Lower Total Peripheral Resistance Research Articles

Preconception Physical Exercise Is Associated with Phenotype-Specific Cardiovascular Alterations in Women at Risk for Gestational Hypertensive Disorders.

Background/Objectives: Gestational hypertensive disorders (GHD) pose significant maternal and fetal health risks during pregnancy. Preconception physical exercise has been associated with a lower incidence of GHD, but insights into the cardiovascular mechanisms remain limited. This study aimed to evaluate the effect of preconception physical exercise on the complete cardiovascular functions of women at risk for GHD in a subsequent pregnancy. Methods: A non-invasive hemodynamics assessment of arteries, veins, and the heart was performed on 40 non-pregnant women at risk for developing GHD in a subsequent pregnancy. Measurements of an electrocardiogram Doppler ultrasound, impedance cardiography and bio-impedance spectrum analysis were taken before and after they engaged in physical exercise (30-50 min, 3×/week, 4-6 months). Results: After a mean physical exercise period of 29.80 weeks, the total peripheral resistance (TPR), diastolic blood pressure and mean arterial pressure decreased in the total study population, without changing cardiac output (CO). However, in 42% (9/21) of women categorized with high or low baseline CO (>P75 or <P25 resp.), a shift in CO was observed towards the normal reference interquartile range (P25-P75). This was associated with improved hepatic venous and central arterial hemodynamic functions. Similar changes in TPR occurred in 38% (11/29) of women classified as having low or high baseline TPR. Conclusions: As in pregnancy, output- or resistance-dominant cardiovascular profiles already exist prior to conception. This study illustrates that preconception physical exercise shifts high or low CO and/or TPR towards the normal midrange, allowing women at risk for GHD to start a subsequent pregnancy with a more gestation-adaptable cardiovascular system.

Low cardiac index and high total peripheral resistance are independent predictors of mortality for acutely admitted medical patients

Abstract Introduction Identification of critically ill and high-risk patients upon hospital admission represents a significant triage task in the emergency department. Rapid identification and treatment of these patients improves survival, reduces complications during admission, decrease hospitalization duration, and lower treatment cost. Hemodynamic variables such as cardiac index (CI) and total peripheral resistance (TPR) hold the potential to improve the diagnosis of critically ill patients by providing better prognostic value. Using arterial waveform and the model flow method, CI and TPR can be measured non-invasively. These methods are validated against thermodilution, which is the golden standard. Purpose The purpose of the study was to examine the association between CI, TPR, and all-cause mortality within 30 and 90-day among patients admitted to acutely the emergency department or cardiac care unit. Methods In this observational prospective cohort study, all patients were included from the emergency department and cardiac care unit. Patients of age 18 years or older admitted to the emergency department or cardiac care unit due to acute medical disease, were included. Patients with a life expectance of 3months or less and patients unable to give informed consent were excluded. Within the first 24 hours of admission, patients underwent a 10-minute non-invasive hemodynamic measurement using arterial waveform analysis and the model-flow method. Patients were followed up to 90 days after discharge. The endpoints 30- and 90-day mortality were obtained through electronic patient journals. Cox proportional-hazard models examined the association between CI, TPR, and outcomes. All hazard models were adjusted for age, sex, BMI, heart failure, early warning score, and Charlson comorbidity score. Results Between May 2019 and January 2023, we included 920 unselected patients from the department of emergency medicine (n=433) and cardiac care unit (n=487) from a metropolitan hospital. We observed a 3% 30-days mortality while 90-days mortality was 4.9%. The median value of CI was 3.3L, the lowest decile was 2L, and the highest decile was 4.7L. Patients with the lowest CI were older, had higher incidents of heart failure, and had more comorbidities according to Charlson’s comorbidity score (table 1). In Cox proportional hazard models, lowest decile of CI at admission was associated with a significantly higher risk of 30- and 90-days mortality. Total peripheral resistance was significantly associated with 90-day mortality (table 2). Conclusion Low CI ≤2.0 liter/min/m2, and high peripheral resistance measured non-invasively were associated with an increased risk of mortality among patients admitted to the emergency department or cardiac care unit. Non-invasive estimation of CI and TPR may assist in identifying high-risk patients.Table 1Table 2

