Cardiac output response to standing and treadmill walking

Abstract

Cardiac output measurements during cardiac catheterization were obtained in normal subjects for several grades of treadmill exercise. Femoral venous blood was sampled and the A-V oxygen difference for the exercising leg obtained. Measurements of central and femoral A-V oxygen difference and total oxygen uptake were also obtained in normal subjects during supine rest and during standing. When subjects merely stood, the A-V oxygen difference for the leg increased (whether the leg bore weight or not) much more than did that for the whole body. During treadmill walking femoral A-V oxygen difference was usually no greater than that during standing. Cardiac output was smaller and total body A-V oxygen difference was greater for treadmill walking than for supine bicycle exercise in which comparable levels of oxygen uptake were achieved. It is clear that change in posture alters the cardiac output response to exercise. An important aspect of the altered response was a marked difference in the circulation within the leg for these two postures both at rest and during exercise. Submitted on August 8, 1960

Pulmonary Circulation in Chronic Bronchitis and Emphysema

“…The patients were only slightly more hypoxic during exertion than at rest; the arterial oxygen saturation decreased by an average of 2-1 per cent. (Reeves et al, 1961a). Table IV and Fig.…”

“…Downloaded from consumption in Fig. 4, and plotted for comparison are 41 estimations of cardiac output from 10 normal subjects (Reeves et al, 1961a). It appears from the figure that the cardiac output in the emphysematous patients walking on the treadmill is similar to the normal.…”

Assessing the human cardiovascular response to moderate exercise: feature extraction by support vector regression

“…Although other researchers (Freedman et al 1955) (Reeves et al 1961b) (Richard et al 2004) (Rowland, Popowski & Ferrone 1997) (Reeves, Grover & Filley 1961) (Dexter et al 1951) (Astrand et al 1964) have described the nonlinear behaviour between stroke volume andV O 2 , they did not demonstrate the relationship from the viewpoint of modelling. We present here for the first time a nonparametric modelling method (that is SVR) to model the relationship between SV% andV O 2 %.…”

“…The rest periods were increased progressively from 5 to 15 minutes after each stint of exercise. Six minutes of exercise was long enough to approach a steady state since the values of oxygen uptake rate and the A-V oxygen difference had become stable by the 5th and 6th minutes even for near maximum exertion (Reeves, Grover & Filley 1961).…”

“…The cardiovascular response to exercise has been widely documented by several investigators (Dexter, Whittenberger, Haynes, Goodale, Gorlin & Sawyer 1951) (Barger, Richards, Metcalfe & Gunther 1956) (Freedman, Snider, Brostoff, Kimelblot & Katz 1955) (Reeves, Grover, Filley & Blount 1961a) (Reeves, Grover, Filley & Blount 1961b) (Rowland, Popowski & Ferrone 1997) (Kobayashi, Andoh, Fujinami, Nakayama, Takada, Takeuchi & Okamoto 1978) (Reeves, Grover & Filley 1961) (Bevegard, Freyschuss & Strandell 1966) (Astrand, Cuddy, Saltin & Stenberg 1964) (Denniston, Maher, Reeves, Cruz, Cymerman & Grover 1976) (Stenberg, Astrand, Ekblom, Royce & B 1967) (Turley & Wilmore 1997) (Fairbarn, Blackie, McElvaney, Wiggs, Pare & Pardy 1994) (Allor, Pivarnik, Sam & Perkins 2000) (Richard, Lonsdorfer-wolf, Dufour, Doutreleau, OswaldMammosser, Billat & Lonsdorfer 2004). Some of the reports demonstrated a linear function between the cardiac output (CO) and oxygen uptake rate during steady state of graded exercise, with a slope of approximately 5-6 in normal and athletic subjects (Rowell 1986).…”