Significant Changes In Heart Rate Research Articles

Concentration-QTc modeling of sitravatinib in patients with advanced solid malignancies.

Sitravatinib (MGCD516) is an orally available, small molecule, tyrosine kinase inhibitor that has been evaluated in patients with advanced solid tumors. Concentration-corrected QT interval (QTc; C-QTc) modeling was undertaken, using 767 matched concentration-ECG observations from 187 patients across two clinical studies in patients with advanced solid malignancies, across a dose range of 10-200 mg, via a linear mixed-effects (LME) model. The effect on heart rate (HR)-corrected QT interval via Fridericia's correction method (QTcF) at the steady-state maximum concentration (Cmax,ss) for the sitravatinib proposed therapeutic dosing regimen (100 mg malate once daily [q.d.]) without and with relevant intrinsic and extrinsic factors were predicted. No significant changes in HR from baseline were observed. Hysteresis between sitravatinib plasma concentration and change in QTcF from baseline (ΔQTcF) was not observed. There was no significant relationship between sitravatinib plasma concentration and ΔQTcF. The final C-QTc model predicted a mean (90% confidence interval [CI]) ΔQTcF of 3.92 (1.95-5.89) ms and 2.94 (0.23-6.10) ms at the proposed therapeutic dosing regimen in patients with normal organ function (best case scenario) and patients with hepatic impairment (worst-case scenario), respectively. The upper bounds of the 90% CIs were below the regulatory threshold of concern of 10 ms. The results of the described C-QTc analysis, along with corroborating results from nonclinical safety pharmacology studies, indicate that sitravatinib has a low risk of QTc interval prolongation at the proposed therapeutic dose of 100 mg malate q.d.

Metformin as an alternative therapeutic intervention in hemorrhagic shock

Hemorrhagic shock (HS) continues to significantly contribute to civilian and military mortality, underscoring the critical need for new resuscitation strategies. Recent discussions have emphasized the pivotal role of impaired oxygen delivery and cellular metabolism in exacerbating HS-related damage. Metformin, a well-established diabetes medication, exhibits promising potential to enhance cellular metabolism and activate pathways linked to improved oxygen uptake, thereby optimizing cellular energy management. Thus, this study aimed to assess metformin's effcacy in ameliorating outcomes in animals subjected to HS. To achieve this, Wistar rats were surgically prepared with femoral artery and vein catheters. HS was induced by controlled blood withdrawal to maintain a mean arterial pressure (MAP) within the range of 35-40 mmHg for 90 minutes. Throughout the protocol, blood pressure (BP) and heart rate (HR) were assessed. The animals were divided into two groups: Lactated Ringer's solution (LR) and LR treated with Metformin (Met). Metformin was administered in three bolus injections: at the start of resuscitation (10mg), 45 minutes into resuscitation (5mg), and 90 minutes into resuscitation (5mg). After 120 minutes, the animals were euthanized, and blood samples were collected for subsequent analysis, including metabolomic profiling of the tricarboxylic acid (TCA) cycle, amino acids, and lipids. Additionally, trypsin-like enzyme activity in the plasma and markers of brain injury were evaluated. Animals treated with Met showed significantly higher systolic blood pressure after resuscitation (LR: 74±5 mmHg vs. LR+Met: 94±3 mmHg) with no significant changes in HR observed. Brain injury markers such as GFAP (Glial fibrillary acidic protein), S100B (astrocytic protein specific to the central nervous system), Tau (microtubule-associated protein), and NFL (axonal protein neurofilament light) were assessed. Animals reperfused with LR and treated with Met displayed a 22% reduction in GFAP levels compared to those reperfused with LR alone, while other markers remained unchanged. Met treatment also led to a reduction in plasmatic metabolites, including Lactate (30%), Succinate (24%), and Fumarate (22%), along with an increase in Citrate (23%) and α-ketoglutarate (24%)—all constituents of the TCA cycle. Additionally, an increase in amino acid metabolites and a decrease in lipid metabolites were observed. Recent research has suggested that HS results in elevated levels of trypsin-like enzymes in the plasma and that inhibiting these enzymes might improve outcomes during resuscitation. Our study revealed that treatment with Met reduced approximately 60% of trypsin-like enzyme activity in the plasma compared to the LR-only group. In conclusion, our study demonstrates that Met, when administered in conjunction with LR as a resuscitation solution, significantly enhances post-resuscitation BP compared to LR alone. This improved outcome may be associated with alterations in the TCA cycle and the inhibition of trypsin-like enzyme activity. However, further investigations are necessary to elucidate the precise role of these changes in the observed enhancements within this experimental model. This work was supported by National Institutes of Health grant R01HL162120. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Effect of series of periodic limb movements in sleep on blood pressure, heart rate and high frequency heart rate variability.

