Reproducibility of Inert Gas Rebreathing Method to Estimate Cardiac Output at Rest and During Cardiopulmonary Exercise Stress Testing

2019 ◽  
Vol 40 (02) ◽  
pp. 125-132 ◽  
Author(s):  
Nduka Okwose ◽  
Jie Zhang ◽  
Shakir Chowdhury ◽  
David Houghton ◽  
Srdjan Ninkovic ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Exercise Testing ◽  
Coefficient Of Variation ◽  
Cardiopulmonary Exercise Testing ◽  
Exercise Stress ◽  
Inert Gas ◽  
Peak Exercise ◽  
Cardiopulmonary Exercise ◽  
Inert Gas Rebreathing ◽  
Rebreathing Method

AbstractThe present study evaluated reproducibility of the inert gas rebreathing method to estimate cardiac output at rest and during cardiopulmonary exercise testing. Thirteen healthy subjects (10 males, 3 females, ages 23–32 years) performed maximal graded cardiopulmonary exercise stress test using a cycle ergometer on 2 occasions (Test 1 and Test 2). Participants cycled at 30-watts/3-min increments until peak exercise. Hemodynamic variables were assessed at rest and during different exercise intensities (i. e., 60, 120, 150, 180 watts) using an inert gas rebreathing technique. Cardiac output and stroke volume were not significantly different between the 2 tests at rest 7.4 (1.6) vs. 7.1 (1.2) liters min−1, p=0.54; 114 (28) vs. 108 (15) ml beat−1, p=0.63) and all stages of exercise. There was a significant positive relationship between Test 1 and Test 2 cardiac outputs when data obtained at rest and during exercise were combined (r=0.95, p<0.01 with coefficient of variation of 6.0%), at rest (r=0.90, p<0.01 with coefficient of variation of 5.1%), and during exercise (r=0.89, p<0.01 with coefficient of variation 3.3%). The mean difference and upper and lower limits of agreement between repeated measures of cardiac output at rest and peak exercise were 0.4 (−1.1 to 1.8) liter min−1 and 0.5 (−2.3 to 3.3) liter min−1, respectively. The inert gas rebreathing method demonstrates an acceptable level of test-retest reproducibility for estimating cardiac output at rest and during cardiopulmonary exercise testing at higher metabolic demands.

scholarly journals Comparison of cardiac output estimates by bioreactance and inert gas rebreathing methods during cardiopulmonary exercise testing

2017 ◽  
Vol 38 (3) ◽  
pp. 483-490 ◽  
Author(s):  
Nduka C. Okwose ◽  
Shakir Chowdhury ◽  
David Houghton ◽  
Michael I. Trenell ◽  
Christopher Eggett ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Exercise Testing ◽  
Cardiopulmonary Exercise Testing ◽  
Inert Gas ◽  
Cardiopulmonary Exercise ◽  
Inert Gas Rebreathing ◽  
Rebreathing Methods

Cardiopulmonary Exercise Testing in Combined Pulmonary Fibrosis and Emphysema

Respiration ◽  
2021 ◽  
pp. 369-377
Author(s):  
Michael Westhoff ◽  
Patric Litterst ◽  
Ralf Ewert
Keyword(s):  
Body Weight ◽  
Pulmonary Fibrosis ◽  
Sensitivity And Specificity ◽  
Exercise Testing ◽  
Cardiopulmonary Exercise Testing ◽  
Arterial Oxygen ◽  
Peak Exercise ◽  
Cutoff Value ◽  
Cardiopulmonary Exercise ◽  
Peak Vo2

