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Aims: Exercise-induced cellular stress and sterile inflammation are of increasing interest. ASC specks are a component of the intracellular NLRP3-inflammasome and can be released into the blood. For example, serum ASC specks are increased after marathon running. We therefore tested whether ASC specks are potentially associated with the individual response to physical training and cardiopulmonary capacity. Methods: We performed a prospective study in 45 healthy athletes. Blood samples were taken before and after cardiopulmonary exercise testing (CPET). ASC speck concentrations were quantitated using flow cytometry. Results: Baseline ASC speck levels correlated with clinical parameters of body composition (height, weight, BMI) and parameters of cardiopulmonary performance (peak VO2, peak oxygen pulse, heart rate after exercise). Athletes with lowest baseline ASC speck concentrations have a significantly lower BMI (22.0 ± 1.8 vs. 24.9 ± 1.6 kg/m2), higher heart rate at rest (72 ± 10 vs. 58 ± 10 beats/min), lower peak VO2 (2692 ± 629 vs. 3404 ± 747 mL/min) and lower peak oxygen pulse (15.6 ± 3.4 vs. 20.7 ± 3.5 mL/heart rate). Overall, ASC speck concentrations showed no significant change after CPET (7.0 ± 4.5 vs. 8.0 ± 5.4 ASC specks/µL, p = 0.3). However, subgroup analysis revealed a significant increase in circulating ASC specks in athletes with the lowest baseline values (2.37 ± 0.84 vs. 8.43 ± 7.52 ASC specks/µL, p < 0.05). Athletes with an increase in ASC speck concentrations in response to CPET had a lower peak oxygen pulse compared to those with a decrease (17.1 ± 4.2 vs. 19.8 ± 4.1, p < 0.05). Conclusion: Low ASC speck baseline values as well as an increase in response to exercise are associated with lower peak oxygen pulse in healthy athletes. [ABSTRACT FROM AUTHOR]

Background and Study Aim. Given the global spread of COVID-19 and its profound effects on public health, understanding its impact on the physical health and performance of young athletes is crucial for developing guidelines to support their recovery and well-being. The goal of this research was to assess the impact of the COVID-19 infection and possible consequences on the functional abilities of schoolchild athletes, and determine whether there are differences compared to their peers who did not suffer the infection. Material and Methods. This study involved 100 teenagers (median age 15.7±1.167), who engage in two different sports (basketball and soccer), divided into two groups. The first group comprised young athletes (n=53, age 15.79±1.854) who had contracted COVID-19 and underwent 14 days of home isolation. The second group consisted of healthy child athletes (n=47, age 15.60±1.313). Participants underwent a comprehensive pre-participation sports medical examination, which included a cardiopulmonary exercise test (CPET) on a treadmill. CPET assessed various physiological parameters: maximum oxygen consumption (VO2max); heart rates at the first and second ventilatory thresholds (HR at VT1 and HR at VT2); respiratory exchange ratio (RER); maximal pulmonary ventilation (VEmax); ventilatory efficiency (VE/VCO2); oxygen pulse (O2/HR); maximum heart rate (HRmax); three-minute heart rate recovery; and potential electrocardiographic changes. Results. The results indicate that COVID-19 infection has led to statistically significant impairments in the cardiorespiratory functions of child athletes. Notably, there were significant reductions in maximum oxygen consumption (VO2max), maximal pulmonary ventilation (VEmax), oxygen pulse (O2/HR), as well as heart rates at the first ventilatory threshold (HR at VT1), maximum heart rate (HRmax), and heart rate recovery following maximal effort, all demonstrating p-values less than 0.05. Conclusions. The assessed parameters demonstrated that the functions were statistically significantly impaired in child athletes who had recovered from COVID-19 compared to their healthy peers of the same age. However, the infection appeared to have a minimal impact on heart rate variability at ventilatory thresholds. These findings offer valuable insights for coaches and sports medicine physicians in adjusting training programs and supporting the rehabilitation process for young adolescent athletes resuming their training after recovering from COVID-19.

AimsExercise-induced cellular stress and sterile inflammation are of increasing interest. ASC specks are a component of the intracellular NLRP3-inflammasome and can be released into the blood. For example, serum ASC specks are increased after marathon running. We therefore tested whether ASC specks are potentially associated with the individual response to physical training and cardiopulmonary capacity.MethodsWe performed a prospective study in 45 healthy athletes. Blood samples were taken before and after cardiopulmonary exercise testing (CPET). ASC speck concentrations were quantitated using flow cytometry.ResultsBaseline ASC speck levels correlated with clinical parameters of body composition (height, weight, BMI) and parameters of cardiopulmonary performance (peak VO2, peak oxygen pulse, heart rate after exercise). Athletes with lowest baseline ASC speck concentrations have a significantly lower BMI (22.0 ± 1.8 vs. 24.9 ± 1.6 kg/m2), higher heart rate at rest (72 ± 10 vs. 58 ± 10 beats/min), lower peak VO2 (2692 ± 629 vs. 3404 ± 747 mL/min) and lower peak oxygen pulse (15.6 ± 3.4 vs. 20.7 ± 3.5 mL/heart rate). Overall, ASC speck concentrations showed no significant change after CPET (7.0 ± 4.5 vs. 8.0 ± 5.4 ASC specks/µL, p = 0.3). However, subgroup analysis revealed a significant increase in circulating ASC specks in athletes with the lowest baseline values (2.37 ± 0.84 vs. 8.43 ± 7.52 ASC specks/µL, p < 0.05). Athletes with an increase in ASC speck concentrations in response to CPET had a lower peak oxygen pulse compared to those with a decrease (17.1 ± 4.2 vs. 19.8 ± 4.1, p < 0.05).ConclusionLow ASC speck baseline values as well as an increase in response to exercise are associated with lower peak oxygen pulse in healthy athletes.

Background: Cardiopulmonary exercise testing (CPET) is used in evaluation of repaired tetralogy of Fallot (rTOF), particularly for pulmonary valve replacement need. Oxygen pulse (O2P) is the CPET surrogate for stroke volume and peripheral oxygen extraction. Objectives: This study assessed O2P curve properties against non-invasive cardiac output monitoring (NICOM) and clinical testing. Methods: This cross-sectional study included 44 rTOF patients and 10 controls. Three new evaluations for O2P curve analysis during CPET were developed. Best fit early and late regression slopes of the O2P curve were used to calculate: 1) the early to late ratio, or “O2 pulse response ratio” (O2PRR); 2) the portion of exercise until slope inflection, or “flattening fraction” (FF); 3) the area under the O2P response curve, or “O2P curve area”. Results: rTOF patients (median age 35.2 (27.6–39.4); 61% female) had a lower VO2 max (23.4 vs 45.6 ml/kg/min; p 50%. FF and O2P curve area significantly correlated with peak cardiac index, stroke volume, left and right ventricular ejection fraction, and right ventricular systolic pressure. Conclusion: CPET remains an integral part in the evaluation of rTOF. We introduce three non-invasive methods to assess exercise hemodynamics using the O2P curve data. These evaluations demonstrated significant correlations with stroke volume, cardiac output, and right ventricular pressure.

