TY - JOUR 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 DO - 10.4187/respcare.02629 SP - respcare.02629 AU - Elisabetta Teopompi AU - Panagiota Tzani AU - Marina Aiello AU - Sara Ramponi AU - Dina Visca AU - Maria Rosaria Gioia AU - Emilio Marangio AU - Walter Serra AU - Alfredo Chetta Y1 - 2013/09/17 UR - http://rc.rcjournal.com/content/early/2013/09/17/respcare.02629.abstract N2 - 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. ER -