Maximal Cardiopulmonary Exercise Testing Research Articles

Effect of bariatric surgery on blood pressure and workload-indexed pressure during submaximal and maximal exercise

Abstract Funding Acknowledgements Type of funding sources: None. Background Obesity is a disease characterized by an increase of resting blood pressure and by an increased risk of developing hypertension and cardiovascular events. Exaggerated blood pressure during exercise increases risk of cardiovascular events independently from the baseline blood pressure levels. Purpose to evaluate the blood pressure response and the Workload-indexed blood pressure, during a cardio-pulmonary exercise test (CPET) before and after bariatric surgery (BS). Methods 257 patients with severe obesity performed maximal incremental CPET one month before and six months after BS under the same experimental protocol. The systolic blood pressure was measured at rest (SBPrest), at the submaximal effort (SBPsubmax) at the same exercise intensity (3 METs), at the exercise peak (SBP max) and lastly in the recovery phase (SBPrec). The submaximal and maximal Workload-indexed Sistolic Blood Pressure (W-SBPsubmax and W-SBPmax, respectively) were calculated with the formula: ΔBP/ΔMETs. Diastolic blood pressure was analysed at rest (DBPrest) and during the recovery phase (DBPrec). Results Age was on average 45 ± 10.3 years, BMI before BS was equal to 43.9 ± 6.4 Kg/m2 and 73.5% were females. After BS, there was a significant weight loss (-25.9 ± 6.2%). SBPrest and DBPrest decrease significantly after BS (ΔSBP: -10.2 ± 15.8 and -5.2 ± 11.6 mmHg; p <0.001, respectively), also when considering percentage variation of pre BS values (ΔSBP%: -7.4 ±12.3% and -5.9 ± 15.9%; p< 0.001, respectively). Submaximal and maximal systolic blood pressure showed significant reduction after BS both as ΔSBP (-15.0 ± 19.7 mmHg and -10.3 ± 25.1mmHg; p < 0.001, respectively) and ΔSBP% (-9.6 ± 13.0% and -5.0 ± 14.0%; p < 0.001, respectively). Furthermore, W-SBP decreased significantly during submaximal exercise (-3.0 ± 12.2 mmHg/METs; p 0.001) and at peak of exercise (-2.1 ± 4.8 mmHg/METs; p < 0.001). Lastly, also systolic and diastolic blood pressure during the recovery phase showed a significant reduction (-7.5 ± 7.0 mmHg and -3.3 ± 6.0 mmHg; p < 0.001). A Spearman’s correlation analysis showed a significant but weak correlation between ΔSBP%submax and % of weight loss (rho = 0.138; p = 0.027). Conclusions After BS, a marked reduction of all blood pressure values was detectable in all phases of CPET. W-SBPsubmax and W-SBPmax, as expression of load independent pressure response, decreased significantly. The reduction in the submaximal blood pressure was significantly but only weakly correlated with changes in body weight, suggesting its substantial independence from weight loss. These findings also support a potential role of CPET in detecting, high risk patients and adequate treatment effectiveness in patients with severe obesity. Abstract Figure. Exercise SBP before and after BS

Cardiac autonomic associations on exercise and ambulatory capacity in individuals with lower-extremity artery disease

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): This work was in part supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP #2019/19596-7), and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq #303399/2018-0). OnBehalf Exercise and Chronic Disease Research Laboratory - Bauru, Brazil; Research Group for Cardiovascular Rehabilitation - Leuven, Belgium. INTRODUCTION Lower-extremity artery disease (LEAD) characterized by progressive atherosclerotic build-up in leg arteries is becoming increasingly prevalent, affecting more than 200 million people worldwide. In line with other atherosclerotic disorders, LEAD is often associated with autonomic dysfunction as evidenced by a reduced heart rate variability (HRV). To date, little is known on the impact of cardiac autonomic function on exercise and ambulatory capacity. PURPOSE We aimed to investigate whether autonomic function is associated with ambulatory capacity and exercise capacity in patients with LEAD. METHODS Thirty-four patients (age≥17 years) diagnosed with LEAD (ankle brachial index: ABI ≤ 0.9 and/or 20% decrease after a maximal treadmill test) suffering from intermittent claudication (Rutherford I-III) were recruited in the PROSECO-IC trial. Patients were grouped based on beta-blocker medication (β-blocker and non β-blocker). Intervals between R waves (i-RR) obtained by heart rate (HR) signal were acquired beat-to-beat via a digital telemetry system (Polar®️ H10) during 15 min of supine rest and were used for 5-minute HRV analysis. Time domain indexes (mean i-RR, SNDD, pNN50%), and frequency domains (high frequency band (HF), low frequency (LF, very LF (VLF)) and the ratio (LF/HF). HRV was analyzed in absolute (abs), normalized (nu) and log units (log). Ambulatory capacity was assessed by means of a submaximal treadmill test, graded maximal treadmill test using Gardner protocol (GTM) and 6 minutes walking test (6MWT); exercise capacity was assessed by means of a graded maximal cardiopulmonary exercise test (HR, blood pressure (BP) and peak oxygen uptake (VO2peak)) at resting, 2 minutes, and peak of exercise. RESULTS Pearson test showed that sympathetic modulation indexes were moderate associated with pain free distance in GTM (LF/HF: r = 0.52, p = 0.04), and pain free time in 6MWT (LFlog: r=-0.62, p = 0.01; VLF: r=-0.52, p = 0.04), respectively, in patients without β-blocker. Similar HR associations with HRV (time and frequency domain) were observed during submaximal treadmill test and cardiopulmonary exercise test (p ≤ 0.05). Test-t demonstrated a significantly increased response intra-groups in HR and BP during both tests (p ≤ 0.05). Average BP were positive associated with the earlier stages of the cardiopulmonary test (resting to 2 min) with LFlog (r = 0.70, p= <0.001) in β-blocker while non-β-blocker were associated from 2 min to peak with LFabs (r = 0.67, p= <0.001) and LF/HF (r = 0.52, p = 0.03). CONCLUSION Sympathetic modulation was correlated with a longer pain free walking capacity in non-β-blockers. Yet, individuals treated by -β-blockers showed an earlier sympathetic modulation through exercise pressor response during the first stages of cardiopulmonary exercise compared to non-β-blockers with LEAD.