Abstract Background SARS-CoV-2 infection has raised concerns about long-term health repercussions. Exercise ventilatory inefficiency (EVin) has emerged as a notable long-term sequela, potentially impacting respiratory and cardiovascular health. This study aims to assess the long-term presence of EVin after 34 months and its association with cardiorespiratory health in post-COVID patients. Methods In a longitudinal study on 32 selected post-COVID subjects, we performed two cardiopulmonary exercise tests (CPETs) at 6 months (T0) and 34 months (T1) after hospital discharge. The study sought to explore the long-term persistence of EVin and its correlation with respiratory and cardiovascular responses during exercise. Measurements included also V̇O2peak, end-tidal pressure of CO2 (PETCO2) levels, oxygen uptake efficiency slope (OUES) and other cardiorespiratory parameters, with statistical significance set at p

Background: SARS-CoV-2 infection has raised concerns about long-term health repercussions. Exercise ventilatory inefficiency (EVin) has emerged as a notable long-term sequela, potentially impacting respiratory and cardiovascular health. This study aims to assess the long-term presence of EVin after 34 months and its association with cardiorespiratory health in post-COVID patients. Methods: In a longitudinal study on 32 selected post-COVID subjects, we performed two cardiopulmonary exercise tests (CPETs) at 6 months (T0) and 34 months (T1) after hospital discharge. The study sought to explore the long-term persistence of EVin and its correlation with respiratory and cardiovascular responses during exercise. Measurements included also V̇O2peak, end-tidal pressure of CO2 (PETCO2) levels, oxygen uptake efficiency slope (OUES) and other cardiorespiratory parameters, with statistical significance set at p < 0.05. The presence of EVin at both T0 and T1 defines a persisting EVin (pEVin). Results: Out of the cohort, five subjects (16%) have pEVin at 34 months. Subjects with pEVin, compared to those with ventilatory efficiency (Evef) have lower values of PETCO2 throughout exercise, showing hyperventilation. Evef subjects demonstrated selective improvements in DLCO and oxygen pulse, suggesting a recovery in cardiorespiratory function over time. In contrast, those with pEvin did not exhibit these improvements. Notably, significant correlations were found between hyperventilation (measured by PETCO2), oxygen pulse and OUES, indicating the potential prognostic value of OUES and Evin in post-COVID follow-ups. Conclusions: The study highlights the clinical importance of long-term follow-up for post-COVID patients, as a significant group exhibit persistent EVin, which correlates with altered and potentially unfavorable cardiovascular responses to exercise. These findings advocate for the continued investigation into the long-term health impacts of COVID-19, especially regarding persistent ventilatory inefficiencies and their implications on patient health outcomes. [ABSTRACT FROM AUTHOR]

Background and Study Aim: Given the global spread of COVID-19 and its profound effects on public health, understanding its impact on the physical health and performance of young athletes is crucial for developing guidelines to support their recovery and well-being. The goal of this research was to assess the impact of the COVID-19 infection and possible consequences on the functional abilities of schoolchild athletes, and determine whether there are differences compared to their peers who did not suffer the infection. Material and Methods: This study involved 100 teenagers (median age 15.7±1.167), who engage in two different sports (basketball and soccer), divided into two groups. The first group comprised young athletes (n=53, age 15.79±1.854) who had contracted COVID-19 and underwent 14 days of home isolation. The second group consisted of healthy child athletes (n=47, age 15.60±1.313). Participants underwent a comprehensive pre-participation sports medical examination, which included a cardiopulmonary exercise test (CPET) on a treadmill. CPET assessed various physiological parameters: maximum oxygen consumption (VO2max); heart rates at the first and second ventilatory thresholds (HR at VT1 and HR at VT2); respiratory exchange ratio (RER); maximal pulmonary ventilation (VEmax); ventilatory efficiency (VE/VCO2); oxygen pulse (O2/HR); maximum heart rate (HRmax); threeminute heart rate recovery; and potential electrocardiographic changes. Results: The results indicate that COVID-19 infection has led to statistically significant impairments in the cardiorespiratory functions of child athletes. Notably, there were significant reductions in maximum oxygen consumption (VO2max), maximal pulmonary ventilation (VEmax), oxygen pulse (O2/HR), as well as heart rates at the first ventilatory threshold (HR at VT1), maximum heart rate (HRmax), and heart rate recovery following maximal effort, all demonstrating p-values less than 0.05. Conclusions: The assessed parameters demonstrated that the functions were statistically significantly impaired in child athletes who had recovered from COVID-19 compared to their healthy peers of the same age. However, the infection appeared to have a minimal impact on heart rate variability at ventilatory thresholds. These findings offer valuable insights for coaches and sports medicine physicians in adjusting training programs and supporting the rehabilitation process for young adolescent athletes resuming their training after recovering from COVID-19. [ABSTRACT FROM AUTHOR]

Context. Improving cattle feed efficiency would reduce feed costs and increase herd profitability. Residual feed intake (RFI) is commonly used to rank cattle for feed efficiency, with low-RFI animals being more efficient than high-RFI animals. However, RFI classification merits further investigation because observed differences in heat energy (HE) production between low- and high-RFI cattle may be related to heat associated with differences in dry-matter intake (DMI) rather than maintenanceenergy requirements. Aims. To determine energy partitioning of beef heifers with low and high residual feed intake. Methods. Angus crossbred heifers (n = 60) were fed a grower diet (metabolisable energy (ME) = 2.17 Mcal/kg DM) for 70 days. Feed intake was recorded daily using the GrowSafe system, and bodyweight (BW) was recorded every 14 days. Residual feed intake was calculated as the residual from the regression of DMI on mid-test BW0.75 and average daily gain (ADG) (R2 = 0.31). Low-RFI (n = 8) and high-RFI (n = 8) heifers were selected for a metabolism experiment to determine energy partitioning at three feed-intake levels, namely, ad libitum intake, and 1.0× and 0.5× expected maintenance-energy requirement. Apparent nutrient digestibility was determined using indigestible neutral detergent fibre (iNDF) as an internal marker. The sulfur hexafluoride (SF6) tracer and oxygen-pulse techniques determined methane emissions and heat production respectively. Metabolisable energy required for maintenance (MEm) and fasting heat production (HeE) were then calculated from the regression of log HP on ME intake (MEI). Efficiencies of ME used for maintenance and growth were calculated from HeE, MEm, and retained energy at ad libitum intake. Key results. Residual feed intake was strongly correlated with DMI (0.83). Low-RFI heifers consumed 31% less (P = 0.01) feed than high-RFI heifers during the performance experiment. Heifers with low RFI had greater MEm, but similar efficiencies of ME use for maintenance and gain as did high RFI heifers. Conclusion. These data indicated that selection based on RFI may not lead to improved energy efficiency in growing heifers. Implications. The results of this study indicated that low-RFI cattle may not have lower maintenance-energy requirements or differences in efficiencies of ME use than do high-RFI cattle. [ABSTRACT FROM AUTHOR]

Background and Aims: As there is growing interest in the application of cardiopulmonary exercise test (CPX) in chronic kidney disease (CKD), it is important to understand the utility of conventional exercise test parameters in quantifying the cardiopulmonary fitness of patients with CKD. Merely extrapolating information from heart failure (HF) patients would not suffice. In the present study, we evaluated the utility of CPX parameters such as the peak O2-pulse and the estimated stroke volume (SV) in assessing the peak SV by comparing with the actual measured values. Furthermore, we compared the anaerobic threshold (AT), peak circulatory power, and ventilatory power with that of the measured values of the peak cardiac power (CPOpeak) in representing the cardiac functional reserve in CKD. We also performed such analyses in patients with HF for comparison. Method: A cross sectional study of 70 asymptomatic male CKD patients [CKD stages 2–5 (pre-dialysis)] without primary cardiac disease or diabetes mellitus and 25 HF patients. A specialized CPX with a CO2 rebreathing technique was utilized to measure the peak cardiac output and peak cardiac power output. The peak O2 consumption (VO2peak) and AT were also measured during the test. Parameters such as the O2-pulse, stroke volume, arteriovenous difference in O2 concentration [C(a-v)O2], peak circulatory power, and peak ventilatory power were all calculated. Pearson's correlation, univariate, and multivariate analyses were applied. Results: Whereas there was a strong correlation between the peak O2-pulse and measured peak SV in HF, the correlation was less robust in CKD. Similarly, the correlation between the estimated SV and the measured SV was less robust in CKD compared to HF. The AT only showed a modest correlation with the CPOpeak in HF and only a weak correlation in CKD. A stronger correlation was demonstrated between the peak circulatory power and CPOpeak, and the ventilatory power and CPOpeak. In HF, the central cardiac factor was the predominant determinant of the standard CPX-derived surrogate indices of cardiac performance. By contrast, in CKD both central and peripheral factors played an equally important role, making such indices less reliable markers of cardiac performance per se in CKD. Conclusion: The results highlight that the standard CPX-derived surrogate markers of cardiac performance may be less reliable in CKD, and that further prospective studies comparing such surrogate markers with directly measured cardiac hemodynamics are required before adopting such markers into clinical practice or research in CKD. [ABSTRACT FROM AUTHOR]