The phenomenon known as periodic limb movements in sleep (PLMS) has been linked to a change in autonomic nervous system (ANS) activity and its effect on circulatory regulation. Autonomic dysfunction or dysregulation in patients with PLMS has been described in some domains; however, any relationship between heart rate variability (HRV) and PLMS has not been clearly established. HRV analysis is a recognised, non-invasive research method that describes the influence of the ANS on heart rate (HR). The aim of our study was to further investigate the dysregulation of autonomic HR control in patients with PLMS. We undertook a retrospective analysis of the polysomnographic (PSG), demographic and medical data of five patients with a total number of 1,348 PLMS. We analysed HR, HRV HF, systolic blood pressure (SBP), and diastolic blood pressure (DBP) for 10 heartbeats before the series of PLMS and 10 consecutive heartbeats as beat-to-beat measurements. The presented method of using successive, short, 10 RR interval segments refers to the time-frequency measurement, which is very clear and useful for presenting changes in the calculated parameters over time and thereby illustrating their dynamics. This method allowed us to assess dynamic changes in HRV HF during successive PLMS series. Statistical analysis was performed using IBM SPSS Statistics (v. 28.0.0.0). The Kruskal-Wallis test was performed to find statistically significant changes from baseline. No statistically significant changes in HR, SBP, or DBP were found in our group, although an increase in the value of the HRV HF was noted, suggesting an increase in intracardiac parasympathetic activity during the subsequent series of PLMS. Our study indicates an increase in parasympathetic activity during the appearance of successive PLMS, which, with the simultaneous lack of changes in HR, may suggest an increase in sympathetic activity, and therefore the appearance of so-called 'autonomic co-activation' resulting in the possibility of life-threatening cardiac events. Our findings add to the literature information regarding HRV in PLMS, and highlight the need for further studies to elucidate the effects of these conditions on the ANS, and on cardiovascular health.

Cardiorespiratory Responses to Acute Intermittent Hypoxia in Humans With Chronic Spinal Cord Injury.

Brief exposure to repeated episodes of low inspired oxygen, or acute intermittent hypoxia (AIH), is a promising therapeutic modality to improve motor function after chronic, incomplete spinal cord injury (SCI). Although therapeutic AIH is under extensive investigation in persons with SCI, limited data are available concerning cardiorespiratory responses during and after AIH exposure despite implications for AIH safety and tolerability. Thus, we recorded immediate (during treatment) and enduring (up to 30 min post-treatment) cardiorespiratory responses to AIH in 19 participants with chronic SCI (>1 year post-injury; injury levels C1 to T6; American Spinal Injury Association Impairment Scale A to D; mean age = 33.8 ± 14.1 years; 18 males). Participants completed a single AIH (15, 60-sec episodes, inspired O2 ≈ 10%; 90-sec intervals breathing room air) and Sham (inspired O2 ≈ 21%) treatment, in random order. During hypoxic episodes: (1) arterial oxyhemoglobin saturation decreased to 82.1 ± 2.9% (p < 0.001); (2) minute ventilation increased 3.83 ± 2.29 L/min (p = 0.008); and (3) heart rate increased 4.77 ± 6.82 bpm (p = 0.010). Considerable variability in cardiorespiratory responses was found among subjects; some individuals exhibited large hypoxic ventilatory responses (≥0.20 L/min/%, n = 11), whereas others responded minimally (<0.20 L/min/%, n = 8). Apneas occurred frequently during AIH and/or Sham protocols in multiple participants. All participants completed AIH treatment without difficulty. No significant changes in ventilation, heart rate, or arterial blood pressure were found 30 min post-AIH p > 0.05). In conclusion, therapeutic AIH is well tolerated, elicits variable chemoreflex activation, and does not cause persistent changes in cardiorespiratory control/function 30 min post-treatment in persons with chronic SCI.