Association Between Penile Color Doppler Ultrasonography and Cardiorespiratory Fitness in Patients With Vascular Erectile Dysfunction.

IntroductionVascular erectile dysfunction (ED) is a burdensome condition, associated with increased cardiovascular risk. Peak systolic velocity (PSV) represents the maximum pulse velocity in the cavernous artery measured by a penile color doppler ultrasonography (PCDU) during a pharmacologically induced erection and is considered a reliable parameter for the diagnosis of vascular ED. However, the cut-off value of standard PSV (30 cm/s) provides high sensitivity only in the diagnosis of advanced arteriogenic disease. Thus, an age-adjusted PSV (6.73 + 0.7 x age cm/s) has been proposed to offer a more accurate diagnosis of vascular ED.AimIn this study it was aimed to answer the following question: “Is there any positive association between indexes of vascular erectile dysfunction and cardiorespiratory fitness?”Main Outcome Measure And Methods25 patients with a medical history of ED (median age 55.3 years) underwent PCDU after pharmacological stimulation. Subsequently, a functional evaluation with ECG-monitored, incremental, maximal cardiopulmonary exercise testing was performed.ResultsPeak oxygen uptake (VO2 peak), peak oxygen uptake per body weight (VO2 peak/kg) and Watt/kg correlated with standard PSV, even when corrected for age and BMI (p < 0.05). No differences emerged in cardiopulmonary fitness between pathological and healthy patients (4 vs 21) identified using the standard PSV cut-off. Conversely, the age-adjusted PSV cut-off identified a greater number of patients as pathological (18 vs 7), presenting a significantly lower cardiopulmonary fitness, exercise capacity and efficiency when compared to patients with normal age-adjusted PSV (all p < 0.05).ConclusionData showed an age and BMI independent association between vascular disfunction of cavernous artery and cardiopulmonary fitness, a known solid predictor of all-cause and disease-specific mortality. Moreover, the age-adjusted PSV better identified a subgroup of patients with vascular ED presenting impaired cardiorespiratory fitness and thus increased cardiovascular risk. De Rocco Ponce M, Vecchiato M, Neunhaeuserer D, et al. Association Between Penile Color Doppler Ultrasonography and Cardiorespiratory Fitness in Patients With Vascular Erectile Dysfunction. Sex Med 2021;9:100347.

A randomized placebo-control trial of the acute effects of oxygen supplementation on exercise hemodynamics, autonomic modulation, and brain oxygenation in patients with pulmonary hypertension