Background: Combined pulmonary fibrosis and emphysema (CPFE) is a distinct entity among fibrosing lung diseases with a high risk for lung cancer and pulmonary hypertension (PH). Notably, concomitant PH was identified as a negative prognostic indicator that could help with early diagnosis to provide important information regarding prognosis. Objectives: The current study aimed to determine whether cardiopulmonary exercise testing (CPET) can be helpful in differentiating patients having CPFE with and without PH. Methods: Patients diagnosed with CPFE in 2 German cities (Hemer and Greifswald) over a period of 10 years were included herein. CPET parameters, such as peak oxygen uptake (peak VO2), functional dead space ventilation (VDf/VT), alveolar-arterial oxygen difference (AaDO2), arterial-end-tidal CO2 difference [P(a-ET)CO2] at peak exercise, and the minute ventilation-carbon dioxide production relationship (VE/VCO2 slope), were compared between patients with and without PH. Results: A total of 41 patients with CPET (22 with PH, 19 without PH) were analyzed. Right heart catheterization was performed in 15 of 41 patients without clinically relevant complications. Significant differences in peak VO2 (861 ± 190 vs. 1,397 ± 439 mL), VO2/kg body weight/min (10.8 ± 2.6 vs. 17.4 ± 5.2 mL), peak AaDO2 (72.3 ± 7.3 vs. 46.3 ± 14.2 mm Hg), VE/VCO2 slope (70.1 ± 31.5 vs. 39.6 ± 9.6), and peak P(a-ET)tCO2 (13.9 ± 3.5 vs. 8.1 ± 3.6 mm Hg) were observed between patients with and without PH (p < 0.001). Patients with PH had significantly higher VDf/VT at rest, VT1, and at peak exercise (65.6 ± 16.8% vs. 47.2 ± 11.6%; p < 0.001) than those without PH. A cutoff value of 44 for VE/VCO2 slope had a sensitivity and specificity of 94.7 and 72.7%, while a cutoff value of 11 mm Hg for P(a-ET)CO2 in combination with peak AaDO2 >60 mm Hg had a specificity and sensitivity of 95.5 and 84.2%, respectively. Combining peak AaDO2 >60 mm Hg with peak VO2/body weight/min <16.5 mL/kg/min provided a sensitivity and specificity of 100 and 95.5%, respectively. Conclusion: This study provided initial data on CPET among patients having CPFE with and without PH. CPET can help noninvasively detect PH and identify patients at risk. AaDO2 at peak exercise, VE/VCO2 slope, peak P(a-ET)CO2, and peak VO2 were parameters that had high sensitivity and, when combined, high specificity.

Abstract 13745: Severity of Functional Mitral Regurgitation During Maximal Exercise Testing in Heart Failure: Additional Value of Combining Echocardiography with Cardiopulmonary Exercise Testing

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Greta Generati ◽  
Francesco Bandera ◽  
Marta Pellegrino ◽  
Valentina Labate ◽  
Eleonora Alfonzetti ◽  
...  
Keyword(s):  
Heart Failure ◽  
Mitral Regurgitation ◽  
Ejection Fraction ◽  
Exercise Testing ◽  
Cardiopulmonary Exercise Testing ◽  
Functional Mitral Regurgitation ◽  
Peak Exercise ◽  
Cardiopulmonary Exercise ◽  
Pulmonary Hemodynamic ◽  
Increased Risk

Background: In heart failure (HF) patients the severity of mitral regurgitation (MR) at rest has a well established prognostic value and its increase during exercise further adds to an increased risk. Our goal was to define the relationship between the degree of exercise MR severity with cardiopulmonary and echocardiographic related phenotypes in a cohort of HF patients. Methods: 71 HF reduced ejection fraction patients (mean age 67±11; male 72%; ischemic etiology 61%; NYHA class I, II, III and IV 13%, 36%, 39% and 12%, mean ejection fraction 33±9%) underwent cardiopulmonary exercise test (CPET) on tiltable cycle-ergometer combined with echocardiography at rest and during exercise. The population was divided into two groups according to the degree of functional peak MR: no to mild/moderate MR (no MR, MR1+ and MR2+) vs moderate/severe MR (MR3+ and MR4+). Results: A good correlation (ρ coefficient= 0.49) was found between the degree of dynamic MR and PASP at peak exercise. Despite similar echocardiographic profile at rest patients with significant peak MR (MR≥3+) had worse exercise performance (lower peak VO2, O2 pulse and workload) and impaired ventilatory efficiency (higher VE/VCO2 slope). Conclusions: In HF patients the severity of exercise-induced MR is associated with the most unfavorable performance and pulmonary hemodynamic response. A combined approach with CPET and echocardiographic assessment can help to early unmask and target functional MR and its related unfavorable phenotypes.

