scholarly journals 342 Cardiorespiratory fitness and systemic vascular resistance: oxygen pressure as a novel marker of peripheral vascular response during cardiopulmonary exercise testing

2021 ◽  
Vol 23 (Supplement_G) ◽  
Author(s):  
Claudio Stefano Centorbi ◽  
Davide Lazzeroni ◽  
Luca Moderato ◽  
Matteo Bini ◽  
Lorenzo Brambilla ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Systemic Vascular Resistance ◽  
Cardiorespiratory Fitness ◽  
Vascular Resistance ◽  
Oxygen Pressure ◽  
Exercise Testing ◽  
Cardiopulmonary Exercise Testing ◽  
Vascular Response ◽  
Peripheral Vascular ◽  
Cardiopulmonary Exercise

Abstract Aims The key role of systemic vascular resistance (SVR) in cardiovascular performance during exercise has been invasively demonstrated, however no data have been non-invasively obtained by analysing SVR response using cardiopulmonary exercise testing (CPET). To investigate the relationship between SVR at peak, maximum oxygen uptake (VO2 peak), and its determinants using CPET. Methods and results 1130 consecutive subjects were enrolled; according to physiology, SVR was determined as the ratio between mean arterial pressure (MAP) and cardiac output (CO). A novel parameter, named oxygen pressure (MAP peak/VO2 peak) was also created. Mean age was 61 ± 12 years and male gender was prevalent (61%); 66% of patients had arterial hypertension, 74% dyslipidaemia, 19% diabetes, 20% had smoking habit, and 26% previous history of cardiovascular (CV) disease. Significant inverse correlations between SVR peak and VO2/kg peak (P < 0.001), oxygen pulse (P < 0.001), CV efficiency (P < 0.001), chronotropic response (P < 0.001), and oxygen uptake exaction slope (P < 0.001) were found. Moreover, positive correlation between SVR peak and VE/VCO2 slope (P < 0.001) was observed. After multivariate analysis, the inverse correlation between peak SVR and peak VO2 remained significant (P < 0.001). Similar results were found considering oxygen pressure. Conclusions Low values of SVR at peak exercise, non-invasively evaluated with CPET, are associated with high levels of cardiorespiratory fitness. Oxygen pressure may represent a novel and simple CPET marker of peripheral vascular response to exercise, thereby representing a promising field of research in exercise medicine.

scholarly journals Can wearable technology be used to approximate cardiopulmonary exercise testing metrics?

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Laura Jones ◽  
Laura Tan ◽  
Suzanne Carey-Jones ◽  
Nathan Riddell ◽  
Richard Davies ◽  
...  
Keyword(s):  
Physical Activity ◽  
High Risk ◽  
Oxygen Uptake ◽  
Anaerobic Threshold ◽  
Exercise Testing ◽  
Low Cost ◽  
Cardiopulmonary Exercise Testing ◽  
Peak Oxygen Uptake ◽  
Wearable Device ◽  
Cardiopulmonary Exercise

