV was measured over time (24 h) and in the frequency domain, in the supine and sitting positions. The healthy group consisted of nine patients (11.0 years old). A value of p < 0.05 was considered statistically significant. The mean ejection fraction (EF) was 60% (34 to 71%). The Kappa coefficient for ECG measurements ranged from 0.64 to 1.00. An increase in the R/S ratio in V1 was observed in 25.9% of the subjects, pathological Q wave in 29.6%, and fragmented QRS in 22.2% in inferior/high lateral regions, with a negative correlation with EF (p = 0.006). There was low HRV, without the influence of any variable, including treatment. With the change in position, there was an increase in HR (p = 0.004), but there was no change in HRV. The LF/HF ratio was 2.7 in the DMD group and 0.7 in the control group (p = 0.002). In DMD subjects, prominent R waves in V1 and changes in the inferior/high lateral regions occurred in almost 30% of the cases. Lower vagal tone was observed without the influence of the variables age, ejection fraction, QT dispersion, and treatment. Despite the increase in HR, there was no adequate HRV response to the change in position.

Impact of Chronotropic Incompetence and Correlation with Exercise Tolerance in Patients with Implantable Cardiac Devices Undergoing a Phase II Cardiac Rehabilitation Program Article Sidebar

Objective: Since patients with implantable cardiac devices tend to develop chronotropic incompetence (CI) associated with the effect of the device itself or the pharmacological effect of the underlying disease, CI could act as a limiting factor in improving exercise tolerance in patients undergoing cardiac rehabilitation program, since an increase in HR is a crucial part in improving cardiac output as a central component of oxygen consumption (VO2). However, it has been observed that there could be other factors contributing to the improvement in exercise tolerance in these patients regardless of the presence of CI. The aim of this research is to clarify the effect of chronotropic incompetence on the improvement in exercise capacity in patients with implantable cardiac devices after a phase II cardiac rehabilitation program (CRP). Methods: Quasi-experimental study applied to patients with implantable cardiac devices (ICDs, CRT, pacemakers) undergoing a supervised concurrent CRP, lasting 4-6 weeks, at an intensity between 65-80% of heart rate reserve (HRR), associated with kinesiotherapy sessions (with strength and endurance training and other biomotor qualities) and interdisciplinary intervention, education, and counseling. CI was calculated using the chronotropic response index, and METs-load measurement was performed at the beginning and at the end of the intervention. Results: Forty patients with a mean age of 61.4 years were included, mostly male (29) 72.5%, (23) 57.5% diagnosed with heart failure, and regarding the type of device, pacemakers (20) 50%, implantable cardioverter-defibrillator (ICD) (12) 30%, and cardiac resynchronization therapy with defibrillator (CRT-D) (20) 8%, of the total patients (35) 87.5% presented chronotropic incompetence and only (5) 12.5% with normal chronotropic response at the end of the intervention. A significant decrease in the chronotropic response index from 0.70 to 0.47 (p &lt;0.001) and a significant increase in METs-load from 5.47 to 9.35 (p &lt;0.001) were found. The value of the differential between initial and final METs (delta-METs) was obtained for both groups, observing a significant increase between initial and final METs in favor of patients with CI (3.8 Vs 3.5, p&lt;0.012) at the end of the intervention. A significant moderate negative correlation (r=-0.395, Spearman, p&lt;0.012) was determined between the degree of CI and final METs-load. Conclusions: It was observed that patients with implantable cardiac devices undergoing a CRP show an increase in exercise tolerance measured in METs, with an inversely proportional correlation to chronotropic incompetence.

Physical functional recovery in the early period after hospitalization for COVID-19: impact of hypertension and outcome prediction model

The aim – to study the influence of hypertension (HT) on the dynamics of natural recovery of physical functional status in the early period after hospitalization for COVID-19 and to develop a model for predicting recovery results at 1 month after discharge.Materials and methods. 221 hospitalized patients with COVID-19 (age 53.4±13.6 years, 53 % women) were included in the study, 176 of whom underwent the 6-minute walk test (6MWT) using an extended protocol within 1-2 days before discharge. A repeat visit to assess the dynamics of natural recovery was performed at 1 month after discharge.Results and discussion. Pre-discharge 6-minute walk distance was 378±57 m in patients with HT and 418±75 m without it, p=0.001, during the second visit – 440±52 versus 478±68, p=0.002; the achieved percentage of the individually predicted distance was 67.4±10.5 vs. 69.5±13.6 % and 81.6±9.9 vs. 81.9±15.7 %, respectively, p&gt;0.05 for both visits. The increase in heart rate during the test at visit 1 was 18.5±8.3 versus 30.1±19.3 bpm, p&lt;0.001, the percentage of chronotropic reserve utilizatoin was 21.3±9.6 % versus 29.2±11.4 %, p&lt;0.001. During the second visit, residual manifestations of this trend were observed, with an increase in HR by 24.0±9.5 vs. 30.8±12.1, p=0.003 and the use of chronotropic reserve of 28.1±10.1 % vs. 33.4±12.4 %, respectively, p=0.029. The developed multivariate linear regression model explained 59 % of the variability in the achieved percentage of the individually predicted 6-minute walk distance at 1 month after discharge. The use of machine learning allowed to create an artificial neural network based regression model that used age, height, use of remdesivir in treatment, and SBP and DBP values at the time of discharge as predictors, and explained 90 % of observed variability.Conclusions. Hospitalized patients with COVID-19 were characterized by a decrease in the general physical functional status as assessed by 6MWT at the time of discharge and incomplete recovery after 1 month. Presence of hypertension was associated with more pronounced disturbances of the autonomic regulation of heart rate, but did not affect the reached percentage of the distance walked. The proposed artificial neural network based regression model allows for a high accuracy prediction of the 6MWT results at 1 month after discharge, which can be used in the selection of candidates for cardiopulmonary rehabilitation programs.

