Mean Peak Heart Rate Research Articles

Higher final speed in 30–15 intermittent fitness tests correlates with soccer's locomotor demands, not heart rate responses in small-sided soccer games

This study aimed to achieve two objectives: firstly, to analyze the relationships between aerobic fitness, as represented by the VIFT, and the heart rate and locomotor responses of youth male soccer players across various teams; and secondly, to compare players with lower and higher VIFT in terms of performance outcomes extracted during small-sided games (SSGs). A total of twenty-six youth male soccer players, aged 16.5 ± 0.32 years, with 3.4 ± 1.1 years of experience, voluntarily participated in the study. These players belonged to two regional-level tier 2 teams (trained/developmental). In the initial week of observation, the 30–15 Intermittent Fitness Test was implemented to measure the final velocity (VIFT) achieved by the players. Subsequently, the 5v5 format of play was conducted twice a week over two consecutive weeks, during which heart rate responses and locomotor demands were measured. The Pearson product-moment correlation test revealed a significant correlation between VIFT and the total distance covered during the 5v5 format (r = 0.471 [95% CI: 0.093; 0.721], p = 0.015). Conversely, small and non-significant correlations were identified between VIFT and mean heart rate (r = 0.280 [95% CI: − 0.126; 0.598]; p = 0.166), VIFT and peak heart rate (r = 0.237 [95% CI: − 0.170; 0.569]; p = 0.243), as well as VIFT and high-speed running (r = 0.254 [95% CI: − 0.153; 0.580]; p = 0.211). Players with higher VIFT demonstrated a significantly greater total distance, with a large effect size (+ 6.64%; p = 0.015; d = 1.033), compared to those with lower VIFT. Our findings suggest that improved performance in VIFT may lead to covering more distance in 5v5 matches. However, the lack of significant associations between VIFT and heart rate levels during SSGs suggests that they are not strongly correlated, possibly because VIFT is more closely linked to locomotor profile. As a practical implication, coaches may consider organizing players during SSGs based on their VIFT if the goal is to standardize locomotor demands.

Comparison of Effect of Feeding Premature Infants with Either Cup, Bottle, and Syringe on Transition to Breastfeeding, Breastfeeding Success, Weight Gain, and Duration of Hospitalization.

Objective: This study was completed with the aim of determining the effect of cup feeding (CF), bottle feeding (BF), and syringe feeding (SF) methods on the transition to breastfeeding, breastfeeding success, physiological parameters, weight gain, and discharge duration for preterm neonates in the neonatal intensive care unit (NICU). Materials and Methods: The study was designed to be randomized, controlled, and single blinded. The study was completed with 102 premature neonates between 29-34 gestational weeks abiding by the case selection criteria receiving treatment and care in the NICU. The 1st group comprised premature neonates receiving CF, the second group received BF, and the third group received SF. For collection of data, the Premature Infant Descriptive Information and Monitoring Form, Bristol Breastfeeding Assessment Tool (BBAT), and Infant-Focused Feeding Scales (IFFS) were used. Results: Comparison of mean peak heart rate in the groups found that the BF group was significantly high (p = 0.047) and comparison of mean SO2 found that the SF group was significantly high (p = 0.000). Infants in the SF group were determined to have significantly higher BBAT scores compared to the infants in the BF and CF groups (p = 0.015). In addition, SF infants were determined to transition to full enteral feeding and breastfeeding in a shorter duration (p < 0.05). There were no significant differences between the groups for weight gain and discharge duration (p > 0.05). Conclusions: The SF method was determined to more positively affect breastfeeding success, transition to full breastfeeding duration, and vital signs compared to the CF and BF methods. In line with the results obtained in the study, the use of the SF method may be recommended to increase breastfeeding success of neonates, to shorten the transition to full breastfeeding and for stable physical parameters.

The effect of hyperthyroidism at thyroidectomy on complication rates in children with Graves' disease.