Comparison of First Analgesic Demand in Post-Operative Period Among Diclofenac Group Versus Paracetamol Group

Background: Pain after major surgery causes delays in patients' postoperative recovery, extended hospitalization periods, excessive use of analgesics, and is extremely stressful for both surgery and anesthesia. Preemptive analgesia is a treatment that begins before surgery to prevent the development of central sensitization caused by incisional and inflammatory damage that occur during surgery and in the early postoperative period. Opioids and nonsteroidal anti-inflammatory medications (NSAIDs) are commonly used for this purpose. Diclofenac sodium is a typical, inexpensive NSAIDS. Preemptive analgesia can reduce the severity and duration of pain while also delaying it. Objectives: The aim of the study was to evaluate the Comparison of first analgesic demand in post-operative period among Diclofenac group versus Paracetamol group. Methods: This randomized controlled trial study was carried out in the Department of Anaesthesiology &amp; ICU Bangladesh Medical College Hospital Dhaka, Bangladesh during 18th January 2020 to 17th July 2020. A total of 50 patients were participated in the study. Sample was selected by random sampling in two groups distributed as- group A (Oral diclofenac sodium), group B (Oral paracetamol). Statistical analyses of the results were be obtained by using window-based Microsoft Excel and Statistical Packages for Social Sciences (SPSS-24). Results: The majority of patients (63.0%) were between 40 and 59 years old, with a mean age of 48.3 ± 11.2 years. In groups A (58%) and B (56%), nearly two-thirds of the patients had an ASA grade of one. There was no statistically significant difference between the two groups (p&gt;0.05). At baseline, no significant change in heart rate, SBP, or DBP was seen across groups. The postoperative heart rate and other haemodynamic state were assessed at two, six-, and twelve-hours following surgery. Conclusion: Preemptive oral Diclofenac sodium had significant effect on reducing postoperative pain and postoperative .......

Respuesta hemodinámica a dosis subanestésicas de ketamina en dolor posoperatorio: revisión sistemática

Introduction: Low-dose ketamine infusions have shown analgesic effectiveness for the management of postoperative pain. The impact of low-dose ketamine infusions on cardiovascular response is dose-dependent and requires a better knowledge about its effects on this population.&#x0D; Objective: To conduct a systematic review to describe changes in systolic, diastolic and mean arterial pressure, and heart rate 24, 48 and 72 hours after surgery.&#x0D; Methods: Randomized, controlled trials were reviewed in the Cochrane Library, PubMed, EMBASE, SciELO, Lilacs and grey literature on low-dose ketamine infusions for the study variables. The quality of the studies was assessed using the Cochrane’s risk of bias tool.&#x0D; Results: Six randomized, controlled trials with 641 patients were included. Low-quality evidence was found suggestive of a lack of certainty of any significant differences in the systolic blood pressure variables at 24 hours (mean standard deviation -1.00, 95 % CI: -7.27 to 5.27). A statistically significant higher mean heart rate at 24 hours was identified in the low-dose ketamine infusion group, (mean standard deviation 1.64 95 % CI: 0.38 to 2.90) which did not reach clinical significance. A lower pain level and less use of opioids was identified in the low-dose ketamine infusion group.&#x0D; Conclusion: Low quality evidence was found, suggesting that low-dose ketamine infusions are not associated with significant changes in blood pressure or heart rate 24 – 48 hours after surgery. It is important to individualize cardiovascular risk for each case, before initiating treatment.

Effects of war-related stress on the cardiovascular system, metabolism and the rate of ageing in women