BackgroundThe integrative physiological effects of O2 treatment on patients with pulmonary hypertension (PH) during exercise, have not been fully investigated. We simultaneously evaluated, for the first time, the effect of oxygen supplementation on hemodynamic responses, autonomic modulation, tissue oxygenation, and exercise performance in patients with pulmonary arterial hypertension (PAH)/Chronic Thromboembolic PH(CTEPH). Material-methodsIn this randomized, cross-over, placebo-controlled trial, stable outpatients with PAH/CTEPH underwent maximal cardiopulmonary exercise testing, followed by two submaximal trials, during which they received supplementary oxygen (O2) or medical-air. Continuous, non-invasive hemodynamics were monitored via photophlythesmography. Cerebral and quadriceps muscle oxygenation were recorded via near-infrared spectroscopy. Autonomic function was assessed by heart rate variability; root mean square of successive differences (RMSSD) and standard-deviation-Poincare-plot (SD1) were used as indices of parasympathetic output. Baroreceptor sensitivity (BRS) was assessed throughout the protocols. ResultsNine patients (51.4 ± 9.4 years) were included. With O2-supplementation patients exercised for longer (p = 0.01), maintained higher cerebral oxygenated hemoglobin (O2Hb;p = 0.02) levels, exhibited an amelioration in cortical deoxygenation (HHb;p = 0.02), and had higher average cardiac output (CO) during exercise (p < 0.05), compared to medical air; with no differences in muscle oxygenation. With O2-supplementation patients exhibited higher BRS and sample-entropy throughout the protocol (p < 0.05) vs. medical air, and improved the blunted RMSSD, SD1 responses during exercise (p = 0.024). ConclusionWe show that O2 administration improves BRS and autonomic function during submaximal exercise in PAH/CTEPH, without significantly affecting muscle oxygenation. The improved autonomic function, along with enhancements in cardiovascular function and cerebral oxygenation, probably contributes to increased exercise tolerance with O2-supplementation in PH patients.

Aerobic reserve capacity in multiple sclerosis-Preliminary evidence.

Aerobic reserve capacity reflects the available energy for performing everyday life tasks, and it has been studied in older adult populations. This preliminary study examined proof of concept and measurement of aerobic reserve capacity in multiple sclerosis (MS). Twenty-one fully ambulatory people with MS performed a maximal, cardiopulmonary exercise test (CPET). We calculated aerobic reserve capacity based on the difference between peak aerobic power (VO2peak ) and first stage oxygen consumption (VO2 ). Participants completed assessments for disability (Expanded Disability Status Scale, EDSS), cognition (Symbol Digit Modalities Test, SDMT), mood (Beck Depression Inventory, BDI), walking endurance (six-minute walk distance, 6MWD), walking speed (Timed Twenty-Foot Walk, T25FW), impact of MS (Multiple Sclerosis Impact Scale, MSIS-29), and anthropometric measurements (height and weight). Aerobic reserve capacity was 9.3±3.7ml/kg/min. Aerobic reserve capacity was positively associated with VO2peak (ρ=.67, p<.01), time to exhaustion (ρ=.63, p<.01), and SDMT (ρ=.51, p<.05). Aerobic reserve capacity was negatively associated with BMI (ρ=-.62, p<.01) and RHR (ρ=-0.47, p<.05). We provide preliminary evidence that aerobic reserve capacity is a feasible outcome derived from maximal CPET (eg, modified Balke protocol) in MS. Aerobic reserve capacity was associated with clinically relevant outcomes and could become an important outcome for rehabilitation in future research.

Peak oxygen consumption achieved at the end of cardiac rehabilitation predicts long-term survival in patients with coronary heart disease

Cardiac rehabilitation (CR) improves survival in patients with coronary heart disease (CHD), which is largely mediated by the improvements in cardiorespiratory fitness (CRF) defined as peak oxygen consumption (VO2). Therefore, measuring CRF is essential to predict long-term outcomes in this population. It is unclear, however, whether peak VO2 achieved at the end of CR (END-peak VO2) predicts survival or whether the changes of CRF achieved during CR provide a greater prognostic value. To determine whether END-peak VO2 independently predicts long-term survival in patients with CHD undergoing CR. We also aimed at identifying cut-offs for END-peak VO2 that could be used in clinical practice. Retrospective analysis of 853 patients with CHD referred to CR who completed a maximal cardiopulmonary exercise test. Survival analysis was performed to examine the risk of all-cause mortality (average follow-up years: 6.65) based on peak VO2. The Contal and O'Quigley's method was used to determine the optimal cut-off of END-peak VO2 based on the log-rank statistic. END-peak VO2 was inversely associated with mortality risk [hazard ratio (HR) = 0.84; 95% confidence interval (CI) = 0.78-0.90], independent of changes in peak VO2 adjusted for the baseline peak VO2. The estimated cut-off of END-peak VO2 at ≥17.6 mL/kg/min best predicted the survival with high predictive accuracy and patients with END-peak VO2 under the cut-off had a greater risk of mortality (HR = 2.93; 95% CI = 1.81-4.74). In patient with CHD undergoing CR, END-peak VO2 is an independent predictor for long-term survival. Studies utilizing higher intensity CR programmes, with and without pharmacologic strategies, to increase peak VO2 to a greater degree in those achieving a suboptimal END-peak VO2, are urgently needed.

Effects of wearing a cloth face mask on performance, physiological and perceptual responses during a graded treadmill running exercise test

ObjectivesTo (1) determine if wearing a cloth face mask significantly affected exercise performance and associated physiological responses, and (2) describe perceptual measures of effort and participants’ experiences while wearing a...

Effects of resistance training on metabolic and cardiovascular responses to a maximal cardiopulmonary exercise test in Parkinson`s disease.