Background: Heart failure (HF) is the only cardiovascular disease with an ever-increasing incidence. Aims: The aim of this study was to assess the predictors of adverse clinical events (CE) and the creation and evaluation of the prognostic value of a novel personalized scoring system in patients with HF. Methods: The study included 113 HF patients (median age 64 years (IQR 58–69); 57.52% male). The new novel prognostic score named GLVC (G, global longitudinal peak strain (GLPS); L, left ventricular diastolic diameter (LVDD); V, oxygen pulse (VO2/HR); and C, high sensitivity C-reactive protein (hs-CRP)) was created. The Kaplan–Meier method and log-rank test were used to compare the CE. Results: Results from final analyses showed that low GLPS (< 13.9%, OR = 2.66, 95% CI = 1.01–4.30, p = 0.002), high LVDD (> 56 mm, OR = 2.37, 95% CI = 1.01–5.55, p = 0.045), low oxygen pulse (< 10, OR = 2.8, 95% CI = 1.17–6.70, p = 0.019), and high hs-CRP (> 2.38 µg/ml, OR = 2.93, 95% CI = 1.31–6.54, p = 0.007) were independent prognostic factors for adverse CE in HF population. All the patients were stratified into a low-risk or high-risk group according to a novel "GLVC" scoring system. The Kaplan–Meier analyses demonstrated that patients in the high-risk group were more predisposed to having higher adverse clinical events compared to patients in the low-risk group. Conclusions: A novel and comprehensive personalized "GLVC" scoring system is an easily available and effective tool for predicting the adverse outcomes in HF. [ABSTRACT FROM AUTHOR]

Background: The performance of young swimmers is the result of a multifactorial process that is influenced by anthropometric characteristics and biological maturation. The purpose of our study was to investigate the effect of stages of biological maturation and body surface area on cardiopulmonary fitness indicators in preadolescent female swimmers, for whom menstruation has not started. Methods: Thirty female preadolescent swimmers (age 13.4 ± 1.0 years) participated in this study. We recorded anthropometric and morphological characteristics, stages of biological maturation, and pulmonary function parameters, and the swimmers underwent cardiopulmonary exercise testing. Results: The cut-off was set for body surface area (BSA) at 1.6 m2 and for biological maturation stages at score 3. The BSA results showed differences in variabilities in maximal effort oxygen pulse (p < 0.001), oxygen uptake (p < 0.001), ventilation (p = 0.041), tidal volume (p < 0.001), and oxygen breath (p < 0.001). Tanner stage score results showed differences in variabilities in maximal effort breath frequency (p < 0.001), tidal volume (p = 0.013), and oxygen breath (p = 0.045). Biological maturation stages and BSA were correlated during maximal effort with oxygen breath (p < 0.001; p < 0.001), oxygen uptake (p = 0.002; p < 0.001), and oxygen pulse (p < 0.001; p < 0.001). Conclusions: In conclusion, the findings of our study showed that the girls who had a smaller body surface area and biological maturation stage presented lower values in maximal oxygen uptake and greater respiratory work. [ABSTRACT FROM AUTHOR]

The ADRB3 gene plays a role in energy expenditure by participating in lipolysis, which affects body composition and performance. The ADRB3 rs4994 polymorphism has been studied in groups of athletes, overweight individuals, and obese and diabetic patients, but it has not been studied in young and healthy adults so far. In the present study, we examined the association of ADRB3 rs4994 polymorphism with body composition, somatotype, cardiorespiratory fitness and physical activity in young, healthy adults (N = 304). All subjects had anthropometric measurements, and somatotypes were assessed using the Heath–Carter method. In addition, cardiorespiratory fitness and physical activity levels were assessed. Genotyping for the ADRB3 gene was performed using a PCR-RFLP method. In the male group, body components were associated with the Trp64Trp genotype (waist circumference (p = 0.035), hip circumference (p = 0.029), BF (%) (p = 0.008), and BF (kg) (p = 0.010), BMI (p = 0.005), WHtR (p = 0.021), and BAI (p = 0.006)). In addition, we observed that the Trp64Trp genotype was associated with somatotype components (p = 0.013). In contrast, the Arg allele was associated with the ectomorphic components (0.006). We also observed a positive impact of the Trp64Trp genotype with maximal oxygen uptake (p= 0.023) and oxygen pulse (p = 0.024). We observed a negative relationship of the Trp64Trp genotype in the female group with reported moderate-intensity exercise (p = 0.036). In conclusion, we found an association of the Trp64 allele with anthropometric traits, somatotype and parameters describing physical performance in the male group. In the female subpopulation, we only found an effect of the polymorphism Trp64Arg on the level of physical activity for moderate-intensity exercise. [ABSTRACT FROM AUTHOR]

Several reports have shown the impact of COVID-19 history on exercise capacity. This study compared the blood pressure (BP) response and oxygen pulse (O2 pulse) characteristics in normotensive patients with and without a history of COVID-19 during the cardiopulmonary exercise test (CPET) and post-exercise recovery. This cross-sectional study involved 130 healthy Caucasian adult volunteers (71 participants with a history of COVID-19). All patients underwent the CPET with blood pressure measurements during exercise and post-exercise recovery. The post-COVID group had significantly higher systolic, diastolic, and mean blood pressure after 9 min of recovery and achieved a significantly lower max O2 pulse (2.02 mL/beat on average) than the controls. It should be noted that the COVID group tended to have higher blood pressure values in all steps, with no differences in heart rate, pulse pressure, and saturation at any step. The COVID-19 outbreak was associated with a higher blood pressure response, significantly, in post-exercise recovery, a lower maximum O2 pulse, and a lower maximum load achievement. Future studies are needed to determine if these abnormalities during the CPET and the blood pressure variation have prognostic value. [ABSTRACT FROM AUTHOR]

Abstract Background Pneumonia in cancer patients is often problematic in order to decide whether to admit and administer antibiotics or pursue a comfort care pathway that may avoid in-hospital death. We aimed to identify factors which are easily assessed at admission in Thailand’s healthcare context that could serve as prognostic factors for in-hospital death. Methods Regression analysis was utilized to identify the prognostic factors from clinical factors collected at admission. The primary outcome was in-hospital death. Data was collected from the electronic medical records of Chiang Mai University Hospital, Thailand, from 2016 to 2017. Data on adult cancer patients admitted due to pneumonia were reviewed. Results In total, 245 patients were included, and 146 (59.6%) were male. The median age of the patients was 66 years (IQR: 57–75). A total of 72 (29.4%) patients died during admission. From multivariate logistic regression, prognostic factors for in-hospital death included: Palliative Performance Scale (PPS) ≤ 30 (OR: 8.47, 95% CI: 3.47–20.66), Palliative Performance Scale 40–50% (OR: 2.79, 95% CI: 1.34–5.81), percentage of lymphocytes ≤ 8.0% (OR: 2.10, 95% CI: 1.08–4.08), and pulse oximetry ≤ 90% (OR: 2.01, 95% CI: 1.04–3.87). Conclusion The in-hospital death rate of cancer patients admitted with pneumonia was approximately 30%. The PPS of 10–30%, PPS of 40–50%, percentage of lymphocytes ≤ 8%, and oxygen saturation