Effect of Powerlifting Exercises on Various Cardiovascular Parameters in Obese Individuals

Powerlifting is an individual endeavor that involves three attempts at lifting the heaviest possible weights in three key lifts: the Squat, Bench Press, and Deadlift. Compared to their lean counterparts, obese individuals tend to have higher cardiac output and lower total peripheral resistance, primarily due to increased stroke volume rather than heart rate changes. The primary objective of this study is to investigate the impact of powerlifting exercises on various cardiovascular parameters in obese individuals. This research employs a single-blinded, randomized controlled trial conducted at a CSJ Sports Rehab Centre, Bangalore, to recruit participants. Individuals with a BMI exceeding 30 and an age range of 25 to 42 years, exclusively male participants, and Regular engagement in gym activities for a minimum of three months. Thirty six individuals included in the study, and they were randomly divided into two groups.&#x0D; The Intervention Group engaged in 30 minutes of Powerlifting exercises and 30 minutes of supervised fitness exercises. Meanwhile, the Control Group participated in 30 minutes of supervised fitness exercises and 30 minutes of aerobics. Participants' abdominal pressure, heart rate, respiratory rate, and SpO2 levels were continuously monitored using pressure biofeedback equipment and a pulse oximeter. This study utilizes SPSS software version 24.0 for statistical analysis. Descriptive data are presented as the range, mean, and standard deviation. This study identified the Z score for the Intra-abdominal pressure as 2.041 (P=0.05), Heart rate as 2.9070 (P=0.05), Respiratory rate 5.109 (P=0.05), and SpO2 as 0.585 (P=0.05). In conclusion, this study shows that the effects of powerlifting exercises revealed a noteworthy decrease in abdominal pressure, heart rate, respiratory rate, and SpO2 levels among obese participants.

Adaptation of functional systems in different generations of Caucasians in the North-East of Russia

BACKGROUND: A substantial body of research has focused on adaptation of the new residents of the European and Asian Far North. However, these publications fail to address the changes occurring in successive generations of native Caucasians who migrated to the regions with harsh climatic conditions.&#x0D; AIM: To study functional adaptations exhibited by individuals born in the Magadan Region to various generations of Caucasians permanently living in the area.&#x0D; METHODS: A total of 1632 male volunteers, all students aged 181.1 years, and of Caucasian ethnicity, participated in this study. These individuals were either migrants or residents of Russia's North-East, born within the first to third generations. We investigated anthropometric characteristics, cardiohemodynamic parameters, and gas exchange to understand the adaptive readjustments that take place within the body's functional systems.&#x0D; RESULTS: Migrants and first-generation residents in the Magadan region experience constant stress and inadequate functioning of their cardiohemodynamic and energy exchange systems under extreme conditions. However, the third-generation subjects exhibited optimal performance of the cardiovascular system. Remarkably, the third-generation residents demonstrate an increased systolic volume at lower arterial pressure and lower total peripheral resistance. Furthermore, they had elevated proportion of the high frequency component and total power of the heart rhythm spectrum. This represents a new level of changed influence on the heart rhythm, as seen in the altered balance of its statistical and spectral wave characteristics. Moreover, the adaptability of the cardiovascular system to the harsh conditions of the North is reflected not only in the physiological indicators of the body but also in the integral structure of their correlations. This includes the magnitude and sign of the correlation coefficients and their significance.&#x0D; CONCLUSIONS: Our main findings suggest that adaptive changes in cardiohemodynamic and gas exchange exhibited by the migrants and several generations of residents of the Far North-East of Russia are directed to minimization of the total energy expenditure in functional systems. Additionally, the parasympathetic contribution increases fostering a novel interaction between the components of autonomic nervous regulation reflected by both qualitative and quantitative alterations in the structure and patterns of correlation clusters. These findings contribute to our understanding of the physiological mechanisms behind the morphofunctional readjustments of Caucasian men in the process of adaptation to the harsh climatic conditions of the Russian North-East.