ABSTRACT:Objective:To evaluate the effects of resistance training on metabolic and cardiovascular responses during maximal cardiopulmonary exercise testing in patients with Parkinson’s disease.Methods:Twenty-four patients with Parkinson’s disease (modified Hoehn and Yahr stages 2 to 3) were randomly assigned to one of two groups: Control or Resistance Training. Patients in the Resistance Training Group completed an exercise program consisting of five resistance exercises (two to four sets of six to 12 repetitions maximum per set) twice a week. Patients in the Control Group maintained their usual lifestyle. Oxygen uptake, systolic blood pressure and heart rate were assessed at rest and during cycle ergometer-based maximal cardiopulmonary exercise testing at baseline and at 12 weeks. Assessments during exercise were conducted at absolute submaximal intensity (slope of the linear regression line between physiological variables and absolute workloads), at relative submaximal intensity (anaerobic threshold and respiratory compensation point) and at maximal intensity (maximal exercise). Muscle strength was also evaluated.Results:Both groups had similar increase in peak oxygen uptake after 12 weeks of training. Heart rate and systolic blood pressure measured at absolute and relative submaximal intensities and at maximal exercise intensity did not change in any of the groups. Muscle strength increased in the Resistance Training but not in the Control Group after 12 weeks.Conclusion:Resistance training increases muscle strength but does not change metabolic and cardiovascular responses during maximal cardiopulmonary exercise testing in patients with Parkinson’s disease without cardiovascular comorbidities.

CARDIOVASCULAR STATUS REFERENCE VALUES OF RECENTLY DIAGNOSED AND NAÏVE TO TREATMENT HUMAN IMMUNODEFICIENCY VIRUS (HIV) PATIENTS. A PILOT STUDY

Abstract Objective: HIV infection is a well recognized risk factor for cardiovascular (CV) disease. Virus induced chronic inflammation plays a key role in the development of early CV disease. The aim of this study is to explore the baseline CV status of recently diagnosed and naïve to treatment HIV patients regarding arterial blood pressure parameters, target organ damage indices as well as aerobic capacity (AC). Design and method: Forty two (42) recently diagnosed and naïve HIV patients were evaluated regarding office and central blood pressure (SBP/DBP), carotid-femoral aortic stiffness estimated by PWV and endothelial function measured by endothelial glycocalyx integrity. Increased perfusion boundary region (PBR) of the sublingual arterial microvessels (ranged from 5–9 micrometers) Using Sideview Darkfield imaging (Microscan, Glycocheck) was measured as a non-invasive accurate index of reduced EG thickness. Finally AC status was evaluated after a maximal cardiopulmonary exercise test (CPET). No one patient had ever received any treatment for HIV or any cardiovascular disease. Results: HIV patients were mostly males (38 men, 90%), young (mean age = 37 + 10 years), smokers (21, 42%) and normotensives (office SBP/DBP = 124 + 13/76 + 10 mmHg and central SBP/DBP = 116 + 12/77 + 10 mmHg). PWV was estimated as 9.2 + 1.7 m/sec. Endothelial glycocalyx intergrity was measured as PBR5–9 = 1.2 + 0.2 micrometers. During maximum aerobic CPET, HIV patients achieved 8 + 2 METS and 28 + 6 ml/kg/min peak VO2 which corresponds to 80 + 14% of peak VO2 predicted. Their SBP was measured as 112 + 10 mmHg at exercise initiation and 169 + 22 mmHg at peak exercise. Two male patients (5%) had a hypertensive response during CPET defined as SBP &gt; 210 mmHg. Conclusions: It seems that recently diagnosed naïve HIV patients have a CV status similar to which corresponds to their age. We are going to re-evaluate those patients, one and three years after HIV treatment initiation, in order to explore any early differences regarding their CV status.

Heart rate response and chronotropic incompetence during cardiopulmonary exercise testing in childhood acute lymphoblastic leukemia survivors

Cardiopulmonary exercise tests (CPET) focusing on analyses of heart rate (HR) responses and chronotropic incompetence (CI) could provide early information about treatment’s negative cardiac effects. We examined childhood acute lymphoblastic leukemia (ALL) survivors’ HR response during maximal CPET and identified survivors with CI. A total of 250 childhood ALL survivors underwent a CPET on ergocycle to assess their HR response. We used a multiparametric structure of three methods to assess survivors’ CI, as follows: 1) age-predicted HRmax (APMHR): failure to achieve 85% of the APMHR at the peak of CPET; 2) HR reserve (HRR): failure to achieve 80% of the HRR at the peak of CPET; and 3) metabolic chronotropic relationship (MCR): failure to reach an MCR slope ratio >0.8 at each stage of the CPET. Among 250 childhood ALL survivors, 216 survivors performed a maximum CPET. We observed that 73 males and 74 females did not achieve their predicted HRmax. We found that 6 survivors did not achieve 85% of their APMHR (80.9 ± 3.9%) and had an MCR below 80% (53.9 ± 13.8%). In addition, 16 survivors did not achieve 80% of their HRR (71.0 ± 7.4%) and among them, 15 survivors had an MCR below 80% (61.0 ± 12.1%). Survivors with CI had a significantly lower cardiorespiratory fitness than those without CI. This study shows that survivors are at risk of developing altered HR responses and CI many years after the end of their cancer treatments. These findings highlight the importance of early detection of cardiac damage due to cancer treatments.

