1. Examination of the Relationship and Dissociation Between Minimum Minute Ventilation/Carbon Dioxide Production and Minute Ventilation vs. Carbon Dioxide Production Slope
- Author
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Hitoshi Adachi, Makoto Murata, and Yasuyuki Kobayashi
- Subjects
Heart Failure ,medicine.diagnostic_test ,Respiratory rate ,business.industry ,Cardiac index ,Regression analysis ,General Medicine ,Carbon Dioxide ,Prognosis ,Dissociation (chemistry) ,y-intercept ,Impedance cardiography ,Oxygen Consumption ,Animal science ,Exercise Test ,Humans ,Medicine ,Cardiology and Cardiovascular Medicine ,business ,Tidal volume ,Respiratory minute volume - Abstract
BACKGROUND: Minute ventilation/carbon dioxide production (VIE/VICO2) is a variable of cardiopulmonary exercise testing (CPET), which is evaluated by arterial CO2pressure and ventilation-perfusion mismatch via invasive methods. This study evaluated substitute non-invasively obtained variables for minimum VIE/VICO2(Min) and VIE vs. VICO2slope (Slope) and the relationship between Min and Slope.MethodsâandâResults:This study enrolled 1,052 patients with heart disease who underwent CPET and impedance cardiography simultaneously. At first, the correlations between the end-tidal CO2pressure (PETCO2), tidal volume/respiratory rate (TV/RR) ratio, VIE and VICO2Y-intercept (Y-int), and cardiac index (CI) and the Min and Slope were investigated. Second, the correlation between Min and Slope was investigated. PETCO2showed the largest correlation value among the 4 variables. These 4 variables could reveal 84.2% and 81.9% of Min and Slope, respectively. Although Slope correlated with Min (R=0.868) and predicted 78.9% of Min, considering these 4 variables, Slope+Y-int was more strongly correlated with Min (R=0.940); the Slope+Y-int revealed 90.6% of the Min relationship in the multiple regression analysis. CONCLUSIONS: Over 80% of the Min and Slope values were revealed with the above-mentioned 4 variables collected non-invasively. The formula, MinâSlope+Y-int, can reveal >90% of the Min/Slope relationships, and the Y-int may be a crucial factor to clarify the relationship between Min and Slope.
- Published
- 2021
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