20-OR: The Renal and Vascular Effects of Combined SGLT2 and Angiotensin Converting Enzyme Inhibition

The goal of this mechanistic trial was to determine the kidney and cardiovascular effects of combined treatment with an SGLT2i (empagliflozin 25mg QD) and an ACEi (ramipril 10mg QD) for 4 weeks in patients at risk of renal hyperfiltration. In this randomized, double-blind, placebo-controlled, cross-over trial, measurements were obtained following each of the 4 treatment phases: 1) no treatment, 2) 4-week ramipril treatment alone, 3) 4-week empagliflozin-ramipril combination treatment, and 4) 4-week placebo-ramipril combination treatment. The primary endpoint was GFR after empagliflozin-ramipril treatment compared to placebo-ramipril. At the end of each study phase the following measurements were performed under clamped euglycemia (4-6 mmol/L) : inulin (GFR) and paraaminohippurate (effective renal plasma flow, ERPF) clearances, tubular sodium handling, ambulatory blood pressure, arterial stiffness, heart rate variability, non-invasive cardiac output monitoring, plasma and urine biochemistry. Empagliflozin-ramipril treatment resulted in an 8ml/min/1.73m2 lower GFR (p=0.0061) , lower absolute proximal fluid reabsorption rate (p=0.0092) , lower absolute proximal sodium reabsorption rate (p=0.0056) , and lower urinary 8-isoprostane (p=0.0084) relative to placebo-ramipril treatment. Empagliflozin-ramipril treatment resulted in additive blood pressure lowering effects (SBP p=0.0112; DBP p=0.0032) and a lower total peripheral resistance (p=0.0368) . There were no other significant changes observed with the addition of empagliflozin. SGLT2i-ACEi combination treatment resulted in an expected GFR “dip”, suppression of oxidative stress markers, and additive declines in blood pressure and total peripheral resistance in this mechanistic study. These changes are consistent with a protective physiological profile characterized by the lowering of intraglomerular pressure and related cardiorenal risk when adding an SGLT2i to conservative therapy. Disclosure Y. Lytvyn: None. K. Kimura: Employee; 3Boehringer Ingelheim Canada Ltd./Ltée. N. Peter: Employee; Boehringer Ingelheim Pharma GmbH &amp; Co.KG. V.S. Lai: Advisory Panel; Baxter. J. Tse: None. L. Cham: None. B.A. Perkins: Advisory Panel; Abbott Diabetes, Insulet Corporation, Sanofi. Board Member; Novo Nordisk. Research Support; BMO Bank of Montreal, Novo Nordisk. Other Relationship; Abbott Diabetes, Insulet Corporation, Medtronic, Novo Nordisk. N. Soleymanlou: Employee; Boehringer Ingelheim Pharmaceuticals Inc., Boehringer Ingelheim Pharmaceuticals Inc. D. Cherney: Research Support; Boehringer Ingelheim-Lilly, Merck, Janssen, Sanofi, AstraZeneca and Novo-Nordisk. Other Relationship; AbbVie Inc., AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Janssen Research &amp; Development, LLC, Lilly, Maze, BMS, CSL-Behring, Merck, Otsuka, Novartis and Novo-Nordisk, Mitsubishi Tanabe Pharma Corporation, Sanofi. Funding Boehringer Ingelheim and CIHR, Diabetes Canada and the Heart and Stroke Richard Lewar Centre of Excellence and the Heart and Stroke Foundation of Canada

Individual differences in emotion regulation and cardiovascular responding to stress.

Instructed use of reappraisal to regulate stress in the laboratory is typically associated with a more adaptive cardiovascular response to stress, indexed by either (a) lower cardiovascular reactivity (CVR; e.g., lower blood pressure) or (b) a challenge-oriented response profile (i.e., greater cardiac output paired with lower total peripheral resistance). In contrast, instructed use of suppression is associated with exaggerated CVR (e.g., greater heart rate, blood pressure). Despite this, few studies have examined if the habitual use of these strategies are related to cardiovascular responding during stress. The current study examined the relationship between cardiovascular responses to acute stress and individual differences in emotion regulation style: trait reappraisal, suppression, and emotion regulation difficulties. Forty-eight participants (25 women, 23 men) completed a standardized laboratory stress paradigm incorporating a 20-minute acclimatization period, a 10-minute baseline, and two 5-minute speech tasks separated by a 10-minute intertask rest period. The emotional valence of the speech task was examined as a potential moderating factor; participants spoke about a block of negative-emotion words and a block of neutral-emotion words. Cardiovascular parameters were measured using the Finometer Pro. Greater habitual use of suppression was associated with exaggerated blood pressure responding to both tasks. However, only in response to the negative-emotion task was greater use of reappraisal associated with a challenge-oriented cardiovascular response. The findings suggest that individual differences in emotion regulation translate to differing patterns of CVR to stress, but the emotional valence of the stressor may play a role. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Síncope