Abstract Background Consumer wrist-worn wearable activity monitors are widely available, low cost and are able to provide a direct measurement of several markers of physical activity. Despite this, there is limited data on their use in perioperative risk prediction. We explored whether these wearables could accurately approximate metrics (anaerobic threshold, peak oxygen uptake and peak work) derived using formalised cardiopulmonary exercise testing (CPET) in patients undergoing high-risk surgery. Methods Patients scheduled for major elective intra-abdominal surgery and undergoing CPET were included. Physical activity levels were estimated through direct measures (step count, floors climbed and total distance travelled) obtained through continuous wear of a wrist worn activity monitor (Garmin Vivosmart HR+) for 7 days prior to surgery and self-report through completion of the short International Physical Activity Questionnaire (IPAQ). Correlations and receiver operating characteristic (ROC) curve analysis explored the relationships between parameters provided by CPET and physical activity. Device selection Our choice of consumer wearable device was made to maximise feasibility outcomes for this study. The Garmin Vivosmart HR+ had the longest battery life and best waterproof characteristics of the available low-cost devices. Results Of 55 patients invited to participate, 49 (mean age 65.3 ± 13.6 years; 32 males) were enrolled; 37 provided complete wearable data for analyses and 36 patients provided full IPAQ data. Floors climbed, total steps and total travelled as measured by the wearable device all showed moderate correlation with CPET parameters of peak oxygen uptake (peak VO2) (R = 0.57 (CI 0.29–0.76), R = 0.59 (CI 0.31–0.77) and R = 0.62 (CI 0.35–0.79) respectively), anaerobic threshold (R = 0.37 (CI 0.01–0.64), R = 0.39 (CI 0.04–0.66) and R = 0.42 (CI 0.07–0.68) respectively) and peak work (R = 0.56 (CI 0.27–0.75), R = 0.48 (CI 0.17–0.70) and R = 0.50 (CI 0.2–0.72) respectively). Receiver operator curve (ROC) analysis for direct and self-reported measures of 7-day physical activity could accurately approximate the ventilatory equivalent for carbon dioxide (VE/VCO2) and the anaerobic threshold. The area under these curves was 0.89 for VE/VCO2 and 0.91 for the anaerobic threshold. For peak VO2 and peak work, models fitted using just the wearable data were 0.93 for peak VO2 and 1.00 for peak work. Conclusions Data recorded by the wearable device was able to consistently approximate CPET results, both with and without the addition of patient reported activity measures via IPAQ scores. This highlights the potential utility of wearable devices in formal assessment of physical functioning and suggests they could play a larger role in pre-operative risk assessment. Ethics This study entitled “uSing wearable TEchnology to Predict perioperative high-riSk patient outcomes (STEPS)” gained favourable ethical opinion on 24 January 2017 from the Welsh Research Ethics Committee 3 reference number 17/WA/0006. It was registered on ClinicalTrials.gov with identifier NCT03328039.

Impact of periodic breathing on measurement of oxygen uptake and respiratory exchange ratio during cardiopulmonary exercise testing

2002 ◽  
Vol 103 (6) ◽  
pp. 543-552 ◽  
Author(s):  
Darrel P. FRANCIS ◽  
L. Ceri DAVIES ◽  
Keith WILLSON ◽  
Roland WENSEL ◽  
Piotr PONIKOWSKI ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Exercise Testing ◽  
Respiratory Exchange Ratio ◽  
Cardiopulmonary Exercise Testing ◽  
Periodic Breathing ◽  
Moving Window ◽  
Carbon Dioxide Output ◽  
Cardiopulmonary Exercise ◽  
Peak Vo2 ◽  
The Difference

Metabolic exercise testing is valuable in patients with chronic heart failure (CHF), but periodic breathing may confound the measurements. We aimed to examine the effects of periodic breathing on the measurement of oxygen uptake (VO2) and respiratory exchange ratio (RER). First, we measured the effects of different averaging procedures on peak VO2 and RER values in 122 patients with CHF undergoing cardiopulmonary exercise testing. Secondly, we studied the effects of periodic breathing on VO2 and RER in healthy volunteers performing computer-guided periodic breathing. Thirdly, we used a Fourier analysis to study the effects of periodic breathing on gas exchange measurements. The first part of the study showed that 1min moving window gave a mean peak VO2 of 13.8mlμmin-1μkg-1 for the CHF patients. A 15s window gave significantly higher values. The difference averaged 1.0mlμmin-1μkg-1 (P<0.0001), but varied widely: 41% of subjects showed a difference greater than 1.0mlμmin-1μkg-1. RER values were also higher by an average of 0.09 (P<0.0001); in 20% of subjects the difference was greater than 0.10. In the second part of the study, we found artefactual elevations of peak VO2 (without averaging) of 2.9mlμmin-1μkg-1 (P<0.01) and of peak RER of 0.13 (P<0.001), which were still significant when 30s averaging was applied [Δ(peak VO2) = 1.8mlμmin-1μkg-1, P<0.01; ΔRER = 0.08, P<0.001]. The third, theoretical, part of the study showed that values of carbon dioxide output and VO2 oscillate with different phases and amplitudes, resulting in oscillations in their ratio, RER. Averaging over 15s or 30s can be expected to give only 10% or 36% attenuation respectively. Thus periodic breathing causes variable artefactual elevations of measured peak VO2 and RER, which can be attenuated by using longer averaging periods. Clinical reports and research publications describing peak VO2 in CHF should be accompanied by details of the averaging technique used.

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