EXPLORING ASSOCIATIONS BETWEEN HEART RATE VARIABILITY AND EXERCISE TOLERANCE IN INDIVIDUALS WITH PERIPHERAL ARTERY DISEASE

Objective: Lower-extremity artery disease (LEAD) characterized by a progressive atherosclerotic build-up in leg arteries affects more than 200 million people worldwide. LEAD is often associated with autonomic dysfunction as evidenced by a reduced heart rate variability (HRV). We aimed to investigate whether the autonomic function is associated with ambulatory capacity and exercise capacity in patients with LEAD. Design and method: Thirty-four patients (age &gt; 17 years) diagnosed with LEAD (ABI &lt; 0.9 and/or 20% decrease after a maximal treadmill test) suffering from intermittent claudication (Rutherford I-III) were recruited in the PROSECO-IC trial. Patients were grouped based on beta-blocker medication (B-blocker and non-B-blocker). Intervals between R waves (i-RR) obtained by heart rate (HR) signal were acquired beat-to-beat (Polar®H10) during 15 min of supine rest and were used for 5-minute HRV analysis. Time-domain indexes (mean i-RR, SDDD)and frequency domains (high-frequency band (HF), low frequency (LF, very LF (VLF)), and the ratio (LF/HF). Ambulatory capacity was assessed by a submaximal treadmill test, graded maximal treadmill test using Gardner protocol (GTM), and 6 minutes walking test (6MWT); exercise capacity was assessed by graded maximal cardiopulmonary exercise test (HR, blood pressure (BP) and peak oxygen uptake (VO2peak)) at resting, 2 minutes and the peak of exercise. Results: Pearson test showed that sympathetic modulation indexes were moderately associated with pain-free distance in GTM (LF/HF: r = 0.52, p = 0.04) and pain-free time in 6MWT (LFlog: r = -0.62, p = 0.01; VLF: r = -0.52, p = 0.04), respectively, in patients without B-blocker. Similar HR associations with HRV (time and frequency domain) were observed during the submaximal treadmill test and cardiopulmonary exercise test (p &lt; 0.05). Test-t demonstrated a significantly increased response intra-groups in HR and BP during both tests (p &lt; 0.05). Average BP was positive associated with the earlier stages of the cardiopulmonary test (resting to 2 min) with LFlog (r = 0.70, p = &lt; 0.001) in B-blocker while non-B-blocker were associated from 2 min to peak with LFabs (r = 0.67, p = &lt; 0.001) and LF/HF (r = 0.52, p = 0.03). Conclusions: Sympathetic modulation was correlated with a longer pain-free walking capacity in non-B-blockers. Yet, individuals treated by -B-blockers showed an earlier sympathetic modulation through exercise pressor response during the first stages of cardiopulmonary exercise compared to non-B-blockers.

Exertional Desaturation in Idiopathic Pulmonary Fibrosis: The Role of Oxygen Supplementation in Modifying Cerebral-Skeletal Muscle Oxygenation and Systemic Hemodynamics

Background: In patients with idiopathic pulmonary fibrosis (IPF) with isolated exertional desaturation, there are limited data regarding the effectiveness of oxygen supplementation during exercise training; the underlying mechanisms that contribute to these responses are unknown. Objectives: To examine in these IPF patients the effects of oxygen supplementation during submaximal exercise (vs. medical air) on cerebral/skeletal muscle oxygenation and systemic hemodynamics. Methods: In this randomized, cross-over, placebo-controlled trial, IPF patients (n = 13; 63.4 ± 9.6 years) without resting hypoxemia but a significant desaturation during maximal cardiopulmonary exercise testing underwent 2 steady-state exercise trials (65% peak-work-load), breathing either oxygen-enriched or medical air. Cerebral/skeletal muscle oxygenation (near-infrared spectroscopy) and beat-by-beat hemodynamics (photoplethysmography) were monitored. Results: In the air protocol, from the initial minutes of submaximal exercise, patients exhibited a marked decline in cerebral oxygenated hemoglobin (O2Hb) and an abrupt rise in deoxygenated hemoglobin (HHb). Oxygen supplementation alleviated desaturation, lessened dyspnea, and prolonged exercise duration (p < 0.01). Oxygen supplementation during exercise (i) attenuated cerebral deoxygenation (cerebral-HHb: 0.7 ± 1.9 vs. 2.5 ± 1.5 μmol/L, O2 and air protocol; p = 0.009) and prevented cerebral-Hbdifference decline (2.1 ± 2.7 vs. −1.7 ± 2.0 μmol/L; p = 0.001), (ii) lessened the decline in muscle O2-saturation index, and (iii) at isotime exercise, it resulted in lower muscle-HHb (p = 0.05) and less leg fatigue (p < 0.05). No differences between protocols were observed in exercise cardiac output and vascular resistance. Conclusions: IPF patients with isolated exertional hypoxemia exhibit an inability to increase/maintain cerebral oxygenation during submaximal exercise. Correcting desaturation with O2 supplementation prevented the decline in brain oxygenation, improved muscle oxygenation, and lessened dyspnea, suggesting an efficacy of acute oxygen supplementation during exercise training in protecting brain hypoxia in these IPF patients.