Chronic war-related stress (WRS) due to disruption of adaptation mechanisms can affect physiological processes in the body, in particular, metabolism, neuroendocrine regulation, and the state of the cardiovascular and respiratory systems. WRS can also cause changes in the body's rate of ageing. Purpose of the Study: To investigate the effects of WRS on the cardiovascular system, metabolism and the rate of ageing in women. The study included 91 women aged from 30 to 74 years who experienced chronic WRS and 79 women examined before the Russian-Ukrainian war (control group). The biological age (BA) was determined according to the indicators of hemodynamics, heart rate variability and metabolism (cardiometabolic age) using a formula that was obtained by multiple stepwise regression. The indicators were selected, which correlate as much as possible with age and little among themselves. During the war, no statistically significant changes in heart rate, or systolic and diastolic blood pressure were observed, but a significant reduction in overall HRV in the supine position was obtained. Additionally, indices of parasympathetic nervous system activity are significantly lower during the war. In women, examined during the war, there is a statistically significant higher concentration of blood plasma glucose at fasting and 2-hour post-standard oral glucose tolerance test, they also exhibit higher plasma insulin concentration and a higher HOMA-IR index. An increased frequency of prediabetic disorders was observed. So, in the group of women examined before the war, an elevated fasting blood plasma glucose level was found in 6 %, while during the war it was observed in 19 %. Impaired glucose tolerance before the war was present in 10 % of women, and during the war, it increased to 25 %. To assess the effect of WRS on the rate of ageing, the BA of women before and during war was calculated. The formula for calculating BA was obtained on a group of healthy women before the war, and the ageing rate was calculated as the difference between BA and chronological age (CA). The average BA in the group of women before the war was 56.5±1.4 years, and in the group during the war – 64.7 ± 1.1 years. The difference between BA and CA is (0.02 ± 0.79) years in the women before the war and (10.8 ± 1.36) years during the war (p &lt; 0.05). Chronic WRS leads to the disruption of the cardiovascular system's functioning and simultaneously triggers an imbalance in the autonomic nervous control in women. These changes indicate a state of heightened stress. Women exposed to chronic WRS experience unfavourable alterations in carbohydrate and lipid metabolism, increasing the risk of diabetes mellitus development. Chronic WRS accelerates the rate of cardiometabolic ageing in women. _________________________________________________________________________________________ Keywords: cardiovascular system; metabolism; biological age; war-related stress; woman

Comparison of different induction techniques on hemodynamic changes in pediatric patients undergoing infra umbilical surgeries using laryngeal mask airway

Background: Post-induction hypotension associated with various agents is well-known in adults undergoing general anesthesia for various procedures. However, this phenomenon has not been addressed well in pediatric patients. We studied the incidence of postinduction hypotension in patients 1–5 years using inhalational induction with sevoflurane, intravenous induction with propofol, and co-induction with sevoflurane plus propofol. Aims and Objectives: To compare three different induction techniques in children 1–5 years undergoing various infra-umbilical surgeries under general anesthesia with laryngeal mask airway using sevoflurane induction, propofol induction, and sevoflurane plus propofol co-induction. Materials and Methods: Out of 150 patients observed in this study, 50 patients (group S) received inhalational induction with sevoflurane, 50 (group P) patients received intravenous induction with propofol, and 50 (group SP) patients received co-induction with propofol and sevoflurane. Results: Intravenous induction with propofol resulted in maximum hemodynamic changes Inhalational induction was responsible for significant changes in heart rate whereas co-induction with propofol (1–1.5 mg/kg) and sevoflurane 5% yielded minimum hemodynamic variations with least adverse effects. Conclusion: We conclude that co-induction with propofol (1–1.5 mg/kg) plus Sevoflurane 5% provided better hemodynamic stability with the least adverse effects.

Clinical-haemostasis assessment of anaesthesia regimens in dogs with the somatic type of pain response

The article investigates into the influence of somatic pain syndrome during osteosynthesis on dogs’ clinical parameters and haemostasis. It was found, that the best variant for osteosynthesis operations in dogs is acepromazine-butorphanol-propofol-ketamine anaesthesia. This regimen has provided complete analgesia in half the time recovery of dogs without significant changes in heart rate (HR), respiratory rate (RR), blood pressure (BP), and haemoglobin saturation (SpO2) during surgery. Acepromazine-ketamine-thiopental anaesthesia has showed pronounced analgesia with a decrease in HR and BP. Xylazine-ketamine-thiopental anaesthesia, under apparent analgesia, led to hypotension (decreased HR, BP) and hypoxia (decreased RR, SpO2). The hypercoagulable syndrome was recorded in dogs of all experimental groups before surgery. It indicates the urgent need for its correction in the postoperative period. The data obtained will optimize the selection of drugs’ combinations for dogs' anaesthesia, taking into account the type of pain response.