Transient loss of consciousness (TLC) is defined as a real or apparent loss of consciousness that is characterized by amnesia during the period of unconsciousness, anomalous motor control, a lack of response, and short duration. The pathophysiological criteria define the different syncope groups. A drop in blood pressure, either due to low total peripheral resistance or low cardiac output, with the end result of cerebral hypoperfusion characterizes a syncopal episode. Syncope is classified in three groups based on the triggering etiology: reflex or neuromediated syncope, syncope due to orthostatic hypertension, or syncope secondary to cardiovascular pathology. The medical history, findings upon examination, and results of additional tests allow for identifying the etiology of the syncope in most cases and stratifying risk. In this update, we summarize the concept, pathophysiology, classification, diagnosis, treatment, and rules for action created by the European Society of Cardiology in their recent guidelines for patients with loss of consciousness and syncope.

Instructed reappraisal and cardiovascular habituation to recurrent stress.

Instructed reappraisal has previously been associated with a challenge-oriented cardiovascular response profile, indexed by greater cardiac output (CO) and lower total peripheral resistance (TPR), in response to a single stress exposure. The present study builds on this research by employing a stress habituation paradigm where participants completed a speech task twice; in which prior to the second task participants heard reappraisal instructions (i.e., view feelings of stress arousal as something that is beneficial) or control instructions. This paradigm allowed us to (a) test if reappraisal aids cardiovascular habituation to recurrent stress, and (b) examine if reappraisal leads to a within-participant change in CO/TPR responding from an uninstructed task to an instructed reappraisal task. Habitual use of reappraisal was assessed using the Emotion Regulation Questionnaire. The analyses report upon 173 young adults (121 women, 52 men). Cardiovascular parameters were measured continuously using the Finometer Pro. All participants demonstrated similar cardiovascular habituation during the second stress exposure (lower SBP, CO, and HR); suggesting that reappraisal did not aid cardiovascular habituation to recurrent stress. Reappraisal instructions did not lead to a challenge-oriented response compared to both the control group and responses to the uninstructed task. This study is the first to examine the relationship between instructed reappraisal and cardiovascular habituation and identifies that habitual use of reappraisal does not interact with reappraisal instructions to influence cardiovascular responses to stress.

Ketamine: yay or neigh? Implications for cardiovascular regulation and considerations for field use.

Ketamine: yay or neigh? Implications for cardiovascular regulation and considerations for field use.

No Effects of Different Doses of New Zealand Blackcurrant Extract on Cardiovascular Responses During Rest and Submaximal Exercise Across a Week in Trained Male Cyclists.

Supplementation with anthocyanin-rich blackcurrant increases blood flow, cardiac output, and stroke volume at rest. It is not known whether cardiovascular responses can be replicated over longer timeframes in fed trained cyclists. In a randomized, double-blind, crossover design, 13 male trained cyclists (age 39 ± 10 years, V˙O2max 55.3 ± 6.7ml·kg-1·min-1) consumed two doses of New Zealand blackcurrant (NZBC) extract (300 and 600mg/day for 1 week). Cardiovascular parameters were measured during rest and submaximal cycling (65% V˙O2max) on day 1 (D1), D4, and D7. Data were analyzed with an RM ANOVA using dose (placebo vs. 300 vs. 600mg/day) by time point (D1, D4, and D7). Outcomes from placebo were averaged to determine the coefficient of variation within our experimental model, and 95% confidence interval (CI) was examined for differences between placebo and NZBC. There were no differences in cardiovascular responses at rest between conditions and between days. During submaximal exercise, no positive changes were observed on D1 and D4 after consuming NZBC extract. On D7, intake of 600mg increased stroke volume (3.08ml, 95% CI [-2.08, 8.26]; d = 0.16, p = .21), cardiac output (0.39L/min, 95% CI [-1.39, .60]; d = 0.14, p = .40) (both +2.5%), and lowered total peripheral resistance by 6.5% (-0.46mmHg·min/ml, 95% CI [-1.80, .89]; d = 0.18, p = .46). However, these changes were trivial and fell within the coefficient of variation of our study design. Therefore, we can conclude that NZBC extract was not effective in enhancing cardiovascular function during rest and submaximal exercise in endurance-trained fed cyclists.

