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

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 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.

Do rebreathing manoeuvres for non-invasive measurement of cardiac output during maximum exercise test alter the main cardiopulmonary parameters?

2019 ◽  
Vol 26 (15) ◽  
pp. 1616-1622 ◽  
Author(s):  
Carlo Vignati ◽  
Marco Morosin ◽  
Laura Fusini ◽  
Beatrice Pezzuto ◽  
Emanuele Spadafora ◽  
...  
Keyword(s):  
New York ◽  
Cardiac Output ◽  
Oxygen Uptake ◽  
Anaerobic Threshold ◽  
Exercise Testing ◽  
Exercise Test ◽  
Cardiopulmonary Exercise Testing ◽  
Heart Association ◽  
Cardiopulmonary Exercise Test ◽  
Cardiopulmonary Exercise

Background Inert gas rebreathing has been recently described as an emergent reliable non-invasive method for cardiac output determination during exercise, allowing a relevant improvement of cardiopulmonary exercise test clinical relevance. For cardiac output measurements by inert gas rebreathing, specific respiratory manoeuvres are needed which might affect pivotal cardiopulmonary exercise test parameters, such as exercise tolerance, oxygen uptake and ventilation vs carbon dioxide output (VE/VCO2) relationship slope. Method We retrospectively analysed cardiopulmonary exercise testing of 181 heart failure patients who underwent both cardiopulmonary exercise testing and cardiopulmonary exercise test+cardiac output within two months (average 16 ± 15 days). All patients were in stable clinical conditions (New York Heart Association I–III) and on optimal medical therapy. Results The majority of patients were in New York Heart Association Class I and II (78.8%), with a mean left ventricular ejection fraction of 31 ± 10%. No difference was found between the two tests in oxygen uptake at peak exercise (1101 (interquartile range 870–1418) ml/min at cardiopulmonary exercise test vs 1103 (844–1389) at cardiopulmonary exercise test-cardiac output) and at anaerobic threshold. However, anaerobic threshold and peak heart rate, peak workload (75 (58–101) watts and 64 (42–90), p < 0.01) and carbon dioxide output were significantly higher at cardiopulmonary exercise testing than at cardiopulmonary exercise test+cardiac output, whereas VE/VCO2 slope was higher at cardiopulmonary exercise test+cardiac output (30 (27–35) vs 33 (28–37), p < 0.01). Conclusion The similar anaerobic threshold and peak oxygen uptake in the two tests with a lower peak workload and higher VE/VCO2 slope at cardiopulmonary exercise test+cardiac output suggest a higher respiratory work and consequent demand for respiratory muscle blood flow secondary to the ventilatory manoeuvres. Accordingly, VE/VCO2 slope and peak workload must be evaluated with caution during cardiopulmonary exercise test+cardiac output.

Angiographic and Prognostic Correlates of Cardiac Output by Cardiopulmonary Exercise Testing in Patients With Anterior Myocardial Infarction

CHEST Journal ◽  
2001 ◽  
Vol 120 (3) ◽  
pp. 825-833 ◽  
Author(s):  
Riccardo Bigi ◽  
Alessandro Desideri ◽  
Riccardo Rambaldi ◽  
Lauro Cortigiani ◽  
Carlo Sponzilli ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Output ◽  
Exercise Testing ◽  
Cardiopulmonary Exercise Testing ◽  
Anterior Myocardial Infarction ◽  
Cardiopulmonary Exercise
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