Can a virtual human increase mindfulness and reduce stress? A randomised trial

BackgroundStress is a significant issue amongst university students, yet limited psychological services are available. Mindfulness is effective for stress reduction and can be delivered digitally to expand access to student populations. However, digital interventions often suffer from low engagement and poor adherence. A virtual human may improve engagement and adherence through its humanlike appearance and behaviours. ObjectiveTo examine whether a virtual human could reduce stress in university students at least as much as a teletherapist, and more than a chatbot, using a mindfulness intervention. MethodsStressed university students (N = 158) were randomly allocated to the virtual human (N = 54), chatbot (N = 54), or teletherapist (N = 50). 36 participants received each condition. Participants completed one lab session and were asked to do online homework sessions at least twice weekly for four weeks. Changes in self-reported stress and mindfulness, physiological stress indices, homework completion, and perceptions of the agent were compared between groups. Thematic analysis was conducted on participants’ responses to open-ended questions about the interventions. ResultsThere were significant reductions in stress and increases in mindfulness across all groups. All groups had higher peripheral skin temperature post-intervention, and only the teletherapy group had higher electrodermal activity (reflecting elevated stress) post-intervention compared to baseline. There were no significant changes in heart rate. Homework adherence was significantly higher in the virtual human group, whereas homework satisfaction and engagement were lowest in the chatbot group. Thematic analysis found that people thought the robotic voice of the virtual human could be improved, the chatbot could be improved by adding audio, and that participants experienced feelings of judgement from the teletherapist. DiscussionOverall, results support use of virtual humans for delivering mindfulness interventions in stressed students. Virtual humans may have the advantage over teletherapy and chatbots of increasing adherence in student populations, but more work is needed to increase perceived empathy and replicate results in other populations.

Validity of heart rate derived core temperature estimation during simulated firefighting tasks

Rectal core temperature monitoring can help fire services mitigate heat injury but can be invasive and impractical. EQ02 + LifeMonitor provides a non-invasive estimation of core temperature. Therefore, the primary purpose of this study was to determine the validity of the EQ02 + LifeMonitor compared to the gold standard rectal thermometer core temperature assessment, as well as the potential influence of turnout gear on the estimated and physiological strain experienced during these activities. Thirteen participants completed simulated firefighting tasks with and without turnout gear, involving four rounds of a 5-min walk on a treadmill at 2.8 mph/2.5% grade and 20 deadlifts over 5 min in an environmental chamber set to 40.6 °C; 50% humidity. During each trial participants wore both an EQ02 + LifeMonitor and DataTherm II rectal thermometer. The results from the devices were statistically equivalent (p < 0.001), yet there was a statistically significant difference in the value (~ 0.1 °C; p < 0.001). There was a significant effect of devices [p < 0.001] and time [p < 0.001], but no interaction effect [p = 0.70] on core temperature drift. Estimated core temperature was marginally different from that measured via the DataTherm II. The EQ02 on average overestimated core temperature. Heart rate, rating of perceived exertion, and area under the curve of core temperature were significantly elevated due to turnout gear [ps < 0.025], but not core temperature skin temperature, or ventilatory rate [ps > 0.372]. These results suggest the EQ02 + LifeMonitor may be a viable, non-invasive alternative for assessing core temperature compared to rectal temperature monitoring, especially during rigorous, intermittent activities. Turnout gear does however increase heart rate, cumulative core temperature, and perceived exertion. Additionally, the validity of the estimated core temperature is not impacted by the use turnout gear. This is likely due to significant changes in heart rate, which allowed the heart-rate derived estimate of core temperature to remain consistent with changes in DataTherm II rectal temperatures.

Long-term QT prolongation in monkeys after doxorubicin administration at doses similar to breast cancer therapy.

