We tested the ability of exercise testing to predict not only survival, but also time to clinical worsening (TTCW) in idiopathic versus associated pulmonary arterial hypertension (PAH). 136 patients with PAH (85 idiopathic and 51 with associated conditions) underwent cardiopulmonary exercise testing and a 6-min walk test. Death or transplantation, and clinical worsening events were recorded. 32...

In patients with fibrotic idiopathic interstitial pneumonia (f-IIP), the diffusing capacity for carbon monoxide (DLCO) has been used to predict abnormal gas exchange in the lung. However, abnormal values for arterial blood gases during exercise are likely to be the most sensitive manifestations of lung disease. The aim of this study was to compare DLCO, resting PaO(2), P(A-a)O(2) at cardiopulmo...

Afundamental requirement for many of the activities of daily living is the ability to perform predominantly aerobic, ie, oxygen-using, work. Such activities require the integrated efforts of the heart, lungs, and circulation to deliver oxygen to the metabolically active muscle mass. Thus, the assessment of functional or aerobic exercise time or peak oxygen consumption provides important diagnos...

OBJECTIVE To compare the behavior of the oxygen uptake efficiency slope (OUES) with that of oxygen uptake at peak exertion (VO₂peak). METHODS This was a prospective cross-sectional study involving 21 patients (15 men) with mild-to-moderate COPD undergoing spirometry, handgrip strength (HGS) testing, cardiopulmonary exercise testing, and determination of lactate at peak exertion (LACpeak). R...

INTRODUCTION Maximal oxygen uptake, V&O2 peak, among athletes is an important foundation for all training programmes to enhance competition performance. In Singapore, the V& O2 peak of athletes is apparently not widely known. There is also controversy in the modelling or scaling of maximal oxygen uptake for differences in body size - the use of ratio-scaling remains common but allometric scalin...

Objective: To evaluate the safety and prognostic capacity of cardiopulmonary exercise testing in patients > 60 years old who are hospitalised with heart failure caused by left ventricular dysfunction. Design: Prospective study. Setting: University hospital. Patients: Study participants were 67 patients (66% men) with clinical heart failure stabilised on medical treatment. The study is a part of...

To investigate the dynamics of tissue oxygen demand and supply during brain functions, we simultaneously recorded Po(2) and local cerebral blood flow (LCBF) with an oxygen microelectrode and laser Doppler flowmetry, respectively, in rat somatosensory cortex. Electrical hindlimb stimuli were applied for 1, 2, and 5 s to vary the duration of evoked cerebral metabolic rate of oxygen (CMR(O(2))). T...

This report describes age differences in oxygen saturation throughout the life cycle in a sample of high altitude native Tibetans residing in villages at 3,800-4,200 m altitude in the Tibet Autonomous Region, China. Oxygen saturation of 3,812 Tibetans was measured by pulse oximetry and a subsample of 1,582 healthy, nonpregnant, nonsmokers from 1 week to 80 years of age was selected for analyses...

BACKGROUND Submaximal oxygen uptake measures are more feasible and may better predict clinical cardiac outcomes than maximal tests in older adults with heart failure (HF). We examined relationships between maximal oxygen uptake, submaximal oxygen kinetics, functional mobility, and physical activity in older adults with HF and reduced ejection fraction. METHODS Older adults with HF and reduced...