Graves' disease (GD) is the most common cause of childhood hyperthyroidism. Surgery is often chosen as a treatment modality given the high relapse rates and side effects of antithyroid drugs and has shown to be safe and efficacious. The goal of our study was to evaluate whether hyperthyroidism at time of thyroidectomy is associated with higher intra and postoperative complication rates. A retrospective cohort study of children who underwent thyroidectomy for GD by high-volume pediatric otolaryngologists between 2014 and 2021. 64 patients met inclusion criteria. Patients with hyperthyroidism (defined as free T4≥1.63ng/dL) were more likely to be treated with beta-blocker preoperatively compared to the euthyroid group (20/24 patients (83%) vs 23/40 patients (58%) respectively, p=0.035). Twenty (83%) patients with hyperthyroidism and 39 euthyroid patients (98%) were treated with methimazole prior to surgery. Intraoperative tachycardia was noted in 5% of euthyroid patients and 20.8% of patients with hyperthyroidism. The mean peak heart rate intra-operatively and the number of patients with heart rate ≥120bmp were significantly higher for patients with hyperthyroidism (96.5±16.2 vs 87.6±22.1bpm, p=0.02). Two patients required administration of esmolol during surgery for heart rate control, both with hyperthyroidism. Intra-operative peak systolic blood pressure, operative time, estimated blood loss, persistent hypocalcemia, length of admission and recurrent laryngeal nerve paralysis rates were similar among groups. Hyperthyroidism at surgery is associated with increased heart rate intraoperatively, with no increased risk for other complications. While optimizing thyroid hormone levels before surgery should be pursued in all children, our data suggest that hyperthyroidism should not delay the surgery.

Metabolic Cost and Mechanical Efficiency of a Novel Handle-Based Device for Wheelchair Propulsion.

To investigate differences in metabolic cost and gross mechanical efficiency of a novel handlebased wheelchair propulsion device and to compare its performance with conventional push-rim propulsion. Double-group comparative study between 2 different propulsion methods. Eight paraplegic individuals and 10 non-disabled persons. Participants performed the same exercise using a push-rim device and the novel handle-based device on a wheelchair- based test rig. The exercise consisted of a combined submaximal and maximal test. Power output, oxygen uptake, ventilation, respiratory exchange ratio and heart rate were recorded continuously during the tests. Analysis of variance was performed to determine the effects of group, mode and on power output. Submaximal exercise resulted in a higher efficiency for the novel device and significant main effects of propulsion mode on all investigated parameters, except heart rate. On the respiratory exchange ratio, a significant interaction effect was found for both mode and group. The maximal exercise resulted in a higher peak power output and lower peak heart rate during propulsion using the handle-based device. A significant main effect on mode for mean peak power output, ventilation and heart rate was also observed. Wheelchair propulsion using the handle-based device resulted in lower physical responses and higher mechanical efficiency, suggesting that this novel design may be well suited for indoor use, thereby offering an attractive alternative to pushrim wheelchairs.

Stroke volume and cardiac output during 6 minute-walk tests are strong predictors of maximal oxygen uptake in people after stroke.

The 6-minute walk test (6MWT) is a field test commonly used to predict peak oxygen consumption (VO2peak) in people after stroke. Inclusion of cardiodynamic variables measured by impedance cardiography (ICG) during a 6MWT has been shown to improve prediction of VO2peak in healthy adults but these data have not been considered in people after stroke. This study investigates whether the prediction of VO2peak can be improved by the inclusion of cardiovascular indices derived by impedance cardiography (ICG) during the 6MWT in people after stroke. This was a cross-sectional study. Patients diagnosed with stroke underwent in random order, a maximal cardiopulmonary exercise test (CPET) and 6MWT in separate dates. Heart rate (HR), stroke volume (SV) and cardiac output (CO) were measured by ICG during all tests. Oxygen consumption was recorded by a metabolic cart during the CPET. Recorded data were subjected to multiple regression analyses to generate VO2peak prediction equations. Fifty-nine patients, mean age 50.0±11.7 years were included in the analysis. The mean distance covered in the 6MWT (6MWD) was 294±13 m, VO2peak was 19.2±3.2 ml/min/kg. Mean peak HR, SV and CO recorded during 6MWT were 109±6 bpm, 86.3±8.8 ml, 9.4±1.2 L/min and during CPET were 135±14 bpm, 86.6±9 ml, 11.7±2 L/min respectively. The prediction equation with inclusion of cardiodynamic variables: 16.855 + (-0.060 x age) + (0.196 x BMI) + (0.01 x 6MWD) + (-0.416 x SV6MWT) + (3.587 x CO 6MWT) has a higher squared multiple correlation (R2) and a lower standard error of estimate (SEE) and SEE% compared to the equation using 6MWD as the only predictor. Inclusion of SV and CO measured during the 6MWT in stroke patients further improved the VO2peak prediction power compared to using 6MWD as a lone predictor.