Abstract Aims Exercise training (ET) has been consistently shown to increase peak oxygen consumption (V̇O2) in patients with heart failure with preserved ejection fraction (HFpEF); however, inter‐individual responses vary significantly. Because it is unlikely that ET‐induced improvements in peak V̇O2 are significantly mediated by an increase in peak heart rate (HR), we aimed to investigate whether baseline peak O2‐pulse (V̇O2 × HR−1, reflecting the product of stroke volume and arteriovenous oxygen difference), not baseline peak V̇O2, is inversely associated with the change in peak V̇O2 (adjusted by body weight) following ET versus guideline control (CON) in patients with HFpEF. Methods and results This was a secondary analysis of the OptimEx‐Clin (Optimizing Exercise Training in Prevention and Treatment of Diastolic Heart Failure, NCT02078947) trial, including all 158 patients with complete baseline and 3 month cardiopulmonary exercise testing measurements (106 ET, 52 CON). Change in peak V̇O2 (%) was analysed as a function of baseline peak V̇O2 and its determinants (absolute peak V̇O2, peak O2‐pulse, peak HR, weight, haemoglobin) using robust linear regression analyses. Mediating effects on change in peak V̇O2 through changes in peak O2‐pulse, peak HR and weight were analysed by a causal mediation analysis with multiple correlated mediators. Change in submaximal exercise tolerance (V̇O2 at the ventilatory threshold, VT1) was analysed as a secondary endpoint. Among 158 patients with HFpEF (66% female; mean age, 70 ± 8 years), changes in peak O2‐pulse explained approximately 72% of the difference in changes in peak V̇O2 between ET and CON [10.0% (95% CI, 4.1 to 15.9), P = 0.001]. There was a significant interaction between the groups for the influence of baseline peak O2‐pulse on change in peak V̇O2 (interaction P = 0.04). In the ET group, every 1 mL/beat higher baseline peak O2‐pulse was associated with a decreased mean change in peak V̇O2 of −1.45% (95% CI, −2.30 to −0.60, P = 0.001) compared with a mean change of −0.08% (95% CI, −1.11 to 0.96, P = 0.88) following CON. None of the other factors showed significant interactions with study groups for the change in peak V̇O2 (P > 0.05). Change in V̇O2 at VT1 was not associated with any of the investigated factors (P > 0.05). Conclusions In patients with HFpEF, the easily measurable peak O2‐pulse seems to be a good indicator of the potential for improving peak V̇O2 through exercise training. While changes in submaximal exercise tolerance were independent of baseline peak O2‐pulse, patients with high O2‐pulse may need to use additional therapies to significantly increase peak V̇O2.

Background: Pneumonia in cancer patients is often problematic in order to decide whether to admit and administer antibiotics or pursue a comfort care pathway that may avoid in-hospital death. We aimed to identify factors which are easily assessed at admission in Thailand's healthcare context that could serve as prognostic factors for in-hospital death. Methods: Regression analysis was utilized to identify the prognostic factors from clinical factors collected at admission. The primary outcome was in-hospital death. Data was collected from the electronic medical records of Chiang Mai University Hospital, Thailand, from 2016 to 2017. Data on adult cancer patients admitted due to pneumonia were reviewed. Results: In total, 245 patients were included, and 146 (59.6%) were male. The median age of the patients was 66 years (IQR: 57–75). A total of 72 (29.4%) patients died during admission. From multivariate logistic regression, prognostic factors for in-hospital death included: Palliative Performance Scale (PPS) ≤ 30 (OR: 8.47, 95% CI: 3.47–20.66), Palliative Performance Scale 40–50% (OR: 2.79, 95% CI: 1.34–5.81), percentage of lymphocytes ≤ 8.0% (OR: 2.10, 95% CI: 1.08–4.08), and pulse oximetry ≤ 90% (OR: 2.01, 95% CI: 1.04–3.87). Conclusion: The in-hospital death rate of cancer patients admitted with pneumonia was approximately 30%. The PPS of 10–30%, PPS of 40–50%, percentage of lymphocytes ≤ 8%, and oxygen saturation < 90% could serve as prognostic factors for in-hospital death. Further prospective studies are needed to investigate the usefulness of these factors. [ABSTRACT FROM AUTHOR]

Background: The performance of young swimmers is the result of a multifactorial process that is influenced by anthropometric characteristics and biological maturation. The purpose of our study was to investigate the effect of stages of biological maturation and body surface area on cardiopulmonary fitness indicators in preadolescent female swimmers, for whom menstruation has not started. Methods: Thirty female preadolescent swimmers (age 13.4 ± 1.0 years) participated in this study. We recorded anthropometric and morphological characteristics, stages of biological maturation, and pulmonary function parameters, and the swimmers underwent cardiopulmonary exercise testing. Results: The cut-off was set for body surface area (BSA) at 1.6 m2 and for biological maturation stages at score 3. The BSA results showed differences in variabilities in maximal effort oxygen pulse (p < 0.001), oxygen uptake (p < 0.001), ventilation (p = 0.041), tidal volume (p < 0.001), and oxygen breath (p < 0.001). Tanner stage score results showed differences in variabilities in maximal effort breath frequency (p < 0.001), tidal volume (p = 0.013), and oxygen breath (p = 0.045). Biological maturation stages and BSA were correlated during maximal effort with oxygen breath (p < 0.001; p < 0.001), oxygen uptake (p = 0.002; p < 0.001), and oxygen pulse (p < 0.001; p < 0.001). Conclusions: In conclusion, the findings of our study showed that the girls who had a smaller body surface area and biological maturation stage presented lower values in maximal oxygen uptake and greater respiratory work.

Aims: Exercise training (ET) has been consistently shown to increase peak oxygen consumption (V̇O2) in patients with heart failure with preserved ejection fraction (HFpEF); however, inter‐individual responses vary significantly. Because it is unlikely that ET‐induced improvements in peak V̇O2 are significantly mediated by an increase in peak heart rate (HR), we aimed to investigate whether baseline peak O2‐pulse (V̇O2 × HR−1, reflecting the product of stroke volume and arteriovenous oxygen difference), not baseline peak V̇O2, is inversely associated with the change in peak V̇O2 (adjusted by body weight) following ET versus guideline control (CON) in patients with HFpEF. Methods and results: This was a secondary analysis of the OptimEx‐Clin (Optimizing Exercise Training in Prevention and Treatment of Diastolic Heart Failure, NCT02078947) trial, including all 158 patients with complete baseline and 3 month cardiopulmonary exercise testing measurements (106 ET, 52 CON). Change in peak V̇O2 (%) was analysed as a function of baseline peak V̇O2 and its determinants (absolute peak V̇O2, peak O2‐pulse, peak HR, weight, haemoglobin) using robust linear regression analyses. Mediating effects on change in peak V̇O2 through changes in peak O2‐pulse, peak HR and weight were analysed by a causal mediation analysis with multiple correlated mediators. Change in submaximal exercise tolerance (V̇O2 at the ventilatory threshold, VT1) was analysed as a secondary endpoint. Among 158 patients with HFpEF (66% female; mean age, 70 ± 8 years), changes in peak O2‐pulse explained approximately 72% of the difference in changes in peak V̇O2 between ET and CON [10.0% (95% CI, 4.1 to 15.9), P = 0.001]. There was a significant interaction between the groups for the influence of baseline peak O2‐pulse on change in peak V̇O2 (interaction P = 0.04). In the ET group, every 1 mL/beat higher baseline peak O2‐pulse was associated with a decreased mean change in peak V̇O2 of −1.45% (95% CI, −2.30 to −0.60, P = 0.001) compared with a mean change of −0.08% (95% CI, −1.11 to 0.96, P = 0.88) following CON. None of the other factors showed significant interactions with study groups for the change in peak V̇O2 (P > 0.05). Change in V̇O2 at VT1 was not associated with any of the investigated factors (P > 0.05). Conclusions: In patients with HFpEF, the easily measurable peak O2‐pulse seems to be a good indicator of the potential for improving peak V̇O2 through exercise training. While changes in submaximal exercise tolerance were independent of baseline peak O2‐pulse, patients with high O2‐pulse may need to use additional therapies to significantly increase peak V̇O2. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of maximal oxygen pulse (O 2 P max) on patients with chronic obstructive pulmonary disease (COPD) and confirmed the predictive effect on acute exacerbations of COPD (AECOPD). This retrospective study included 91 participants who underwent cardiopulmonary exercise testing (CPET), lung function testing, a dyspnea scale assessment, and a 3-year follow-up. The participants were divided into two groups according to the O 2 P max value. Exercise capacity, ventilatory conditions, gas exchange efficiency, and dyspnea symptoms were compared, and the correlations between O 2 P max and these indices were evaluated. The ability of O 2 P max to predict AECOPD was examined. Exercise capacity, ventilatory conditions, and gas exchange efficiency were lower, and dyspnea symptom scores were higher in the impaired O 2 P max group (P < 0.05). O 2 P max was positively correlated with forced vital capacity (FVC)%, forced expiratory volume in 1 sec (FEV- 1)%, FEV 1 /FVC%, anaerobic threshold (AT), work rate (WR)%, aximal oxygen uptake (VO 2max)%, VO 2 /kg max , VO 2 /kg max %, WR AT , WR max , VO 2AT , VO 2max , and V Emax , and was negatively correlated with EqCO 2AT , and EqCO 2max (P < 0.05). Most importantly, O 2 P max could be used to predict AECOPD, and the best cut-off value was 89.5% (area under the curve, 0.739; 95% CI, 0.609–0.869). O 2 P max reflected exercise capacity, ventilation capacity, gas exchange capacity, and dyspnea symptoms in patients with COPD and may be an independent predictor of AECOPD. [ABSTRACT FROM AUTHOR]

