Relations between ejection fraction and ventricular volume, and their alteration by chronic beta-blockade

This study describes the newly discovered relation between ejection fraction and end-systolic volume index (ESVI) of the left ventricle as obtained by angiography at the time of cardiac catheterisation. Linear regression analysis shows that ejection fraction (%)=82.0-0.62 ESVI (ml/m²) but the correlation for patients receiving beta-adrenergic blocking drugs is significantly lower compared with the untreated group. Non-linear analysis, applied to cover also the asymptotic range for ejection fraction <20%, shows similar results. The good relation between the two indices indicates that the index ejection fraction may derive its clinical importance directly from the more fundamental index end systolic volume index by virtue of the operation of the beta-adrenergic system on the heart.