Continuous heart rate dynamics preceding in-hospital pulseless electrical activity or asystolic cardiac arrest of respiratory etiology

IntroductionRespiratory failure is a common cause of pulseless electrical activity (PEA) and asystolic cardiac arrest, but the changes in heart rate (HR) pre-arrest are not well described. We describe HR dynamics prior to in-hospital cardiac arrest (IHCA) among PEA/asystole arrest patients with respiratory etiology. MethodsIn this retrospective study, we evaluated 139 patients with 3–24 hours of continuous electrocardiogram data recorded preceding PEA/asystole IHCA from 2010-2017. We identified respiratory failure cases by chart review and evaluated electrocardiogram data to identify patterns of HR changes, sinus bradycardia or sinus arrest, escape rhythms, and development right ventricular strain prior to IHCA. ResultsA higher proportion of respiratory cases (58/73, 79 %) fit a model of HR response characterized by tachycardia followed by rapid HR decrease prior to arrest, compared to non-respiratory cases (30/66, 45 %, p < 0.001). Among the 58 respiratory cases fitting this model, 36 (62 %) had abrupt increase in HR occurring 64 (IQR 23–191) minutes prior to arrest, while 22 (38 %) had stable tachycardia until time of HR decrease. Mean peak HR was 123 ± 21 bpm. HR decrease occurred 3.0 (IQR 2.0–7.0) minutes prior to arrest. Sinus arrest occurred during the bradycardic phase in 42/58 of cases; escape rhythms were present in all but 2/42 (5 %) cases. Right ventricular strain ECG pattern, when present, occurred at a median of 2.2 (IQR −0.05–17) minutes prior to onset of HR decrease. ConclusionIHCAs of respiratory etiology follow a model of HR increase from physiologic compensation to hypoxia, followed by rapid HR decrease prior to arrest.

Abstract 10125: Continuous Heart Rate Dynamics Preceding In-Hospital Cardiac Arrest of Respiratory Etiology

Introduction: Respiratory failure is a common cause of pulseless electrical activity (PEA) arrest in hospitalized patients, but how pathophysiologic changes in these conditions affect heart rate (HR) pre-arrest is not well described. We describe HR dynamics prior to in-hospital cardiac arrest (IHCA) among PEA/asystole arrest patients with respiratory etiology. Methods: In this retrospective descriptive study, we evaluated 67 patients with ≥3 hours of continuous ECG data recorded immediately preceding PEA/asystole IHCA in a single institution from 2010-2014. We identified respiratory arrest cases (eg. pneumonia, aspiration, pulmonary embolism, acute respiratory distress syndrome) by chart review and evaluated ECG patterns up to 24 hours prior to arrest to identify patterns of HR increase, HR decrease, sinus arrest, and escape rhythms. Results: We identified 31/67 patients with respiratory etiology (age 59±17 years, 52% male, 83% return of spontaneous circulation, 41% survived to discharge); of these 23/31(74%) fit an a priori model of HR response (Figure). Twelve cases demonstrated clear onset of HR increase at a median of 44 (IQR 28-507) minutes prior to arrest, while the remaining 11 cases started the monitoring period in sinus tachycardia. The mean peak HR was 120±20 bpm. An abrupt onset of HR decrease occurred at a median of 3.4 (IQR 2.3-5.9) minutes prior to arrest. Sinus arrest occurred during the HR decrease phase in 18/23 cases; the first escape rhythm was atrial in 11 (61%), junctional in 2 (11%) and ventricular in 3 (17%) cases. Conclusion: The majority of IHCA due to respiratory etiology (74%) follow a typical model of HR increase due to physiologic compensation to hypoxia, followed by rapid HR decrease leading to PEA arrest, likely from the vagal effect of hypoxia and sinus node suppression from acidosis. Understanding HR trends can aid clinical management as well as development of artificial intelligence models for prediction of IHCA.

Brief Exercise at Work (BE@Work): A Mixed-Methods Pilot Trial of a Workplace High-Intensity Interval Training Intervention.

Introduction: The efficacy of high-intensity interval training (HIIT) for improving markers of physical fitness and cardiometabolic health is promising. The workplace is one non-laboratory setting where the effectiveness of HIIT could be explored. The aim of this study was to undertake a mixed-methods exploratory pilot trial of a workplace HIIT intervention named Brief Exercise at Work (BE@Work).Methods: Fifty-four healthy employees (mean ± standard deviation [SD] age 46 ± 10 years) from two workplaces in Northeast England were allocated to 8 weeks of thrice-weekly workplace HIIT based on boxing, stair climbing and stepping, comprising 4–7 60 s high-intensity intervals interspersed with 75 s rest (n = 30), or a no-intervention control (n = 24). The primary outcome was the change SD of predicted maximal oxygen consumption (VO2max). Markers of physical fitness, cardiometabolic health and mental well-being were also measured at baseline and follow-up. Participant perceptions of the intervention were explored in post-intervention focus groups (n = 9).Results: Mean (±SD) session attendance was 82% (±15%). Mean peak heart rate across the intervention was 87% of age-predicted maximal heart rate with a within- and between-subject SD of 5.5% and 3.7%, respectively. The SD of changes in predicted VO2max was 6.6 mL·kg−1·min−1 across both groups, which can be used to inform sample size estimations for a future full trial. The control-adjusted mean increase (95% confidence interval) in predicted VO2max was 3.9 (−0.2 to 8.1) mL·kg−1·min−1, corresponding to a Cohen's D of 0.47. We also observed preliminary evidence of small to moderate effects in favour of the intervention group for non-dominant leg extensor muscle power, markers of health-related quality of life, well-being and perceived stress and small to moderate effects in favour of the controls in perceived pain, physical activity and high-density lipoprotein cholesterol. During HIIT, focus group participants reported physiological responses they perceived as unpleasant or tiring (e.g., breathlessness, local muscular fatigue), but also that they felt alert and energised afterwards.Conclusion: The findings of this exploratory pilot trial support the implementation of a definitive randomised controlled trial to quantify the effectiveness of a workplace HIIT intervention.

