Heart rate responses to autonomic challenges in obstructive sleep apnea.

Obstructive sleep apnea (OSA) is accompanied by structural alterations and dysfunction in central autonomic regulatory regions, which may impair dynamic and static cardiovascular regulation, and contribute to other syndrome pathologies. Characterizing cardiovascular responses to autonomic challenges may provide insights into central nervous system impairments, including contributions by sex, since structural alterations are enhanced in OSA females over males. The objective was to assess heart rate responses in OSA versus healthy control subjects to autonomic challenges, and, separately, characterize female and male patterns. We studied 94 subjects, including 37 newly-diagnosed, untreated OSA patients (6 female, age mean ± std: 52.1 ± 8.1 years; 31 male aged 54.3 ± 8.4 years), and 57 healthy control subjects (20 female, 50.5 ± 8.1 years; 37 male, 45.6 ± 9.2 years). We measured instantaneous heart rate with pulse oximetry during cold pressor, hand grip, and Valsalva maneuver challenges. All challenges elicited significant heart rate differences between OSA and control groups during and after challenges (repeated measures ANOVA, p<0.05). In post-hoc analyses, OSA females showed greater impairments than OSA males, which included: for cold pressor, lower initial increase (OSA vs. control: 9.5 vs. 7.3 bpm in females, 7.6 vs. 3.7 bpm in males), OSA delay to initial peak (2.5 s females/0.9 s males), slower mid-challenge rate-of-increase (OSA vs. control: -0.11 vs. 0.09 bpm/s in females, 0.03 vs. 0.06 bpm/s in males); for hand grip, lower initial peak (OSA vs. control: 2.6 vs. 4.6 bpm in females, 5.3 vs. 6.0 bpm in males); for Valsalva maneuver, lower Valsalva ratio (OSA vs. control: 1.14 vs. 1.30 in females, 1.29 vs. 1.34 in males), and OSA delay during phase II (0.68 s females/1.31 s males). Heart rate responses showed lower amplitude, delayed onset, and slower rate changes in OSA patients over healthy controls, and impairments may be more pronounced in females. The dysfunctions may reflect central injury in the syndrome, and suggest autonomic deficiencies that may contribute to further tissue and functional pathologies

Differential heart rate reactivity and recovery after psychosocial stress (TSST) in healthy children, younger adults, and elderly adults: The impact of age and gender

In addition to numerous reports about psychophysiological stress responses to acute stressors, there are few data available on gender differences of stress-induced heart rate responses in multiple age groups applying the same psychological stressor. Second, the assessment of poststress recovery appears to be neglected in the empirical literature. For this study, data from 5 independent studies were reanalyzed to investigate the impact of age and gender on heart rate responses and poststress recovery to a standardized psychosocial stress task (Trier Social Stress Test; TSST) in 28 children, 34 younger adults, and 26 older adults. As expected, prestressor baselines correlated significantly with chronological age (r = -.27, p = .01). There was a marked age-related decrease in the heart rate stress response (p = .0003) with children and younger adults showing significantly higher increases than elderly persons. The analysis of gender effects showed that girls had higher heart rate increases during the stress exposure than boys (p = .03). In younger adults, stress responsivity was also higher in women (p = .03). Peak heart rate responses were comparable in older men and women, with only men returning to prestressor baselines during the observation period. In sum, this reanalysis revealed differential heart rate responses and recovery after exposition to the TSST in healthy children, younger adults, and elderly adult

The Effects of Mood and Stress on Cardiovascular Responses

The "reactivity hypothesis" posits that elevations in cardiovascular reactivity may increase the risk of developing adverse cardiovascular events over time. Negative emotions and stress may exacerbate cardiovascular reactivity, as represented by increases in blood pressure and heart rate responses. However, prior studies have reported mixed results. Therefore the primary goal of the present study was to examine the effects of stimuli intended to elicit either sadness (negative mood induction) or mental stress (stressor tasks) on blood pressure and heart rate responses, in particular, when placed alongside each other in one experimental paradigm. One hundred and six participants were randomized to one of four conditions: Mood Induction (Sad or Neutral) Only or Mood Induction (Sad or Neutral) plus Stressor Tasks. Continuous measures of heart rate and blood pressure were collected, in addition to periodic self-report measurements of sadness and perceived stress. It was first hypothesized that participants in the Mood Induction plus Stressor Task conditions would exhibit greater blood pressure and heart rate responses than the participants in the Mood Induction Only conditions. It was also hypothesized that the elicitation of a negative emotion would not predict significant increases in blood pressure and heart rate. Third, it was hypothesized that the elicitation of a negative emotion would not affect the relationship between the stressor tasks and blood pressure and heart rate. Finally, it was hypothesized that males would exhibit greater blood pressure responses than female participants. Data were analyzed using reactivity scores in a series of statistical analyses. Results supported several of the hypotheses, confirming that certain stressor tasks significantly increase blood pressure and heart rate responses. Findings also provided evidence that a negative mood induction is associated with significant increases in blood pressure and heart rate responses, even though these responses may not be unique to this specific negative emotion. Implications for future work, including clinical applications, are discussed

Effect of vicarious fear learning on children's heart rate responses and attentional bias for novel animals

Research with children has shown that vicarious learning can result in changes to 2 of Lang's (1968) 3 anxiety response systems: subjective report and behavioral avoidance. The current study extended this research by exploring the effect of vicarious learning on physiological responses (Lang's final response system) and attentional bias. The study used Askew and Field's (2007) vicarious learning procedure and demonstrated fear-related increases in children's cognitive, behavioral, and physiological responses. Cognitive and behavioral changes were retested 1 week and 1 month later, and remained elevated. In addition, a visual search task demonstrated that fear-related vicarious learning creates an attentional bias for novel animals, which is moderated by increases in fear beliefs during learning. The findings demonstrate that vicarious learning leads to lasting changes in all 3 of Lang's anxiety response systems and is sufficient to create attentional bias to threat in children

Heart Rate Responses of Referees During the 2011 Eurobasket Championship.