Emotion regulation contagion: Stress reappraisal promotes challenge responses in teammates.

The current research examined the interpersonal dynamics of emotion regulation in a stressful collaborative context. Little is known about how regulating one's own stress responses impacts teammates. In this article, we propose that individual efforts to regulate emotions can impact teammates for the better. We tested hypotheses arising from this claim using a dyadic experiment (N = 266) that assessed in vivo physiological stress responses during collaborative work (a face-to-face product design task) and then individual work (a product pitch to evaluators). Throughout the experiment, the manipulated teammate was randomly assigned to reappraise their stress arousal, suppress their emotional displays, or receive no instructions. The nonmanipulated teammate received no instructions in all experimental conditions. Stress reappraisal benefited both teammates, eliciting challenge-like physiological responses (higher cardiac output, lower total peripheral resistance) relative to the suppression and control conditions. These effects were observed during both collaborative and individual work. A mediation model suggested that face-to-face interpersonal effects of stress reappraisal fed forward to promote nonmanipulated teammates' improved stress responses during individual performance. Moreover, manipulated teammates' displays of positive and negative affect emerged as potential mechanisms for improvements in nonmanipulated teammates' stress responses in moderation analyses. Thus, participants benefited by interacting with a person who reappraised their stress as functional. This work has theoretical implications for the interpersonal dynamics of emotion regulation, and relevance for applied settings is also discussed. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

When enhanced awareness threatens: Interactive effects of domain-specific awareness and acceptance manipulations on cardiovascular indices of challenge and threat.

Mindfulness includes acceptance and awareness subcomponents, and emerging theories imply that cultivating both acceptance and awareness may benefit health by diminishing stress reactivity. Yet, no prior work has examined the effects of mindful acceptance and awareness on cardiovascular markers of threat and challenge-cardiac output and total peripheral resistance-despite the unique insights these indices yield into stress-related evaluations and motivation. The current research integrates Monitor and Acceptance Theory with the Biopsychosocial Model of Challenge and Threat to elucidate how an awareness manipulation and a brief acceptance training are associated with cardiovascular stress responses underlying states of challenge and threat. Healthy young adults (N=202) were enrolled in a 2×2 between-subjects experimental design manipulating both awareness (enhanced awareness vs. no enhanced awareness) and acceptance (acceptance training vs. no acceptance training) of physiological responses to a social-evaluative cold pressor test. Cardiovascular indices were recorded throughout. The combination of enhanced awareness and acceptance training led to higher cardiac output and lower total peripheral resistance (indexing greater challenge, less threat) to the cold pressor test than the combination of enhanced awareness and no acceptance training. However, the combination of no enhanced awareness and no acceptance training also led to higher cardiac output and lower total peripheral resistance than the combination of enhanced awareness and no acceptance training. These results add to a growing body of work suggesting that mindful awareness and acceptance subcomponents interact to influence stress reactivity and imply that enhanced stressor awareness without acceptance may lead to increased threat.

Selected sex related differences in pathophysiology of cardiovascular system.

