Circulatory Data in Normal Subjects at Rest and During Exercise in Recumbent Position, with Special Reference to the Stroke Volume at Different Work Intensities

Abstract Right heart catheterization has been performed in 18 healthy subjects, 14 males and 4 females, including estimation of cardio‐vascular pressures and cardiac output at rest and during different intensities of exercise in recumbent position. During exercise the cardiac output increased linearly with the oxygen uptake. The increase of the arterio‐venous oxygen difference in relation to the work load or the pulse rate was higher in the males than in the females. With change from rest to work the stroke volume increased slightly but significantly in the males. By increasing work load it successively decreased to the size at rest. There was a high correlation between the stroke volume on one hand and the work performed at pulse rate 170, the heart volume, and the blood volume on the other. The mean pressure in the pulmonary artery was 5 mm Hg higher during exercise than at rest but was constant at different work loads. The end‐diastolic pressure in the right ventricle and the mean pulmonary venous pressure (PC V‐pressure) did not change significantly with the increase in pulse rate.