The influence of extreme thermal stress on the physiological and psychological characteristics of young women who sporadically use the sauna: practical implications for the safe use of the sauna.

Many individuals who use the sauna at a temperature of 120°C of higher are not aware of the negative consequences of extreme thermal stress. Despite extensive research into sauna use, the impact of extreme thermal stress on the physiological and psychological characteristics of sauna users have not been examined to date. The aim was to determine the effect of 20 min sauna sessions with a temperature of 80°C and 120°C on the physiological and psychological characteristics of women who sporadically visit the sauna. The study was conducted on 22 full-time female university students. Physical activity (PA) levels were evaluated with the Polish short version of the International Physical Activity Questionnaire (IPAQ). Anthropometric characteristics were measured before the first sauna session by the InBody270 body composition analyzer. Physiological parameters, including heart, energy expenditure, physical effort, and blood pressure (systolic blood pressure - SBP, and diastolic blood pressure - DBP), were assessed indirectly using Polar V800 heart rate monitors and the Omron M6 Comfort blood pressure monitor. The participants' wellbeing was assessed with the Profile of Mood States (POMS) questionnaire. The presence of significant correlations between heat exhaustion and heat stress variables and syncope during the second sauna session was examined with the use of classification and regression trees (CRT) and the cross-validation technique. Twenty-minute sauna sessions with a temperature of 80°C and 120°C induced a significant (p < 0.001) decrease in the values of SBP (excluding the temperature of 120°C), DBP, and body mass, as well as a significant increase in HR and forehead temperature. Exposure to a temperature of 80°C led to a significant (p < 0.001) increase in vigor with a simultaneous decrease in tension, depression, anger, fatigue, and confusion. In turn, sauna bathing at a temperature of 120°C had an opposite effect on the above mood parameters. Vomiting and confusion were the main predictors of syncope that occurred in some of the surveyed women. Excessive air temperature can induce symptoms characteristic of heat exhaustion and heat stress nausea, heavy sweating, fast weak or strong HR, high body temperature, and confusion. Therefore, sauna bathing at a temperature of 80°C can be recommended to women who sporadically use the sauna, whereas exposure to a temperature of 120°C is not advised in this group of sauna users. The present findings provide highly valuable inputs for managing wellness and SPA centers.

Physicochemical properties of flowable composites using isobornyl methacrylate as diluent monomer.

this study sought to evaluate the effect of isobornyl methacrylate (IBOMA) as a diluent monomer on the physicochemical properties of experimental flowable resin composites. the organic resin matrix of a modal flowable resin composite was formulated with 50 wt.% of bisphenol-A-glycidyl methacrylate (Bis-GMA) and 50 wt.% of a diluent monomer, in which IBOMA was used as a combining or substituent diluent monomer to triethylene glycol dimethacrylate (TEGDMA). The resin matrices were filled with 55 wt.% particles, of which 10 wt.% was 0.05-μm fumed silica, and 45 wt.% was 0.7-μm BaBSiO2 glass. Polymerization shrinkage stress (PSS; n=10), degree of conversion (DC; n=3), maximum rate of polymerization (Rpmax; n=3), film thickness (FT; n=10), sorption (Wsp; n=10), solubility (Wsl; n=10), flexural strength (FS; n=10), flexural modulus (FM; n=10), Knoop microhardness (KH; n=10), and microhardness reduction after chemical softening (HR; n=10) were evaluated. Data were analyzed using one-way ANOVA, followed by Tukey's test (α=0.05; β=0.2). the results showed that the substitution or addition of IBOMA reduced FT (p=0.001), PSS (p=0.013), Rpmax (p=0.001), DC (p=0.001), FM (p=0.006) Wsp (p=0.032), and Wsl (p=0.021). However, when used as a complete substituent, IBOMA demonstrated significantly lower FS (p=0.017) and KH (p=0.008), while TEGDMA demonstrated significantly lower HR (p=0.022). the flowable composite containing IBOMA combined with TEGDMA showed no effect in KH and FS and effectively reduced the PSS, RP, FT, Wsp, and Wsl. However, it showed a reduction in DC, FS, and an increase in HR.

RELAÇÃO ENTRE O PERFIL COGNITIVO E MOTOR EM INDIVÍDUOS COM SÍNDROME DE DOWN POR MEIO DA EXECUÇÃO DE TAREFA VIRTUAL

The objective of the study was to verify if there is a relationship between the cognitive and motor profile in individuals with Down Syndrome (DS). Cross-sectional study (CAAE:58089622.5.0000.5515), with 27 individuals, 15 from the SD Group with a mean age of 17.5±5.5 years, and 12 from the Control Group, with a mean age of 19.1±5.2 years, evaluated by the Mini Mental State Examination (MMSE) and MoveHero software (to analyze the motor profile), the Borg Scale was also used. The SD group had a statistically significant MMSE score when compared to the Control group (p&lt;0.001). Post-hoc comparisons showed that the SD Group had a greater EA in MoveHero (p= 0.008) and the SD Group had an increase in HR from rest to the end of the activity (p= 0.050). Thus, it can be concluded that individuals with down syndrome have a greater motor performance deficit, under the influence of the cognitive profile.