The annual incidence of cardiovascular diseases is age-dependently increasing both in men and women, however, the prevalence is higher in men until midlife. The higher incidence of cardiovascular disease in men than in women of similar age, and the menopause-associated increase in cardiovascular disease in women, has led to speculation that gender-related differences in sex hormones might have a key role in the development and evolution of cardiovascular disease. There are several suggested pathways in which gender and sex hormones can affect human cardiovascular system to produce original sexually different pathophysiology between women and men. Sex steroid hormones and their receptors are critical determinants of cardiovascular gender differences. Also arterial blood pressure is typically lower in women than in men what could be explained particularly by greater synthesis of nitric oxide (NO) in women. Female cardiomyocytes have a greater survival advantage when challenged with oxidative stress, suggesting that female hormones may play an important role in antioxidative protection of myocardium. It was also demonstrated in animal models that combination of XX chromosomes versus an XY chromosomes enhances sex differences in higher HDL cholesterol. Women were found to have reduced sympathetic activity (reflected by lower total peripheral resistance) and pulmonary artery pressure and enhanced parasympathetic activity relative to men. Similarly, men were found to have higher plasma norepinephrine levels than women. Regarding differences between the sexes in electrophysiology of the heart, two principle mechanisms have been proposed to explain them: hormonal effects on the expression or function of ion channels or, conversely, differences in autonomic tone. To improve diagnosis and treatment of cardiovascular diseases, greater focus on understanding the molecular and cellular physiology of the sex steroid hormones and their receptors in the cardiovascular system will be required.

A Randomized Controlled Trial of a Mindfulness-Based Weight Loss Intervention on Cardiovascular Reactivity to Social-Evaluative Threat Among Adults with Obesity.

Mindfulness-based interventions have been found to reduce psychological and physiological stress reactivity. In obesity, however, stress reactivity is complex, with studies showing both exaggerated and blunted physiological responses to stressors. A nuanced view of stress reactivity is the "challenge and threat" framework, which defines adaptive and maladaptive patterns of psychophysiological stress reactivity. We hypothesized that mindfulness training would facilitate increased challenge-related appraisals, emotions, and cardiovascular reactivity, including sympathetic nervous system activation paired with increased cardiac output (CO) and reduced total peripheral resistance (TPR) compared to a control group, which would exhibit an increased threat pattern of psychophysiological reactivity to repeated stressors. Adults (N=194) with obesity were randomized to a 5.5-month mindfulness-based weight loss intervention or an active control condition with identical diet-exercise guidelines. Participants were assessed at baseline and 4.5 months later using the Trier Social Stress Task. Electrocardiogram, impedance cardiography, and blood pressure were acquired at rest and during the speech and verbal arithmetic tasks to assess pre-ejection period (PEP), CO, and TPR reactivity. Mindfulness participants showed significantly greater maintenance of challenge-related emotions and cardiovascular reactivity patterns (higher CO and lower TPR) from pre to post-intervention compared to control participants, but groups did not differ in PEP. Findings were independent of changes in body mass index. Mindfulness training may increase the ability to maintain a positive outlook and mount adaptive cardiovascular responses to repeated stressors among persons with obesity though findings need to be replicated in other populations and using other forms of mindfulness interventions.

The influence of self-talk on challenge and threat states and performance

ObjectivesA psychophysiological response called a challenge state has been associated with better performance than a threat state. However, to date, challenge-promoting interventions have rarely been tested. Therefore, this study investigated whether instructional and/or motivational self-talk promoted a challenge state and improved task performance. DesignA three-group, randomised-controlled experimental design was used. MethodSixty-two participants (52 males, 10 females; Mage = 24 years, SD = 6) were randomly assigned to one of three self-talk groups: instructional, motivational, or control (verbalising trial number). Participants performed four dart-throwing tasks. Cognitive and cardiovascular measures of challenge and threat states were recorded before the first and final task. ResultsThe motivational, but not the instructional group, improved their performance between the first and final tasks more than the control group. Self-talk had no effect on the cognitive or cardiovascular challenge and threat measures. However, evaluating the task as more of a challenge (coping resources match/exceed task demands) was related to better performance. Cardiovascular reactivity more reflective of a challenge state (higher cardiac output and/or lower total peripheral resistance reactivity) was more positively related to performance in the motivational than in the control group, and in the control than the instructional group. ConclusionsMotivational self-talk improved performance more than control self-talk. Furthermore, motivational self-talk may have strengthened, whereas instructional self-talk may have weakened, the relationship between challenge and threat states and performance. Hence, athletes in a challenge state may benefit from motivational self-talk, whereas those in a threat state may profit from instructional self-talk.

