Total body oxygen uptake (VO2) increases during the transition from machine-assisted ventilation to spontaneous breathing. Since the volume of oxygen consumed by the respiratory muscles must contribute to the increase in VO2 (delta VO2), we explored whether delta VO2 and/or measurements of respiratory power output (Wresp) provide clinically useful information in the evaluation of disease state ...

The computer model of the bioenergetic system in skeletal muscle, developed previously, was used to study the effect of the characteristic decay time of the parallel activation of oxidative phosphorylation [τ(OFF)] during muscle recovery on the muscle oxygen consumption rate (Vo2) and phosphocreatine (PCr) work-to-rest transition (off)-kinetics and on the relationship between the Vo2 and PCr re...

The VO2 polymorphs, i.e., VO2(A), VO2(B), VO2(M1) and VO2(R), have a wide spectrum of functionalities useful for many potential applications in information and energy technologies. However, synthesis of phase pure materials, especially in thin film forms, has been a challenging task due to the fact that the VO2 polymorphs are closely related to each other in a thermodynamic framework. Here, we ...

OBJECTIVE To compare measured and predicted oxygen consumption (VO2) in children with congenital heart disease. DESIGN Retrospective study. SETTING The cardiac catheterisation laboratory in a university hospital. PATIENTS 125 children undergoing preoperative cardiac catheterisation. INTERVENTIONS VO2 was measured using indirect calorimetry; the predicted values were calculated from regr...

purpose validity of the 20-meter multi stage shuttle run test (20-m mst) has not been studied in nepalese population. the purpose of this study was to validate the applicability of the 20-m mst in nepalese adult females. methods forty female college students (age range, 20.42 ~24.75 years) from different colleges of nepal were recruited for the study. direct estimation of vo2 max comprised trea...

We studied the effects of cardiac cooling by 7 +/- 2 degrees C (SD) from 36 degrees C on both contractility index (Emax) and the relation between O2 consumption per beat (VO2) and systolic pressure-volume area (PVA) of the left ventricle in the excised cross-circulated dog heart preparation. PVA represents the total mechanical energy generated by a contraction. The VO2-PVA relation divides meas...

The purpose of the present study was to assess the relationship between the rapidity of increased oxygen uptake (VO2) and increased cardiac output (CO) during heavy exercise. Six subjects performed repeated bouts on a cycle ergometer above the ventilatory threshold (approximately 80% of peak VO2) separated by 10-min recovery cycling at 35% peak VO2. VO2 was determined breath-by-breath and CO wa...

Both systolic pressure-volume area (PVA) and force-time integral (FTI) have been used as measures of oxygen consumption per beat (VO2) in the isolated left ventricle. The reciprocal of the slope of the VO2-PVA relation has been considered to reflect the chemomechanical energy transduction efficiency of the contractile machinery (contractile efficiency), whereas its VO2 intercept consists of ene...

VO2 and heart rate (HR) are widely used when determining appropriate training intensities for clinical, healthy, and athletic populations. It has been shown that if the % reserve (%R) is used, rather than % of max, HR and VO2 can be used interchangeably to accurately prescribe exercise intensities. Thus, heart rate reserve (HRR) can be prescribed if VO2 reserve (VO2R) is known. Therefore, the p...

The aim of this study is to compare the relation between ventilation (VE) and oxygen uptake (VO2) [VO2=ƒ(VE)] and between heart rate (HR) and VO2 [VO2=ƒ(HR)]. Each one of the subjects performed three types of activities of different intensities (walking without load, walking with load and intermittent work). VO2, VE, and HR were measured continuously by using indirect calorimetry and an electro...