scholarly journals Cardiopulmonary exercise testing as a predictor of complications in oesophagogastric cancer surgery

2013 ◽  
Vol 95 (2) ◽  
pp. 125-130 ◽  
Author(s):  
LH Moyes ◽  
CJ McCaffer ◽  
RC Carter ◽  
GM Fullarton ◽  
CK Mackay ◽  
...  
Keyword(s):  
High Risk ◽  
Exercise Testing ◽  
Cardiopulmonary Exercise Testing ◽  
Major Surgery ◽  
Peak Exercise ◽  
Icu Admission ◽  
Cardiopulmonary Exercise ◽  
High Dependency ◽  
Cardiopulmonary Complications ◽  
Oesophagogastric Cancer

Introduction An anaerobic threshold (AT) of <11ml/min/kg can identify patients at high risk of cardiopulmonary complications after major surgery. The aim of this study was to assess the value of cardiopulmonary exercise testing (CPET) in predicting cardiopulmonary complications in high risk patients undergoing oesophagogastric cancer resection. Methods Between March 2008 and October 2010, 108 patients (83 men, 25 women) with a median age of 66 years (range: 38–84 years) underwent CPET before potentially curative resections for oesophagogastric cancers. Measured CPET variables included AT and maximum oxygen uptake at peak exercise (VO2 peak). Outcome measures were length of high dependency unit stay, length of hospital stay, unplanned intensive care unit (ICU) admission, and postoperative morbidity and mortality. Results The mean AT and VO2 peak were 10.8ml/min/kg (standard deviation [SD]: 2.8ml/min/kg, range: 4.6–19.3ml/min/kg) and 15.2ml/min/kg (SD: 5.3ml/min/kg, range: 5.4–33.3ml/min/kg) respectively; 57 patients (55%) had an AT of <11ml/min/ kg and 26 (12%) had an AT of <9ml/min/kg. Postoperative complications occurred in 57 patients (29 cardiopulmonary [28%] and 28 non-cardiopulmonary [27%]). Four patients (4%) died in hospital and 21 (20%) required an unplanned ICU admission. Cardiopulmonary complications occurred in 42% of patients with an AT of <9ml/min/kg compared with 29% of patients with an AT of ≥9ml/min/kg but <11ml/min/kg and 20% of patients with an AT of ≥11ml/min/kg (p=0.04). There was a trend that those with an AT of <11ml/min/kg and a low VO2 peak had a higher rate of unplanned ICU admission. Conclusions This study has shown a correlation between AT and the development of cardiopulmonary complications although the discriminatory ability was low.

scholarly journals Ventilatory compensation during the incremental exercise test is inversely correlated with air trapping in COPD

F1000Research ◽  
2020 ◽  
Vol 8 ◽  
pp. 1661
Author(s):  
Rottem Kuint ◽  
Neville Berkman ◽  
Samir Nusair
Keyword(s):  
Gas Exchange ◽  
Exercise Testing ◽  
Exercise Test ◽  
Cardiopulmonary Exercise Testing ◽  
Incremental Exercise ◽  
Peak Exercise ◽  
Air Trapping ◽  
Incremental Exercise Test ◽  
Cardiopulmonary Exercise ◽  
Copd Patients