Intake Duration Effects of New Zealand Blackcurrant Extract on Cardiovascular Responses During Moderate Intensity Exercise in Males (P23-015-19)

ObjectivesNew Zealand blackcurrant (NZBC) is an anthocyanin-rich berry with potential effects on cardiovascular health (e.g., 7-day NZBC extract lowered total peripheral resistance at rest). We examined effects of 7- and 14-day intake of NZBC extract on cardiovascular responses during moderate intensity exercise. MethodsFifteen healthy men (mean ± SD, age: 24 ± 6 yr, body mass: 79 ± 16 kg, height: 178 ± 6 cm, BMI: 24.7 ± 4.3 kg·m−2, IPAQ score: 4534 ± 1576 MET·week−1) volunteered. Resting metabolic equivalent (1-MET) was measured using Douglas bags (1-MET: 3.97 ± 0.66 ml·kg−1·min−1) with an incremental walking test to determine the relationship between walking speed and MET. A randomised, cross-over experimental design was used for baseline, 7-day and 14-day intake. Participants consumed 2 capsules of NZBC extract (600 mg and containing 210 mg of anthocyanins, CurraNZ™ Health Currancy Ltd., UK) with breakfast with a 14-day washout. On the morning of testing, the final 2 capsules were ingested 2-hr before the 30-min walk at 4 (n = 3) or 5 (n = 12) METs (speed: 5.68 ± 0.67 km·hr−1). Cardiovascular responses were measured at 7–10, 17–20 and 27–30 min during the walk (Portapres Model 2), averaged and analysed (ANOVA and post-hoc t-tests). ResultsIntake duration had no effect on heart rate (e.g., baseline: 102 ± 18 beats·min−1), systolic blood pressure (e.g., baseline 158 ± 18 mm Hg) and ejection time (e.g., baseline: 0.28 ± 0.03 s). Cardiac output (baseline: 11.7 ± 2.0, 7-day: 12.7 ± 2.5, 14-day: 12.7 ± 2.1 L·min−1, P = 0.012) and stroke volume (baseline: 114 ± 13, 7-day: 123 ± 22, 14-day: 126 ± 21 mL·min−1, P = 0.017) were increased, and total peripheral resistance (baseline: 0.51 ± 0.11, 7-day: 0.46 ± 0.17, 14-day: 0.44 ± 0.12 mmHg·L−1·min−1, P = 0.018) and diastolic blood pressure (baseline 71 ± 9, 7-day: 66 ± 10, 14-day: 63 ± 11 mm Hg, P = 0.002) were lower for 7- and 14-day intake. Only 14-day intake resulted in lower mean arterial pressure (baseline: 93 ± 10, 7-day: 89 ± 9, 14-day: 87 ± 11 mm Hg, P = 0.034). ConclusionsBeneficial effects of anthocyanin-rich NZBC extract intake on cardiovascular responses during moderate intensity exercise do not require long-duration intake. Funding SourcesHealth Currancy (UK) Ltd and CurraNZ (NZ) Ltd provided supplements and support for conference attendance with Blackcurrant New Zealand Inc. (NZ).

Examining the effect of challenge and threat states on endurance exercise capabilities

This paper presents the first two studies to explore the effect of challenge and threat states on endurance exercise capabilities. In study one, relationships between cardiovascular markers of challenge and threat states, ratings of perceived exertion (RPE), and exercise tolerance were explored during moderate- and severe-intensity cycling. Cardiovascular reactivity more reflective of a challenge state (i.e., relatively higher cardiac output and/or lower total peripheral resistance reactivity) predicted lower RPE throughout moderate- but not severe-intensity cycling. Building on these findings, study two experimentally manipulated participants into challenge, threat, and neutral groups, and compared 16.1 km time-trial performances, where pacing is self-regulated by RPE. Participants completed familiarisation, control, and experimental visits while physiological (oxygen uptake), perceptual (RPE), and performance-based (time to completion [TTC] and power output [PO]) variables were assessed. When compared to the threat group, the challenge group demonstrated cardiovascular responses more indicative of a challenge state, and delivered faster early-race pacing (PO) at similar RPE. Although there were no significant differences in TTC, results revealed that augmentations in PO for the challenge group were facilitated by tempered perceptions of fatigue. The findings suggest that an individual’s pre-exercise psychophysiological state might influence perceived exertion and endurance exercise capabilities.

