Noninvasive measurement of cardiac output during exercise by inert gas rebreathing technique : a new tool for heart failure evaluation

breathing mechanics; breathing pattern; cardiopulmonary hemodynamics; disease classification; evaluation; exercise test; gas analysis; heart catheter; heart ejection fraction; heart failure; heart muscle oxygen consumption; heart output; human; letter; lung blood flow; medical assessment; non invasive measurement; oxygen dissociation curve; oxygen saturation; patient monitoring; priority journal; sample size; thermodilution; tidal volume; inert gas