Volumetric responses of right and left ventricles during upright exercise in normal subjects

D. A. Mahler , R. A. Matthay , P. E. Snyder , L. Pytlik , B. L. Zaret , and J. Loke

$1985.-We evaluated the volumetric responses the right and of left ventricles to upright using two noninvasive methods, first-pass radionuclide angiocardiography and the CO, rebreathing technique, in nine normal subjects.Right (RV) and left (LV) ventricular ejection fractions, heart rate, and cardiac index were determined at rest and during steady-state on the bicycle ergometer at 50% of maximal O2consumption. From these data, stroke volume index (SVI), end-diastolic volume index (EDVI), and end-systolic volume index (ESVI) were derived. SVI increasedfrom 40 t 7 ml/m2 at rest to 59 * 13 ml/m2 with (P < 0.001). RVEDVI increased significantly from 82 t 16 ml/m2 at rest to 95 t 21 ml/m2 during (P = O.OOS), while there was no significant changein RVESVI with . Changes in LVEDVI and LVESVI during upright were similar to the right ventricle. The increasein systolic blood pressureduring , along with no changein LVESVI, indicated enhancedventricular contractility. The normal augmentation in SVI during submaximal was dueto both the Frank-Starling mechanismand an increased contractile state. Application of these or similar techniquesmay be useful in evaluating ventricular performance in patients with cardiorespiratory dysfunction. first pass radionuclide angiocardiography; indirect Fick method; carbon dioxide rebreathing; end-diastolic volume; endsystolic volume ficult due to$

Volumetric responses of right and left ventricles during upright exercise in normal subjects

D. A. Mahler , R. A. Matthay , P. E. Snyder , L. Pytlik , B. L. Zaret , and J. Loke

Follow Journal of Applied Physiology , Volume 58: 1818 The American Physiological Society – Jun 1, 1985