The Significance of the Measurement of Oxygen Uptake with Step-up Exercise

I．　Introduction

　The writers have several times^1）〜5）　em-phasized that a markedly decreased oxygen　uptake with step-up exercise for one minute，　less than 500ml／min／M²,　B.　S.　A.,　indirectly　indicates increased pulmonary vascular　resistance, without using the complicated　maniplation of catheterizing the right heart　in order to know the mean pulmonary　arterial pressure and the cardiac output;