Cardiodynamic variables measured by impedance cardiography during a 6-minute walk test are reliable predictors of peak oxygen consumption in young healthy adults.

Accurate prediction of aerobic capacity is necessary to guide appropriate exercise prescription. It is common to use 6-minute walk distance (6MWD) to predict peak oxygen uptake (VO2peak) in the clinical environment. The aim of this study was to determine whether prediction of VO2peak can be improved by the inclusion of cardiovascular indices derived by impedance cardiography (ICG) during the 6MWT. A total of 62 healthy university students aged 21±1 years completed in separate days, a cardiopulmonary exercise test (CPET) and two 6MWTs (30 min apart), during which heart rate (HR), stroke volume (SV) and cardiac output (CO) were measured by ICG (PhysioFlow® PF07 EnduroTM). The CPET was conducted with the Ergoselect 200 Ergoline and oxygen consumption measured by a MasterScreenTM CPX breath-by-breath metabolic cart. Multiple regression analyses were conducted to generate VO2peak prediction equations using 6MWD with, or without the cardiovascular indices recorded at the end of the best performed 6MWT as predictor variables. The mean peak HR (bpm), SV (ml) and CO (L/min) recorded during 6MWT were 156±18, 95.6±9, 15±2.8 and during CPET were 176±16, 91.3±8, 16.2±2.7, respectively. Analyses revealed the following VO2peak prediction equation: VO2peak = 100.297+(0.019x6MWD)+(-0.598xHR6MWT)+(-1.236xSV6MWT) + (8.671 x CO6MWT). This equation has a squared multiple correlation (R2) of 0.866, standard error of the estimate (SEE) of 2.28 mL/kg/min and SEE:VO2peak (SEE%) of 7.2%. Cross-validation of equation stability using predicted residual sum of squares (PRESS) statistics showed a R2 (Rp2), SEE (SEEp) and SEEp% of 0.842, 2.38 mL/kg/min and 7.6% respectively. The minimal shrinkage of R2 implied regression model stability. Correlation between measured and predicted VO2peak using this equation was strong (r = 0.931, p<0.001). When 6MWD alone was used as the predictor for VO2peak, the generated equation had a lower R2 (0.549), and a higher SEE (4.08 mL/kg/min) and SEE% (12.9%). This is the first study which included cardiac indices during a 6MWT as variables for VO2peak prediction. Our results suggest that inclusion of cardiac indices measured during the 6MWT more accurately predicts VO2peak than using 6MWD data alone.

Smart technology for physical activity and health assessment during COVID-19 lockdown

The worldwide lockdown in response to COVID-19 pandemics has often led to physical inactivity and social distancing. When combined, these factors may affect quality and life and increase the risk of different diseases. Therefore, assessment of physical activity levels should be encouraged to monitor and identify those at a higher risk of inactivity. Smart technology is a promising tool to assess physical activity and health and may be particularly useful during a period of general lockdown. An online survey was developed and shared among the Italian general population to collect data about physical activity and daily routine changes between January 2020 and the lockdown period from March 23 to March 29. Participants were asked to provide data such as daily step count (Steps) or heart rate (HR) measured and collected by their smart technology devices. Four hundred participants were included in the final analysis. During the lockdown, the number of steps dropped from 8284±4390 to 3294±3994 steps (P<0.001), while mean peak HR decreased from 61.3±18.2% to 55.9±17.3% (P<0.001). These findings provide objective data about the effects of the COVID-19 lockdown on physical activity, thus encouraging the use of smart devices to monitor and promote healthy lifestyles while faced with a confinement condition.

The Effect of Left Cardiac Sympathetic Denervation on Exercise in Patients With Long QT Syndrome.