Studies in small animals and human patients have suggested that anthracyclines may prolong cardiac repolarization, or at least inhibit repolarization reserve, predisposing to QT prolongation and dangerous arrhythmias such as Torsades de pointes. This association in humans is difficult to confirm due to multiple confounding variables such as the presence of other medications and concurrent illness. Identify a long-term association between anthracycline administration and repolarization prolongation in nonhuman primates, which can be measured as prolonged QT/QTc intervals on surface electrocardiogram. Five female African Green monkeys (AGMs) aged 13 ± 1 years received Doxorubicin (Dox) at doses similar to women treated for breast cancer (30-60 mg/m2/biweekly IV, total cumulative dose: 240 mg/m2) and underwent 12-lead electrocardiogram (ECG) before and 15 weeks after the final dose of Dox treatment. A blinded paired analysis was performed on ECG derived heart rate (HR), QRS, QT and QT corrected for HR (QTc) interval durations. After Dox, all monkeys exhibited increased QT (BL: 323.2 ± 27.4 ms vs. Post-Dox: 366.4 ± 18.7 ms, p = 0.002) and QTc (BL: 440.2 ± 22.8 ms vs. Post-Dox: 500.8 ± 22.0 ms, p = 0.009) intervals, without any significant changes in HR or QRS duration (p = 0.92 and p = 0.47 respectively). AGMs treated with Dox exhibited long-term QT and QTc prolongation, along with the expected cardiotoxicity (LVEF decrease). While similar findings were shown in small animal studies, confounders make human association difficult to prove. Our finding provides a valuable intermediary step, showing direct effect of Dox on repolarization in nonhuman primates.

Effect of direct exposure to ringing mobile phone waves on ECG heart rate and rhythm among healthy adults

The effect of electromagnetic wave from mobile phones on human health is of great interest, the current study was designed to investigate the effect of mobile phone electromagnetic waves on ECG heart rate and rhythm among different healthy adult volunteers’ ages and sex while mobile phone was placed on the chest pocket level during ringing mode. It was an experimental, comparative study conducted in the period from march 2014 to August 2016 in north of Sudan at Elsheikh Abdallah Elbadri University among 850 volunteers, Sudanese and other nationalities.500 male and 350 females, aged 16 - 49 years were included in the study. ECG was done before and after exposure to ringing mobile phone. Significant changes in ECG heart rate and rhythm was detected and the results was found to be consistent in males and females’ group. The study conclude that mobile phone is not a safety device and should not be used by medical staff inside the ECG rooms.

Feasibility of the CART In‐Home Technology Platform in a Pilot Study of Hispanic Older Adults Residing in South Texas

AbstractBackgroundAs Alzheimer’s disease (AD) prevalence rises, the development of effective screening tools is necessary to aid in earlier AD diagnosis. In the USA, Hispanic and Non‐Hispanic Black adults are at a disproportionately higher risk of developing dementia than non‐Hispanic whites but are poorly represented in AD research. A digital assessment system ‐ the Collaborative Aging Research using Technology (CART) platform, has been developed to remotely and continuously detect early declines in cognition by analyzing changes in everyday activity levels. Although the platform is promising, installing digital technology in a home can cause concerns over privacy and user friendliness, especially in older adults. In our CART pilot study at UTHSCSA, we sought to determine the feasibility of deploying the CART platform in an underrepresented, mostly Hispanic population and to gain insight from their experiences.MethodSeven cognitively intact participants were enrolled in our year‐long pilot study. The CART platform consisted of a watch‐actigraph, digital scale, electronic pillbox, bed mat (measuring sleep), and wall‐mounted motion sensors. Participants completed weekly online surveys including mood assessments, the UDS3 neuropsychological battery at baseline and one‐year follow‐up, and an end‐of‐study user experiences survey. Wilcoxon signed rank exact tests were used to determine significance.ResultOur cohort consisted of five Hispanic, one non‐Hispanic Black, and one non‐Hispanic white participant, ages 65‐80. There were no significant changes in cognition, daily steps, sleep, weight, or heart and respiratory rate measured during sleep over the course of the study (p&gt;0.05). Self‐reported depressive symptoms decreased (p = 0.034) (Figure 1J). Weekly survey results supported this finding because self‐reported feelings of loneliness and “blue mood” also decreased. Responses to the user experience survey demonstrated that participants found the technology installation satisfactory (43%) or very satisfactory (57%) and thought that their privacy concerns were addressed satisfactorily (43%) or very satisfactorily (57%) (Figure 2).ConclusionOur results suggest that the CART platform was widely accepted by our mostly Hispanic older adult participants and that they were comfortable with the study devices. The findings support the feasibility of increasing representation of diverse older adults in dementia prevention research using digital devices.

Can a Simple Distraction Lower Fear Levels During a Sudden Scary Outdoor Situation?

