[The right ventricle at rest and during exercise. I. Pump-function of the normal right ventricle (author's transl)]

Right ventricular volumes and function were assessed by biplane cincventriculography at rest and during exercise in 7 normals. Simultaneously pressure in the left ventricle was measured. 1. Stroke volume index of the right ventricle increased from (x +/- SEM) 46.8 +/- R.R ml/m2 at rest to 66.8 +/- 5.5 ml/m2 (p less than .05) during exercise. Ejection fraction increased from 56.4 +/- 3 to 70.3 +/- 3.7% (p less than .02). Enddiastolic volume increased from 82 +/- 5.8 to 95 +/- 7 ml/m2. Enddiastolic right ventricular pressure increased from 5. +/- .8 to 8 +/- 1 mm Hg (p less than .05). Increase of R.V. stroke volume during exercise is achieved at least in part by increased fiber stretch. 2. Endsystolic volume decreased from 36 +/- 3.2 to 28 +/- 4 ml/m2 (p less than .02). Right ventricular mean velocity of diameter shortening (VD) increased from 1.2 +/- .08 to 1.65 +/- .14 D/s (p less than .05). Decrease of endsystolic volume may be caused by decrease of afterload or increase of contractility. Our data do not enable evaluation of these mechanisms.