This study evaluated the effect of left cardiac sympathetic denervation (LCSD) on heart rate, cardiac contractility, and cardiopulmonary fitness in human subjects. The primary treatment for long QT syndrome (LQTS) is beta-blocker (BB) therapy, but some patients experience breakthrough cardiac events or intolerable side effects. LCSD provides a significant antifibrillatory, protective effect in LQTS. However, the effect of LCSD on cardiopulmonary fitness in humans has not been previously described. A retrospective analysis of patients with LQTS and LCSD (2006 to 2017) who had both pre- and post-LCSD exercise stress tests (N= 55; 39 females; mean age at LCSD 22 ± 12 years; mean follow-up 5.1 ± 2.5 years; 36 patients with LQT1; 15 patients with LQT2). Forty patients (73%) were receiving BBs pre-LCSD. Mean peak heart rate before LCSD was 143 ± 23 beats/min, mean peak oxygen consumption (VO2) was 32±10ml/kg/min, and mean peak respiratory exchange ratio was 1.14 ± 0.12. There was no difference in peak heart rate, peak VO2, peak QTc, or respiratory exchange ratio pre- and post-LCSD. To evaluate the isolated effect of LCSD, the study performed a subset analysis of patients with LCSD monotherapy (n= 10) or no change in BB dose (n= 12). Patient-matched pre- and post-LCSD exercise testing showed no difference in heart rate, VO2, or left ventricular function following LCSD. LCSD provides increased protection from an LQTS-triggered event without negatively affecting peakheart rate, cardiopulmonary fitness, or cardiac contractility, as assessed by both treadmill exercise stress testingandechocardiography.

Comparison of Anesthesia Techniques Used in Cesarean Deliveries on the Neonate - Anesthesia Techniques and Neonate?

Background: Though there are many studies on the effects of anesthesia methods used for cesarean section on the newborn, research on this topic still continues. In our prospective observational study, we investigated the effects of different anesthesia techniques used in routine cesarean deliveries on early neonatal outcomes in our hospital. Methods: This prospective, observational, randomized study included a total of 222 ASA II risk group pregnant women undergoing elective cesarean section at term (38-41 weeks’ gestation) without fetal distress. The women were randomized into three groups. In the general anesthesia with propofol group (Group P, n = 74), anesthesia was induced with 2 mg∙kg-1 propofol and 0.6-0.9 mg∙kg-1 rocuronium. In the general anesthesia with thiopental sodium group (Group T, n = 74), anesthesia was induced with 5 mg∙kg-1 thiopental sodium and 0.6-0.9 mg∙kg-1 rocuronium. Women in the spinal anesthesia group (Group SA, n = 74) were administered 0.5% (10 mg) hypertonic bupivacaine and 10 mcg fentanyl. Results: There were no significant differences between Group SA, Group P, and Group T in terms of delivery time; neonatal 1- and 5-min Apgar scores; neonatal jaundice rates; neonatal systolic, diastolic, or mean blood pressure or peak heart rate; neonatal intensive care requirement; pH, PCO2, PO2 values in cord blood gas; or neonatal glucose and lactate values. The rate of ephedrine use was significantly higher in Group SA than in Group P and Group T. Maternal satisfaction score was higher in Group SA at postoperative 4 hours and in Group P at 24 hours. The number of newborns taken into intensive care unit in Group T was significantly higher in the 1st hour, 4th hour, 5th hour and total. Respectively p value (0.006, 0,048, 0,048, and 0,005). Pain on injection was present in 55% of patients (n = 81), mild in 36% (n = 54), and severe in 18% (n = 27). Myoclonies occurred in 4% of patients (n = 7) and local rash in 6% of patients (n = 10). Differences between formulations did not reach statistical significance. Conclusion: None of the three anesthesia methods showed superiority after elective cesarean delivery. However, spinal anesthesia and general anesthesia with propofol are more appropriate for pregnant women in terms of effects on the neonate.

Postexercise Heart Rate Recovery in Adults Born Preterm

To evaluate postexercise heart rate recovery (HRR) in adults born preterm. We studied the association between preterm birth and postexercise HRR in 545 adults (267 women) at 23.3years of age (range 19.9-26.3years). One hundred three participants were born early preterm (<34 completed weeks), 178 late preterm (34-36), and 264 were full term (control group). HRR was calculated as change in heart rate (HR) 30seconds and 60seconds after cessation of submaximal step test and maximum HR slope during the first minute after. Mean peak HR was 159.5 bpm in the early preterm (P=.16 with controls), 157.8 bpm in the late preterm (P=.56), and 157.0 bpm in the control group. Mean HRR 30seconds after exercise was 3.2 bpm (95% CI 1.1-5.2) lower in the early preterm group and 2.1 bpm (0.3-3.8) lower in the late preterm group than the full term controls. Mean 60s HRR was 2.5 (-0.1 to 5.1) lower in the early preterm group and 2.8 bpm (0.6-4.9) lower in the late preterm group. Mean maximum slope after exercise was 0.10 beats/s (0.02-0.17) lower in the early preterm group and 0.06 beats/s (0.00-0.12) lower in the late preterm group. Our results suggest reduced HRR after exercise in adults born preterm, including those born late preterm. This suggests altered reactivation of the parasympathetic nervous system, which may contribute to cardiovascular risk among adults born preterm.

