INTRODUCTION: In patients with heart failure (HF), end-tidal CO2 pressure (PetCO2) is related to ventricular function at rest and has been shown to predict prognosis. However, little is known about the association between ventricular performance and PetCO2 responses to exercise. METHODS: Forty-eight patients with HF and 13 normal subjects underwent cardiopulmonary exercise testing (CPX), while cardiac output and other hemodynamic measurements at rest and during exercise were obtained using a novel, noninvasive, bioreactance device based on assessment of relative phase shifts of electric currents injected across the thorax, heart rate, and ventricular ejection time. CPX responses and indices of cardiac performance were compared between normal subjects and HF patients achieving above and below a PetCO2 of 36 mm Hg at the ventilatory threshold (PetCO2@VT).
Tags: arrhythmia, Cardiac output, clinical, efficiency, exercise, heart, heart failure, heart rate, methods, New York, NICOM, Oxygen, patients, pressure, Prognosis, Rest, Thorax, Time, Ventricular Function