A critical appraisal of the prognostic value of the VE/VCO2 slope in chronic heart failure

Increased ventilatory drive, reflected by the slope of increase of ventilation relative to carbon dioxide production (VE/VCO2 slope), has been shown to have a high prognostic value in patients with chronic heart failure (CHF). However, there is no consensus on how to calculate it, as the relation between VE and VCO2 becomes nonlinear near the end of exercise, when ventilation is driven both by CO2 output and by decrease in plasma pH. This may influence the results. Ninety-seven CHF patients with ejection fraction