Background: Air trapping and gas exchange abnormalities are major causes of exercise limitation in chronic obstructive pulmonary disease (COPD). During incremental cardiopulmonary exercise testing, actual nadir values of ventilatory equivalents for carbon dioxide (V E/VCO 2) and oxygen (V E/VO 2) may be difficult to identify in COPD patients because of limited ventilatory compensation capacity. Therefore, we aimed in this exploratory study to detect a possible correlation between the magnitude of ventilation augmentation, as manifested by increments in ventilatory equivalents from nadir to peak exercise values and air trapping, detected with static testing.    Methods: In this observational study, we studied data obtained previously from 20 COPD patients who, during routine follow-up, underwent a symptom-limited incremental exercise test and in whom a plethysmography was obtained concurrently. Air trapping at rest was assessed by measurement of the residual volume (RV) to total lung capacity (TLC) ratio (RV/TLC). Gas exchange data collected during the symptom-limited incremental cardiopulmonary exercise test allowed determination of the nadir and peak exercise values of V E/VCO 2 and V E/VO 2, thus enabling calculation of the difference between peak exrcise value and nadir values of  V E/VCO 2 and V E/VO 2, designated ΔV E/VCO 2 and ΔV E/VO 2, respectively. Results: We found a statistically significant inverse correlation between both ΔV E/VCO 2 (r = -0. 5058, 95% CI -0.7750 to -0.08149, p = 0.0234) and ΔV E/VO 2 (r = -0.5588, 95% CI -0.8029 to -0.1545, p = 0.0104) and the degree of air trapping (RV/TLC). There was no correlation between ΔV E/VCO 2 and forced expiratory volume in the first second, or body mass index.  Conclusions: The ventilatory equivalents increment to compensate for acidosis during incremental exercise testing was inversely correlated with air trapping (RV/TLC).

scholarly journals Interest of cardiac output (CO) measurement by Inert-Gas-Rebreathing method (IGR) in cardiac rehabilitation

2011 ◽  
Vol 54 ◽  
pp. e154-e155
Author(s):  
O. Troisgros ◽  
V. Gremeaux ◽  
C. Touzery ◽  
M. Zeller ◽  
L. Dufour ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Cardiac Rehabilitation ◽  
Inert Gas ◽  
Inert Gas Rebreathing ◽  
Rebreathing Method

Noninvasive Cardiac Output Determination for Children by the Inert Gas-Rebreathing Method

2010 ◽  
Vol 31 (8) ◽  
pp. 1214-1218 ◽  
Author(s):  
Gesa Wiegand ◽  
Gunter Kerst ◽  
Winfried Baden ◽  
Michael Hofbeck
Keyword(s):  
Cardiac Output ◽  
Inert Gas ◽  
Inert Gas Rebreathing ◽  
Noninvasive Cardiac Output ◽  
Cardiac Output Determination ◽  
Rebreathing Method

scholarly journals 53 Exercise oxygen kinetic in hypertrophic cardiomyopathy: results from a multicentre cardiopulmonary exercise testing study

2021 ◽  
Vol 23 (Supplement_G) ◽  
Author(s):  
Massimo Mapelli ◽  
Simona Romani ◽  
Damiano Magrì ◽  
Marco Merlo ◽  
Marco Cittar ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Hypertrophic Cardiomyopathy ◽  
Exercise Testing ◽  
Cardiopulmonary Exercise Testing ◽  
Systolic Pressure ◽  
Carbon Dioxide Production ◽  
Temporal Behaviour ◽  
Cardiopulmonary Exercise ◽  
O2 Pulse ◽  
Dynamic Relationships

