RT Journal Article
SR Electronic
T1 Ventilatory Response to Carbon Dioxide Output in Patients with Chronic Heart Failure and in Patients with Chronic Obstructive Pulmonary Disease with Comparable Exercise Capacity
JF Respiratory Care
FD American Association for Respiratory Care
SP respcare.02629
DO 10.4187/respcare.02629
A1 Elisabetta Teopompi
A1 Panagiota Tzani
A1 Marina Aiello
A1 Sara Ramponi
A1 Dina Visca
A1 Maria Rosaria Gioia
A1 Emilio Marangio
A1 Walter Serra
A1 Alfredo Chetta
YR 2013
UL http://rc.rcjournal.com/content/early/2013/09/17/respcare.02629.abstract
AB BACKGROUND: Patients with Chronic Heart Failure (CHF) or with COPD may share an increased response in minute ventilation (VE) to carbon dioxide output (VCO2) during exercise. OBJECTIVE: To ascertain whether or not the VE/VCO2slope and VE/VCO2intercept values may discriminate CHF from COPD patients at equal peak oxygen uptake (VO2peak). METHODS: We studied 46 patients with CHF (mean age: 61± 9 years) and 46 COPD patients (mean age: 64 ± 8 years), who performed a cardiopulmonary exercise test. RESULTS: The VE/VCO2slope values were significantly higher in CHF than in COPD patients (39.5±9.5 vs 31.8±7.4; p<0.01) at VO2peak < 16 ml/kg/min, but not ≥ 16 ml/kg/min (28.3±5.3 vs 28.9±6.6). The VE/VCO2intercept values were significantly higher in both subgroups of COPD patients, as compared to the corresponding values of the CHF patients (3.60 L/min ±1.7 vs -0.16 L/min ±1.7; p<0.01 and 3.63 L/min ± 2.7 vs 0.87 L/min ± 1.5; p<0.01). According to ROC curve analysis, when all patients with a VO2peak < 16 ml/kg/min were considered, COPD patients had a highest likelihood to have a VE/VCO2intercept value greater than 2.14 L/min (0.92 sensitivity, 0.96 specificity). Regardless of VO2peak value, the end-tidal pressure of CO2 (PETCO2) values at peak exercise were not different in CHF (p=0.42) and significantly higher in COPD (p<0.01) patients, as compared to the corresponding unloaded PETCO2 values. CONCLUSIONS: The ventilatory response to VCO2 during exercise was significantly different between CHF and COPD patients in terms of VE/VCO2slope values in patients with moderate to severe reduction in exercise capacity, and in terms of VE/VCO2intercept values, regardless of the exercise capacity.