Adventure-based teaching can foster social and personal growth yet can scare and cause long-lasting anxiety in some group members. This study examined the effects of a simple distraction to lower stress levels during an approaching scary event. Forty-eight males (M = 20.2 years) were randomly assigned to one of four groups. The stressor involved participants walking on a 3-m tower while blindfolded and jumping off into a pool. Self-report questionnaires, digital counters, heart rate, and peripheral temperature measures were used. A two-way analysis of variance indicated no significant difference in trait and state anxiety/ sensation seeking. However, a post hoc Scheffé’s test found significant changes in heart rate between the experimental groups and the control groups. Though not statistically different, the study’s results suggest that distractions affect heart rate, peripheral temperature, and state anxiety/sensation seeking, with raw scores rising (5% and 18%, respectively, for the latter). Future studies should consider other distraction-type strategies in which stress levels may hamper safety during group adventure activities.

Physical exercise and cardiovascular response: design and implementation of a pediatric CMR cohort study

To examine feasibility and reproducibility and to evaluate the cardiovascular response to an isometric handgrip exercise in low-risk pediatric population using Cardiovascular Magnetic Resonance measurements. In a subgroup of 207 children with a mean age of 16 years participating in a population-based prospective cohort study, children performed an isometric handgrip exercise. During rest and exercise, continuous heart rate and blood pressure were measured. Cardiovascular magnetic resonance (CMR) measurements included left ventricular mass, aortic distensibility and pulse wave velocity at rest and left ventricular end-diastolic and end-systolic volumes, ejection fraction, stroke volume and cardiac output during rest and exercise. 207 children had successful CMR measurements in rest and 184 during exercise. We observed good reproducibility for all cardiac measurements. Heart rate increased with a mean ± standard deviation of 42.6% ± 20.0 and blood pressure with 6.4% ± 7.0, 5.4% ± 6.1 and 11.0% ± 8.3 for systolic, diastolic and mean arterial blood pressure respectively (p-values < 0.05). During exercise, left ventricular end-diastolic and end-systolic volumes and cardiac output increased, whereas left ventricular ejection fraction slightly decreased (p-values < 0.05). Stroke volume did not change significantly. A sustained handgrip exercise of 7 min at 30–40% maximal voluntary contraction is a feasible exercise-test during CMR in a healthy pediatric population, which leads to significant changes in heart rate, blood pressure and functional measurements of the left ventricle in response to exercise. This approach offers great novel opportunities to detect subtle differences in cardiovascular health.

Determination of the Effects of a Series of Ten Whole-Body Cryostimulation Sessions on Physiological Responses to Exercise and Skin Temperature Behavior following Exercise in Elite Athletes.

The present study investigated the effects of a series of 10 whole-body cryostimulation (WBC) sessions (3 min; -110 °C) on physiological and thermal responses to a submaximal exercise test in 17 elite athletes. Participants performed an exercise test twice at similar levels of intensity before and after a series of ten WBC sessions. Before and during the test, each participant's oxygen uptake (VO2), heart rate (HR), internal temperature (Ti), and skin temperature in selected areas of the skin were measured, and the mean arterial pressure (MAP), physiological strain index (PSI), and mean skin temperature (Tsk) were calculated. The results show that during exercise, increases in Ti and the PSI were significantly lower after the WBC sessions, and although there were no significant changes in HR or the MAP, the Tsk was significantly higher. Following exercise, an increase in skin temperature asymmetry over the lower-body muscles was detected. A series of WBC sessions induced a tendency toward a decrease in temperature asymmetry over the thigh muscles. In conclusion, a series of ten WBC sessions does not induce significant modifications in physiological variables but does influence the PSI and Ti during exercise. Moreover, a series of ten WBC sessions influences the distribution of skin temperature and the magnitude of temperature asymmetries in the early phase of recovery.

Sedation Quality and Cardiorespiratory, Echocardiographic, Radiographic and Electrocardiographic Effects of Intramuscular Alfaxalone and Butorphanol in Spanish Greyhound Dogs.

