Niewydolność serca. Ocena kliniczna i prognostyczna w oparciu o parametry wentylacji wysiłkowej

Background: Patients with chronic heart failure (CHF) are characterised by an increased ventilatory response to exercise. The role of exercise ventilation in the risk stratification and evaluation of patients with CHF has not yet been established.Aim: To examine the relationship between exercise ventilation indices and clinical parameters of CHF and to assess the prognostic value of the ventilatory response to exercise.Methods: The study group consisted of 87 patients with CHF (72 males, mean age 58 years) with a mean left ventricular ejection fraction of 32%. Ten patients were in NYHA class I, 38 - in NYHA class II, 34 - in NYHA class III, and 5 - in NYHA class IV. The control group consisted of 20 patients without CHF (13 males, mean age 58 years, mean LVEF - 61%). All studied subjects underwent maximal exercise test with gas-exchange measurement. The following parameters were analysed: peak exercise oxygen consumption [peak VO2 (ml/kg/min)], VE-VCO2 index [a coefficient of linear regression analysis depicting an association between ventilation (VE) and carbon dioxide production (VCO2) during exercise] and VE/VCO2 ratio at peak exercise to VE/VCO2 ratio while at rest (VE/VCO2 peak/rest).Results: Ventilatory response indices were significantly higher in patients with CHF compared with controls: VE-VCO2 - 37.9±11.1 vs 27.1±4.1; VE-VCO2 peak/rest - 0.89±0.14 vs 0.75±0.10 (