Acute effect of inhaled iloprost on exercise dynamic hyperinflation in COPD patients: A randomized crossover study.

We tested whether the prostacyclin analog inhaled iloprost modulates dead space, dynamic hyperinflation (DH), and systemic inflammation/oxidative stress during maximal exercise in subjects with chronic obstructive pulmonary disease (COPD) who were not selected based on pulmonary hypertension (PH). Twenty-four COPD patients with moderate-severe obstruction (age 59±7 years, FEV1 53±13% predicted) participated in a randomized, double-blind, placebo-controlled crossover trial. Each subject received a single nebulized dose of 5.0μg iloprost or placebo on non-consecutive days followed by maximal cardiopulmonary exercise tests. The primary outcome was DH quantified by end-expiratory lung volume/total lung capacity ratio (EELV/TLC) at metabolic isotime. Inhaled iloprost was well-tolerated and reduced submaximal alveolar dead-space fraction but did not significantly reduce DH (0.70±0.09 vs 0.69±0.07 following placebo and iloprost, respectively, p=0.38). Maximal exercise time (9.1±2.3 vs 9.3±2.2min, p=0.31) and peak oxygen uptake (17.4±6.3 vs 17.9±6.9mL/kg/min, p=0.30) were not significantly different following placebo versus iloprost. A single dose of inhaled iloprost was safe and reduced alveolar dead space fraction; however, it was not efficacious in modulating DH or improving exercise capacity in COPD patients who were not selected for the presence of PH.

Association of physical function and performance with peak VO2 in elderly patients with end stage kidney disease.

Physical function is impaired in end stage renal disease (ESRD). Various instruments have been used to assess the functional capabilities and health status of patients with ESRD, but it is not known which has the best association with peak VO2. To assess the association between functional measures in ESRD. Thirty nine elderly ESRD patients were evaluated with commonly used functional, health status, and quality of life measures, including maximal cardiopulmonary exercise testing (CPET), 6-min walk (6MWT), sit-to-stand test (STS), Veterans Specific Activity Questionnaire (VSAQ), upper and lower body strength, pulmonary function tests, and body composition determined by dual X-ray absorptiometry. The association between performance on these functional tools, clinical variables, and exercise test responses was assessed, and a non-exercise test multivariate model was developed to predict peak VO2. Peak VO2 was modestly related to VSAQ score (r = 0.59, p < 0.01), indices of upper and lower body strength (r = 0.45, p < 0.01 for both), and FEV1 (r = 0.51, p < 0.01). Functional and quality of life questionnaires were generally poorly related to one another and to peak VO2. In a multivariate model, 6MWT performance, forced expiratory volume in 1s (FEV1), and VSAQ score were the best predictors of peak VO2, yielding a multiple R = 0.82, accounting for 67% of the variance in peak VO2. Exercise capacity can be reasonably estimated using non-exercise test variables in patients with ESRD, including a symptom questionnaire (VSAQ), 6MWT and FEV1. ClinicalTrials.gov identifier: NCT01990495. Registered Nov 21, 2013.

EFFECT OF RECREATIONAL SCUBA DIVING ON CARDIORESPIRATORY FITNESS IN MALAYSIAN NOVICE DIVERS

Objective: The aim of this study was to investigate scuba diving induced exercise response in novice divers as required in open water scuba diving certification. Methods: Maximal cardiopulmonary exercise test (CPET) was performed in 30 novice divers before and within 24 hours after a standard scuba diving open water certification diving protocol of four open water dives. Results: A significant increase in maximal oxygen consumption (VO2max) in mL·kg-1·min-1 after scuba diving training [25.84 (6.0) vs. 27.04 (7.0)] (p&lt;0.05) suggestive of an increase in exercise performance. Ventilatory drive (VE/VCO2) also showed a significant increase 27.95 (2.7) vs. 30.07 (5.3). Ventilatory anaerobic threshold (VAT), blood pressure and lung function parameters showed no significant differences with open water scuba diving certification training. Conclusion: In novice divers, repeated training exposure during open water scuba diving certification results in increased cardiorespiratory fitness. Although further corroborating studies are needed, this would suggest that recreational scuba diving may be an option for exercise promotion in the future.