The quality of sedation and changes in cardiorespiratory variables after the intramuscular administration of alfaxalone and butorphanol in Spanish greyhound dogs were evaluated. Twenty-one adult dogs were included. The dogs received alfaxalone (2 mg/kg) and butorphanol (0.2 mg/kg) intramuscularly. Sedation scoring, cardiorespiratory parameters (including blood gas analysis), echocardiography, thoracic radiography and electrocardiography were performed before sedation and 30 min after drug administration. Moderate sedation was observed, and side effects, such as tremors, nystagmus and auditory hyperesthesia, were noticed. Statistically significant changes in heart rate, invasive blood pressure, pH, arterial saturation of O2 and partial pressure of O2 and CO2 were found. Echocardiographic variables, including end-diastolic volume, left ventricular diameter in diastole, aortic and pulmonic flow, diastolic transmitral flow and left atrial/aortic ratio, and electrocardiography parameters, including PQ interval and QT interval, showed statistically significant changes. In conclusion, the intramuscular administration of alfaxalone and butorphanol to healthy dogs produced moderate sedation with mild cardiorespiratory, echocardiographic and electrocardiographic changes, without alterations in cardiac size on radiographic images.

Use of Suctioning during Newborn Resuscitation and Its Effects on Heart Rate in a Low-Resource Setting, Tanzania.

Suctioning of newborns immediately after birth, as part of delivery room resuscitation, is only recommended if the airway is obstructed. The aim of this study was to describe the use of suctioning during newborn resuscitation among survivors versus those who died within 3 days and potential suction-related heart rate responses and associations to newborn characteristics. This was a retrospective observational study from July 2013 to July 2016 in a referral hospital in rural Tanzania. Research assistants observed and documented all deliveries, newborn resuscitations were video-recorded, and newborn heart rates were captured with a dry-electrode electrocardiogram. Liveborn infants ≥34 weeks gestation who received ventilation and with complete datasets were eligible. All 30 newborns who died were included, and a total of 46 survivors were selected as controls. Videos were annotated and heart rate patterns were observed before and after the suction events. Suctioning was performed more frequently than recommended. No differences were found in suctioning characteristics between newborns who died versus those who survived. In 13% of suction events, a significant heart rate change (i.e., arrhythmia or brief/sustained >15% fall in heart rate) was observed in relation to suctioning. This represents a potential additional harm to already depressed newborns undergoing resuscitation.

Effect of Fluoxetine and Escitalopram on Heart Rate Variability (HRV) and Serum Potassium Level in Patients of Depression and Anxiety Disorders

Background The present study was conducted to generate data regarding the effect of fluoxetine as an anti-depressant and escitalopram as an antianxiety agent on heart rate variability (HRV). There is a scarcity of data regarding the correlation between selective serotonin reuptake inhibitors (SSRIs) and serum potassium levels. Purpose To find out the effect of SSRIs on HRV, and whether it is either dependent or independent of serum potassium level. Materials and Methods In this prospective, open-label, observational study, 70 participants were enrolled and divided into two groups, the fluoxetine group ( n = 35) and the escitalopram group ( n = 35) suffering from depression and anxiety, respectively. Parameters, like HRV, serum potassium level, heart rate, respiratory rate, and blood pressure, were measured baseline and after the first, second, and third months of treatment. HRV was calculated by root mean square deviation of successive differences between adjacent RR intervals (RMSSD). ECG (electrocardiogram) was recorded by Physio Pac Digital Polygraph software. All values were expressed as mean ± SD, and statistical analysis was done by using the repeated measure analysis of variance (ANOVA) test with Greenhouse–Geisser correction, post hoc analysis with Bonferroni correction, and SPSS 20.0 software. Results Among a total of 70 participants, post hoc tests using the Bonferroni correction showed a statistically significant difference between the HRV of the pretreatment group and after the second, and third month of fluoxetine therapy ( p &lt; 0.05). In the escitalopram group, the Bonferroni correction showed a significant difference between the HRV of the pretreatment and third-month value ( p &lt; 0.05). Repeated measure ANOVA with Greenhouse–Geisser correction showed no statistical significance of serum potassium at different time points ( p &gt; 0.05). There were also no significant changes in heart rate, respiratory rate, and blood pressure at different points of time in both groups. Pearson’s correlation coefficient test for a relationship between HRV and serum potassium was negative at different time points. Conclusion Fluoxetine significantly increased HRV from the pretreatment value to the second and third months of treatment, whereas in the escitalopram group of participants, the third-month value of HRV was increased compared to the first month. The effect of SSRIs on HRV was independent of serum potassium levels at different time points suggesting that the effect of SSRIs on HRV was independent of serum potassium level.