Abstract Aims Reduced cardiac output (CO) has been considered crucial in symptoms’ genesis in hypertrophic cardiomyopathy (HCM). We evaluated the cardiopulmonary exercise testing (CPET) response in HCM focusing on parameters strongly associated with stroke volume (SV) and cardiac output (CO), such as oxygen uptake (VO2) and O2-pulse, considering both their absolute values and temporal behaviour during physical exercise. Methods and results We enrolled 312 non-end stage HCM patients, divided according to left ventricle outflow tract obstruction (LVOTO) at rest or during Valsalva manoeuver (72% with LVOTO &lt; 30; 10% between 30 and 49; and 18% ≥50 mmHg). Peak VO2 (percent of predicted), O2-pulse, and ventilation to carbon dioxide production (VE/VCO2) slope did not change across LVOTO groups. Ninety-six (31%) HCM patients presented an abnormal O2-pulse temporal behaviour, irrespective of LVOTO values. These patients showed lower peak systolic pressure, workload (106 ± 45 vs. 130 ± 49 W), VO2 (74 ± 17% vs. 80 ± 20%) and O2-pulse (12 [9–14] vs. 14 [11–17]ml/beat), with higher VE/VCO2 slope (28 [25–31] vs. 27 [24–31]) (P &lt; 0.005 for all). Only two patients had an abnormal VO2/work slope. Conclusions None of CPET parameters, either as absolute values or dynamic relationships, were associated with LVOTO. Differently, an abnormal O2-pulse exercise behaviour, which is strongly related to inadequate SV during exercise, correlates with reduced functional capacity (peak and anaerobic threshold VO2 and workload) and increased VE/VCO2 slope, helping identifying more advanced disease irrespectively of LVOTO. Adding O2-pulse kinetics evaluation to standard CPET could lead to a potential incremental benefit in terms of HCM prognostic stratification and, then, therapeutic management.

scholarly journals Mechanisms of Exercise Capacity Improvement after Cardiac Rehabilitation Following Myocardial Infarction Assessed with Combined Stress Echocardiography and Cardiopulmonary Exercise Testing

2021 ◽  
Vol 10 (18) ◽  
pp. 4083
Author(s):  
Krzysztof Smarz ◽  
Tomasz Jaxa-Chamiec ◽  
Beata Zaborska ◽  
Maciej Tysarowski ◽  
Andrzej Budaj
Keyword(s):  
Myocardial Infarction ◽  
Heart Rate ◽  
Cardiac Rehabilitation ◽  
Exercise Capacity ◽  
Exercise Testing ◽  
Cardiopulmonary Exercise Testing ◽  
Oxygen Extraction ◽  
Peak Exercise ◽  
Cardiopulmonary Exercise ◽  
Peak Vo2

Cardiac rehabilitation (CR) is indicated in all patients after acute myocardial infarction (AMI) to improve prognosis and exercise capacity (EC). Previous studies reported that up to a third of patients did not improve their EC after CR (non-responders). Our aim was to assess the cardiac and peripheral mechanisms of EC improvement after CR using combined exercise echocardiography and cardiopulmonary exercise testing (CPET-SE). The responders included patients with an improved EC assessed as a rise in peak oxygen uptake (VO2) ≥ 1 mL/kg/min. Peripheral oxygen extraction was calculated as arteriovenous oxygen difference (A-VO2Diff). Out of 41 patients (67% male, mean age 57.5 ± 10 years) after AMI with left ventricular ejection fraction (LVEF) ≥ 40%, 73% improved their EC. In responders, peak VO2 improved by 27% from 17.9 ± 5.2 mL/kg/min to 22.7 ± 5.1 mL/kg/min, p < 0.001, while non-responders had a non-significant 5% decrease in peak VO2. In the responder group, the peak exercise heart rate, early diastolic myocardial velocity at peak exercise, LVEF at rest and at peak exercise, and A-VO2Diff at peak exercise increased, the minute ventilation to carbon dioxide production slope decreased, but the stroke volume and cardiac index were unchanged after CR. Non-responders had no changes in assessed parameters. EC improvement after CR of patients with preserved LVEF after AMI is associated with an increased heart rate response and better peripheral oxygen extraction during exercise.

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