Aims Oxygen-pulse morphology and gas exchange analysis measured during cardiopulmonary exercise testing (CPET) has been associated with myocardial ischaemia. The aim of this analysis was to examine the relationship between CPET parameters, myocardial ischaemia and anginal symptoms in patients with chronic coronary syndrome and to determine the ability of these parameters to predict the placebo-controlled response to percutaneous coronary intervention (PCI). Methods and results Patients with severe single-vessel coronary artery disease (CAD) were randomized 1:1 to PCI or placebo in the ORBITA trial. Subjects underwent pre-randomization treadmill CPET, dobutamine stress echocardiography (DSE) and symptom assessment. These assessments were repeated at the end of a 6-week blinded follow-up period. A total of 195 patients with CPET data were randomized (102 PCI, 93 placebo). Patients in whom an oxygen-pulse plateau was observed during CPET had higher (more ischaemic) DSE score [+0.82 segments; 95% confidence interval (CI): 0.40 to 1.25, P  = 0.0068] and lower fractional flow reserve (−0.07; 95% CI: −0.12 to −0.02, P  = 0.011) compared with those without. At lower (more abnormal) oxygen-pulse slopes, there was a larger improvement of the placebo-controlled effect of PCI on DSE score [oxygen-pulse plateau presence (Pinteraction = 0.026) and oxygen-pulse gradient (Pinteraction = 0.023)] and Seattle angina physical-limitation score [oxygen-pulse plateau presence (Pinteraction = 0.037)]. Impaired peak VO2, VE/VCO2 slope, peak oxygen-pulse, and oxygen uptake efficacy slope was significantly associated with higher symptom burden but did not relate to severity of ischaemia or predict response to PCI. Conclusion Although selected CPET parameters relate to severity of angina symptoms and quality of life, only an oxygen-pulse plateau detects the severity of myocardial ischaemia and predicts the placebo-controlled efficacy of PCI in patients with single-vessel CAD. [ABSTRACT FROM AUTHOR]

Background: Cardiopulmonary exercise testing (CPET) is used in evaluation of repaired tetralogy of Fallot (rTOF), particularly for pulmonary valve replacement need. Oxygen pulse (O 2 P) is the CPET surrogate for stroke volume and peripheral oxygen extraction., Objectives: This study assessed O 2 P curve properties against non-invasive cardiac output monitoring (NICOM) and clinical testing., Methods: This cross-sectional study included 44 rTOF patients and 10 controls. Three new evaluations for O 2 P curve analysis during CPET were developed. Best fit early and late regression slopes of the O 2 P curve were used to calculate: 1) the early to late ratio, or "O 2 pulse response ratio" (O 2 PRR); 2) the portion of exercise until slope inflection, or "flattening fraction" (FF); 3) the area under the O 2 P response curve, or "O 2 P curve area"., Results: rTOF patients (median age 35.2 (27.6-39.4); 61% female) had a lower VO 2 max (23.4 vs 45.6 ml/kg/min; p < 0.001) and O 2 P max (11.5 vs 19.1 ml/beat; p < 0.001) compared to controls. Those with a FF occurring <50% through exercise had a lower peak cardiac index and stroke volume, but not VO 2 max, compared to those >50%. FF and O 2 P curve area significantly correlated with peak cardiac index, stroke volume, left and right ventricular ejection fraction, and right ventricular systolic pressure., Conclusion: CPET remains an integral part in the evaluation of rTOF. We introduce three non-invasive methods to assess exercise hemodynamics using the O 2 P curve data. These evaluations demonstrated significant correlations with stroke volume, cardiac output, and right ventricular pressure.

Promsrisuk T, Kongsui R, Sriraksa N, Srithawong A, Nabheerong P, Suttikullabud K, Boonla O. Oxygen Pulse at Anaerobic Threshold and Maximal Exercise and Their Correlation with Age, Weight, Height, and Pulmonary Function in Healthy Thais. JEPonline 2022;25(4):26-36. Oxygen pulse (O2 pulse) is a surrogate for stroke volume (SV) and arteriovenous oxygen difference, and it is an important index of cardiovascular efficiency. The purpose of this study was to investigate O2 pulse at anaerobic threshold and maximal exercise and to verify the correlation of age, weight, height, and pulmonary function with O2 pulse in healthy Thais. Two hundred healthy Thai subjects (100 males and 100 females) between 20 and 69 years of age were recruited. All the subjects underwent cardiopulmonary exercise testing using a treadmill ramp protocol until symptom limitation. O2 pulse, SV, cardiac output (Qt), and systolic blood pressure (SBP) at anaerobic threshold in males were significantly higher than in females by 40%, 46%, 48%, and 16%, respectively (P<0.001). O2 pulse, SV, Qt, and SBP at maximal exercise in males were significantly higher than in females by 46%, 47%, 50%, 9%, and 4%, respectively (P<0.001). Moreover, we found a positive correlation between O2 pulse at anaerobic threshold and weight (r = 0.6673), height (r = 0.6058), FEV1 (r = 0.2373), FEV1/FVC (r = 0.4195), and MVV (r = 0.3132) (P<0.001) in both genders. O2 pulse at maximal exercise was negatively correlated with O2 pulse at maximal exercise and age (r = -0.1866, P<0.01), and positively correlated with weight (r = 0.6639), height (r = 0.6401), FEV1 (r = 0.3376), FEV1/FVC (r = 0.4348), and MVV (r = 0.4392) (P<0.001) in both genders. The present study provides values for O2 pulse at anaerobic threshold and maximal exercise for healthy Thai adults of both genders. O2 pulse values vary with age, gender, and body size in healthy subjects. Moreover, O2 pulse increases with increasing pulmonary function. [ABSTRACT FROM AUTHOR]

Aim: To analyze the impact of obesity on cardiopulmonary response to exercise in people with chronic post-COVID-19 syndrome. Patients & methods: Consecutive subjects with chronic post-COVID syndrome 6 months after nonsevere acute infection were included. All patients received a complete clinical evaluation, lung function tests and cardiopulmonary exercise testing. A total of 51 consecutive patients diagnosed with chronic post-COVID-19 were enrolled in this study. Results: More than half of patients with chronic post-COVID-19 had a significant alteration in aerobic exercise capacity (VO2peak) 6 months after hospital discharge. Obese long-COVID-19 patients also displayed a marked reduction of oxygen pulse (O2pulse). Conclusion: Obese patients were more prone to have pathological pulmonary limitation and pulmonary gas exchange impairment to exercise compared with nonobese COVID-19 patients. [ABSTRACT FROM AUTHOR]

Low forced vital capacity (FVC) is associated with decreased exercise capacity in CHD. Multiple prior cardiac surgeries have been associated with low FVC. We seek to understand the relationship between low FVC, number of cardiac surgeries and cardiopulmonary response leading to decreased exercise capacity. Retrospective chart review of demographics, surgical history and exercise testing including spirometry was performed in patients with CHD. Single ventricle patients were excluded. Low FVC was defined as a Z-score below the lower limit of normal. Exercise parameters were expressed as a percent of predicted. There were 93 patients with 2 ventricle CHD identified over 34 months with cardiopulmonary exercise testing. The FVC Z-score directly correlated with peak V̇O2% (R2 = 0.07, p < 0.05), and the O2 pulse% (R2 = 0.25, p < 0.0001). The VE/VCO2 was inversely related to the FVC Z-score (R2 = 0.11, p < 0.01). Patients with minimum three prior surgeries had decreased peak VO2% (63.7 vs. 72.8, p < 0.05), decreased peak O2 pulse% (80.8 vs. 97.9, p < 0.01) and a lower mean FVC Z-score (− 1.9 vs − 0.38, p < 0.01). The FVC Z-score and number of surgeries both predicted peak V̇O2% in multivariate analysis. Our study demonstrated that low FVC and three or more prior cardiac surgeries were associated with lower exercise capacity and lower stroke volume response. More cardiac surgeries were also associated with low FVC. However, both low FVC and the number of surgeries were independent predictors of exercise capacity. [ABSTRACT FROM AUTHOR]