Frequency and characteristics of exercise-induced second-degree atrioventricular block in patients undergoing stress testing

BackgroundSpontaneous second-degree atrioventricular block induced by exercise (Ex2AVB) is rare, but it can cause profound exercise intolerance. ObjectiveWe sought to determine the frequency of Ex2AVB in our exercise testing practice and to describe characteristics of patients with Ex2AVB. We hypothesized that the number of patients would be small, but they would require invasive treatment. MethodsWe reviewed the Mayo Clinic Integrated Stress Center database for nonimaging tests performed from 2006 through 2010. All exercise tests coded as “second-degree atrioventricular block” were captured and reviewed. Tests were excluded if results showed evidence of second-degree atrioventricular block at rest. ResultsFrom 40,715 tests performed, definite Ex2AVB was found in only 19 patients (0.05%; 5 women and 14 men). Ex2AVB occurred as a Mobitz type II block in 4 patients and as a Mobitz type I block in 15. In 3 patients, Ex2AVB occurred only in recovery. Ex2AVB was intermittent in 11 patients and persistent in 8. Mean peak heart rate was higher with intermittent Ex2AVB than with persistent Ex2AVB (126 ± 39 vs 88 ± 28 bpm, P < .01), as was mean functional aerobic capacity (87% ± 20% vs 59% ± 14%, P < .01). Seven patients with persistent Ex2AVB received a permanent pacemaker; 1 underwent pacemaker adjustment. ConclusionEx2AVB is uncommon but can cause exercise intolerance that requires pacemaker implantation. Structural or ischemic heart disease and resting conduction abnormalities are common findings in patients with Ex2AVB. Intervention is seldom required for intermittent Ex2AVB.

High-intensity interval training in people with Parkinson’s disease: a randomized, controlled feasibility trial

Objectives: To investigate whether people with Parkinson’s disease can exercise at a high-intensity across a 12-week intervention and to assess the impact of the intervention on cardiorespiratory fitness. Design: This is a randomized, controlled, feasibility study with waiting list control. Assessors were blinded to group allocation. Setting: The intervention took place at an exercise centre and assessments at a district general hospital. Subjects: This study included 20 people with idiopathic Parkinson’s disease. Intervention: A total of 36 exercise sessions over 12 weeks, with each session lasting ~45 minutes, were conducted. Main measures: The main measures were maximal heart rates achieved during exercise, recruitment rate, attendance, drop-out, change in peak oxygen consumption, cardiac output, cognitive function and quality of life. The study was considered technically feasible if participants achieved ⩾85% of maximal heart rate during exercise. Results: There were 12 male and 8 female participants; they had a mean age of 68.5 years (standard deviation 6.825). Two participants were of Hoehn and Yahr stage I, 11 stage II and 7 stage III. In all, 17 participants completed the intervention. The median (interquartile range) proportion of repetitions delivered across the intervention which met our high-intensity criterion was 80% (67% to 84%). Mean peak heart rate was 88.8% of maximal. Peak oxygen consumption increased by 2.8 mL kg−1 min−1 in the intervention group and 1.5 mL kg−1 min−1 in the control group after 12 weeks of exercise. We estimate that a fully powered randomized controlled trial would require 30 participants per group. Conclusion: High-intensity interval exercise is feasible in people with Parkinson’s disease. Improvements in cardiorespiratory function are promising.