Cardiopulmonary exercise testing was used to evaluate objectively and quantitatively the holistic function in patients after neoadjuvant chemotherapy

Objective: Cardiopulmonary exercise testing(CPET)was used to evaluate objectively and quantitatively the holistic function in patients accepted preoperative chemotherapy. Methods: This study investigated reliable objective and quantitative assessment methods of symptom limited maximal incremental CPET before and after chemotherapy in patients with 6 esophageal cancer. We re-analyzed the changes in cardiopulmonary, metabolism, and other functions physiologic parameters of CPET. Results: After patients accepted preoperative chemotherapy,Peak oxygen consumption (Peak VO2)(P<0.05), anaerobic threshold (AT) and peak oxygen pulse (Peak O2 paulse), oxygen uptake efficiency plateau (OUEP)were decreased (P<0.01). The lowest of ventilatory equivalent for carbon dioxide and slope of ventilatory equivalent for carbon dioxide were increased (P<0.05). For individual of all patients, except one patient's Peak VO2 and OUEP slightly increased,all of the above indicators were reduced in the remaining patients. The lowest of ventilatory equivalent for carbon dioxide and slope of ventilatory equivalent for carbon dioxide increased in all the patients,except one patient's slope of ventilatory equivalent for carbon dioxide decreased slightly. The heart rate of 6 patients showed an upward trend in each state, but there was no statistical difference. Three of the 6 patients had blood pressure measurement, and the other 3 patients had a significant decrease in diastolic blood pressure (P<0.05) except at extreme state.The patients had lower oxygen uptake at AT(P<0. 01) and extreme state (P<0. 05) than that before chemotherapy. The oxygen uptake efficiency in a warm-up state(P<0. 01),and an AT state(P<0. 05)after chemotherapy were lower than those before chemotherapy. The ventilator equivalent for carbon dioxide after chemotherapy was in the each states presented an upward trend, but only ventilator equivalent for carbon dioxide after in the warm-up state (P<0.05) and AT(P<0.01) had statistical significance. oxygen pulse in all four states showed a decreasing trend, and only at AT (P<0.05) showed a significant decrease.After chemotherapy,the PETCO2 in a warm-up state after chemotherapy was lower than that before chemotherapy(P<0. 05); the PETO2 in a quiescent state,a warm - up state,and an extreme state after chemotherapy were higher than those before chemotherapy;but there was nosignificant difference. Conclusion: The holistic functional capacity of patients with esophageal significantly decreased after 136 days chemotherapy. The circulatory functionalandentilator functional parameters significantly decreased after chemotherapy.

Associations between peak oxygen uptake, lung function, and bronchiectasis in children with cystic fibrosis in the era of CFTR modulators.

With the emergence of cystic fibrosis transmembrane conductance regulator (CFTR) modulators, forced expiratory volume in 1 s (FEV1 ) may become a less sensitive measure of pulmonary disease progression in children with cystic fibrosis (CF). Increasing evidence shows that peak oxygen uptake (VO2peak ) is a strong predictor of prognosis in CF. The primary aim of this study was to describe the associations between peak oxygen uptake, lung function, and bronchiectasis in children with CF in the era of CFTR modulators. Spirometry and a maximal cardiopulmonary exercise test (CPET) were performed on the same day and compared to markers of disease severity. Markers of disease severity included a number of pulmonary exacerbations resulting in hospital admission within the preceding 12 months, body mass index, Pseudomonas aeruginosa (PsA) infection, and bronchiectasis. Fifty-two subjects (24 female) with CF participated in the study with a mean (SD) age of 13.8 (2.4) years, range 8-18 years. Forty-nine participants met satisfactory criteria for a maximal CPET. A significant correlation was found between relative VO2peak %predicted and FEV1 %predicted (r = .546, p < .001). A total of 4/49 children demonstrated an impaired aerobic capacity despite normal spirometry. Participants who had experienced one or more pulmonary exacerbations in the previous 12 months had a significantly lower relative VO2peak %predicted (p = .02). In children with CF who have mild pulmonary disease, there is significant correlation between FEV1 and VO2peak . In all, 8.2% of participants had an abnormal CPET result despite normal spirometry, and preceding pulmonary exacerbations were associated with poorer CPET outcomes. CPET may offer important prognostic information for clinical decision making in this new era of CFTR modulators.