Abstract Background Studies suggest that acute decreases in lung hyperinflation at rest improves cardiac function and increases lung vascular perfusion from decompression of a compromised heart. In those studies, changes in resting oxygen uptake induced by medications, an alternative explanation for compensatory increased cardiac function, were not explored. Methods This double-blind, multicenter, double-crossover study enrolled adults with chronic obstructive pulmonary disease, resting hyperinflation, and > 10% improvement in inspiratory capacity after 2 inhalations of budesonide/formoterol 160/4.5 μg. Metabolic, cardiac, and ventilatory function were measured 60 min pre−/post-dose at each visit. Primary endpoint was change in resting oxygen uptake for budesonide/formoterol versus placebo. Results Fifty-one patients (median age: 63 years) received treatment. Compared with placebo, budesonide/formoterol significantly increased resting oxygen uptake (mean change from baseline: 1.25 vs 11.37 mL/min; P = 0.007) as well as tidal volume and minute ventilation. This occurred despite improvements in the inspiratory capacity, forced vital capacity, and expiratory volume in 1 s. No significant treatment differences were seen for oxygen saturation, respiratory rate, and resting dyspnea. There was a numerical increase in oxygen pulse (oxygen uptake/heart rate). Correlations between inspiratory capacity and oxygen pulse were weak. Conclusions Budesonide/formoterol treatment in resting hyperinflated patients with COPD results in significant deflation. The increase in oxygen uptake and minute ventilation at lower lung volumes, without changes in heart rate and with minimal improvement in oxygen pulse, suggests increased oxygen demand as a contributor to increased cardiac function. Trial registration ClinicalTrials.gov identifier: NCT02533505.

Cardiopulmonary exercise testing (CPET) guidelines recommend analysis of the oxygen (O2) pulse for a late exercise plateau in evaluation for obstructive coronary artery disease (OCAD). However, whether this O2 pulse trajectory is within the range of normal has been debated, and the diagnostic performance of the O2 pulse for OCAD in physically fit individuals, in whom V˙O2 may be more likely to plateau, has not been evaluated. Using prospectively collected data from a sports cardiology program, patients were identified who were free of other cardiac disease and underwent clinically‐indicated CPET within 90 days of invasive or computed tomography coronary angiography. The diagnostic performance of quantitative O2 pulse metrics (late exercise slope, proportional change in slope during late exercise) and qualitative assessment for O2 pulse plateau to predict OCAD was assessed. Among 104 patients (age:56 ± 12 years, 30% female, peak V˙O2 119 ± 34% predicted), the diagnostic performance for OCAD (n = 24,23%) was poor for both quantitative and qualitative metrics reflecting an O2 pulse plateau (late exercise slope: AUC = 0.55, sensitivity = 68%, specificity = 41%; proportional change in slope: AUC = 0.55, sensitivity = 91%, specificity = 18%; visual plateau/decline: AUC = 0.51, sensitivity = 33%, specificity = 67%). When O2 pulse parameters were added to the electrocardiogram, the change in AUC was minimal (−0.01 to +0.02, p ≥ 0.05). Those patients without OCAD with a plateau or decline in O2 pulse were fitter than those with linear augmentation (peak V˙O2 133 ± 31% vs. 114 ± 36% predicted, p < 0.05) and had a longer exercise ramp time (9.5 ± 3.2 vs. 8.0 ± 2.5 min, p < 0.05). Overall, a plateau in O2 pulse was not a useful predictor of OCAD in a physically fit population, indicating that the O2 pulse should be integrated with other CPET parameters and may reflect a physiologic limitation of stroke volume and/or O2 extraction during intense exercise. [ABSTRACT FROM AUTHOR]

Abstract Cardiopulmonary exercise testing (CPET) guidelines recommend analysis of the oxygen (O2) pulse for a late exercise plateau in evaluation for obstructive coronary artery disease (OCAD). However, whether this O2 pulse trajectory is within the range of normal has been debated, and the diagnostic performance of the O2 pulse for OCAD in physically fit individuals, in whom V˙O2 may be more likely to plateau, has not been evaluated. Using prospectively collected data from a sports cardiology program, patients were identified who were free of other cardiac disease and underwent clinically‐indicated CPET within 90 days of invasive or computed tomography coronary angiography. The diagnostic performance of quantitative O2 pulse metrics (late exercise slope, proportional change in slope during late exercise) and qualitative assessment for O2 pulse plateau to predict OCAD was assessed. Among 104 patients (age:56 ± 12 years, 30% female, peak V˙O2 119 ± 34% predicted), the diagnostic performance for OCAD (n = 24,23%) was poor for both quantitative and qualitative metrics reflecting an O2 pulse plateau (late exercise slope: AUC = 0.55, sensitivity = 68%, specificity = 41%; proportional change in slope: AUC = 0.55, sensitivity = 91%, specificity = 18%; visual plateau/decline: AUC = 0.51, sensitivity = 33%, specificity = 67%). When O2 pulse parameters were added to the electrocardiogram, the change in AUC was minimal (−0.01 to +0.02, p ≥ 0.05). Those patients without OCAD with a plateau or decline in O2 pulse were fitter than those with linear augmentation (peak V˙O2 133 ± 31% vs. 114 ± 36% predicted, p

Purpose: This study aimed to compare physiological factors and cycle characteristics during cross-country (XC) roller-skiing at matched inclines and speeds using the double-poling (DP) and diagonal-stride (DS) sub-techniques in junior female and male XC skiers. Methods: Twenty-three well-trained junior XC skiers (11 women, 12 men; age 18.2 ± 1.2 yr.) completed two treadmill roller-skiing tests in a randomized order using either DP or DS. The exercise protocols were identical and included a 5 min warm-up, 4 × 5 min submaximal stages, and an incremental test to exhaustion, all performed at a 5° incline. Results: No significant three-way interactions were observed between sex, submaximal exercise intensity, and sub-technique. For the pooled sample, higher values were observed for DP versus DS during submaximal exercise for the mean oxygen uptake kinetics response time (33%), energy cost (18%), heart rate (HR) (9%), blood lactate concentration (5.1 versus 2.1 mmol·L−1), rating of perceived exertion (12%), and cycle rate (25%), while cycle length was lower (19%) (all P < 0.001). During the time-to-exhaustion (TTE) test, peak oxygen uptake ( V ˙ O2peak), peak HR, and peak oxygen pulse were 8%, 2%, and 6% lower, respectively, for DP than DS, with a 29% shorter TTE during DP (pooled data, all P < 0.001). Conclusion: In well-trained junior XC skiers, DP was found to exert a greater physiological load than DS during uphill XC roller-skiing at submaximal intensities. During the TTE test, both female and male athletes were able to ski for longer and reached markedly higher V ˙ O2peak values when using DS compared to DP. [ABSTRACT FROM AUTHOR]

Background: The clinical utility of cardiopulmonary exercise testing (CPET) has not been extensively studied yet in heart transplantation (HTX) patients. Objective: To analyze the predictive value of the CPET on hospitalizations and mortality in HTX recipients. Methods: A retrospective cohort was performed from a secondary database. Patients > 18 years with HTX who underwent a CPET between 3 and 12 months after transplantation were included. Time to the first primary endpoint (HTX‐related hospitalization) was analyzed and adjusted using Cox proportional hazards regression model. Results: A total of 122 patients (mean age 50.1 years, 77.0% men) were included. Fifty‐seven patients (46.7%) had the primary endpoint. Peak VO2 (HR.95; CI 95%.90–.99, P =.03), oxygen pulse (HR.57; CI 95%.34–.96, P =.03) and predicted VO2 (HR.97; CI 95%.96–.99, P =.002) were associated with the endpoint. We did not find a significant association between the other variables and the outcome. Conclusion: In HTX recipients, peak VO2, oxygen pulse, and predicted VO2 were independently associated with hospitalizations at follow up. [ABSTRACT FROM AUTHOR]