The Role of Dobutamine Dose on the Cardiac Parameters

Objectives: The report presents the effects of dobutamine dose on the cardiac parameters such as blood pressures (basal, systolic, diastolic and maximum), heart rates (basal, peak and maximum), baseline cardiac ejection fraction, and ejection fraction on dobutamine dose.Background: There is a little literature about the effects of dobutamine dose on the cardiac parameters and events.Materials and Methods: The effects of dobutamine dose on the cardiac parameters have been examined based on a real echocardiography stress data set, collected at University of California, Los Angeles on 558 patients with 31 explanatory variables/factors. The distribution of the considered cardiac parameters is gamma with non-constant variance. So, the cardiac parameters have been analyzed by joint generalized linear gamma models.Results: The mean basal blood pressure (BBP) decreases as the double product of maximum heart rate (MHR) and maximum blood pressure (MBP) at dobutamine dose (DPMAXDO) (P<0.0001) increases, while the variance of BBP increases as the DPMAXDO (P=0.0008) increases. The mean systolic blood pressure (SBP) increases as the dobutamine dose (DOSE) (P=0.0268) increases, while the mean SBP increases as the DPMAXDO (P<0.0001) decreases. The mean MBP increases as the DPMAXDO (P<0.0001) increases. The mean baseline cardiac ejection fraction (BEF) decreases as the DOSE (P=0.0255) increases. The mean ejection fraction on dobutamine dose (DOBEF) increases as the DOSE (P=0.0110) increases, while the variance of DOBEF increases as the dobutamine dose at maximum double product (DOBDOSE) (P=0.0015) decreases. The mean basal heart rate (BHR) increases as the DPMAXDO (P<0.0001), or DOBDOSE (P=0.0740) decreases. The mean peak heart rate (PHR), or maximum heart rate (MHR) increases as the DPMAXDO (P<0.0001) increases, while the variance of PHR (MHR) increases as the DOBDOSE (P<0.0001) decreases (increases). On the other hand, dobutamine dose is associated with many cardiac parameters such as SBP, MBP, new myocardial infraction (new MI), history of MI (hxofMI) etc.Conclusion: Only the marginal effects of dobutamine dose are observed on SBP, MBP, DOBEF, newMI, histMI, etc, while the joint effects of dobutamine dose (i.e., DPMAXDO and DOBDOSE) are observed on each cardiac parameters. The results are new inputs in the dobutamine dose study literature.

The Effects of the Quincke Spinal Needle Bevel Insertion on Postdural Puncture Headache and Hemodynamics in Obstetric Patients.

Aim:Spinal anesthesia is a widely used procedure in modern anesthesia. Although it is a reliable and frequently used anesthetic procedure, it involves complications, including postdural puncture headache caused by arachnoid punctured, which significantly affects postoperative well-being. In this study, we aimed to observe headache frequency with 26-G Quincke spinal needle in either transverse or sagittal planes.Materials and Methods:One hundred patients with American Society of Anesthesiologists status classes I and II who were scheduled for elective cesarean delivery with no contraindications for performing spinal anesthesia were randomly divided into two groups: Group I (transverse n = 50) and Group II (sagittal n = 50). Spinal anesthesia was performed with a 26-G Quincke needle, using 1.5–2.0 ml 0.75% hyperbaric bupivacaine. The anesthesiologists' experience, number of attempts for spinal anesthesia, volume of fluid administered preoperatively and intraoperatively, intervertebral space where spinal anesthesia was administered, and patient movements during the attempts were recorded. Mean arterial pressure and peak heart rates were recorded for 60 min intraoperatively and postoperatively. Headache and back pain complications were observed for 1 week postoperatively. Chi-square tests and statistical comparisons of the rates (statistical significance, P < 0.05) were used for assessments.Results and Conclusions:No significant differences were observed with respect to age, height, weight, headache, or incidence of back pain. No significant differences were observed for the number of spinal attempts, intervertebral space where spinal anesthesia was administered, experience of the anesthesiologists, patient movements during the attempts, volumes of fluid administered preoperatively and intraoperatively, or low back pain incidence. Significant reductions in mean arterial pressure were observed between groups after 10, 15, 30, 40, and 50 min. No significant differences were observed in headache or back pain frequency with 26-G Quincke spinal needle in either transverse or sagittal planes. Hypotension was frequently observed in the transverse group.

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OBJECTIVES/SPECIFIC AIMS: Cocaine use is a significant health problem in the United States and associated with increased risk of adverse cardiovascular outcomes. Our goal was to evaluate the effects of rapid cocaine infusions on cardiovascular hemodynamics among patients with cocaine abuse disorder. METHODS/STUDY POPULATION: Patients with a history of cocaine abuse but no overt cardiovascular disease received 4 consecutive intravenous infusions of cocaine (0, 10, 20, 40 mg) given in randomized, double-blinded order. The infusion procedure was repeated on 2 consecutive days (4 infusions each day). Following each dose, patients underwent continuous monitoring via fingertip plethysmography for 30 minutes, followed by an additional 30 minutes washout procedure. Patients were surveyed throughout this timeline to record symptoms of cocaine response. Finger tracings were then used to calculate arterial pressure curves and parameters of heart rate, blood pressure, cardiac output, stroke volume, and systemic vascular resistance according to device-specific algorithms. Mean values were calculated over the entire 30 minutes follow-up and peak values were defined as the maximum value sustained over any 60-second interval during the follow-up period. RESULTS/ANTICIPATED RESULTS: Seven patients were enrolled and received cocaine infusions of 2 consecutive days. Cocaine dose was positively associated with mean cardiac output (R=0.489, p&lt;0.001), peak diastolic blood pressure (R=0.435, p=0.001), mean heart rate (R=0.401, p=0.003), peak systolic blood pressure (R=0.399, p=0.003), peak mean arterial pressure (R=0.362, p=0.008), mean systolic blood pressure (R=0.399, p=0.003), +dP/dt (R=0.346, p=0.012), and peak heart rate (R=0.334, p=0.015). Hemodynamic parameters were also predictive of patient-reported symptoms of cocaine response. DISCUSSION/SIGNIFICANCE OF IMPACT: These data confirm the known pharmacologic effect of cocaine to prevent reuptake of neurotransmitters and demonstrate the feasibility of conducting a noninvasive assessment of cardiovascular hemodynamics as a measure of responsiveness to cocaine infusions. This procedure also provides a benchmark to evaluate the potential impact of pharmacologic treatments on cocaine-induced hemodynamic changes and patient perceptions of cocaine response.

