Comprehensive assessment of ventilatory functions of patients with chronic heart failure

OBJECTIVE: A comprehensive assessment of the ventilatory functions of patients with chronic heart failure (CHF) both at rest and during a cardiopulmonary exercise test (CPET). We studied 42 males, divided into two groups--patients with CHF (n = 21) and age, weight, height and BMI matched healthy controls (n = 21). All subjects underwent a symptom-limited ramp CPET, arterial blood gas analysis, and complex functional examination of the pulmonary system. Subjective rating of dyspnea and exertion were measured by the Borg and ATS dyspnea scales. CHF patients showed a slight, but statistically significant decrease of the spirographic and diffusion parameters, as well as of the indices of respiratory muscle strength. There were no changes in blood gases and in tidal breathing parameters. The exercise capacity was markedly reduced (VO2peak ml.min-1 1352 +/- 335 CHF patients vs 2077 +/- 276 healthy controls; p < 0.001) and the anaerobic threshold occurred earlier (< 40% of predicted VO2peak) during CPET in CHF patients. The increase in VE/VCO2 in CHF patients (35.7 +/- 5.1 CHF; 28.9 +/- 2.5 HC, p < 0.001) indicates a compromised ventilatory efficiency which leads to a higher dyspneic cost of exercise (Borg peak 9.5 +/- 1.03 CHF; 6.0 +/- 1.28 HC; p < 0.001) as compared with healthy controls.