Chronotropic incompetence is more frequent in obese adolescents and relates to systemic inflammation and exercise intolerance

BackgroundAdults with obesity may display disturbed cardiac chronotropic responses during cardiopulmonary exercise testing, which relates to poor cardiometabolic health and an increased risk for adverse cardiovascular events. It is unknown whether cardiac chronotropic incompetence (CI) during maximal exercise is already present in obese adolescents and, if so, how that relates to cardiometabolic health. MethodsSixty-nine obese adolescents (body mass index standard deviation score = 2.23 ± 0.32, age = 14.1 ± 1.2 years; mean ± SD) and 29 lean adolescents (body mass index standard deviation score = –0.16 ± 0.84, age = 14.0 ± 1.5 years) performed a maximal cardiopulmonary exercise testing from which indicators for peak performance were determined. The resting heart rate and peak heart rate were used to calculate the maximal chronotropic response index. Biochemistry (lipid profile, glycemic control, inflammation, and leptin) was studied in fasted blood samples and during an oral glucose tolerance test within obese adolescents. Regression analyses were applied to examine associations between the presence of CI and blood or exercise capacity parameters, respectively, within obese adolescents. ResultsCI was prevalent in 32 out of 69 obese adolescents (46%) and 3 out of 29 lean adolescents (10%). C-reactive protein was significantly higher in obese adolescents with CI compared to obese adolescents without CI (p = 0.012). Furthermore, peak oxygen uptake and peak cycling power output were significantly reduced (p < 0.05) in obese adolescents with CI vs. obese adolescents without CI. The chronotropic index was independently related to blood total cholesterol (standardized coefficient β = –0.332; p = 0.012) and C-reactive protein concentration (standardized coefficient β = –0.269; p = 0.039). ConclusionCI is more common in the current cohort of obese adolescents, and is related to systemic inflammation and exercise intolerance.

Factors related to the discontinuation and mortality rates of a cardiac rehabilitation programme in patients with Chagas disease: a 6-year experience in a Brazilian tertiary centre.

To describe the clinical and sociodemographic characteristics of participants as well as discontinuation and mortality rates in a cardiac rehabilitation programme (CRP) tailored to Chagas disease (CD). Participants underwent functional capacity, anthropometry and cardiac function evaluations before beginning a CRP. Univariate and multivariate Cox proportional hazards models were performed to investigate the associations between clinical and sociodemographic characteristics at baseline with discontinuation rates and deaths. Forty-two patients were enrolled in the CRP (61.9% men, mean age of 58.1±11.8years). During a median follow-up period of 10.8months, 74% discontinued and 14% died while enrolled in CRP. 34% of the patients who discontinued CRP died during follow-up. White race (HR=0.09; 95% CI 0.01-1.00), right ventricular systolic dysfunction (HR=10.54; 95% CI 1.24-89.50) and oxygen pulse (HR=0.69; 95% CI 0.48-0.99) were independently associated with death while enrolled in CRP. Married status (HR=0.44; 95% CI 0.21-0.95) was independently associated with discontinuation rates from CRP. VO2 peak (HR=0.85; 95% CI 0.74-0.98) and CRP discontinuation due to CD-related reasons (HR=8.33; 95% CI 1.91-36.27) were the variables independently associated with death after discontinuation of CRP. In this population, sociodemographic aspects and severity of CD were important determinants of CRP discontinuation and mortality.

Effects of cycling bouts performed with different intensities and amounts of energy expended on central pressure and pulse wave reflection in normotensive and hypertensive men.

This study investigated pulse wave analysis in normotensive and hypertensive men after cycling bouts with different intensities and amounts of energy expended. Twenty-four men were assigned into normotensive (n = 14; age: 40.7 ± 2.8 years; 24-h ambulatory SBP/DBP:121 ± 2/74 ± 1 mmHg) and hypertensive (n = 10; age: 39.2 ± 2.3 years; 24-h ambulatory SBP/DBP:139 ± 3/86 ± 2 mmHg) groups. Participants undertook a maximal cardiopulmonary exercise test, a nonexercise control session (CTL) and three cycling bouts [two prolonged bouts expending 300 kcal at 50% (i.e. P-MOD) and 70% (i.e. P-VIG) oxygen uptake reserve (VO2R) and one short bout expending 150 kcal at 50% VO2R (i.e. S-MOD)] performed in a randomized order. Central SBP (cSBP), pulse pressure (cPP), augmentation pressure, augmentation index (AIx), heart rate (HR) and AIx adjusted for HR (AIx@75) were determined 10 min before, and 30- and 70-min postintervention. Compared to CTL, only the P-VIG changed the cSBP [70-min (Δ -11.7 mmHg)], cPP [70-min (Δ:-7.4 mmHg)], augmentation pressure [30-min (Δ:-5.7 mmHg); 70-min (Δ:-7.3 mmHg)], AIx [30-min (Δ:-15.3 %); 70-min (Δ:-16.4 %)], AIx@75 [30-min (Δ:-12.8 %); 70-min (Δ:-13.9 %)] and HR [70-min (Δ: 9.9 bpm)] in the hypertensive group. However, all exercise bouts mitigated the increased cSBP responses post-CTL in the hypertensive group. The present study provides evidence that vigorous-intensity aerobic exercise reduces acute central pressure and pulse wave reflection in hypertensive men.