The acute and long-term hemodynamic benefit from atrial synchronization in ventricular (VAT) pacing has been investigated at rest and during exercise in 10 patients undergoing pacemaker implantation for complete A-V block. The results were compared to conventional (VOO) ventricular stimulation at rates of 70 BPM and 96 BPM. Cardiac index (CI) in VAT-pacing increased at rest by 8% and during exercise by 15% more than with VOO pacing (p less than 0.01). No significant change between the two different rates of asynchronous pacing was observed. CI at rest and during exercise was unchanged after 10 weeks of VAT-pacing. CI is regulated by change of stroke volume in VOO-pacing and by heart rate only with VAT-pacing. In contrast to earlier results with asynchronous ventricular pacing, the hemodynamic benefit of pacing in an atrial synchronized mode is long-lasting. Physiologic mechanisms regulate hemodynamics during exercise and in heart failure.
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BMC Public Health
January 2025
Advanced Wellbeing Research Centre, Sheffield Hallam University, Sheffield, UK.
Background: Workplace health screening rarely includes measures of cardiorespiratory fitness, despite it being a greater predictor of cardiovascular disease and all-cause mortality than other routinely measured risk factors. This study aimed to determine the comparative acceptability of using a novel seismocardiography device to measure cardiorespiratory fitness via VO max during a workplace health check.
Methods: Participants were invited to participate in workplace health screening sessions where VO max was assessed by both seismocardiography at rest and sub-maximal exercise testing, in order for acceptability of both to be compared across multiple domains.
Eur J Appl Physiol
January 2025
Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, 125 University, Montpetit Hall, Room 367, Ottawa, ON, Canada.
Sleep deprivation has been associated with impaired thermoregulatory function. However, whether these impairments translate to changes in whole-body heat exchange during exercise-heat stress remains unknown. Therefore, following either a night of normal sleep or 24 h of sleep deprivation, 10 young men (mean (SD): 23 (3) years) completed three 30-min bouts of semi-recumbent cycling at increasing fixed rates of metabolic heat production (150, 200, 250 W/m), each separated by a 15-min rest in dry heat (40 °C, ~ 13% relative humidity).
View Article and Find Full Text PDFInt J Obes (Lond)
January 2025
Department of Health, Kinesiology, and Applied Physiology, Concordia University, Montreal, QC, Canada.
Objective: Compared to adulthood-onset obesity (AO), those with childhood-onset obesity (CO) are at greater risk of metabolic disease. However, the differences between these two obesity phenotypes are not clear. The aim of this study is to investigate how the age of obesity onset (CO vs.
View Article and Find Full Text PDFInt J Sports Physiol Perform
January 2025
Sports Science Research Center, Rey Juan Carlos University, Madrid, Spain.
Purpose: To analyze tactical behaviors associated with performance in track middle-distance global championship finals.
Methods: Finalists' season-best finishing race time, 100-m section times, and intermediate positions were obtained from 800- and 1500-m men's and women's finals in 2 Olympic Games and 5 World Championships. Differences between medalists, fourth- to eighth-ranked (T8), and ninth- to 12th/13th-ranked finalists in relative performance (relative to season-best), race time, and section times were determined.
J Occup Environ Hyg
January 2025
Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada.
With mines extending deeper and rising surface temperatures, workers are exposed to hotter environments. This study aimed to characterize heat stress and strain in the Canadian mining industry and evaluate the utility of the Heat Strain Score Index (HSSI), combined with additional self-reported adverse health outcomes. An exploratory web-based survey was conducted among workers ( = 119) in the Canadian mining industry.
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