High-altitude exposure changes the electrical conduction of the heart. However, reports on electrocardiogram (ECG) characteristics and potent prophylactic agents during high-altitude acclimatization and de-acclimatization are inadequate. This study aimed to investigate the effects of ubiquinol on electrophysiology after high-altitude hypoxia and reoxygenation. The study was a prospective, randomized, double-blind, placebo-controlled trial. Forty-one participants were randomly divided into two groups receiving ubiquinol 200 mg daily or placebo orally 14 days before flying to high altitude (3900 m) until the end of the study. Cardiopulmonary exercise testing was performed at baseline (300 m), on the third day after reaching high altitude, and on the seventh day after returning to baseline. Acute high-altitude exposure prolonged resting ventricular repolarization, represented by increased corrected QT interval (455.9 ± 23.4 vs. 427.1 ± 19.1 ms, P < 0.001) and corrected T peak -T end interval (155.5 ± 27.4 vs. 125.3 ± 21.1 ms, P < 0.001), which recovered after returning to low altitude. Ubiquinol supplementation shortened the hypoxia-induced extended T peak -T end interval (−7.7 ms, [95% confidence interval (CI), −13.8 to −1.6], P = 0.014), T peak -T end /QT interval (−0.014 [95% CI, −0.027 to −0.002], P = 0.028), and reserved maximal heart rate (11.9 bpm [95% CI, 3.2 to 20.6], P = 0.013) during exercise at high altitude. Furthermore, the decreased resting amplitude of the ST-segment in the V3 lead was correlated with decreased peak oxygen pulse (R = 0.713, P < 0.001) and maximum oxygen consumption (R = 0.595, P < 0.001). Our results illustrated the electrophysiology changes during high-altitude acclimatization and de-acclimatization. Similarly, ubiquinol supplementation shortened the prolonged T peak -T end interval and reserved maximal heart rate during exercise at high altitude. URL: www.chictr.org.cn ; Unique identifier: ChiCTR2200059900 • Short-term exposure to hypoxia did not cause sustained changes in the ECG. • Ubiquinol could shorten the hypoxia-induced extended ventricular repolarization. • The rest ST-segment amplitude in V3 could predict exercise capacity under hypoxia. [ABSTRACT FROM AUTHOR]

Adult survivors with congenital heart disease represent rapidly evolving cohorts of complex patients that pose unique challenges to our adult cardiology clinics. These patients are at high risk of cardiovascular complications and premature death as young adults. Regular assessment at specialist centers by multidisciplinary expert teams is key to optimal management. Serial exercise testing has proven to be a powerful tool for optimal management of these patients.In this overview, the major tasks of exercise testing are reviewed. This includes prognostication and risk stratification as well, as the evaluation of specific causes of impaired exercise capacity based on analysis of the different components of cardio-pulmonary exercise testing. While peak oxygen consumption has proven to be a robust marker of outcome in adult cardiology, in patients with congenital heart disease, reference values may need to be adapted to specific congenital heart disease entities and the prognostic validity for specific patient cohorts requires further elucidation. Careful analysis of results from exercise testing often reveal important insights into the individual patient's cardiac physiology and may allow targeted interventions that improve exercise capacity and potentially outcome. This requires integration of clinical findings and findings from cardiac imaging. Occasionally, exercise testing during cardiac catheterization may reveal insights into exercise hemodynamics and may be important for decision-making, particularly for decision-making about occlusion of intra-cardiac shunts.From a research perspective, the analysis of exercise capacity and its components will enable us to make more evidence-based decisions for cardiac interventions and will allow a better understanding of prognosis.

Electrical Muscle Stimulation (EMS) and voluntary muscle contraction (VMC) are both acceptable rehabilitative modalities to preserve muscle strength loss. The study aimed to compare respiratory, metabolic, and cardiac parameters during quadriceps muscle contraction (QMC) using either EMS or VMC with comparable generated low intensity muscle force. Thirty healthy non-smoker males, age 20–58 years with normal BMI and low to moderate physical activity, underwent two 20-min sessions of comparable QMC using EMS vs VMC at the same day. The BIODEX III isokinetic dynamometer was used to assess maximum isometric force and the comparable force generated during each condition (EMS vs VMC), while the METAMAX 3B portable metabolic system was used to measure continuously the physiological parameters. Tolerable EMS was used (mean: 33 ± 1.5 mA, at 75 Hz). Each contraction lasted 10 sec followed by 20 sec rest. Paired t-tests were used for comparisons between sessions. A relatively low proportion of maximum isometric force (EMS: 8.5% vs VMC: 8.6%) and torque (EMS: 16 ± 1.3 vs VMC: 16 ± 1.1 Nm) were generated during each session. Mean minute ventilation (EMS: 10.8 L vs VMC: 9.8 L), tidal volume (EMS: 0.6 L vs VMC: 0.5 L), O2 uptake (EMS: 0.31 L/min vs VMC: 0.26 L/min) and O2 pulse (EMS: 3.9 ml/beat vs VMC: 3.6 ml/beat) were different between sessions (p ≤.05); while heart rate (EMS: 72 beats/min vs VMC: 71 beats/min) was equal. Quadriceps muscle EMS induces higher respiratory and metabolic responses compared to equal magnitude VMC in healthy males. [ABSTRACT FROM AUTHOR]

Purpose: The cardiac output (CO) response to exercise is a useful marker to grade the prognosis and severity of chronic heart failure (CHF). The recovery of the oxygen pulse (OP) is a non‐invasive parameter, which is related to exercise capacity in cardiac patients. However, the relation between OP recovery and the central haemodynamic response to exercise remains to be determined. We hypothesized that an impaired OP recovery is associated with a reduced CO response to exercise in CHF patients. Methods: Sixty one CHF patients performed cardiopulmonary exercise test with simultaneous measurement of CO. Impaired OP recovery was defined as an overshoot during the first minute of recovery or OP at 1‐min recovery as a percentage of peak OP (OPRR). Results: An OP overshoot was observed in 9% (n = 5) of patients. In these patients, peak CO and VO2 were significantly lower (peak CO 7.9 ± 0.8 versus 11.2 ± 4.3 L/min and peak VO2 14.1 ± 4.7 versus 19.6 ± 5.8 ml min−1 kg−1). Mean relative recovery of OP was 78 ± 20%. Slow OP recovery (negative OPRR) was seen in 13% (n = 8). Peak CO and VO2 were significantly lower in the negative OPRR group (11 ± 4 versus 8 ± 0.7 L/min and 19.7 ± 5.9 versus 14.6 ± 3.7 ml kg min−1). There was a significant relation between OPRR and stroke volume (SV) RR (r =.57), as well as between OPRR and a‐v O2 diff RR (rs =.4). Conclusion: An impaired OP recovery is associated with a reduced CO response to exercise and worse functional status. Therefore, the OP recovery can be used to grade the severity of CHF. [ABSTRACT FROM AUTHOR]

Background: Studies suggest that acute decreases in lung hyperinflation at rest improves cardiac function and increases lung vascular perfusion from decompression of a compromised heart. In those studies, changes in resting oxygen uptake induced by medications, an alternative explanation for compensatory increased cardiac function, were not explored.Methods: This double-blind, multicenter, double-crossover study enrolled adults with chronic obstructive pulmonary disease, resting hyperinflation, and > 10% improvement in inspiratory capacity after 2 inhalations of budesonide/formoterol 160/4.5 μg. Metabolic, cardiac, and ventilatory function were measured 60 min pre-/post-dose at each visit. Primary endpoint was change in resting oxygen uptake for budesonide/formoterol versus placebo.Results: Fifty-one patients (median age: 63 years) received treatment. Compared with placebo, budesonide/formoterol significantly increased resting oxygen uptake (mean change from baseline: 1.25 vs 11.37 mL/min; P = 0.007) as well as tidal volume and minute ventilation. This occurred despite improvements in the inspiratory capacity, forced vital capacity, and expiratory volume in 1 s. No significant treatment differences were seen for oxygen saturation, respiratory rate, and resting dyspnea. There was a numerical increase in oxygen pulse (oxygen uptake/heart rate). Correlations between inspiratory capacity and oxygen pulse were weak.Conclusions: Budesonide/formoterol treatment in resting hyperinflated patients with COPD results in significant deflation. The increase in oxygen uptake and minute ventilation at lower lung volumes, without changes in heart rate and with minimal improvement in oxygen pulse, suggests increased oxygen demand as a contributor to increased cardiac function.Trial Registration: ClinicalTrials.gov identifier: NCT02533505. [ABSTRACT FROM AUTHOR]