Ergonomic evaluation of physiological stress of building construction workers associated with manual material handling tasks

Purpose: In India, the cost of manpower is very low; hence Manual Material Handling (MMH) is the cheapest solution. This study aimed to quantify the cardiac strain and postural stress of male building construction workers associated with MMH tasks. Materials and methods: Mean (SD) age (years) and job experience (years) of the workers were 31.0(4.65) and 8.8 (3.23), respectively (n=35). Working peak heart rate was recorded by polar heart rate monitor, posture analysis was done by the Ovako Working Posture Analysis System (OWAS) and the Rapid Entire Body Assessment (REBA) method, body part discomfort was assessed by the Nordic questionnaire, and perceived exertion was evaluated by the Borg scale. Two-tailed unpaired Student’s t test was performed between peak heart rate of workers associated with MMH tasks and upper extremity intensive tasks (n=31). Results: Results revealed that mean peak heart rate of the workers was significantly different (higher) compared with that of the upper extremity intensive workers (p&lt;0.05). This study showed that most of the working postures were hazardous. The magnitude of risk for musculoskeletal disorders (MSD) was much higher as per REBA compared with OWAS. Most of the workers suffered from pain in the head, neck, shoulder, lower back, and arm region. As per the Borg scale, the rate of perceived exertion was ‘hard and heavy’ among most of the workers (68.57%). Conclusions: Postural stress and cardiac strain beyond the safe limit indicates the heavy nature of the job. Load limit optimization, ergonomic lifting technique, and rescheduled work-rest cycle are essential to reducing physiological and perceived work load.

Firefighter Incident Rehabilitation: Interpreting Heart Rate Responses

The primary objective of this observational study was to document the heart rate (HR) responses of firefighters during incident rehabilitation following firefighting activity in a high-rise building with a simulated fire on the 10th floor. Additionally, the study investigated potential factors, including firefighting workload, ambient temperature, firefighter movement, and individual characteristics, that may have affected HR during recovery. Firefighters (n = 198) were assigned to perform a simulation of fire suppression, search and rescue, or material support during one of six firefighting trials that involved different crew sizes and ascent modes, and were performed in different environmental conditions. After completing the simulated firefighting activity, firefighters reported to a rehabilitation area on the 8th floor. The rehabilitation area was staffed by firefighter/paramedics. HR was monitored continuously during simulated firefighting activity and a 15-minute rehabilitation period. Average HR during rehabilitation (HRmean) was calculated and compared across trials. Simulated firefighting activity was performed in the summer in Virginia, USA, and ambient conditions varied among trials (mean ± SD: 31 ± 4°C; 46 ± 15% relative humidity; 32 ± 4°C heat index). Duration of simulated firefighting activity ranged from 12.0 to 20.3 minutes among trials (mean: 15.4 ± 5.2 minutes). Over all trials, mean peak HR during simulations was 173 ± 18 beats·min−1. Mean HR over all trials at entry into rehabilitation was 149 ± 24 beats·min−1. Following 15 minutes of recovery, mean HR over all trials was 126 ± 23 beats·min−1. Exploratory analyses revealed that higher workload during firefighting (stair trials), higher ambient temperature (≥30°C), greater movement during rehabilitation (≥0.1 g-force), higher age (≥45 years), and higher BMI (≥30.0 kg·m−2) were associated with higher HR responses during rehabilitation. During complex emergency operations, emergency medical service personnel will likely encounter considerable variability in HR responses upon initial evaluation and throughout rehabilitation. Following one bout of firefighting activity during a simulated fire scenario, HR decreased but remained elevated well above resting values following 15 minutes of rehabilitation. Based on current fire service recommendations, the majority of firefighters (88%) would not have been released from rehabilitation and eligible for reassignment after a 15-minute rehabilitation period following a brief bout of simulated firefighting activity. Key words: medical monitoring, cardiac strain, firefighting