Challenge and threat states, performance, and attentional control during a pressurized soccer penalty task.

The integrative framework of stress, attention, and visuomotor performance was developed to explain the benefits of responding to competitive pressure with a challenge rather than a threat state. However, the specific predictions of this framework have not been tested. Forty-two participants completed 2 trials of a pressurized soccer penalty task. Before the first trial, challenge and threat states were assessed via demand and resource evaluations and cardiovascular reactivity. Performance and gaze behavior were then recorded during the first trial. Before the second trial, challenge and threat states were measured again through demand and resource evaluations and cardiovascular reactivity. A challenge state, indexed by evaluations that coping resources matched or exceeded task demands, and higher cardiac output and/or lower total peripheral resistance reactivity, was associated with superior performance, with the cardiovascular response predicting performance more strongly. Furthermore, a challenge-like cardiovascular response was related to longer quiet eye durations and lower search rates, marginally more fixations toward the goal and ball, and more time spent fixating on the goal and other locations (e.g., ground). However, none of the attentional variables mediated the relationship between challenge and threat states and performance, suggesting more research is needed to elucidate underlying mechanisms. Finally, although performing well on Trial 1 was marginally associated with evaluating the second trial as a challenge, no support was found for the other feedback loops. The findings offer partial support for the integrative framework and imply that practitioners should foster a challenge state to optimize performance under pressure.

The value of non-invasive measurement of cardiac output and total peripheral resistance to categorize significant changes of intradialytic blood pressure: a prospective study

BackgroundBlood pressure (BP) is currently the main hemodynamic parameter used to assess the influence of fluid removal during hemodialysis session. Since BP is dependent on cardiac output (CO) and total peripheral resistance (TPRI), investigating these parameters may help to better understand the influence of fluid removal on patient’s hemodynamics. We used a novel non-invasive whole-body bio-impedance cardiography device, recently validated in hemodialysis patients, to examine mechanisms of intradialytic hemodynamics in a Chinese dialysis population.MethodsChronic hemodialysis patients in Sichuan Provincial People’s Hospital were enrolled. Demographic data and dialysis prescriptions were collected. Hemodynamic measurements were made pre-treatment, every 20 min during treatment and immediately after treatment in each random dialysis session. These included blood pressure, cardiac index (CI), total peripheral resistance (TPRI) and cardiac power index (CPI). Patients were divided into 5 hemodynamic groups as per their major hemodynamic response to fluid removal: low CPI, low TPRI, high TPRI, High CPI and those with normal hemodynamics.ResultsTwenty-seven patients were enrolled, with 12 (44.4%) males. The average age was 65 ± 12 y. The average body mass index (BMI) was 23.7 ± 3.9 kg/m2. 12 (44.4%) patients were diabetic. Three hundred twenty-four hemodynamic measurements were made. Weight, BMI, total fluid removal, pretreatment systolic BP, CI, TPRI and CI differed significantly among the 5 hemodynamic groups.11.1% of patients had low CPI, 25.9% had low TPRI, 18.5% had high CPI, 3.7% had high TPRI and 40.7% had normal hemodynamics. Hemodynamic differences among the 5 subgroups were significant.ConclusionThis technology provides multi-dimensional insight into intradialytic hemodynamic parameters, which may be more informative than blood pressure only. Using hemodynamic parameters to describe patients’ status is more specific and accurate, and could help to work out specific and effective therapeutic actions according to underlying abnormalities.

Loneliness and cardiovascular reactivity to acute stress in younger adults.

Loneliness is connected to poorer health outcomes with stress reactivity proposed as an underlying mechanism. The present study explored whether the relationship between loneliness and cardiovascular reactivity (CVR) varies across acute psychological stress tasks. Eighty-eight healthy younger adults completed a psychometric measure of loneliness and participated in a standardised cardiovascular stress-testing protocol, with a public speaking and a mental arithmetic task. Cardiovascular functioning was assessed before and during the acute stress exposure. Higher levels of loneliness significantly predicted lower total peripheral resistance (TPR) reactivity to the public speaking task but not to the arithmetic challenge. This suggests that the effect of loneliness on cardiovascular reactivity to acute stress may vary by stressor type. These findings are discussed in relation to future research.