Endurance training sessions and maximal strength training are different in general. That makes training sessions and aerobic, and pulmonary performance completely different in weight lifters and soccer players. Weight lifting requires maximal power and concentration, while football requires endurance, combinability and speed. Cardiopulmonary exercise testing is a basic method for evaluation of the functions of cardiovascular system in sportsmen, healthy people and in different diseases. Spiroergometry tests give additional information about the adaptation of the body to physical loadings, aerobic performance and oxygen pulse. Oxygen pulse estimates left ventricular stroke volume changes during exercise, and it is the ratio of VO2 extracted per heartbeat. The aim of the study was to investigate aerobic and cardiac performance, and the oxygen pulse of elite weight lifters and soccer players. Two groups of 12 weight lifters and 17 soccer players, men, members of elite sport teams, voluntary underwent spiroergometry test on system AT-104 (Schiller, Switzerland). There was no difference in the age between weight lifters (group WL, n=12, 19.33±1.67 years) and soccer players (group S, n=17, 20.47±1.66 years), (P>0.05). The body mass index of WL (26.4±1.47 kg/m2) and S (24.99±3.58) was also similar (P>0.05). Before the beginning of the tests we have obtained informed consent. The sportsmen denied diseases, usage of drugs and doping. Medical examinations were performed. The day before the test was without heavy physical activity. Veloergometer stepwise incremental protocol was applied. Physical working capacity, represented as peak loading was lower in group WL as compared with group S (120±13.43 vs. 160±14.62 W, P<0.0001). Maximal heart rate was higher in S as compared with WL (172.59±14.51 vs. 137.18±12.8 b.p.m., P<0.0001).Maximal level of the systolic blood pressure was higher in S as compared with WL (179.12±24.70 vs. 137.50±15.88 mmHg, P<0.0001).Maximal level of the diastolic blood pressure was higher in S as compared with WL (93.24±12.37 vs. 79.08±10.10 mmHg, P<0.0001).Not surprising aerobic performance was better in the group of the soccer players. Oxygen pulse at the level of the anaerobic threshold was higher in soccer players' group as compared with WL (12.07±3.60 vs. 7.95±2.09, ml per beat, P=0.002), but maximal VO2pulse was similar for WL (15.15±5.40, ml per beat) and S (17.29±3.20, ml per beat), (P>0.05). There were no differences between the groups in the values of VO2pulse during the levels of loading from 30 to 120 The heart rate recovery after physical loading was determined in three grade scale (1-poor; 2-normal; 3-good) and there were no significant differences between the groups, WL (2.45±0.52), S (2.38±0.50), (P>0.05). Despite the differences in aerobic and cardiac performance between the weight lifters and soccer players there were no differences in the values of the peak VO2pulse. The values of the VO2pulse during the levels of physical loading from 30 to 120 W was similar in both groups. Further investigations are need to evaluate the importance of VO2pulse values as an index for determining the physical condition in different diseases, healthy people, and sportsmen. [ABSTRACT FROM AUTHOR]

Objective: This study measured acute physiological responses in pregnant women during short duration exercise in the supine (Sup), side-lying (Side), sitting (Sit), and standing (Std) positions. Methods: In a cross-sectional study, 42 healthy pregnant women were divided into 3 groups of 14 persons each: G1, G2, and G3 (first, second, and third trimester, respectively). Baseline assessments were performed following a 30-min rest in the sitting position. Subsequent measurements were then obtained while exercising, without resistance, in the Sup, Side, Sit, and Std, respectively. Physiological parameters, including heart rate (HR), minute ventilation (), oxygen consumption (), carbon dioxide production (), and oxygen pulse (/HR), were collected using the indirect calorimetry. Results: Comparing resting values, all groups had a significantly increased (1) HR, , and during the Std, (2) values during the Sit and Std, and (3) O2 pulse values during short duration exercise in all positions except the Std, whereas only G2 and G3 had a significantly decreased HR during the Sup. Conclusion: This study points that acute physiological responses to the positional challenge similarly occur in all trimester of pregnant women. Short duration exercise in the Std positions exerts more physiologic stresses on cardiorespiratory functions than in the Sup, Side, and Sit positions. [ABSTRACT FROM AUTHOR]

Purpose: The clinical relevance of abnormal exercise testing (ET) results (at least 0.1 mV ST segment depression measured during exercise or recovery in three consecutive beats) in athletes without obstructive coronary artery disease (CAD) is not well understood. It is unknown whether this phenomenon reflects a physiological adaptation to sport or a truly ischemic response and a concomitant attenuated stroke volume (SV) response. The aim of this study was to investigate if athletes with abnormal ET results without obstructive CAD showed signs of an attenuated SV response using cardiopulmonary ET parameters. Methods: A total of 78 male master athletes with abnormal ET results without obstructive CAD underwent cardiopulmonary ET. ΔO2 pulse/Δwork rate (WR), ΔV˙O2/ΔWR, and Δheart rate (HR)/ΔWR were assessed and compared with data from 78 male master athletes with normal ET results, matched for age, sports characteristics, and exercise capacity. Results: The ΔO2 pulse/ΔWR ratio beyond anaerobic threshold in athletes with abnormal ET results was lower than that in athletes with normal ET results (0.73 ± 0.41 vs 1.12 ± 0.54, respectively, P < 0.001). The ΔV˙O2/ΔWR ratio was also lower in athletes with abnormal ET results (0.9 ± 0.2 vs 1.0 ± 0.3, respectively, P = 0.041). Furthermore, these athletes showed a greater increase in HR in the last 2 min of exercise (ΔHR/ΔWR ratio: 1.19 ± 0.5 vs 0.80 ± 0.6, P < 0.001). Conclusion: Athletes with abnormal ET results without obstructive CAD showed an attenuated O2 pulse slope, decreased ΔV˙O2/ΔWR ratio, and increased ΔHR/ΔWR ratio beyond anaerobic threshold when compared with athletes with a normal ET result. These results support the hypothesis that at least a part of the athletes with an abnormal ET in absence of obstructive CAD have an attenuated SV response at high-intensity exercise. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A new O 2 pulse method for determining the metal surface area of MgO-supported Ni catalysts is proposed. • Pulse Thermal Analysis coupled with mass-spectrometry allows precise determination of Ni dispersion. • Uncertainties linked with the complex Ni oxide stoichiometry could be ruled out. • Comparison with already established techniques confirmed the applicability of the method. Abstract A new method for determining the Ni0 metal surface area of MgO supported catalysts is proposed. Different series of MgO supported Ni catalysts were prepared and titrated by chemical adsorption of oxygen inside an STA-MS setup. Simultaneous recording of the mass gain upon oxidation, the enthalpy of formation of the oxide and the evolved gas allowed a precise quantification of the metallic Ni surface area. In addition, any uncertainties linked with the complex Ni oxide stoichiometry could be ruled out. A comparison of the newly developed oxygen pulse method with already established techniques using H 2 or N 2 O confirmed the applicability of the method and further revealed its surface sensitivity and accuracy with respect to MgO supported Ni catalysts. [ABSTRACT FROM AUTHOR]

This study investigated the value of oxygen (O2) pulse curves obtained during cardiopulmonary exercise testing (CPET) for the diagnosis of coronary artery disease (CAD). Forty patients with known coronary anatomy (35.0% normal, 27.0% single-vessel and 38.0% multivessel CAD) underwent CPET with radiotracer injection at peak exercise, followed by myocardial scintigraphy. O2 pulse curves were classified as: A-normal, B-probably normal (normal slope with low peak value); C-probably abnormal (flat, with low peak value); or D- definitely abnormal (descending slope). Sensitivity, specificity, positive and negative predictive values of the O2 pulse curve pattern (A or B vs. C or D) for the diagnosis of CAD were, respectively, 38.5%, 81.3%, 76.9%, and 44.8%. The concordance rate between the abnormal O2 pulse curve pattern and ischemia in myocardial scintigraphy was 38.1%. Age and the extent of scintigraphic perfusion defect, but not the abnormal O2 pulse curve patterns (B or C or both combined) were independently associated with CAD. In conclusion, the O2 pulse curve pattern has low diagnostic performance for the diagnosis of obstructive CAD, and the abnormal curve pattern was not associated with myocardial ischemia defined by scintigraphy. [ABSTRACT FROM AUTHOR]