The purpose of the study was to describe heart rate responses of referees during a major international basketball championship. Heart rate (HR) data was collected from 26 international referees officiating 48 matches (95 matches ‘worth’ of data) at the 2011 Eurobasket Championship. HR was subsequently normalised to percentage of theoretical maximum, and used to calculate time spent in different exercise intensity zones (Light, moderate, heavy, very heavy) across successive phases of the tournament and successive quarters (Q) of matches. Mean HR was 81.89±13.4% of theoretical maximum during match play, and there were no significant differences in HR recorded during different phases of the championship. However, relative HR progressively decreased with each quarter of the matches (Q1; 91.43±7.6%, Q2;90.51±7.1%, Q3; 88.23±7.3%, Q4; 88.21±7.5% HRmax). This decrease in %HRmax recorded relative to Q1 reached statistical significance (P<0.05) in Q3 and Q4. Although percentage of total match time spent in ‘hard’ and ‘light’ exercise intensity categories remained similar across quarters of matches, there was a reduction in time spent in ‘very hard’ activity from 10.93±16.08% in Q1 to 5.73±10.36% in Q3 and 5.55±10.74% in Q4 (both P<0.05). This reduction in ‘very hard’ activity was accompanied by an increase in ‘moderate’ intensity activity from 15.06±14.29% in Q1 to 23.37±17.12% in Q3 and 24.35±20.31% in Q4 (both P<0.01). The data suggests that international basketball referees are unable to maintain initial exercise intensity for four successive quarters of championship play. This is in contrast to available data suggesting elite players are able to maintain or increase exercise intensity as matches progress. This has implications for the physical conditioning requirements of international level match officials

Impact of Human and Other Disturbance on Behaviour and Heart Rate of Incubating Adélie Penguins (Pygoscelis adeliae)

The study presented here provides qualitative and quantitative evidence on existence and extent of incubating Adélie penguins’ behavioural and heart rate responses to human and conspecific disturbance, and additionally reports observations on disturbance by predators and aircraft noise

Heart Rate Responses during Simulated Fire Ground Scenarios among Full-Time Firefighters

International Journal of Exercise Science 13(2): 374-382, 2020. Simulated fire ground scenarios (SFGS) provide firefighters with an opportunity to maintain skills, receive feedback, and optimize performance. Although there is extensive research on heart rate (HR) changes in the firefighter population, few examine the differences between positions. Firefighters are primarily responsible for fire suppression and control (23), officers for emergency operations and organizational management, paramedics for providing on-scene emergency medical care, and drivers are responsible for driving the fire apparatus. Utilizing HR analysis to quantify the physical demands of SFGS among firefighting crews by position. Sixty-seven male (age: 38.97 ± 9.17; ht: 177.99 ± 6.45 cm. wt: 88.83 ± 13.55 kg) firefighters (FF) participated in this investigation. FF crews performed two SFGS involving the suppression and control of a structural fire. Participants were outfitted with heart rate (HR) monitors and average heart rate (HRavg) and maximum heart rate (HRmax) data were collected for each of the two SFGS. Significant differences were observed for Age (P = 0.01), APMHR (P = 0.01), HRmax1(P = 0.04), and HRmax2(P = 0.04) in which firefighters had higher values for Age-predicted maximal heart rate (APMHR), HRmax1, HRmax2compared to the officers. SFGS can be very physically demanding events that may elicit maximal or near maximal HR responses regardless of position. Based on the metabolic demands of these events and the individual firefighter’s capabilities, this information can be used to develop resistance training and conditioning programs that optimize performance at maximal or near maximal heart rates

Characterization of Adult Heart Rate Responses During Recreational Skateboarding at Community Skateparks

International Journal of Exercise Science 13(2): 501-510, 2020. Youth participating in recreational skating at community skate parks attain exercise intensities and durations that are comparable with the CDC’s exercise recommendations for cardiovascular fitness for their age group. However, it is currently unclear if adults who skateboard in the same environment also achieve the recommended intensities and durations for cardiovascular fitness. Therefore, the purpose of this study was to test the hypothesis that skateboarding would elicit heart rates and durations consistent with the CDC’s recommendations for cardiovascular fitness in adults. Fifty-five subjects between ages 18-55 were recruited from six community skateparks for this study. Subjects completed a questionnaire and were instrumented with a Polar V800 heart rate receiver on the left wrist and an H7 Bluetooth heart rate transmitter around the chest below the pectoralis major. Participants were instructed to engage in a typical skateboarding session on their own board with the duration and intensity of activity to be determined by the participant. The mean age of the participants was 27.4 ± 8.5 years, and participants reported skateboarding at a community skate park a mean of 3.1 ± 1.8 days/week. Participants had a mean heart rate of 138.2 ± 21.9 beats per minute (71.7% of age predicted maximum), skated for 65.5 ± 36.2 minutes, and traveled 4.56 ± 4.5 kilometers. Subjects spent 70% of their total duration at moderate-intensity or above and 30% within the low, and below low-intensity range. Results from this study suggest that adults participating in recreational skateboarding in community skateparks achieve the CDC’s exercise recommendations for cardiovascular fitness. These findings may have implications for community skatepark design and professional training programs for adult skateboarding athletes